- A server which is the heart of Woodpecker and ships the webinterface.
- Next to one server you can deploy any number of agents which will run the pipelines.
> Each agent is able to process one pipeline step by default.
>
> If you have 4 agents installed and connected to the Woodpecker server, your system will process 4 builds in parallel.
>
> You can add more agents to increase the number of parallel builds or set the agent's `WOODPECKER_MAX_PROCS=1` environment variable to increase the number of parallel builds for that agent.
Woodpecker needs to know its own address. You must therefore provide the public address of it in `<scheme>://<hostname>` format. Please omit trailing slashes:
```diff
# docker-compose.yml
version: '3'
services:
woodpecker-server:
[...]
environment:
- [...]
+ - WOODPECKER_HOST=${WOODPECKER_HOST}
```
As agents run pipeline steps as docker containers they require access to the host machine's Docker daemon:
```diff
# docker-compose.yml
version: '3'
services:
[...]
woodpecker-agent:
[...]
+ volumes:
+ - /var/run/docker.sock:/var/run/docker.sock
```
Agents require the server address for agent-to-server communication:
```diff
# docker-compose.yml
version: '3'
services:
woodpecker-agent:
[...]
environment:
+ - WOODPECKER_SERVER=woodpecker-server:9000
```
The server and agents use a shared secret to authenticate communication. This should be a random string of your choosing and should be kept private. You can generate such string with `openssl rand -hex 32`:
Authentication is done using OAuth and is delegated to one of multiple version control providers, configured using environment variables. The example above demonstrates basic GitHub integration.
See the complete reference for all supported version control systems [here](./11-vcs/10-overview.md).
## Database
By default Woodpecker uses a sqlite database which requires zero installation or configuration. See the [database settings](./30-database.md) page to further configure it or use MySQL or Postgres.
## SSL
Woodpecker supports ssl configuration by using Let's encrypt or by using own certificates. See the [SSL guide](./60-ssl.md).
## Metrics
A [Prometheus endpoint](./90-prometheus.md) is exposed.
## Behind a proxy
See the [proxy guide](./70-proxy.md) if you want to see a setup behind Apache, Nginx, Caddy or ngrok.