From 5749801bd5a8ffcc175798afb7f5a118dc8301f5 Mon Sep 17 00:00:00 2001
From: Till Maas <opensource@till.name>
Date: Apr 16 2019 16:51:16 +0000
Subject: docker: Use is-active to determine docker status


Only run `systemctl start docker` when `systemctl is-active docker`
fails. The start command is privileged and therefore requires manual
authentication if it is run by a non-root user even if the service is
already active. The check with is-active is possible without special
privileges. This allows to use the inventory file if the current user is
in the docker group.

---

diff --git a/inventory/standard-inventory-docker b/inventory/standard-inventory-docker
index bc3371d..d4ef327 100755
--- a/inventory/standard-inventory-docker
+++ b/inventory/standard-inventory-docker
@@ -86,13 +86,18 @@ def inv_host(subject, docker_extra_args):
         raise RuntimeError("Could not parse DOCKER_EXTRA_ARGS")
     logger.info("Launching Docker container for {0}".format(image))
     # Make sure the docker service is running
-    cmd = [
-        "/usr/bin/systemctl", "start", "docker"
-    ]
     try:
-        subprocess.check_call(cmd, stdout=sys.stderr.fileno())
+        subprocess.check_call(["/usr/bin/systemctl", "is-active", "--quiet", "docker"],
+                              stdout=sys.stderr.fileno())
     except subprocess.CalledProcessError:
-        raise RuntimeError("Could not start docker service")
+        try:
+            cmd = [
+                "/usr/bin/systemctl", "start", "docker"
+            ]
+            subprocess.check_call(cmd, stdout=sys.stderr.fileno())
+        except subprocess.CalledProcessError:
+            raise RuntimeError("Could not start docker service")
+
     # And launch the actual container
     cmd = [
         "/usr/bin/docker", "run", "--detach", "--cidfile={0}".format(cidfile),