DEVX-28: fix: add rootless socket fallback and GITHUB_ENV export

src/devx/molecule/start_docker.py

@@ -6,8 +6,9 @@ Docker socket mounted. This module verifies Docker is accessible and
 sets ``DOCKER_HOST`` explicitly so molecule's Python docker library
 connects to the same socket as the Docker CLI.
 
-If the host socket is not available, it starts a local ``dockerd``
-with the vfs storage driver (requires privileged container).
+If the host socket is not available, it tries the rootless socket, then
+starts a local ``dockerd`` with the vfs storage driver (requires
+privileged container).
 
 Usage::
 
@@ -28,6 +29,8 @@ from devx.i18n import _
 
 DEFAULT_TIMEOUT = 30
 DOCKER_SOCK = "/var/run/docker.sock"
+# Rootless socket fallback (e.g. /run/user/994/docker.sock)
+ROOTLESS_SOCK = f"/run/user/{os.getuid()}/docker.sock"
 
 
 def is_docker_ready() -> bool:
@@ -93,8 +96,9 @@ def start_docker_daemon(timeout: int = DEFAULT_TIMEOUT) -> bool:
     """Ensure Docker is ready for molecule tests.
 
     First tries the host socket. If that works, sets ``DOCKER_HOST`` and
-    returns immediately. If not, starts a local ``dockerd`` with vfs
-    storage driver (requires privileged container).
+    returns immediately. If not, tries the rootless socket. If neither
+    works, starts a local ``dockerd`` with vfs storage driver (requires
+    privileged container).
 
     Returns ``True`` if Docker is ready, ``False`` if it failed to
     start within the timeout.
@@ -112,6 +116,13 @@ def start_docker_daemon(timeout: int = DEFAULT_TIMEOUT) -> bool:
         click.echo(_("Docker daemon already running"))
         return True
 
+    # Try rootless socket (e.g. /run/user/994/docker.sock)
+    click.echo(f"Trying rootless socket: {ROOTLESS_SOCK}")
+    os.environ["DOCKER_HOST"] = f"unix://{ROOTLESS_SOCK}"
+    if os.path.exists(ROOTLESS_SOCK) and is_docker_ready():
+        click.echo(_("Docker daemon already running"))
+        return True
+
     click.echo(_("Host Docker not available, starting local dockerd..."))
 
     # Start local dockerd (requires privileged container)
@@ -162,6 +173,12 @@ def start_docker_daemon(timeout: int = DEFAULT_TIMEOUT) -> bool:
 def main(timeout: int) -> None:
     """Start Docker daemon for CI molecule tests."""
     if start_docker_daemon(timeout):
+        # Export DOCKER_HOST to GITHUB_ENV for subsequent CI steps
+        github_env = os.environ.get("GITHUB_ENV")
+        if github_env and os.environ.get("DOCKER_HOST"):
+            with open(github_env, "a") as f:
+                f.write(f"DOCKER_HOST={os.environ['DOCKER_HOST']}\n")
+            click.echo(f"Exported DOCKER_HOST={os.environ['DOCKER_HOST']} to GITHUB_ENV")
         sys.exit(0)
     sys.exit(1)