[dock] Add support for custom tmpfs

In order to allow container with special needs like
ROS requiring some read/write space, the Container
class now parses the new custom "beat.env.custom_tmpfs"
label and add the corresponding entries to the dictionnary
dedicated to them.

Fixes #106

beat/core/dock.py

@@ -795,6 +795,17 @@ class Container:
         self._entrypoint = None
         self._temporary_filesystems = {"/tmp": "500k", "/run": "500k"}  # nosec
 
+        client = docker.from_env()
+        docker_image = client.images.get(image)
+        custom_tmpfs = docker_image.labels.get("beat.env.custom_tmpfs")
+
+        if custom_tmpfs is not None:
+            # import ipdb; ipdb.set_trace()
+            custom_tmpfs = json.loads(custom_tmpfs)
+
+            for path, size in custom_tmpfs.items():
+                self._temporary_filesystems[path] = size
+
     def set_name(self, name):
         """ Set the name to be used by the container in place of the docker
         auto generated one.

beat/core/test/test_docker.py

@@ -107,8 +107,7 @@ class NetworkTest(NoDiscoveryTests):
 class UserTest(NoDiscoveryTests):
     @slow
     def test_user(self):
-        """Test that the uid property is correctly used.
-        """
+        """Test that the uid property is correctly used."""
 
         container = self.host.create_container("debian:8.4", ["id"])
         container.uid = 10000
@@ -127,8 +126,7 @@ class UserTest(NoDiscoveryTests):
 class EnvironmentVariableTest(NoDiscoveryTests):
     @slow
     def test_environment_variable(self):
-        """Test that the uid property is correctly used.
-        """
+        """Test that the uid property is correctly used."""
 
         container = self.host.create_container("debian:8.4", ["env"])
         container.add_environment_variable("DOCKER_TEST", "good")
@@ -143,8 +141,7 @@ class EnvironmentVariableTest(NoDiscoveryTests):
 class WorkdirTest(NoDiscoveryTests):
     @slow
     def test_workdir(self):
-        """Test that the workdir property is correctly used.
-        """
+        """Test that the workdir property is correctly used."""
 
         with TemporaryDirectory() as tmp_folder:
             test_file = "test.txt"
@@ -169,8 +166,7 @@ class WorkdirTest(NoDiscoveryTests):
 class EntrypointTest(NoDiscoveryTests):
     @slow
     def test_entrypoint(self):
-        """Test that the entrypoint property is correctly used.
-        """
+        """Test that the entrypoint property is correctly used."""
 
         container = self.host.create_container("debian:8.4", ["42"])
         container.set_entrypoint("echo")
@@ -187,8 +183,7 @@ class EntrypointTest(NoDiscoveryTests):
 
 class TmpfsTest(NoDiscoveryTests):
     def test_tmpfs(self):
-        """Test that the tmpfs are properly mounted and usable.
-        """
+        """Test that the tmpfs are properly mounted and usable."""
 
         container = self.host.create_container(
             "debian:8.4", ["touch", "/dummy/test.txt"]
@@ -213,33 +208,6 @@ class TmpfsTest(NoDiscoveryTests):
         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
@@ -300,7 +268,7 @@ class AsyncTest(NoDiscoveryTests):
         self.assertEqual(self.host.logs(container), "")
 
 
-class AsyncWithEnvironmentTest(unittest.TestCase):
+class WithDiscoveryTests(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         cls.host = Host(raise_on_errors=False)
@@ -314,6 +282,31 @@ class AsyncWithEnvironmentTest(unittest.TestCase):
         self.host.teardown()
         self.assertFalse(self.host.containers)  # All containers are gone
 
+
+class TmpfsWithEnvironmentTest(WithDiscoveryTests):
+    def test_tmpfs_from_label(self):
+        """Test that the tmpfs are respected."""
+
+        container = self.host.create_container(
+            "Python for tests (1.3.0)",
+            ["dd", "if=/dev/zero", "of=/custom_tmpfs/test.txt"],
+        )
+
+        tmpfs_list = container.temporary_filesystems
+
+        self.assertEqual(len(tmpfs_list), 3)
+        print(tmpfs_list)
+        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 AsyncWithEnvironmentTest(WithDiscoveryTests):
     @slow
     def test_memory_limit(self):