Dropped outdated arcfour cipher (#12)

OpenSSL 7.6 removed support for arcfour. rsync which uses ssh is trying
to establish connection with use of it. For newer installations this process
is ending with an error to establish connection.
Replaced arcfour with [email protected] to allow it to work.
However, user can overwrite this by providing --cloud-rsync-cipher argument

Author: dasm

AUTHORS.rst

@@ -9,6 +9,7 @@ Authors
 These people have contributed to `pytest-cloud`, in alphabetical order:
 
 * `Andreas Pelme <[email protected]>`_
+* `Dariusz Smigiel <[email protected]>`_
 * `Loic Dachary <[email protected]>`_
 * `Michael Overmeyer <[email protected]>`_
 * `Orthographic Pedant <[email protected]>`_

CHANGES.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+3.1.0
+-----
+
+- Add config option to select cipher for ssh connection (dasm)
+
 3.0.1
 -----
 

README.rst

@@ -85,6 +85,10 @@ Command-line options
     Optional process count limit for `rsync` processes. By default there's no limit so rsyncing will be in parallel
     for all test nodes.
 
+* `--cloud-rsync-cipher`
+    Optional ssh cipher selection for `rsync` processes. [email protected] by default.
+    Default cipher is chosen to have the least possible network overhead. Network overhead is system, compilation
+    and CPU architecture dependent, however chosen cipher is showing good results in majority of use cases.
 
 Ini file options
 ----------------

pytest_cloud/plugin.py

@@ -121,6 +121,10 @@ def pytest_addoption(parser):
         "--cloud-rsync-bandwidth-limit",
         help="maximum number of processes per test node", type='int', action="store",
         dest='cloud_rsync_bandwidth_limit', metavar="NUMBER", default=10000)
+    parser.addoption(
+        "--cloud-rsync-cipher",
+        help="cipher for ssh connection used by rsync", type=str,
+        dest="cloud_rsync_cipher", metavar="STRING", default="[email protected]")
     parser.addini(
         'cloud_develop_eggs', 'list of python package paths to install in develop mode on the remote side',
         type="pathlist")
@@ -216,7 +220,7 @@ def get_develop_eggs(root_dir, config):
 
 def get_nodes_specs(
         nodes, python=None, chdir=None, virtualenv_path=None, mem_per_process=None,
-        max_processes=None, rsync_max_processes=None, rsync_bandwidth_limit=None, config=None):
+        max_processes=None, rsync_max_processes=None, rsync_bandwidth_limit=None, rsync_cipher=None, config=None):
     """Get nodes specs.
 
     Get list of node names, connect to each of them, get the system information, produce the list of node specs out of
@@ -262,6 +266,7 @@ def get_nodes_specs(
             jobs=rsync_max_processes or len(nodes),
             bwlimit=rsync_bandwidth_limit,
             bandwidth_limit=rsync_bandwidth_limit,
+            ssh_cipher=rsync_cipher,
             **n_m.rsyncoptions)
         print('Detecting connectable test nodes...')
         for node in nodes:
@@ -326,6 +331,7 @@ def check_options(config):
             rsync_bandwidth_limit=config.option.cloud_rsync_bandwidth_limit,
             max_processes=config.option.cloud_max_processes,
             mem_per_process=mem_per_process,
+            rsync_cipher=config.option.cloud_rsync_cipher,
             config=config)
         if node_specs:
             print('Scheduling with {0} parallel test sessions'.format(len(node_specs)))

pytest_cloud/rsync.py

@@ -33,7 +33,7 @@ class RSync(object):
     # pylint: disable=R0913,W0613
     def __init__(
             self, sourcedir, targetdir, verbose=False, ignores=None, includes=None, jobs=None, debug=False,
-            bwlimit=None, **kwargs):
+            bwlimit=None, ssh_cipher=None, **kwargs):
         """Initialize new RSync instance."""
         self.sourcedir = str(sourcedir)
         self.targetdir = str(targetdir)
@@ -44,6 +44,7 @@ def __init__(
         self.targets = set()
         self.jobs = jobs
         self.bwlimit = bwlimit
+        self.ssh_cipher = ssh_cipher
 
     def get_ignores(self):
         """Get ignores."""
@@ -86,10 +87,11 @@ def send(self, raises=True):
                     '--inplace '
                     '--delete-excluded '
                     '--delete '
-                    '-e \"ssh -T -c arcfour -o Compression=no -x\" '
+                    '-e \"ssh -T -c {ssh_cipher} -o Compression=no -x\" '
                     '. {{}}:{chdir}'.format(
                         verbose='v' if self.verbose else '',
                         bwlimit='--bwlimit={0} '.format(self.bwlimit) if self.bwlimit else '',
+                        ssh_cipher=self.ssh_cipher,
                         chdir=self.targetdir,
                         ignores=ignores_path,
                         includes=includes_path,