feat: enable build of multiple versions of the index_advisor extension on different PostgreSQL versions

flake.nix

@@ -1383,6 +1383,8 @@
           inherit (basePackages) wal-g-2 wal-g-3;
         } // pkgs.lib.optionalAttrs (system == "aarch64-linux") {
           inherit (basePackages) postgresql_15_debug postgresql_15_src postgresql_orioledb-17_debug postgresql_orioledb-17_src postgresql_17_debug postgresql_17_src;
+        } // pkgs.lib.optionalAttrs (system == "x86_64-linux") {
+          index_advisor = import ./nix/ext/tests/index_advisor.nix { inherit self; inherit pkgs; };
         };
 
         # Apps is a list of names of things that can be executed with 'nix run';

nix/ext/index_advisor.nix

@@ -1,29 +1,84 @@
-{ lib, stdenv, fetchFromGitHub, postgresql }:
+{
+  pkgs,
+  lib,
+  stdenv,
+  fetchFromGitHub,
+  postgresql,
+}:
 
-stdenv.mkDerivation rec {
+let
   pname = "index_advisor";
-  version = "0.2.0";
+  allVersions = (builtins.fromJSON (builtins.readFile ./versions.json)).${pname};
+  supportedVersions = lib.filterAttrs (
+    _: value: builtins.elem (lib.versions.major postgresql.version) value.postgresql
+  ) allVersions;
+  versions = lib.naturalSort (lib.attrNames supportedVersions);
+  latestVersion = lib.last versions;
+  numberOfVersions = builtins.length versions;
+  build =
+    version: hash:
+    stdenv.mkDerivation rec {
+      inherit pname version;
 
-  buildInputs = [ postgresql ];
+      buildInputs = [ postgresql ];
 
-  src = fetchFromGitHub {
-    owner = "olirice";
-    repo = pname;
-    rev = "v${version}";
-    hash = "sha256-G0eQk2bY5CNPMeokN/nb05g03CuiplRf902YXFVQFbs=";
-  };
+      src = fetchFromGitHub {
+        owner = "olirice";
+        repo = pname;
+        rev = "v${version}";
+        inherit hash;
+      };
+
+      installPhase = ''
+        mkdir -p $out/{lib,share/postgresql/extension}
+
+        create_sql_files() {
+          echo "Creating SQL files for previous versions..."
+          if [[ "${version}" == "${latestVersion}" ]]; then
+            cp *.sql $out/share/postgresql/extension
+          fi
+        }
+
+        create_control_files() {
+          sed -e "/^default_version =/d" \
+              -e "s|^module_pathname = .*|module_pathname = '\$libdir/${pname}'|" \
+            ${pname}.control > $out/share/postgresql/extension/${pname}--${version}.control
+
+          if [[ "${version}" == "${latestVersion}" ]]; then
+            {
+              echo "default_version = '${latestVersion}'"
+              cat $out/share/postgresql/extension/${pname}--${latestVersion}.control
+            } > $out/share/postgresql/extension/${pname}.control
+          fi
+        }
 
-  installPhase = ''
-    mkdir -p $out/{lib,share/postgresql/extension}
+        create_sql_files
+        create_control_files
+      '';
 
-    cp *.sql     $out/share/postgresql/extension
-    cp *.control $out/share/postgresql/extension
-  '';
+      meta = with lib; {
+        description = "Recommend indexes to improve query performance in PostgreSQL";
+        homepage = "https://github.com/olirice/index_advisor";
+        license = licenses.postgresql;
+        inherit (postgresql.meta) platforms;
+      };
+    };
+  packages = builtins.attrValues (
+    lib.mapAttrs (name: value: build name value.hash) supportedVersions
+  );
+in
+pkgs.buildEnv {
+  name = pname;
+  paths = packages;
+  pathsToLink = [
+    "/lib"
+    "/share/postgresql/extension"
+  ];
 
-  meta = with lib; {
-    description = "Recommend indexes to improve query performance in PostgreSQL";
-    homepage = "https://github.com/olirice/index_advisor";
-    platforms = postgresql.meta.platforms;
-    license = licenses.postgresql;
+  passthru = {
+    inherit versions numberOfVersions;
+    pname = "${pname}-all";
+    version =
+      "multi-" + lib.concatStringsSep "-" (map (v: lib.replaceStrings [ "." ] [ "-" ] v) versions);
   };
 }

nix/ext/tests/index_advisor.nix

@@ -0,0 +1,148 @@
+{ self, pkgs }:
+let
+  pname = "index_advisor";
+  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;
+      };
+
+      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")
+    '';
+}

nix/ext/versions.json

@@ -0,0 +1,11 @@
+{
+  "index_advisor": {
+    "0.2.0": {
+      "postgresql": [
+        "15",
+        "17"
+      ],
+      "hash": "sha256-G0eQk2bY5CNPMeokN/nb05g03CuiplRf902YXFVQFbs="
+    }
+  }
+}