action.yml

name: 'Docker on tmpfs'
description: "Updates the runner's swap space, mounts a tmpfs on /var/lib/docker and restarts the daemon."
author: 'JonasAlfredsson'
branding:
  icon: 'shuffle'
  color: 'yellow'

inputs:
  tmpfs_size:
    description: 'Size of the tmpfs mount to be used (in gigabytes)'
    required: false
    type: number
    default: 5
  swap_size:
    description: 'Size of the new swap space (in gigabytes)'
    required: false
    type: number
    default: 4
  swap_location:
    description: 'Path to the new swap file'
    required: false
    default: '/mnt/swapfile'

runs:
  using: "composite"
  steps:
    - name: Replace the current swap file
      if: inputs.swap_size != 4 || inputs.swap_location != '/mnt/swapfile'
      shell: bash
      run: |
        sudo swapoff /mnt/swapfile

        sudo rm -v /mnt/swapfile

        sudo fallocate -l ${{ inputs.swap_size }}G "${{ inputs.swap_location }}"

        sudo chmod 600 "${{ inputs.swap_location }}"

        sudo mkswap "${{ inputs.swap_location }}"

        sudo swapon "${{ inputs.swap_location }}"

    - name: Show current memory and swap status
      shell: bash
      run: |
        sudo free -h
        echo
        sudo swapon --show

    - name: Mount a tmpfs over /var/lib/docker
      shell: bash
      run: |
        if [ ! -d "/var/lib/docker" ]; then
          echo "Directory '/var/lib/docker' not found"
          exit 1
        fi

        sudo mount -t tmpfs -o size=${{ inputs.tmpfs_size }}G tmpfs /var/lib/docker

        sudo systemctl restart docker

        sudo df -h | grep docker