action.yml

name: 'Install Postgres'
description: 'From zero to running Postgres faster than you can say "Postgres".'
branding:
  icon: 'fast-forward'
  color: 'orange'
inputs:
  version:
    description: 'The full, exact, version of postgres to install (e.g. 17.2.0).'
    required: true
    default: '17.2.0'
outputs:
  dsn:
    description: 'The DSN for connecting to the embedded postgres.'
  data:
    description: 'The path to the data directory of the embedded postgres.'
runs:
  using: composite
  steps:
    - name: Install Postgres
      shell: bash
      env:
        version: ${{ inputs.version }}
        os: ${{ runner.os }}
        arch: ${{ runner.arch }}
      run: |
        #!/bin/bash

        # Install Postgres
        #
        # version is the version of the embedded postgres to install.
        # The format must be in <major>.<minor>.<patch> format.
        set -ueo pipefail

        main() {
          # Step 1: Validate and coearse the following version, or, and arch into
          # their equivalent in the embedded postgres binaries file names.
          #
          # The os is taken from the runner.os context.
          # From the docs:
          # 
          #     https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs
          #
          #     runner.os
          #         The operating system of the runner executing the job.
          #         Possible values are Linux, Windows, or macOS.
          #
          #     runner.arch
          #         The architecture of the runner executing the job. Possible
          #         values are X86, X64, ARM, or ARM64.
          #
          #
          # The matrix is:
          #
          #     # Darwin (macOS) binaries:
          #     embedded-postgres-binaries-darwin-amd64/         macOS    X64
          #     embedded-postgres-binaries-darwin-arm64v8/       macOS    ARM64
          #     
          #     # Linux binaries:
          #     embedded-postgres-binaries-linux-amd64/          Linux    X64
          #     embedded-postgres-binaries-linux-amd64-alpine/   Linux    X64
          #     embedded-postgres-binaries-linux-arm32v6/        Linux    ARM
          #     embedded-postgres-binaries-linux-arm32v7/        Linux    ARM
          #     embedded-postgres-binaries-linux-arm64v8/        Linux    ARM64
          #     embedded-postgres-binaries-linux-i386/           Linux    X86
          #     embedded-postgres-binaries-linux-ppc64le/        Linux    -      (PPC64LE not supported in Actions)
          #     
          #     # Windows binaries:
          #     embedded-postgres-binaries-windows-amd64/        Windows  X64
          #     embedded-postgres-binaries-windows-i386/         Windows  X86
          #
          case $os in
            macOS)
              os=darwin
              case $arch in
                X64)
                  arch=amd64
                  ;;
                ARM64)
                  arch=arm64v8
                  ;;
                *)
                  echo "Unsupported $os arch: $arch"
                  echo "Only X64 and ARM64 are supported on macOS."
                  ;;
              esac
              ;;
            Linux)
              os=linux
              case $arch in
                X64)
                  arch=amd64
                  ;;
                ARM)
                  arch=arm32v6
                  ;;
                ARM64)
                  arch=arm64v8
                  ;;
                X86)
                  arch=i386
                  ;;
                *)
                  echo "Unsupported $os arch: $arch"
                  echo "Only X64, ARM, ARM64, and X86 are supported on Linux."
                  exit 1
                  ;;
              esac
              ;;
            Windows)
              os=windows
              case $arch in
                X64)
                  arch=amd64
                  ;;
                X86)
                  arch=i386
                  ;;
                *)
                  echo "Unsupported arch: $arch"
                  echo "Only X64 and X86 are supported on Windows."
                  exit 1
                  ;;
              esac
              ;;
            *)
              echo "Unsupported OS: $os"
              echo "Only Linux, Windows, and macOS are supported."
              exit 1
              ;;
          esac

          mkdir -p "$HOME"/.local
          cd "$HOME"/.local

          url="https://repo1.maven.org/maven2/io/zonky/test/postgres/embedded-postgres-binaries-$os-$arch/$version/embedded-postgres-binaries-$os-$arch-$version.jar"
          
          echo "Downloading Postgres:"
          echo
          echo "    Version: $version"
          echo "    OS:      $os"
          echo "    Arch:    $arch"
          echo "    URL:     $url"

          # Download the embedded postgres binaries
          curl -s -o /tmp/pg.jar -L "$url"
          if [ ! -f /tmp/pg.jar ]; then
            echo "Failed to find embedded postgres binaries for version $version on $os-$arch."
            echo "Please find the right os, arch, and version here https://repo1.maven.org/maven2/io/zonky/test/postgres/"
            echo "and update your step's version, os, and arch inputs accordingly."
            exit 1
          fi

          # Extract the embedded postgres binaries
          unzip -p /tmp/pg.jar "postgres-$os-*.txz" | xz -d | tar xvf - 1>/dev/null

          export PATH=$PWD/bin:$PATH
          echo "PATH=$PATH" >> $GITHUB_ENV

          echo "Postgres $version added to PATH ($PWD/bin/postgres)"

          # Custom Envs
          #
          # NOTE: DATABASE_URL is set using the DSN form so that, which allows
          # for modification via appending, which the URL form does not. This enables
          # the user to add additional parameters to the DSN as needed.
          export PGDATA=${PGDATA:-$HOME/.local/share/postgres/data}
          export PGHOST=${PGHOST:-/tmp}
          export PGPORT=${PGPORT:-5432}
          export PGUSER=${PGUSER:-postgres}
          export PGPASSWORD=${PGPASSWORD:-postgres}
          export PGDATABASE=${PGDATABASE:-postgres}
          export PGSSLMODE=${PGSSLMODE:-disable}
          env | grep '^PG' >> "$GITHUB_ENV"

          DATABASE_URL="dbname=$PGDATABASE user=$PGUSER password=$PGPASSWORD host=$PGHOST port=$PGPORT sslmode=$PGSSLMODE"
          echo "DATABASE_URL=$DATABASE_URL" >> "$GITHUB_ENV"

          echo "Initializing database at $PGDATA"
          initdb -D "$PGDATA" -U "$PGUSER"

          echo "Starting Postgres at $PGHOST:$PGPORT"
          pg_ctl -D "$PGDATA" \
            -l "$PGDATA"/postgres.log \
            -o "-d 2 -c shared_buffers=12MB -c fsync=off -c synchronous_commit=off -c full_page_writes=off -c log_line_prefix=\"%d ::LOG::\"" \
            start

          # Outputs
          echo "url=$DATABASE_URL" >> "$GITHUB_OUTPUT"
          echo "data=$PGDATA" >> "$GITHUB_OUTPUT"
        }

        time main