fix(pg_partman): use correct library name for background worker

The pg_partman extension uses a different library name (pg_partman_bgw) than its extension name (pg_partman). This change separates the library name from the extension name to properly handle the background worker library installation and version switching.

Author: jfroche

nix/ext/pg_partman.nix

@@ -10,6 +10,7 @@
 
 let
   pname = "pg_partman";
+  libName = "pg_partman_bgw";
   build =
     version: hash:
     stdenv.mkDerivation rec {
@@ -28,7 +29,7 @@ let
         mkdir -p $out/{lib,share/postgresql/extension}
 
         # Install versioned library
-        install -Dm755 src/*${postgresql.dlSuffix} $out/lib/${pname}-${version}${postgresql.dlSuffix}
+        install -Dm755 src/${libName}${postgresql.dlSuffix} $out/lib/${libName}-${version}${postgresql.dlSuffix}
 
         # Only install SQL files for the latest version
         if [[ "${version}" == "${latestVersion}" ]]; then
@@ -79,7 +80,7 @@ pkgs.buildEnv {
       echo "default_version = '${latestVersion}'"
       cat $out/share/postgresql/extension/${pname}--${latestVersion}.control
     } > $out/share/postgresql/extension/${pname}.control
-    ln -sfn ${pname}-${latestVersion}${postgresql.dlSuffix} $out/lib/${pname}${postgresql.dlSuffix}
+    ln -sfn ${libName}-${latestVersion}${postgresql.dlSuffix} $out/lib/${libName}${postgresql.dlSuffix}
 
 
     # checks
@@ -90,16 +91,21 @@ pkgs.buildEnv {
     )
 
     makeWrapper ${lib.getExe switch-ext-version} $out/bin/switch_pg_partman_version \
-      --prefix EXT_WRAPPER : "$out" --prefix EXT_NAME : "${pname}"
+      --prefix EXT_WRAPPER : "$out" --prefix EXT_NAME : "${pname}" --prefix LIB_NAME : "${libName}"
   '';
 
   passthru = {
-    inherit versions numberOfVersions switch-ext-version;
+    inherit
+      versions
+      numberOfVersions
+      switch-ext-version
+      libName
+      ;
     pname = "${pname}-all";
     hasBackgroundWorker = true;
     defaultSchema = "partman";
     defaultSettings = {
-      shared_preload_libraries = [ "pg_partman" ];
+      shared_preload_libraries = [ libName ];
     };
     version =
       "multi-" + lib.concatStringsSep "-" (map (v: lib.replaceStrings [ "." ] [ "-" ] v) versions);

nix/ext/tests/default.nix

@@ -154,6 +154,8 @@ let
           sql_test_directory = Path("${../../tests}")
           pg_regress_test_name = "${(installedExtension "15").pgRegressTestName or pname}"
           ext_schema = "${(installedExtension "15").defaultSchema or "public"}"
+          lib_name = "${(installedExtension "15").libName or pname}"
+          print(f"Running tests for extension: {lib_name}")
 
           ${builtins.readFile ./lib.py}
 
@@ -177,7 +179,7 @@ let
 
           if ext_has_background_worker:
             with subtest("Test switch_${pname}_version"):
-              test.check_switch_extension_with_background_worker(Path("${psql_15}/lib/${pname}.so"), "15")
+              test.check_switch_extension_with_background_worker(Path(f"${psql_15}/lib/{lib_name}.so"), "15")
 
           with subtest("Check pg_regress with postgresql 15 after installing the last version"):
             test.check_pg_regress(Path("${psql_15}/lib/pgxs/src/test/regress/pg_regress"), "15", pg_regress_test_name)

nix/packages/switch-ext-version.nix

@@ -31,28 +31,32 @@ writeShellApplication {
       echo "  NIX_PROFILE - Path to nix profile (default: /var/lib/postgresql/.nix-profile)"
       echo "  LIB_DIR - Override library directory"
       echo "  EXTENSION_DIR - Override extension directory"
+      echo "  LIB_NAME - Override library name"
       exit 1
     fi
 
     VERSION="$1"
-    echo "$VERSION"
+
+    if [ -z "''${LIB_NAME:-}" ]; then
+      LIB_NAME="$EXT_NAME"
+    fi
 
     # Enable overlay on the wrapper package to be able to switch version
     ${lib.getExe overlayfs-on-package} "$EXT_WRAPPER"
 
     # Check if version exists
     EXT_WRAPPER_LIB="$EXT_WRAPPER/lib"
-    EXT_LIB_TO_USE="$EXT_WRAPPER_LIB/$EXT_NAME-$VERSION${postgresql.dlSuffix}"
+    EXT_LIB_TO_USE="$EXT_WRAPPER_LIB/$LIB_NAME-$VERSION${postgresql.dlSuffix}"
     if [ ! -f "$EXT_LIB_TO_USE" ]; then
       echo "Error: Version $VERSION not found in $EXT_WRAPPER_LIB"
       echo "Available versions:"
       #shellcheck disable=SC2012
-      ls "$EXT_WRAPPER_LIB/$EXT_NAME"-*${postgresql.dlSuffix} 2>/dev/null | sed "s/.*$EXT_NAME-/  /" | sed 's/${postgresql.dlSuffix}$//' || echo "  No versions found"
+      ls "$EXT_WRAPPER_LIB/$LIB_NAME"-*${postgresql.dlSuffix} 2>/dev/null | sed "s/.*$LIB_NAME-/  /" | sed 's/${postgresql.dlSuffix}$//' || echo "  No versions found"
       exit 1
     fi
 
     # Update library symlink
-    ln -sfnv "$EXT_LIB_TO_USE" "$EXT_WRAPPER_LIB/$EXT_NAME${postgresql.dlSuffix}"
+    ln -sfnv "$EXT_LIB_TO_USE" "$EXT_WRAPPER_LIB/$LIB_NAME${postgresql.dlSuffix}"
 
     # Handle extension specific steps
     if [ -x "''${EXTRA_STEPS:-}" ]; then