From ce151599a3593b7f38195898324993872ba556f1 Mon Sep 17 00:00:00 2001
From: Federico Ressi <fressi@redhat.com>
Date: Mon, 2 Aug 2021 09:35:28 +0200
Subject: [PATCH] Fix is_docker_running function when dockerd is not running

Ignore PS command error when looking for docker URLs

When docker daemon is not found running but default URL is
readable then check it is valid before raising an error.

Change-Id: I9bc39930bf4ce1960d327a21c3d9b9d7abc854f3
---
 tobiko/docker/_shell.py | 89 +++++++++++++++++++++++++++--------------
 1 file changed, 59 insertions(+), 30 deletions(-)

diff --git a/tobiko/docker/_shell.py b/tobiko/docker/_shell.py
index 0d2b23f88..47fee083d 100644
--- a/tobiko/docker/_shell.py
+++ b/tobiko/docker/_shell.py
@@ -33,45 +33,74 @@ def discover_docker_urls(
         ssh_client: ssh.SSHClientType = None,
         default_url='unix:/var/run/docker.sock',
         check_urls=True,
-        sudo=False):
+        sudo=False) \
+        -> typing.List[str]:
+    last_error: typing.Optional[Exception] = None
     urls = []
-    processes = sh.list_processes(command='^dockerd',
-                                  ssh_client=ssh_client,
-                                  sudo=sudo)
+    try:
+        urls += list_docker_urls(ssh_client=ssh_client,
+                                 sudo=sudo)
+    except _exception.DockerUrlNotFoundError as ex:
+        last_error = ex
+    if default_url not in urls:
+        urls.append(default_url)
+    if check_urls:
+        urls = select_valid_urls(ssh_client=ssh_client,
+                                 urls=urls,
+                                 sudo=sudo,
+                                 last_error=last_error)
+    return urls
+
+
+def list_docker_urls(
+        ssh_client: ssh.SSHClientType,
+        sudo=False) \
+        -> typing.List[str]:
+    urls = []
+    try:
+        processes = sh.list_processes(command='^dockerd',
+                                      ssh_client=ssh_client,
+                                      sudo=sudo)
+    except sh.PsError as ex:
+        raise _exception.DockerUrlNotFoundError(
+            "Docker demon is not running") from ex
 
     for process in processes:
         if process.command_line:
             urls += urls_from_command_line(process.command_line)
-
-    urls.append(default_url)
     urls = list(collections.OrderedDict.fromkeys(urls))
-
-    error: typing.Optional[Exception] = None
-    if check_urls:
-        valid_urls = []
-        for url in urls:
-            parsed_url = parse.urlparse(url)
-            if (parsed_url.scheme == 'unix' and
-                    parsed_url.path.startswith('/')):
-                try:
-                    sh.execute(f"test -r '{parsed_url.path}'",
-                               ssh_client=ssh_client,
-                               sudo=sudo)
-                except sh.ShellCommandFailed as ex:
-                    LOG.exception(
-                        f"Can't read from socket: {parsed_url.path}")
-                    ex.__cause__ = error
-                    error = ex
-                else:
-                    valid_urls.append(url)
-
-        if not valid_urls:
-            raise _exception.DockerUrlNotFoundError(
-                "Docker is not running") from error
-        urls = valid_urls
     return urls
 
 
+def select_valid_urls(
+        ssh_client: ssh.SSHClientType,
+        urls: typing.List[str],
+        sudo=False,
+        last_error: Exception = None) \
+        -> typing.List[str]:
+    valid_urls = []
+    for url in urls:
+        parsed_url = parse.urlparse(url)
+        if (parsed_url.scheme == 'unix' and
+                parsed_url.path.startswith('/')):
+            try:
+                sh.execute(f"test -r '{parsed_url.path}'",
+                           ssh_client=ssh_client,
+                           sudo=sudo)
+            except sh.ShellCommandFailed as ex:
+                LOG.exception(
+                    f"Can't read from socket: {parsed_url.path}")
+                ex.__cause__ = last_error
+                last_error = ex
+            else:
+                valid_urls.append(url)
+
+    if not valid_urls:
+        raise _exception.DockerUrlNotFoundError(
+            "Docker is not running") from last_error
+    return valid_urls
+
+
 def urls_from_command_line(command_line: sh.ShellCommand,
                            default_url='unix:/var/run/docker.sock') \
         -> typing.List[str]: