# Drone CI

When it comes to automation, [GitLab CI](https://gitlab.com) has been my go-to for running builds, tests and deployments of projects from static websites to 3D open-world games.
This has generally been on a self-hosted installation, and often makes use of physical runners.
However, I have some gripes: I mostly only use it for the CI, but it comes with an issue tracker and Git hosting solution too - great for some cases, but overkill in so many others.
Because it's such a complete solution, GitLab is a bit of a resource hog, and can often run frustratingly slowly.

Recently I've been playing with a friend's self-hosted instance of [Drone CI](https://drone.io/) as a lightweight alternative, and I much prefer it.
I didn't set up the instance, so that part is out of scope for this post, but in case it's relevant, we're using a self-hosted [Gitea](gitea.io) instance to host the source.
You can find out about configuring Drone with Gitea [here](https://docs.drone.io/server/provider/gitea/).


## Yet Another Yaml Config

Like GitLab, Drone is configured via a YAML file at the project root, called `.drone.yml`.
Drone is configured by creating 'steps' to the pipeline, where GitLab uses 'jobs'.

My first project's automation requirements were small - all I needed for a deployment was to copy all the files in a directory on every push to the `main` branch.
This means I needed secure access to the host, and the ability to copy files to it.
I didn't want to dedicate any permanent resources to such a small project, so opted for the `docker` pipeline option.

My pipeline would contain a single `deploy` step which would configure SSH access to the host, and then use it to copy the relevant files from the checked out version of the project.
I decided to use `ubuntu` as the Docker image for familiarity and accessibility - there are probably better options.
Drone widely supports Docker image registries; I have not used Docker much, but would like to get more experience with it.

```yml
kind: pipeline
type: docker
name: deploy

steps:
- name: deploy
  image: ubuntu
  when:
    branch:
    - main

  commands:
    - echo hello world
```

## Secrets

A hugely important aspect of automation is ensuring the security of one's pipelines.
Automated access between pipelines is a big risk, and should be locked down as much as possible.
For passing around secrets such as passwords and SSH keys, Drone has a concept of secrets.
I created a private key on my local machine for the runner's access to the remote host, and added a [per-repository secret](https://docs.drone.io/secret/repository/) to contain the value.
This is a named string value which can be accessed from within the context of a single pipeline step.

I also created secrets to contain values for the remote host address and the user to login as.
These are less of a security concern than the private SSH key, but we should obfuscate them anyway.
It's also a useful step towards generalising the pipeline for other projects, which we'll get into later.

This block was placed in the same step definition as above, below the `image:` entry:

```
environment:
  HOST:
    from_secret: host
  USER:
    from_secret: user
  SSH_KEY:
    from_secret: ssh_key
```

## Templates

## References

* [GitLab CI config to deploy via SSH](https://medium.com/@hfally/a-gitlab-ci-config-to-deploy-to-your-server-via-ssh-43bf3cf93775)