Merge branch '101_add_tmpfs_when_running_a_container' into 'master'

Add minimal rw tmpfs for /tmp and /run

Closes #101

See merge request !125

beat/core/dock.py

@@ -558,6 +558,9 @@ class Host(object):
         # Mount the volumes
         cmd.extend(container.volumes)
 
+        # Add tmpfs entries
+        cmd.extend(container.temporary_filesystems)
+
         # Expose the ports
         cmd.extend(container.ports)
 
@@ -792,6 +795,7 @@ class Container:
         self._name = None
         self._workdir = None
         self._entrypoint = None
+        self._temporary_filesystems = {"/tmp": "500k", "/run": "500k"}  # nosec
 
     def set_name(self, name):
         """ Set the name to be used by the container in place of the docker
@@ -822,6 +826,16 @@ class Container:
 
         self._volumes[path] = {"bind": mount_path, "mode": "ro" if read_only else "rw"}
 
+    def add_tmpfs(self, path, size):
+        """Add a tmpfs to be mounted on the container
+
+        Parameters:
+            :param str path: Target path for the tmpfs
+            :param str size: Size of the tmps. Unlimited if empty
+        """
+
+        self._temporary_filesystems[path] = size
+
     def add_port(self, container_port, host_port, host_address=None):
         """Add a port binding
 
@@ -901,6 +915,17 @@ class Container:
                 volumes.append("--volume=%s:%s:%s" % (k, v["bind"], v["mode"]))
         return volumes
 
+    @property
+    def temporary_filesystems(self):
+        tempfs_list = []
+        for path, size in self._temporary_filesystems.items():
+            tmpfs_string = "--tmpfs={}:rw,noexec,nosuid".format(path)
+            if size:
+                tmpfs_string += ",size={}".format(size)
+
+            tempfs_list.append(tmpfs_string)
+        return tempfs_list
+
     @property
     def ports(self):
         """Returns the ports of this container in a suitable form to build

beat/core/test/test_docker.py

@@ -188,6 +188,62 @@ class EntrypointTest(NoDiscoveryTests):
         self.assertEqual(logs, "42\n")
 
 
+class TmpfsTest(NoDiscoveryTests):
+    def test_tmpfs(self):
+        """Test that the tmpfs are properly mounted and usable.
+        """
+
+        container = self.host.create_container(
+            "debian:8.4", ["touch", "/dummy/test.txt"]
+        )
+
+        tmpfs_list = container.temporary_filesystems
+
+        self.assertEqual(len(tmpfs_list), 2)
+
+        container.add_tmpfs("/dummy", "1M")
+
+        tmpfs_list = container.temporary_filesystems
+
+        self.assertEqual(len(tmpfs_list), 3)
+
+        self.host.start(container)
+        status = self.host.wait(container)
+        logs = self.host.logs(container)
+        if status != 0:
+            print(logs)
+
+        self.assertEqual(status, 0)
+        self.assertEqual(logs, "")
+
+    def test_tmpfs_size(self):
+        """Test that the tmpfs are respected.
+        """
+
+        container = self.host.create_container(
+            "debian:8.4", ["dd", "if=/dev/zero", "of=/dummy/test.txt"]
+        )
+
+        tmpfs_list = container.temporary_filesystems
+
+        self.assertEqual(len(tmpfs_list), 2)
+
+        container.add_tmpfs("/dummy", "1M")
+
+        tmpfs_list = container.temporary_filesystems
+
+        self.assertEqual(len(tmpfs_list), 3)
+
+        self.host.start(container)
+        status = self.host.wait(container)
+        logs = self.host.logs(container)
+        if status != 0:
+            print(logs)
+
+        self.assertEqual(status, 1)
+        self.assertTrue("No space left" in logs)
+
+
 class AsyncTest(NoDiscoveryTests):
     @slow
     def test_echo(self):