Merge "Check if volume paths exist before executing Docker." into stable/queens

paunch/__init__.py

@@ -126,8 +126,8 @@ def debug(config_id, container_name, action, config, managed_by, labels=None,
             '--name',
             r.unique_container_name(container_name)
         ]
-        builder.docker_run_args(cmd, container_name)
-        return r.execute_interactive(cmd)
+        if builder.docker_run_args(cmd, container_name):
+            return r.execute_interactive(cmd)
     elif action == 'dump-yaml':
         print(yaml.safe_dump(config, default_flow_style=False))
     elif action == 'dump-json':

paunch/builder/compose1.py

@@ -13,6 +13,7 @@
 
 import json
 import logging
+import os
 import tenacity
 import yaml
 
@@ -60,10 +61,15 @@ class ComposeV1Builder(object):
                     self.runner.unique_container_name(container)
                 ]
                 self.label_arguments(cmd, container)
-                self.docker_run_args(cmd, container)
+                validations_passed = self.docker_run_args(cmd, container)
             elif action == 'exec':
                 cmd = [self.runner.docker_cmd, 'exec']
-                self.docker_exec_args(cmd, container)
+                validations_passed = self.docker_exec_args(cmd, container)
+
+            if not validations_passed:
+                LOG.debug('Validations failed. Skipping container: %s' %
+                          container)
+                continue
 
             (cmd_stdout, cmd_stderr, returncode) = self.runner.execute(cmd)
             if cmd_stdout:
@@ -132,6 +138,12 @@ class ComposeV1Builder(object):
         ])
 
     def docker_run_args(self, cmd, container):
+        """Prepare the run command args, from the container configuration.
+
+        :param cmd: The list of command options to be modified
+        :param container: A dict with container configurations
+        :returns: True if configuration is valid, otherwise False
+        """
         cconfig = self.config[container]
         if cconfig.get('detach', True):
             cmd.append('--detach=true')
@@ -192,7 +204,29 @@ class ComposeV1Builder(object):
         cmd.append(cconfig.get('image', ''))
         cmd.extend(self.command_argument(cconfig.get('command')))
 
+        # NOTE(xek): If the file to be mounted doesn't exist, Docker version
+        # 1.13.1 creates a directory in it's place. This behavior is different
+        # then Podman, which throws an error. We want to replicate the Podman
+        # behavior. Creating directories in place of files creates errors which
+        # are very difficult to diagnose.
+        for volume in cconfig.get('volumes', []):
+            host_path = volume.split(':', 1)[0]
+            if host_path and not os.path.exists(host_path):
+                LOG.error("Error running %s.\n" % cmd)
+                LOG.error('stderr: Error: error checking path "%s":'
+                          ' stat %s: no such file or directory\n' % (
+                              host_path, host_path))
+                return False
+
+        return True
+
     def docker_exec_args(self, cmd, container):
+        """Prepare the exec command args, from the container configuration.
+
+        :param cmd: The list of command options to be modified
+        :param container: A dict with container configurations
+        :returns: True if configuration is valid, otherwise False
+        """
         cconfig = self.config[container]
         if 'privileged' in cconfig:
             cmd.append('--privileged=%s' % str(cconfig['privileged']).lower())
@@ -206,6 +240,8 @@ class ComposeV1Builder(object):
                 command[0], self.config_id)
         cmd.extend(command)
 
+        return True
+
     def pull_missing_images(self, stdout, stderr):
         images = set()
         for container in self.config:

paunch/tests/test_builder_compose1.py

@@ -450,7 +450,47 @@ three-12345678 three''', '', 0),
             cmd
         )
 
-    def test_docker_run_args_lists(self):
+    @mock.patch('os.path.exists')
+    def test_docker_run_args_validation_true(self, path_exists):
+        path_exists.return_value = True
+        config = {
+            'one': {
+                'image': 'foo',
+                'volumes': ['/foo:/foo:rw', '/bar:/bar:ro'],
+            }
+        }
+        builder = compose1.ComposeV1Builder('foo', config, None)
+
+        cmd = ['docker']
+        self.assertTrue(builder.docker_run_args(cmd, 'one'))
+        self.assertEqual(
+            ['docker', '--detach=true',
+             '--volume=/foo:/foo:rw', '--volume=/bar:/bar:ro', 'foo'],
+            cmd
+        )
+
+    @mock.patch('os.path.exists')
+    def test_docker_run_args_validation_false(self, path_exists):
+        path_exists.return_value = False
+        config = {
+            'one': {
+                'image': 'foo',
+                'volumes': ['/foo:/foo:rw', '/bar:/bar:ro'],
+            }
+        }
+        builder = compose1.ComposeV1Builder('foo', config, None)
+
+        cmd = ['docker']
+        self.assertFalse(builder.docker_run_args(cmd, 'one'))
+        self.assertEqual(
+            ['docker', '--detach=true',
+             '--volume=/foo:/foo:rw', '--volume=/bar:/bar:ro', 'foo'],
+            cmd
+        )
+
+    @mock.patch('os.path.exists')
+    def test_docker_run_args_lists(self, path_exists):
+        path_exists.return_value = True
         config = {
             'one': {
                 'image': 'centos:7',