feat: add nixos test for pg_cron extension

Author: jfroche

nix/checks.nix

@@ -309,6 +309,10 @@
             ;
         }
         // pkgs.lib.optionalAttrs (system == "x86_64-linux") {
+          pg_cron = import ./ext/tests/pg_cron.nix {
+            inherit self;
+            inherit pkgs;
+          };
           pg_net = import ./ext/tests/pg_net.nix {
             inherit self;
             inherit pkgs;

nix/ext/tests/pg_cron.nix

@@ -0,0 +1,151 @@
+{ self, pkgs }:
+let
+  pname = "pg_cron";
+  inherit (pkgs) lib;
+  installedExtension =
+    postgresMajorVersion: self.packages.${pkgs.system}."psql_${postgresMajorVersion}/exts/${pname}-all";
+  versions = postgresqlMajorVersion: (installedExtension postgresqlMajorVersion).versions;
+  postgresqlWithExtension =
+    postgresql:
+    let
+      majorVersion = lib.versions.major postgresql.version;
+      pkg = pkgs.buildEnv {
+        name = "postgresql-${majorVersion}-${pname}";
+        paths = [
+          postgresql
+          postgresql.lib
+          (installedExtension majorVersion)
+          self.packages.${pkgs.system}."psql_${majorVersion}/exts/hypopg" # dependency
+        ];
+        passthru = {
+          inherit (postgresql) version psqlSchema;
+          lib = pkg;
+          withPackages = _: pkg;
+        };
+        nativeBuildInputs = [ pkgs.makeWrapper ];
+        pathsToLink = [
+          "/"
+          "/bin"
+          "/lib"
+        ];
+        postBuild = ''
+          wrapProgram $out/bin/postgres --set NIX_PGLIBDIR $out/lib
+          wrapProgram $out/bin/pg_ctl --set NIX_PGLIBDIR $out/lib
+          wrapProgram $out/bin/pg_upgrade --set NIX_PGLIBDIR $out/lib
+        '';
+      };
+    in
+    pkg;
+in
+self.inputs.nixpkgs.lib.nixos.runTest {
+  name = pname;
+  hostPkgs = pkgs;
+  nodes.server =
+    { config, ... }:
+    {
+      virtualisation = {
+        forwardPorts = [
+          {
+            from = "host";
+            host.port = 13022;
+            guest.port = 22;
+          }
+        ];
+      };
+
+      services.postgresql = {
+        enable = true;
+        package = postgresqlWithExtension self.packages.${pkgs.system}.postgresql_15;
+        settings = {
+          "cron.database_name" = "postgres";
+          shared_preload_libraries = "pg_cron";
+        };
+      };
+
+      specialisation.postgresql17.configuration = {
+        services.postgresql = {
+          package = lib.mkForce (postgresqlWithExtension self.packages.${pkgs.system}.postgresql_17);
+        };
+
+        systemd.services.postgresql-migrate = {
+          serviceConfig = {
+            Type = "oneshot";
+            RemainAfterExit = true;
+            User = "postgres";
+            Group = "postgres";
+            StateDirectory = "postgresql";
+            WorkingDirectory = "${builtins.dirOf config.services.postgresql.dataDir}";
+          };
+          script =
+            let
+              oldPostgresql = postgresqlWithExtension self.packages.${pkgs.system}.postgresql_15;
+              newPostgresql = postgresqlWithExtension self.packages.${pkgs.system}.postgresql_17;
+              oldDataDir = "${builtins.dirOf config.services.postgresql.dataDir}/${oldPostgresql.psqlSchema}";
+              newDataDir = "${builtins.dirOf config.services.postgresql.dataDir}/${newPostgresql.psqlSchema}";
+            in
+            ''
+              if [[ ! -d ${newDataDir} ]]; then
+                install -d -m 0700 -o postgres -g postgres "${newDataDir}"
+                ${newPostgresql}/bin/initdb -D "${newDataDir}"
+                ${newPostgresql}/bin/pg_upgrade --old-datadir "${oldDataDir}" --new-datadir "${newDataDir}" \
+                  --old-bindir "${oldPostgresql}/bin" --new-bindir "${newPostgresql}/bin"
+              else
+                echo "${newDataDir} already exists"
+              fi
+            '';
+        };
+
+        systemd.services.postgresql = {
+          after = [ "postgresql-migrate.service" ];
+          requires = [ "postgresql-migrate.service" ];
+        };
+      };
+    };
+  testScript =
+    { nodes, ... }:
+    let
+      pg17-configuration = "${nodes.server.system.build.toplevel}/specialisation/postgresql17";
+    in
+    ''
+      versions = {
+        "15": [${lib.concatStringsSep ", " (map (s: ''"${s}"'') (versions "15"))}],
+        "17": [${lib.concatStringsSep ", " (map (s: ''"${s}"'') (versions "17"))}],
+      }
+
+      def run_sql(query):
+        return server.succeed(f"""sudo -u postgres psql -t -A -F\",\" -c \"{query}\" """).strip()
+
+      def check_upgrade_path(pg_version):
+        with subtest("Check ${pname} upgrade path"):
+          firstVersion = versions[pg_version][0]
+          server.succeed("sudo -u postgres psql -c 'DROP EXTENSION IF EXISTS ${pname};'")
+          run_sql(f"""CREATE EXTENSION ${pname} WITH VERSION '{firstVersion}' CASCADE;""")
+          installed_version = run_sql(r"""SELECT extversion FROM pg_extension WHERE extname = '${pname}';""")
+          assert installed_version == firstVersion, f"Expected ${pname} version {firstVersion}, but found {installed_version}"
+          for version in versions[pg_version][1:]:
+            run_sql(f"""ALTER EXTENSION ${pname} UPDATE TO '{version}';""")
+            installed_version = run_sql(r"""SELECT extversion FROM pg_extension WHERE extname = '${pname}';""")
+            assert installed_version == version, f"Expected ${pname} version {version}, but found {installed_version}"
+
+      start_all()
+
+      server.wait_for_unit("multi-user.target")
+      server.wait_for_unit("postgresql.service")
+
+      check_upgrade_path("15")
+
+      with subtest("Check ${pname} latest extension version"):
+        server.succeed("sudo -u postgres psql -c 'DROP EXTENSION ${pname};'")
+        server.succeed("sudo -u postgres psql -c 'CREATE EXTENSION ${pname} CASCADE;'")
+        installed_extensions=run_sql(r"""SELECT extname, extversion FROM pg_extension;""")
+        latestVersion = versions["15"][-1]
+        assert f"${pname},{latestVersion}" in installed_extensions
+
+      with subtest("switch to postgresql 17"):
+        server.succeed(
+          "${pg17-configuration}/bin/switch-to-configuration test >&2"
+        )
+
+      check_upgrade_path("17")
+    '';
+}