Only stop index container if one is actually running (#70)

So far, `qlever index` always called `docker rm -f ...` or `podman rm -f ...` before starting a new index build. However, old versions of podman return an error message when no container with the specified name is running. This is now fixed by checking explicitly whether a container is running and only if there is, trying to stop and remove it. Fixes #66.

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "qlever"
 description = "Script for using the QLever SPARQL engine."
-version = "0.5.6"
+version = "0.5.7"
 authors = [
     { name = "Hannah Bast", email = "[email protected]" }
 ]

src/qlever/commands/index.py

@@ -119,11 +119,14 @@ def execute(self, args) -> bool:
         # Remove already existing container.
         if args.system in Containerize.supported_systems() \
                 and args.overwrite_existing:
-            try:
-                run_command(f"{args.system} rm -f {args.index_container}")
-            except Exception as e:
-                log.error(f"Removing existing container failed: {e}")
-                return False
+            if Containerize.is_running(args.system, args.index_container):
+                log.info("Another index process is running, trying to stop it ...")
+                log.info("")
+                try:
+                    run_command(f"{args.system} rm -f {args.index_container}")
+                except Exception as e:
+                    log.error(f"Removing existing container failed: {e}")
+                    return False
 
         # Write settings.json file.
         try:

src/qlever/containerize.py

@@ -9,6 +9,7 @@
 from typing import Optional
 
 from qlever.log import log
+from qlever.util import run_command
 
 
 class ContainerizeException(Exception):
@@ -78,6 +79,17 @@ def containerize_command(cmd: str, container_system: str,
                              f" -c {shlex.quote(cmd)}")
         return containerized_cmd
 
+    @staticmethod
+    def is_running(container_system: str, container_name: str) -> bool:
+        # Note: the `{{{{` and `}}}}` result in `{{` and `}}`, respectively.
+        containers = (
+            run_command(f"{container_system} ps --format=\"{{{{.Names}}}}\"",
+                        return_output=True)
+            .strip()
+            .splitlines()
+        )
+        return container_name in containers
+
     @staticmethod
     def stop_and_remove_container(container_system: str,
                                   container_name: str) -> bool: