The GitHub Actions ubuntu-latest default runner currently includes an installation of PostgreSQL 13. The server is not running by default but you can interact with it like this:
$ /usr/lib/postgresql/13/bin/postgres --version\npostgres (PostgreSQL) 13.3 (Ubuntu 13.3-1.pgdg20.04+1)\nYou can install alternative PostgreSQL versions by following the PostgreSQL Ubuntu instructions - like this:
\nsudo sh -c 'echo \"deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main\" > /etc/apt/sources.list.d/pgdg.list'\nwget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -\nsudo apt-get update\nsudo apt-get -y install postgresql-12\nThis works with postgresql-10 and postgresql-11 as well as postgresql-12.
I wanted to use a GitHub Actions matrix to run my tests against all four versions of PostgreSQL. Here's my complete workflow - the relevant sections are below:
\nname: Test\n\non: [push]\n\njobs:\n test:\n runs-on: ubuntu-latest\n strategy:\n matrix:\n postgresql-version: [10, 11, 12, 13]\n steps:\n - name: Install PostgreSQL\n env:\n POSTGRESQL_VERSION: ${{ matrix.postgresql-version }}\n run: |\n sudo sh -c 'echo \"deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main\" > /etc/apt/sources.list.d/pgdg.list'\n wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -\n sudo apt-get update\n sudo apt-get -y install \"postgresql-$POSTGRESQL_VERSION\"\n - name: Run tests\n env:\n POSTGRESQL_VERSION: ${{ matrix.postgresql-version }}\n run: |\n export POSTGRESQL_PATH=\"/usr/lib/postgresql/$POSTGRESQL_VERSION/bin/postgres\"\n export INITDB_PATH=\"/usr/lib/postgresql/$POSTGRESQL_VERSION/bin/initdb\"\n pytestI modified my tests to call the postgres and initdb binaries specified by the POSTGRESQL_PATH and INITDB_PATH environment variables.