Package: zenoh-bridge-mqtt
Version: 1.0.0~alpha.6-1
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 20119
Filename: 1.0.0-alpha.6/zenoh-bridge-mqtt_1.0.0~alpha.6-1_armel.deb
Size: 4802712
MD5sum: edb7fd6b30e2c6b1ebcd29d6b5adbc16
SHA1: 158fe98e13a45fa5524aa5fef709a871c99a95d7
SHA256: e70867380ef7c532dce1ddc5ad555e282dbf27c03760bd6e8b54ec4b9039faf4
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-bridge-mqtt
Version: 1.0.0~alpha.6-1
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 19852
Filename: 1.0.0-alpha.6/zenoh-bridge-mqtt_1.0.0~alpha.6-1_armhf.deb
Size: 4832484
MD5sum: cf85233bec5f8cd3de27e1c60e9a0d9e
SHA1: 1f081453095d510bf48550aa41ea97611ce57e5c
SHA256: 4beea3c61ae40b2aeb4172a5eec019cae78ac05fc6c18724e8b2c215ef40c882
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-bridge-mqtt
Version: 1.0.0~alpha.6-1
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 20645
Depends: libc6 (>= 2.29)
Filename: 1.0.0-alpha.6/zenoh-bridge-mqtt_1.0.0~alpha.6-1_amd64.deb
Size: 4999224
MD5sum: 0ac46c7f169c9733689b7519c7396bee
SHA1: daaa1b5bb17737981a21b2a1fd8b95a7c4edb108
SHA256: f9f5796c1ebfc7814a2805f21977007d5f5c8cb9881b133ebbcf6622ba3f76da
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-bridge-mqtt
Version: 1.0.0~alpha.6-1
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 18688
Filename: 1.0.0-alpha.6/zenoh-bridge-mqtt_1.0.0~alpha.6-1_arm64.deb
Size: 4501932
MD5sum: 2d7cfcd64ffaa2642659a1d2d4d6f389
SHA1: aa68b66ec7cfac4adc09634a528d2c6265363d6f
SHA256: 7c4afea97039505132f0f339148b8b61aca8108e95a41ad1a04ffe1653e82901
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-plugin-mqtt
Version: 1.0.0~alpha.6-1
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 12201
Depends: zenohd (=1.0.0~alpha.6-1)
Filename: 1.0.0-alpha.6/zenoh-plugin-mqtt_1.0.0~alpha.6-1_arm64.deb
Size: 2531840
MD5sum: d521f057c7a0f9f0eebd32ca268a6cac
SHA1: bc6a859c6a007d16dce0ec422f53b8d633166cb2
SHA256: 482e9ee9d04b1483554e2446560806c2457cf54cfc4bf1ca80afe739d266af96
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Docker image:** see [below](#Docker-image)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
* zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to
connect to (typically another bridge or a zenoh router). Repeat this option to
connect to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for
the REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP
server to a specific interface).
* MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT
server to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use
for generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use
for generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT
client username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate
for the MQTT server. If specified a valid private key for the server must also
be provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
- ```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS
certificate but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
https://doc.rust-lang.org/stable/rustc/platform-support.html
.
Choose your platform and download:
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
Then either:
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install
zenoh-bridge-mqtt`.
.
.
## Docker image
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
$ git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
$ cd zenoh-plugin-mqtt
$ cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-plugin-mqtt
Version: 1.0.0~alpha.6-1
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 12270
Depends: zenohd (=1.0.0~alpha.6-1)
Filename: 1.0.0-alpha.6/zenoh-plugin-mqtt_1.0.0~alpha.6-1_armel.deb
Size: 2614108
MD5sum: 90b4ed6ffa280f874facaabd57345617
SHA1: 064dba437d6dc8e1b8c7d3de2738c32c6c924497
SHA256: 4b55a6cd1ece927d1b0482c3cc22eed3866b4c11cfc00d15e02b2a79995a0a88
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Docker image:** see [below](#Docker-image)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
* zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to
connect to (typically another bridge or a zenoh router). Repeat this option to
connect to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for
the REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP
server to a specific interface).
* MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT
server to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use
for generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use
for generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT
client username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate
for the MQTT server. If specified a valid private key for the server must also
be provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
- ```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS
certificate but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
https://doc.rust-lang.org/stable/rustc/platform-support.html
.
Choose your platform and download:
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
Then either:
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install
zenoh-bridge-mqtt`.
.
.
## Docker image
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
$ git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
$ cd zenoh-plugin-mqtt
$ cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-plugin-mqtt
Version: 1.0.0~alpha.6-1
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 13509
Depends: zenohd (=1.0.0~alpha.6-1)
Filename: 1.0.0-alpha.6/zenoh-plugin-mqtt_1.0.0~alpha.6-1_amd64.deb
Size: 2843508
MD5sum: a3c397a85c42a45ec8e7e61420521651
SHA1: 6e38bf1bcbb41754309aa6be2dd9071d05320497
SHA256: f44a2c5633ef432f8f2cf49e3ec6c45443a9d887b1e7309301157e8e5c73146f
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Docker image:** see [below](#Docker-image)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
* zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to
connect to (typically another bridge or a zenoh router). Repeat this option to
connect to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for
the REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP
server to a specific interface).
* MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT
server to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use
for generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use
for generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT
client username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate
for the MQTT server. If specified a valid private key for the server must also
be provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
- ```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS
certificate but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
https://doc.rust-lang.org/stable/rustc/platform-support.html
.
Choose your platform and download:
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
Then either:
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install
zenoh-bridge-mqtt`.
.
.
## Docker image
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
$ git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
$ cd zenoh-plugin-mqtt
$ cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Package: zenoh-plugin-mqtt
Version: 1.0.0~alpha.6-1
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 12186
Depends: zenohd (=1.0.0~alpha.6-1)
Filename: 1.0.0-alpha.6/zenoh-plugin-mqtt_1.0.0~alpha.6-1_armhf.deb
Size: 2657032
MD5sum: b78eaf851477884786b32e0ff715f722
SHA1: c09abd6d3fbf1f629d8663b76b33d30a6c3aa336
SHA256: 12b81f54d10f5dbcb644920a3c2b5fcbf12baf9ce0d2b073d5782b3ce3c981ff
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Docker image:** see [below](#Docker-image)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
* zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to
connect to (typically another bridge or a zenoh router). Repeat this option to
connect to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for
the REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP
server to a specific interface).
* MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT
server to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use
for generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use
for generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT
client username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate
for the MQTT server. If specified a valid private key for the server must also
be provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
- ```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS
certificate but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
https://doc.rust-lang.org/stable/rustc/platform-support.html
.
Choose your platform and download:
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
Then either:
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install
zenoh-bridge-mqtt`.
.
.
## Docker image
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
$ git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
$ cd zenoh-plugin-mqtt
$ cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-mqtt