add chroot support

Author: fengxx

testinfra/backend/__init__.py

@@ -27,6 +27,7 @@
     "winrm": "testinfra.backend.winrm.WinRMBackend",
     "lxc": "testinfra.backend.lxc.LxcBackend",
     "openshift": "testinfra.backend.openshift.OpenShiftBackend",
+    "chroot": "testinfra.backend.chroot.ChrootBackend",
 }
 
 

testinfra/backend/chroot.py

@@ -0,0 +1,38 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import os.path
+
+from testinfra.backend import base
+
+
+class ChrootBackend(base.BaseBackend):
+    """Run commands in a chroot folder
+
+    Requires root access or sudo
+    Can be invoked by --hosts=/path/to/chroot/ --connection=chroot --sudo
+    """
+
+    NAME = "chroot"
+
+    def __init__(self, name, *args, **kwargs):
+        self.name = name
+        super().__init__(self.name, *args, **kwargs)
+
+    def run(self, command, *args, **kwargs):
+        if not os.path.exists(self.name) and os.path.isdir(self.name):
+            raise RuntimeError(
+                "chroot path {} not found or not a directory".format(self.name)
+            )
+        cmd = self.get_command(command, *args)
+        out = self.run_local("chroot %s /bin/sh -c %s", self.name, cmd)
+        out.command = self.encode(cmd)
+        return out