Package: zenoh-plugin-webserver
Version: 1.2.1
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 10089
Depends: zenohd (=1.2.1)
Filename: 1.2.1/zenoh-plugin-webserver_1.2.1_armhf.deb
Size: 2137960
MD5sum: 608faa84406ff57b18899a1b93af013c
SHA1: 71ea16b55502e245f24836d797c60da65ec5eea8
SHA256: 744b240979f377fc566201619e29671b28e356395ba1d44c586926750f2d8785
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
.
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
[https://download.eclipse.org/zenoh/zenoh-plugin-webserver/](https://download.eclipse.org/zenoh/zenoh-plugin-webserver/)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
-------------------------------
.
## :warning: Documentation for previous 0.5 versions
.
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
.
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
.
## **Examples of usage**
.
Assuming you have a static website, you can:
.
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
.
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
.
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
.
4. Start the zenoh router (`zenohd`). It will automatically load the Web Server
plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on
[http://localhost:8080/my-site](http://localhost:8080/my-site).
.
For more advanced use cases you can also:
.
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make them
available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
.
## **Configuration**
.
In its configuration part, the plugin supports those settings:
.
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
.
## **Troubleshooting**
.
### _Address already in use_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
.
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
.
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### _Permission denied_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
.
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
.
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
.
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
.
```bash
zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
.
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
.
```bash
cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
.
```bash
cargo build --release -p zenoh-plugin-webserver
```
Package: zenoh-plugin-webserver
Version: 1.2.1
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 12504
Depends: zenohd (=1.2.1)
Filename: 1.2.1/zenoh-plugin-webserver_1.2.1_arm64.deb
Size: 2351276
MD5sum: a9a052ff39f36dca93c979a3b92a5a3c
SHA1: 42ec48b48f1f8e60824d4d2786496a871c231145
SHA256: 8ac5fd522722f7cf954aa4de3cff28c6aea840846656f348e18b6af2d002d1b8
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
.
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
[https://download.eclipse.org/zenoh/zenoh-plugin-webserver/](https://download.eclipse.org/zenoh/zenoh-plugin-webserver/)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
-------------------------------
.
## :warning: Documentation for previous 0.5 versions
.
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
.
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
.
## **Examples of usage**
.
Assuming you have a static website, you can:
.
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
.
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
.
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
.
4. Start the zenoh router (`zenohd`). It will automatically load the Web Server
plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on
[http://localhost:8080/my-site](http://localhost:8080/my-site).
.
For more advanced use cases you can also:
.
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make them
available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
.
## **Configuration**
.
In its configuration part, the plugin supports those settings:
.
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
.
## **Troubleshooting**
.
### _Address already in use_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
.
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
.
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### _Permission denied_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
.
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
.
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
.
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
.
```bash
zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
.
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
.
```bash
cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
.
```bash
cargo build --release -p zenoh-plugin-webserver
```
Package: zenoh-plugin-webserver
Version: 1.2.1
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 10219
Depends: zenohd (=1.2.1)
Filename: 1.2.1/zenoh-plugin-webserver_1.2.1_armel.deb
Size: 2150584
MD5sum: e00677b228ae35e5c70eb6df864cdea5
SHA1: 9ccd64cd87b2e620316277e8de70ef6bc8669ae3
SHA256: 2b77b3e8143457075a0929a84cfd05654d578d11fc032b724a62ad4e49414cf4
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
.
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
[https://download.eclipse.org/zenoh/zenoh-plugin-webserver/](https://download.eclipse.org/zenoh/zenoh-plugin-webserver/)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
-------------------------------
.
## :warning: Documentation for previous 0.5 versions
.
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
.
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
.
## **Examples of usage**
.
Assuming you have a static website, you can:
.
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
.
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
.
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
.
4. Start the zenoh router (`zenohd`). It will automatically load the Web Server
plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on
[http://localhost:8080/my-site](http://localhost:8080/my-site).
.
For more advanced use cases you can also:
.
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make them
available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
.
## **Configuration**
.
In its configuration part, the plugin supports those settings:
.
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
.
## **Troubleshooting**
.
### _Address already in use_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
.
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
.
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### _Permission denied_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
.
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
.
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
.
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
.
```bash
zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
.
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
.
```bash
cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
.
```bash
cargo build --release -p zenoh-plugin-webserver
```
Package: zenoh-plugin-webserver
Version: 1.2.1
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 13313
Depends: zenohd (=1.2.1)
Filename: 1.2.1/zenoh-plugin-webserver_1.2.1_amd64.deb
Size: 2521080
MD5sum: 267920f44c850b4011404975fd2da8a9
SHA1: 74b6bdb36dc053641f3764368140a7c394c2df81
SHA256: aad8a07df3fb1efc33d037db5bf839c5c2c01936e30940acc3fbb22d92d57162
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
.
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
[https://download.eclipse.org/zenoh/zenoh-plugin-webserver/](https://download.eclipse.org/zenoh/zenoh-plugin-webserver/)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
-------------------------------
.
## :warning: Documentation for previous 0.5 versions
.
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
.
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
.
## **Examples of usage**
.
Assuming you have a static website, you can:
.
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
.
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
.
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
.
4. Start the zenoh router (`zenohd`). It will automatically load the Web Server
plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on
[http://localhost:8080/my-site](http://localhost:8080/my-site).
.
For more advanced use cases you can also:
.
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make them
available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
.
## **Configuration**
.
In its configuration part, the plugin supports those settings:
.
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
.
## **Troubleshooting**
.
### _Address already in use_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
.
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
.
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### _Permission denied_
.
If in `zenohd` logs you see such error log at startup:
.
```raw
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
.
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
.
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
.
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
.
```bash
zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
.
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
.
```bash
cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
.
```bash
cargo build --release -p zenoh-plugin-webserver
```