Add the ability to include last command output in the alert

Update readme to document the new templating vars

Makefile

@@ -1,5 +1,5 @@
 DOCKER_TAG := minitor-dev
-OPEN_CMD := $(shell type xdg-open > /dev/null && echo 'xdg-open' || echo 'open')
+OPEN_CMD := $(shell type xdg-open &> /dev/null && echo 'xdg-open' || echo 'open')
 
 .PHONY: default
 default: test

README.md

@@ -42,7 +42,16 @@ The Docker image uses a default `config.yml` that is copied from `sample-config.
 
 ### Configuring
 
-In this repo, you can explore the `sample-config.yml` file for an example, but the general structure is as follows. It should be noted that environment variable interpolation happens on load of the YAML file. Also, when alerts are executed, they will be passed through Python's format function with arguments for some attributes of the Monitor. Currently this is limited to `{monitor_name}`.
+In this repo, you can explore the `sample-config.yml` file for an example, but the general structure is as follows. It should be noted that environment variable interpolation happens on load of the YAML file. Also, when alerts are executed, they will be passed through Python's format function with arguments for some attributes of the Monitor. The following monitor specific variables can be referenced using Python formatting syntax:
+
+|token|value|
+|---|---|
+|`{alert_count}`|Number of times this monitor has alerted|
+|`{alert_message}`|The exception message that was raised|
+|`{failure_count}`|The total number of sequential failed checks for this monitor|
+|`{last_output}`|The last returned value from the check command to either stderr or stdout|
+|`{last_success}`|The ISO datetime of the last successful check|
+|`{monitor_name}`|The name of the monitor that failed and triggered the alert|
 
 ## Contributing
 

minitor/main.py

@@ -127,10 +127,11 @@ def __init__(self, config):
         self.alert_after = settings.get('alert_after')
         self.alert_every = settings.get('alert_every')
 
+        self.alert_count = 0
         self.last_check = None
+        self.last_output = None
         self.last_success = None
         self.total_failure_count = 0
-        self.alert_count = 0
 
         self.logger = logging.getLogger(
             '{}({})'.format(self.__class__.__name__, self.name)
@@ -155,8 +156,10 @@ def check(self):
             self.command,
             shell=isinstance(self.command, str),
         )
+        output = maybe_decode(output)
         self.logger.debug(output)
         self.last_check = datetime.now()
+        self.last_output = output
 
         if ex is None:
             self.success()
@@ -240,9 +243,10 @@ def alert(self, message, monitor):
             self._formated_command(
                 alert_count=monitor.alert_count,
                 alert_message=message,
-                monitor_name=monitor.name,
                 failure_count=monitor.total_failure_count,
+                last_output=monitor.last_output,
                 last_success=self._format_datetime(monitor.last_success),
+                monitor_name=monitor.name,
             ),
             shell=isinstance(self.command, str),
         )

tests/alert_test.py

@@ -25,7 +25,8 @@ def echo_alert(self):
                     'echo', (
                         '{monitor_name} has failed {failure_count} time(s)!\n'
                         'We have alerted {alert_count} time(s)\n'
-                        'Last success was {last_success}'
+                        'Last success was {last_success}\n'
+                        'Last output was: {last_output}'
                     )
                 ]
             }
@@ -45,13 +46,15 @@ def test_simple_alert(
         last_success,
         expected_success
     ):
-        monitor.total_failure_count = 1
         monitor.alert_count = 1
+        monitor.last_output = 'beep boop'
         monitor.last_success = last_success
+        monitor.total_failure_count = 1
         with patch.object(echo_alert.logger, 'error') as mock_error:
             echo_alert.alert('Exception message', monitor)
         mock_error.assert_called_once_with(
             'Dummy Monitor has failed 1 time(s)!\n'
             'We have alerted 1 time(s)\n'
-            'Last success was ' + expected_success
+            'Last success was ' + expected_success + '\n'
+            'Last output was: beep boop'
         )

tests/monitor_test.py

@@ -107,15 +107,19 @@ def test_monitor_should_check(self, monitor, last_check):
         assert monitor.should_check()
 
     def test_monitor_check_fail(self, monitor):
+        assert monitor.last_output is None
         with patch.object(monitor, 'failure') as mock_failure:
             monitor.command = ['ls', '--not-real']
             assert not monitor.check()
             mock_failure.assert_called_once()
+            assert monitor.last_output is not None
 
     def test_monitor_check_success(self, monitor):
+        assert monitor.last_output is None
         with patch.object(monitor, 'success') as mock_success:
             assert monitor.check()
             mock_success.assert_called_once()
+            assert monitor.last_output is not None
 
     @pytest.mark.parametrize('failure_count', [0, 1])
     def test_monitor_success(self, monitor, failure_count):

tox.ini

@@ -7,7 +7,7 @@ deps =
 commands =
     coverage erase
     coverage run --source=minitor/ -m pytest --capture=no -vv {posargs:tests}
-    coverage report -m --fail-under 50
+    coverage report -m --fail-under 70
     pre-commit run --all-files
 
 [testenv:pre-commit]