testbeds: Add docker testbed

This adds support for a testbed based on Docker containers running on
the local host. Bridging the containers can be done using built-in
Linux bridging or using OpenVSwitch bridges.

A new resource 'executor' has been added to abstract away command
execution on nodes on the testbed. Executors have been created for
local command execution, docker exec based command execution and
SSH-based command execution. This has also been changed in the
prototypes to execute using the correct executor.

1 files changed, 80 insertions, 0 deletions

diff --git a/rumba/executors/docker.py b/rumba/executors/docker.py
new file mode 100644
index 0000000..e1e1480
--- /dev/null
+++ b/rumba/executors/docker.py
@@ -0,0 +1,80 @@
+#
+# A library to manage ARCFIRE experiments
+#
+#    Copyright (C) 2017 Nextworks S.r.l.
+#    Copyright (C) 2017 imec
+#
+#    Sander Vrijders   <sander.vrijders@ugent.be>
+#    Dimitri Staessens <dimitri.staessens@ugent.be>
+#    Vincenzo Maffione <v.maffione@nextworks.it>
+#    Marco Capitani    <m.capitani@nextworks.it>
+#    Nick Aerts        <nick.aerts@ugent.be>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., http://www.fsf.org/about/contact/.
+#
+
+from rumba import model as mod
+
+import tempfile
+import tarfile
+
+from rumba import log
+
+logger = log.get_logger(__name__)
+
+
+class DockerException(Exception):
+    pass
+
+
+class DockerExecutor(mod.Executor):
+    def __init__(self, testbed):
+        self.testbed = testbed
+        self.running_containers = testbed.running_containers
+
+    def execute_command(self, node, command, sudo=False, time_out=3):
+        logger.debug("%s >> %s" % (node.name, command))
+
+        c, o = self.running_containers[node.name].exec_run(["sh", "-c",
+                                                            command])
+        if c:
+            raise DockerException('A remote command returned an error. '
+                                  'Output:\n\n\t' + o.decode("utf-8"))
+
+        return o.decode("utf-8")
+
+    def fetch_file(self, node, path, destination, as_root=False):
+        if not path.startswith("/"):
+            workingdir = self.running_containers[node.name].attrs["Config"][
+                "WorkingDir"]
+            path = os.path.join(workingdir, path)
+
+        try:
+            with tempfile.NamedTemporaryFile() as tmp:
+                archive, _ = self.running_containers[node.name].get_archive(
+                    path)
+
+                for c in archive:
+                    tmp.write(c)
+
+                tmp.seek(0)
+
+                tarfile.TarFile(fileobj=tmp, mode='r').extract(
+                    path.basename(path), destination)
+        except:
+            logger.error("Error when extracting %s" % path)
+
+    def copy_file(self, node, path, destination):
+        pass