feat: ability to use postgres as store for starter distro

The starter distribution now comes with all the required packages to
support persistent stores—like the agent store, metadata, and
inference—using PostgreSQL.  We’ve added a new run YAML file,
run-with-postgres-store.yaml, to make this setup easy. The file is
included in the container image, so users can simply override the
entrypoint to use the Postgres-specific config.  The documentation has
been updated with instructions on how to do that.

Closes: #2619
Signed-off-by: Sébastien Han <seb@redhat.com>

llama_stack/core/utils/config_resolution.py

@@ -52,7 +52,17 @@ def resolve_config_or_distro(
             logger.info(f"Using distribution: {distro_config}")
             return distro_config
 
-    # Strategy 3: Try as built distribution name
+    # Strategy 3: Try as distro config path (if no .yaml extension and contains a slash)
+    # eg: starter::run-with-postgres-store.yaml
+    # Use :: to avoid slash and confusion with a filesystem path
+    if "::" in config_or_distro:
+        distro_name, config_name = config_or_distro.split("::")
+        distro_config = _get_distro_config_path(distro_name, config_name)
+        if distro_config.exists():
+            logger.info(f"Using distribution: {distro_config}")
+            return distro_config
+
+    # Strategy 4: Try as built distribution name
     distrib_config = DISTRIBS_BASE_DIR / f"llamastack-{config_or_distro}" / f"{config_or_distro}-{mode}.yaml"
     if distrib_config.exists():
         logger.info(f"Using built distribution: {distrib_config}")
@@ -63,12 +73,15 @@ def resolve_config_or_distro(
         logger.info(f"Using built distribution: {distrib_config}")
         return distrib_config
 
-    # Strategy 4: Failed - provide helpful error
+    # Strategy 5: Failed - provide helpful error
     raise ValueError(_format_resolution_error(config_or_distro, mode))
 
 
-def _get_distro_config_path(distro_name: str, mode: Mode) -> Path:
+def _get_distro_config_path(distro_name: str, mode: str) -> Path:
     """Get the config file path for a distro."""
+    if mode.endswith(".yaml"):
+        return DISTRO_DIR / distro_name / mode
+
     return DISTRO_DIR / distro_name / f"{mode}.yaml"
 
 

llama_stack/core/utils/exec.py

@@ -84,6 +84,14 @@ def run_command(command: list[str]) -> int:
             text=True,
             check=False,
         )
+
+        # Print stdout and stderr if command failed
+        if result.returncode != 0:
+            if result.stdout:
+                log.error(f"STDOUT: {result.stdout}")
+            if result.stderr:
+                log.error(f"STDERR: {result.stderr}")
+
         return result.returncode
     except subprocess.SubprocessError as e:
         log.error(f"Subprocess error: {e}")