Merge ~os369510/maas/+git/maas:master into maas:master

[jeremyszu]

Add SSH Power driver

In our development environment, we need to daily deploy the daily built image to various platforms. (such as workstation, laptop, IoT board, etc...)

There's many platforms not support either:
1. Power on when AC detected (which means can not be wake up by PDU).
2. Wake on LAN.

and also these platforms won't be power-off after last deployment completed.
Therefore, here is the idea to power control device through ssh command.

Requirements:
1. Generate ssh keys on MaaS server (e.g. put ssh key in /var/lib/maas/id_rsa).
2. Add the pair public key of above one to MaaS account.
3. Assign a static IP for target device.
4. Need to know a super user name on target device.

Then the device would be reboot after 5 secs (to prevent got ssh connection closed error) when deploying image if the device has been deployed by MaaS in previous stage.

I've already test it with version 2.5.0-7442-gdf68e30a5-0ubuntu1~18.04.1.

I'm new in MaaS world and would like to know more opinions.
Please let me know if anything I'm missing.

[MAAS Lander (maas-lander)]

UNIT TESTS
-b master lp:~os369510/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/6996/console
COMMIT: 2b908804f95049bce87509dac8f14b2248c0f4b9

review: Needs Fixing

[jeremyszu (os369510)]

Hi Maintainers,

I can not access this link 'http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/6996/console', could you please share more detail for building failed?

81e273a... by jeremyszu on 2019-12-29

Add SSH Power driver

Applied change based on lint suggestion.

[MAAS Lander (maas-lander)]

UNIT TESTS
-b master lp:~os369510/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/7044/console
COMMIT: 81e273a95028115b6ee45d5ca823aea122f4f485

review: Needs Fixing

234306d... by jeremyszu on 2020-01-16

Add SSH Power driver

Change the order of importing library

[MAAS Lander (maas-lander)]

UNIT TESTS
-b master lp:~os369510/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 234306d206d270802d9397a35da84e14e4784d53

review: Approve

[jeremyszu (os369510)]

@Adam,

Does this MP missing anything? or any improvements need to be applied?
Would you please let me know whether missing anything?

Unmerged commits

234306d... by jeremyszu on 2020-01-16

Add SSH Power driver

Change the order of importing library

81e273a... by jeremyszu on 2019-12-29

Add SSH Power driver

Applied change based on lint suggestion.

2b90880... by jeremyszu on 2019-11-23

Add SSH Power driver

diff --git a/src/provisioningserver/drivers/power/registry.py b/src/provisioningserver/drivers/power/registry.py
index 8ea5b27..cd2f8cf 100644
--- a/src/provisioningserver/drivers/power/registry.py
+++ b/src/provisioningserver/drivers/power/registry.py
@@ -23,6 +23,7 @@ from provisioningserver.drivers.power.openbmc import OpenBMCPowerDriver
 from provisioningserver.drivers.power.recs import RECSPowerDriver
 from provisioningserver.drivers.power.redfish import RedfishPowerDriver
 from provisioningserver.drivers.power.seamicro import SeaMicroPowerDriver
+from provisioningserver.drivers.power.ssh import SSHPowerDriver
 from provisioningserver.drivers.power.ucsm import UCSMPowerDriver
 from provisioningserver.drivers.power.virsh import VirshPowerDriver
 from provisioningserver.drivers.power.vmware import VMwarePowerDriver
@@ -67,6 +68,7 @@ power_drivers = [
     VirshPowerDriver(),
     VMwarePowerDriver(),
     WedgePowerDriver(),
+    SSHPowerDriver(),
 ]
 for driver in power_drivers:
     PowerDriverRegistry.register_item(driver.name, driver)
diff --git a/src/provisioningserver/drivers/power/ssh.py b/src/provisioningserver/drivers/power/ssh.py
new file mode 100644
index 0000000..974950c
--- /dev/null
+++ b/src/provisioningserver/drivers/power/ssh.py
@@ -0,0 +1,103 @@
+# Copyright 2015-2016 Canonical Ltd.  This software is licensed under the
+# GNU Affero General Public License version 3 (see the file LICENSE).
+
+"""SSH Power Driver.
+
+Issue command to control power through SSH.
+"""
+
+__all__ = []
+
+from subprocess import PIPE, Popen
+
+from twisted.internet.defer import maybeDeferred
+
+from provisioningserver.drivers import make_setting_field
+from provisioningserver.drivers.power import PowerActionError, PowerDriver
+from provisioningserver.logger import get_maas_logger
+from provisioningserver.utils import shell
+from provisioningserver.utils.shell import get_env_with_locale
+
+maaslog = get_maas_logger("drivers.power.ssh")
+
+
+class SSHPowerDriver(PowerDriver):
+    """Power control through issuing SSH command."""
+
+    name = "ssh"
+    chassis = True
+    description = "Issue Command through SSH"
+    settings = [
+        make_setting_field("username", "Username", required=True),
+        make_setting_field(
+            "device_address", "IP for Target Device", required=True
+        ),
+        make_setting_field(
+            "key_path", "Paired key on MaaS server", required=True
+        ),
+    ]
+    ip_extractor = None
+    queryable = False
+
+    def detect_missing_packages(self):
+        binary, package = ["ssh", "openssh-client"]
+        if not shell.has_command_available(binary):
+            return [package]
+        return []
+
+    @classmethod
+    def run_process(cls, command):
+        """Run SSH command in subprocess."""
+        proc = Popen(
+            command.split(),
+            stdout=PIPE,
+            stderr=PIPE,
+            env=get_env_with_locale(),
+        )
+        stdout, stderr = proc.communicate()
+        stdout = stdout.decode("utf-8")
+        stderr = stderr.decode("utf-8")
+        if proc.returncode != 0:
+            raise PowerActionError(
+                "APC Power Driver external process error for command %s: %s: %s"
+                % (command, stdout, stderr)
+            )
+
+    def on(self, system_id, context):
+        """Override `on` as we do not need retry logic."""
+        return maybeDeferred(self.power_on, system_id, context)
+
+    def off(self, system_id, context):
+        """Override `off` as we do not need retry logic."""
+        return maybeDeferred(self.power_off, system_id, context)
+
+    def query(self, system_id, context):
+        """Override `query` as we do not need retry logic."""
+        return maybeDeferred(self.power_query, system_id, context)
+
+    def power_on(self, system_id, context):
+        """Power on machine through ssh."""
+        maaslog.info("You need to power on %s manually.", system_id)
+        self.run_process(
+            "ssh "
+            + "-o StrictHostKeyChecking=no "
+            + "-o UserKnownHostsFile=/dev/null "
+            + "-i "
+            + context["key_path"]
+            + " -t "
+            + context["username"]
+            + "@"
+            + context["device_address"]
+            + " (sleep 5; sudo reboot) &"
+        )
+
+    def power_off(self, system_id, context):
+        """Power off machine manually."""
+        maaslog.info("You need to power off %s manually.", system_id)
+
+    def power_query(self, system_id, context):
+        """Power query machine manually."""
+        maaslog.info(
+            "You need to check power state of %s manually.", system_id
+        )
+        return "unknown"