Add 'postgres-version' input parameter

One of the foundational principles of this action was to use
preinstalled PostgreSQL binaries. The rationale was simple:

 * Make sure the action is fast and no installation is required.
 * Make sure it's safe and doesn't reach out to external servers.
 * Make sure it's auditable and everyone can verify it contains no
   malicious code.

It's quite common, however, for applications to follow upstream
PostgreSQL releases and switch to them as soon as possible. This
applications look to install the latest stable version instead.

This patch adds a new `postgres-version` input parameter that controls
what major version of PostgreSQL to install. Please note, the parameter
receives only major part of the version, e.g. "14'. It's impossible to
request any minor release.

Co-Authored-By: Roman Podoliaka <[email protected]>
Co-Authored-By: Ruslan Kiyanchuk <[email protected]>
Resolves: #14

Author: 3 people

.github/workflows/ci.yml

@@ -33,6 +33,7 @@ jobs:
           SERVICE_NAME: ${{ steps.postgres.outputs.service-name }}
           EXPECTED_CONNECTION_URI: postgresql://postgres:postgres@localhost:5432/postgres
           EXPECTED_SERVICE_NAME: postgres
+          EXPECTED_SERVER_VERSION: "15"
         shell: bash
 
   parametrized:
@@ -53,6 +54,7 @@ jobs:
           password: GrandMaster
           database: jedi_order
           port: 34837
+          postgres-version: "13"
         id: postgres
 
       - name: Run tests
@@ -64,4 +66,5 @@ jobs:
           SERVICE_NAME: ${{ steps.postgres.outputs.service-name }}
           EXPECTED_CONNECTION_URI: postgresql://yoda:GrandMaster@localhost:34837/jedi_order
           EXPECTED_SERVICE_NAME: yoda
+          EXPECTED_SERVER_VERSION: "13"
         shell: bash

action.yml

@@ -21,6 +21,10 @@ inputs:
     description: The server port to listen on.
     default: "5432"
     required: false
+  postgres-version:
+    description: The PostgreSQL (major) version to install.
+    default: "15"
+    required: false
 outputs:
   connection-uri:
     description: The connection URI to connect to PostgreSQL.
@@ -31,13 +35,34 @@ outputs:
 runs:
   using: composite
   steps:
-    - name: Prerequisites
+    - name: Install PostgreSQL
       run: |
         if [ "$RUNNER_OS" == "Linux" ]; then
-          echo "$(pg_config --bindir)" >> $GITHUB_PATH
+          sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
+          wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
+          sudo apt-get update
+          sudo apt-get -y install postgresql-${{ inputs.postgres-version }}
+
+          # Add PostgreSQL binaries to PATH, so they become globally available.
+          /usr/lib/postgresql/${{ inputs.postgres-version }}/bin/pg_config --bindir >> $GITHUB_PATH
+
+        elif [ "$RUNNER_OS" == "macOS" ]; then
+          brew install postgresql@${{ inputs.postgres-version }}
+
+          # Ling PostgreSQL binaries to /usr/local/bin so they become globally
+          # available. The overwrite option is required because they might be a
+          # preinstalled linked bottle.
+          brew link --overwrite postgresql@${{ inputs.postgres-version }}
+
         elif [ "$RUNNER_OS" == "Windows" ]; then
-          echo "$PGBIN" >> $GITHUB_PATH
-          echo "PQ_LIB_DIR=$PGROOT\lib" >> $GITHUB_ENV
+          choco install postgresql${{ inputs.postgres-version }}
+
+          # Add PostgreSQL binaries to PATH, so they become globally available.
+          "C:/Program Files/PostgreSQL/${{ inputs.postgres-version }}/bin/pg_config.exe" --bindir >> $GITHUB_PATH
+
+          # Set the path to LIBPQ to link against. On Windows it comes together
+          # with PostgreSQL distribution.
+          echo "PQ_LIB_DIR=$('C:/Program Files/PostgreSQL/${{ inputs.postgres-version }}/bin/pg_config.exe' --libdir)" >> $GITHUB_ENV
         fi
       shell: bash
 
@@ -65,8 +90,7 @@ runs:
           --pwfile="$PWFILE" \
           --auth="scram-sha-256" \
           --encoding="UTF-8" \
-          --locale="en_US.UTF-8" \
-          --no-instructions
+          --locale="en_US.UTF-8"
 
         # Do not create unix sockets since they are created by default in the
         # directory we have no permissions to (owned by system postgres user).

test_action.py

@@ -84,6 +84,13 @@ def test_locale(connection: psycopg.Connection):
     assert locale.normalize(lc_ctype) == "en_US.UTF-8"
 
 
+def test_server_version(connection: psycopg.Connection):
+    """Test that PostgreSQL's version is expected."""
+
+    server_version = connection.execute("SHOW SERVER_VERSION").fetchone()[0]
+    assert server_version.split(".")[0] == os.getenv("EXPECTED_SERVER_VERSION")
+
+
 def test_user_permissions(connection: psycopg.Connection):
     """Test that a user has super/createdb permissions."""