Merge pull request #393 from ChrisMacNaughton/feature/ssh

#393

Fixes #79

Author: jujubot

juju/machine.py

@@ -194,7 +194,7 @@ async def _scp(self, source, destination, scp_opts):
         if process.returncode != 0:
             raise JujuError("command failed: %s" % cmd)
 
-    def ssh(
+    async def ssh(
             self, command, user=None, proxy=False, ssh_opts=None):
         """Execute a command over SSH on this machine.
 
@@ -204,7 +204,24 @@ def ssh(
         :param str ssh_opts: Additional options to the `ssh` command
 
         """
-        raise NotImplementedError()
+        if proxy:
+            raise NotImplementedError('proxy option is not implemented')
+        address = self.dns_name
+        destination = "{}@{}".format(user, address)
+        cmd = [
+            'ssh',
+            '-i', os.path.expanduser('~/.local/share/juju/ssh/juju_id_rsa'),
+            '-o', 'StrictHostKeyChecking=no',
+            '-q',
+            destination
+        ]
+        cmd.extend(ssh_opts.split() if isinstance(ssh_opts, str) else ssh_opts)
+        cmd.extend([command])
+        loop = self.model.loop
+        process = await asyncio.create_subprocess_exec(*cmd, loop=loop)
+        await process.wait()
+        if process.returncode != 0:
+            raise JujuError("command failed: %s" % cmd)
 
     def status_history(self, num=20, utc=False):
         """Get status history for this machine.

juju/unit.py

@@ -232,7 +232,7 @@ def ssh(
         :param str ssh_opts: Additional options to the `ssh` command
 
         """
-        raise NotImplementedError()
+        self.machine.ssh(command, user, proxy, ssh_opts)
 
     def status_history(self, num=20, utc=False):
         """Get status history for this unit.

tests/integration/test_unit.py

@@ -99,6 +99,33 @@ async def test_scp(event_loop):
             assert f.read() == b'testcontents'
 
 
+@base.bootstrapped
+@pytest.mark.asyncio
+async def test_ssh(event_loop):
+    # ensure that asyncio.subprocess will work;
+    try:
+        asyncio.get_child_watcher().attach_loop(event_loop)
+    except RuntimeError:
+        pytest.skip('test_ssh will always fail outside of MainThread')
+    async with base.CleanModel() as model:
+        app = await model.deploy('ubuntu')
+
+        await asyncio.wait_for(
+            model.block_until(lambda: app.units),
+            timeout=60)
+        unit = app.units[0]
+        await asyncio.wait_for(
+            model.block_until(lambda: unit.machine),
+            timeout=60)
+        machine = unit.machine
+        await asyncio.wait_for(
+            model.block_until(lambda: (machine.status == 'running' and
+                                       machine.agent_status == 'started')),
+            timeout=480)
+        output = await unit.ssh("echo test")
+        assert(output == "test")
+
+
 @base.bootstrapped
 @pytest.mark.asyncio
 async def test_resolve(event_loop):