Jenkins with Docker Compose

Jenkins docker compose file (and instructions) to configure your jenkins controller and agent.

Configuring Jenkins

Create the jenkins_home folder in your local environment
```
mkdir jenkins_sandbox_home
```

Create a file named .env and add the following:

JENKINS_HOME_PATH=/home/user/jenkins_sandbox_home # your local jenkins_home path.
JENKINS_AGENT_SSH_PUBLIC_KEY=<< leave empty for now >>

Run Jenkins controller:
```
docker-compose up -d
```
Get the password to proceed installation:
```
docker logs jenkins_sandbox | less
```
Go to http://localhost:8080/ and enter the password.
Select Install Suggested Plugins, create the admin user and password, and leave the Jenkins URL http://localhost:8080/.

Use ssh-keygen to create a new key pair:
```
ssh-keygen -t rsa -f jenkins_key
```
Go to Jenkins and click Manage jenkins > Manage credentials.
Under Stores scoped to Jenkins, click Global credentials, next click Add credentials and set the following options:
- Select SSH Username with private key.
- Limit the scope to System.
- Give the credential an ID.
- Provide a description.
- Enter a username.
- Under Private Key check Enter directly.
- Paste the content of private key in the text box.
Click Ok to save.
Paste the public key on the JENKINS_AGENT_SSH_PUBLIC_KEY variable, in the .env file.

Recreate the services:

docker-compose down
docker-compose up -d