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From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Thu, 21 Jun 2018 07:25:59 +0100
Message-Id: <20180621062605.941-52-alex.bennee@linaro.org>
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Subject: [Qemu-devel] [PULL v2 51/57] docker: docker.py use "version" to
 probe usage
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To: peter.maydell@linaro.org
Cc: qemu-devel@nongnu.org, cota@braap.org, famz@redhat.com, berrange@redhat.com, f4bug@amsat.org, richard.henderson@linaro.org, balrogg@gmail.com, aurelien@aurel32.net, agraf@suse.de, =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>

The "images" command is a fairly heavyweight command to run as it
involves searching the whole docker file-system inventory. On a
machine with a lot of images this makes start-up fairly expensive.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

diff --git a/tests/docker/docker.py b/tests/docker/docker.py
index b28ad87034..e6437d64a7 100755
--- a/tests/docker/docker.py
+++ b/tests/docker/docker.py
@@ -52,7 +52,9 @@ def _guess_docker_command():
     commands = [["docker"], ["sudo", "-n", "docker"]]
     for cmd in commands:
         try:
-            if subprocess.call(cmd + ["images"],
+            # docker version will return the client details in stdout
+            # but still report a status of 1 if it can't contact the daemon
+            if subprocess.call(cmd + ["version"],
                                stdout=DEVNULL, stderr=DEVNULL) == 0:
                 return cmd
         except OSError:
-- 
2.17.1