Merge ~sajoupa/charm-telegraf:snap-support into charm-telegraf:master

[Laurent Sesquès]

Add support for either deb or snap install (defaults to deb)

[Laurent Sesquès (sajoupa)]

Successfully passes `make test`.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Stuart Bishop (stub)]

Looks great. Some minor comments inline, but nothing requiring changes.

[Paul Goins (vultaire)]

LGTM

review: Approve

[Xav Paice (xavpaice)]

Needs a rebase against master to resolve merge conflicts.

Tests all pass, including the focal/snap test.

review: Needs Fixing

[Laurent Sesquès (sajoupa)]

- rebase done
- fixed a few regressions introduced in recent commits in master
- followed stub's advice for {!r}
- successfully passes `make test`

[Laurent Sesquès (sajoupa)]

replied to the inline comments.

[Joe Guo (guoqiao)]

Hi Laurent,

Did you run `make test` as root?
I just ran `make unittest` as non-root, it will pop up dialogues to ask for authentication.
You may need to add this line in unit_tests/test_telegraf.py::setup:

monkeypatch.setattr(telegraf.host, 'service_pause', lambda svc: None)

review: Needs Fixing

[Joe Guo (guoqiao)]

Other than above, both unit and functional tests passed.

[Stuart Bishop (stub)]

Yup. Some trivial formatting issues, inline.

review: Approve

[Laurent Sesquès (sajoupa)]

> Hi Laurent,
>
> Did you run `make test` as root?
> I just ran `make unittest` as non-root, it will pop up dialogues to ask for
> authentication.
> You may need to add this line in unit_tests/test_telegraf.py::setup:
>
> monkeypatch.setattr(telegraf.host, 'service_pause', lambda svc: None)

Hi Joe,

I've always run it successfully as a normal user.
But your suggestion makes sense, I added it.

[Laurent Sesquès (sajoupa)]

Pushed updates addressing guoqiao's and stub's comments.
Still passes `make test` successfully.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision ac0af7b8cb76e77adc913ec67c2f28272f77980d

diff --git a/README.md b/README.md
index d5ae81e..636dcda 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,16 @@ address rather than the unit's private address.
 
 # Configuration
 
+## Installation method: deb or snap
+
+The charm can deploy using either a deb (default) or a snap installation.
+    juju config telegraf install_method=deb  # to use the debian package
+    juju config telegraf install_method=snap  # to use the snap
+Only the needed package (deb or snap) will be installed.
+
+To change the snap channel:
+    juju config telegraf snap_channel=beta
+
 ## Prometheus Output
 
 By default, Prometheus output is presented available for scraping.
diff --git a/config.yaml b/config.yaml
index 215baff..454e461 100644
--- a/config.yaml
+++ b/config.yaml
@@ -97,6 +97,16 @@ options:
     # description and type comes from the apt layer.
     default: |
       - null
+  install_method:
+    type: string
+    default: "deb"
+    description: >
+        Installation method. Valid values are "deb" or "snap".
+  snap_channel:
+    default: "stable"
+    type: string
+    description: |
+        Snap Store channel from which to install the telegraf snap.
   extra_options:
     default: ""
     type: string
@@ -125,7 +135,7 @@ options:
     type: string
     description: |
         Extra plugins, manually configured. This is expected to be a string
-        and will be saved "as is" in /etc/telegraf/telegraf.d/extra_plugins.conf
+        and will be saved "as is" in telegraf.d/extra_plugins.conf
   disabled_plugins:
     type: string
     default: ""
diff --git a/files/telegraf_exec_metrics.py b/files/telegraf_exec_metrics.py
index 8525e0e..0a08c13 100755
--- a/files/telegraf_exec_metrics.py
+++ b/files/telegraf_exec_metrics.py
@@ -203,7 +203,7 @@ class NetNSCmdMetric(CmdMetric):
     name_override = "{name}"
     data_format = "json"
     tag_keys = ["namespace", "id"]
-    interval = 600
+    interval = "600s"
     ''')
 
     def parse(self, content):
diff --git a/layer.yaml b/layer.yaml
index 346e4d8..057a4c2 100644
--- a/layer.yaml
+++ b/layer.yaml
@@ -20,6 +20,7 @@ includes:
     - layer:leadership
     - layer:ntpmon
     - layer:promreg-client
+    - layer:snap
     - interface:elasticsearch
     - interface:grafana-dashboard
     - interface:http
@@ -41,7 +42,4 @@ options:
             - sysstat
             - python3-yaml
             - python3-netifaces
-    apt:
-        packages:
-            - telegraf
 repo: https://git.launchpad.net/telegraf-charm
diff --git a/reactive/telegraf.py b/reactive/telegraf.py
index 28ee023..d62efd2 100644
--- a/reactive/telegraf.py
+++ b/reactive/telegraf.py
@@ -28,6 +28,8 @@ import re
 import netifaces
 import subprocess
 
+from charms import apt
+from charms.layer import snap
 from charms.reactive import (
     endpoint_from_flag,
     helpers,
@@ -45,11 +47,11 @@ from charmhelpers.core import hookenv, host, unitdata
 from charmhelpers.core.templating import render
 from charmhelpers.core.host import is_container
 from charmhelpers.contrib.charmsupport import nrpe
-from charmhelpers.fetch import apt_cache
 import charms.promreg
 from jinja2 import Template, Environment, FileSystemLoader, exceptions
 
-BASE_DIR = '/etc/telegraf'
+DEB_BASE_DIR = '/etc/telegraf'
+SNAP_BASE_DIR = '/var/snap/telegraf/current'
 
 CONFIG_FILE = 'telegraf.conf'
 
@@ -59,16 +61,51 @@ GRAFANA_DASHBOARD_TELEGRAF_FILE_NAME = 'Telegraf.json.j2'
 
 GRAFANA_DASHBOARD_NAME = 'telegraf'
 
+SNAP_SERVICE = 'snap.telegraf.telegraf'
+DEB_SERVICE = 'telegraf'
+
 # Utilities #
 
 
-def exec_timeout_supported():
-    cache = apt_cache()
-    pkg = cache['telegraf']
-    timeout_support = True
-    if '0.12' in pkg.current_ver.ver_str:
-        timeout_support = False
-    return timeout_support
+class InvalidInstallMethod(Exception):
+    pass
+
+
+def get_install_method():
+    config = hookenv.config()
+    if config['install_method'] in ['deb', 'snap']:
+        return config['install_method']
+    else:
+        hookenv.log(
+            "Invalid install_method for telegraf: {}".format(config['install_method']),
+            level=hookenv.ERROR)
+        raise InvalidInstallMethod()
+
+
+def get_base_dir():
+    config = hookenv.config()
+    if config['install_method'] == 'deb':
+        return DEB_BASE_DIR
+    elif config['install_method'] == 'snap':
+        return SNAP_BASE_DIR
+    else:
+        hookenv.log(
+            "Invalid install_method for telegraf: {}".format(config['install_method']),
+            level=hookenv.ERROR)
+        raise InvalidInstallMethod()
+
+
+def get_service():
+    config = hookenv.config()
+    if config['install_method'] == 'deb':
+        return DEB_SERVICE
+    elif config['install_method'] == 'snap':
+        return SNAP_SERVICE
+    else:
+        hookenv.log(
+            "Invalid install_method for telegraf: {}".format(config['install_method']),
+            level=hookenv.ERROR)
+        raise InvalidInstallMethod()
 
 
 def get_templates_dir():
@@ -76,11 +113,11 @@ def get_templates_dir():
 
 
 def get_main_config_path():
-    return os.path.join(BASE_DIR, CONFIG_FILE)
+    return os.path.join(get_base_dir(), CONFIG_FILE)
 
 
 def get_configs_dir():
-    return os.path.join(BASE_DIR, CONFIG_DIR)
+    return os.path.join(get_base_dir(), CONFIG_DIR)
 
 
 def get_files_dir():
@@ -314,13 +351,15 @@ def update_sysstat_config_with_sdac_xall(path='/etc/sysstat/sysstat'):
         hookenv.log("sysstat config file not found: {}".format(path), level=hookenv.WARNING)
 
 
-# States
-
-@when('apt.installed.telegraf')
-@when_not('telegraf.configured')
-def configure_telegraf():  # noqa: C901 (compexity 15)
+def configure_telegraf():  # noqa: C901
     update_sysstat_config_with_sdac_xall()
-    config_path = get_main_config_path()
+    config = hookenv.config()
+    context = config.copy()
+    try:
+        config_path = get_main_config_path()
+    except InvalidInstallMethod:
+        hookenv.status_set('blocked', 'Wrong install_method provided: {!r}'.format(config['install_method']))
+        return
     if get_remote_unit_name() is None:
         hookenv.status_set('waiting', 'Waiting for juju-info relation')
         # if UNIT_NAME in hostname config and relation not yet available,
@@ -329,8 +368,6 @@ def configure_telegraf():  # noqa: C901 (compexity 15)
             os.unlink(config_path)
         return
 
-    config = hookenv.config()
-    context = config.copy()
     inputs = config.get('inputs_config', '')
     outputs = config.get('outputs_config', '')
     # just for the migration out of base64
@@ -370,8 +407,10 @@ def configure_telegraf():  # noqa: C901 (compexity 15)
     context["hostname"] = get_hostname_label()
 
     logfile_path = os.path.normpath(context["logfile"])
-    if context["logfile"] and not logfile_path.startswith("/var/log/"):
-        # only allow logging in /var/log or in syslog
+    if (context["logfile"] and not logfile_path.startswith("/var/log/") and not
+       (config["install_method"] == 'snap' and
+           logfile_path.startswith("/var/snap/telegraf/common/"))):
+        # only allow logging in /var/log, syslog, or /var/snap/telegraf/common
         hookenv.log("logfile value reset to stderr."
                     " Original value: {}".format(context["logfile"]),
                     hookenv.DEBUG)
@@ -401,10 +440,64 @@ def configure_telegraf():  # noqa: C901 (compexity 15)
     hookenv.log("Updating main config file")
     render(source='telegraf.conf.tmpl', templates_dir=get_templates_dir(),
            target=config_path, context=context)
-    host.service_resume('telegraf')  # unmask and enable service, start it if not yet
-    host.service_reload('telegraf')  # reload or restart service, to apply config changes
+    for service in [DEB_SERVICE, SNAP_SERVICE]:
+        if service == get_service():
+            host.service_resume(service)
+            host.service_reload(service)
+        else:
+            try:
+                host.service_pause(service)
+            except ValueError:
+                # On machines not supporting snaps, it won't find the service
+                # If we're using the snap, and the deb failed to install, it's fine too
+                pass
     set_flag('telegraf.configured')
     set_flag('telegraf.needs_reload')
+    if config["install_method"] == 'deb':
+        set_flag('telegraf.apt.configured')
+    else:
+        set_flag('telegraf.snap.configured')
+
+
+# States
+
+@when_not('telegraf.installed')
+def install_telegraf():
+    try:
+        install_method = get_install_method()
+    except InvalidInstallMethod:
+        hookenv.status_set('blocked', "Wrong install_method provided. Expected either 'deb' or 'snap'.")
+        return
+    if install_method == 'deb':
+        try:
+            snap.remove('telegraf')
+        except Exception:
+            # the snap may already be absent, or snaps may not even be supported in this environment
+            pass
+        apt.queue_install(['telegraf'])
+    elif install_method == 'snap':
+        apt.purge('telegraf')
+        config = hookenv.config()
+        snap_channel = config.get('snap_channel')
+        snap.install('telegraf', channel=snap_channel, classic=True)
+    if install_method:
+        set_flag('telegraf.installed')
+
+
+@when('telegraf.installed')
+@when('apt.installed.telegraf')
+@when_not('telegraf.configured')
+@when_not('telegraf.apt.configured')
+def configure_telegraf_deb():
+    configure_telegraf()
+
+
+@when('telegraf.installed')
+@when('snap.installed.telegraf')
+@when_not('telegraf.configured')
+@when_not('telegraf.snap.configured')
+def configure_telegraf_snap():
+    configure_telegraf()
 
 
 @hook('upgrade-charm')
@@ -413,6 +506,8 @@ def upgrade_charm():
         clear_flag('plugins.{}.configured'.format(plugin))
     clear_flag('extra_plugins.configured')
     clear_flag('telegraf.configured')
+    clear_flag('telegraf.apt.configured')
+    clear_flag('telegraf.snap.configured')
 
 
 @when('config.changed')
@@ -424,7 +519,11 @@ def handle_config_changes():
     # if something else changed, let's reconfigure telegraf itself just in case
     if config.changed('extra_plugins'):
         clear_flag('extra_plugins.configured')
+    if config.changed('install_method') or config.changed('snap_channel') or config.changed('install_sources'):
+        clear_flag('telegraf.installed')
     clear_flag('telegraf.configured')
+    clear_flag('telegraf.apt.configured')
+    clear_flag('telegraf.snap.configured')
     clear_flag('telegraf.nagios-setup.complete')
 
 
@@ -788,11 +887,8 @@ def exec_input(exec_rel):
     if not commands:
         hookenv.log("No Commands defined in the exec relation, doing nothing.")
         return
-    timeout_support = exec_timeout_supported()
     pre_proc_cmds = []
     for command in commands:
-        if not timeout_support:
-            command.pop('timeout')
         run_on_this_unit = command.pop('run_on_this_unit')
         if run_on_this_unit:
             pre_proc_cmds.append(command)
@@ -1089,12 +1185,13 @@ def start_or_restart():
     states = sorted([k for k in get_states().keys()
                      if k.startswith('plugins') or k.startswith('extra_plugins')])
 
+    service = get_service()
     config_files_changed = helpers.any_file_changed(list_config_files())
     active_plugins_changed = helpers.data_changed('active_plugins', states or '')
-    if not host.service_running('telegraf') \
+    if not host.service_running(service) \
             or config_files_changed or active_plugins_changed:
         hookenv.log("Restarting telegraf")
-        host.service_restart('telegraf')
+        host.service_restart(service)
     else:
         hookenv.log("Not restarting: active_plugins_changed={} | "
                     "config_files_changed={}".format(active_plugins_changed,
@@ -1102,10 +1199,10 @@ def start_or_restart():
 
     # Give telegraf time to restart.
     timeout = time.time() + 15
-    while not host.service_running('telegraf') and time.time() < timeout:
+    while not host.service_running(service) and time.time() < timeout:
         time.sleep(0.1)
 
-    if host.service_running('telegraf'):
+    if host.service_running(service):
         hookenv.status_set('active',
                            'Monitoring {}'.format(get_remote_unit_name()))
         clear_flag('telegraf.needs_reload')
@@ -1130,10 +1227,12 @@ def update_status():
         hash_type='sha256')
     if changed:
         clear_flag('telegraf.configured')
+        clear_flag('telegraf.apt.configured')
+        clear_flag('telegraf.snap.configured')
 
 
 @when('nrpe-external-master.available')
-@when('apt.installed.telegraf')
+@when('telegraf.installed')
 @when('telegraf.configured')
 @when_not('telegraf.nagios-setup.complete')
 def configure_nagios(nagios):
diff --git a/tests/bundles/focal-snap.yaml b/tests/bundles/focal-snap.yaml
new file mode 100644
index 0000000..cfd7e2a
--- /dev/null
+++ b/tests/bundles/focal-snap.yaml
@@ -0,0 +1,14 @@
+series: focal
+
+applications:
+  telegraf:
+    num_units: 0
+    options:
+      install_method: 'snap'
+  ubuntu:
+    charm: cs:ubuntu
+    num_units: 1
+
+relations:
+  - - ubuntu:juju-info
+    - telegraf:juju-info
diff --git a/tests/test_telegraf.py b/tests/test_telegraf.py
index 592f415..19feb41 100644
--- a/tests/test_telegraf.py
+++ b/tests/test_telegraf.py
@@ -29,7 +29,8 @@ DEFAULT_HTTPGET_TIMEOUT = 10
 DEFAULT_RETRIES = 12
 DEFAULT_RETRIES_TIMEOUT = 5
 DEFAULT_TELEGRAF_EXPORTER_PORT = "9103"
-TELEGRAF_CONF = "/etc/telegraf/telegraf.conf"
+DEB_TELEGRAF_CONF = "/etc/telegraf/telegraf.conf"
+SNAP_TELEGRAF_CONF = "/var/snap/telegraf/current/telegraf.conf"
 
 
 class BaseTelegrafTest(unittest.TestCase):
@@ -53,11 +54,6 @@ class TestTelegraf(BaseTelegrafTest):
         # findall returns a list, [] when no match
         self.assertTrue(re.findall(re_pattern, text, flags=re.M))
 
-    def check_re_pattern(self, re_pattern, text):
-        logging.info('checking metrics %s', re_pattern)
-        # findall returns a list, [] when no match
-        self.assertTrue(re.findall(re_pattern, text, flags=re.M))
-
     def test_01_service(self):
         principal_units = (model.get_units(app)
                            for app in juju.get_principle_applications(self.application_name))
@@ -99,15 +95,35 @@ class TestTelegraf(BaseTelegrafTest):
                 self.fail(msg)
 
     def test_02_telegraf_logfile(self):
-        """Check logfile parameter exists in /etc/telegraf/telegraf.conf."""
-        cmd = "cat {}".format(TELEGRAF_CONF)
+        """Check logfile parameter exists in ${BASE_DIR}/telegraf.conf."""
+        install_method = model.get_application_config('telegraf')['install_method']['value']
+        if install_method == 'deb':
+            telegraf_conf = DEB_TELEGRAF_CONF
+        else:
+            telegraf_conf = SNAP_TELEGRAF_CONF
+        cmd = "cat {}".format(telegraf_conf)
         response = model.run_on_unit(self.lead_unit_name, cmd)
         if response["Code"] != "0":
-            self.fail("test_02_telegraf_logfile: could not read file {}".format(TELEGRAF_CONF))
+            self.fail("test_02_telegraf_logfile: could not read file {}".format(telegraf_conf))
 
         for line in response["Stdout"].splitlines():
             if line.strip() == 'logfile = "/var/log/telegraf/telegraf.log"':
                 logging.info("test_02_telegraf_logfile: logfile config parameter found")
                 return
 
-        self.fail("test_02_telegraf_logfile: logfile parameter not found in {}".format(TELEGRAF_CONF))
+        self.fail("test_02_telegraf_logfile: logfile parameter not found in {}".format(telegraf_conf))
+
+    def test_03_system_service(self):
+        """Check that the right service is running, e.g. either the deb's or the snap's."""
+        install_method = model.get_application_config('telegraf')['install_method']['value']
+        services = {'deb': 'telegraf', 'snap': 'snap.telegraf.telegraf'}
+        for method in services.keys():
+            service = services[method]
+            cmd = "service {} status".format(service)
+            response = model.run_on_unit(self.lead_unit_name, cmd)
+            if install_method == method and response["Code"] != "0":
+                self.fail("test_03_system_service: service {} should be running on {} but is not. "
+                          "install_method is {}.".format(service, self.lead_unit_name, install_method))
+            elif install_method != method and response["Code"] == "0":
+                self.fail("test_03_system_service: service {}  is running on {} but shouldn't. "
+                          "install_method is {}.".format(service, self.lead_unit_name, install_method))
diff --git a/tests/tests.yaml b/tests/tests.yaml
index 57e7325..2230082 100644
--- a/tests/tests.yaml
+++ b/tests/tests.yaml
@@ -6,6 +6,7 @@ gate_bundles:
   - bionic-postgres
   - bionic-monitoring
   - focal
+  - focal-snap
 smoke_bundles:
   - bionic-postgres
   - focal
diff --git a/unit_tests/test_mysql.py b/unit_tests/test_mysql.py
index e28973c..0904e94 100644
--- a/unit_tests/test_mysql.py
+++ b/unit_tests/test_mysql.py
@@ -61,8 +61,10 @@ class TestMySQL(unittest.TestCase):
     @patch('reactive.telegraf.render_extra_options')
     @patch('charmhelpers.core.host.write_file')
     @patch('reactive.telegraf.get_templates_dir')
-    def test_render_mysql_tmpl(self, get_templates_dir, write_file,
+    @patch('reactive.telegraf.get_base_dir')
+    def test_render_mysql_tmpl(self, get_base_dir, get_templates_dir, write_file,
                                extra_options):
+        get_base_dir.return_value = '/etc/telegraf'
         get_templates_dir.return_value = os.path.join(
             os.path.dirname(__file__), '..', 'templates')
         extra_options.return_value = ''
@@ -81,8 +83,10 @@ class TestMySQL(unittest.TestCase):
 
     @patch('os.unlink')
     @patch('os.path.exists')
-    def test_render_mysql_tmpl_no_context(self, exists, unlink):
+    @patch('reactive.telegraf.get_base_dir')
+    def test_render_mysql_tmpl_no_context(self, get_base_dir, exists, unlink):
         exists.return_value = False
+        get_base_dir.return_value = '/etc/telegraf'
         reactive.telegraf.render_mysql_tmpl([])
         exists.assert_called_once_with(
             '/etc/telegraf/telegraf.d/mysql.conf'
diff --git a/unit_tests/test_postgresql.py b/unit_tests/test_postgresql.py
index 1c56a0c..a0423c7 100644
--- a/unit_tests/test_postgresql.py
+++ b/unit_tests/test_postgresql.py
@@ -21,8 +21,14 @@ from unittest.mock import ANY, call, MagicMock, patch, sentinel
 
 # Mock layer modules
 import charms
+apt = MagicMock()
+layer = MagicMock()
 promreg = MagicMock()
+charms.apt = apt
+charms.layer = layer
 charms.promreg = promreg
+sys.modules['charms.apt'] = apt
+sys.modules['charms.layer'] = layer
 sys.modules['charms.promreg'] = promreg
 
 import reactive
@@ -88,9 +94,11 @@ class TestPostgreSQL(unittest.TestCase):
 
     @patch('charmhelpers.core.host.write_file')
     @patch('reactive.telegraf.get_templates_dir')
-    def test_render_postgresql_tmpl(self, get_templates_dir, write_file):
+    @patch('reactive.telegraf.get_base_dir')
+    def test_render_postgresql_tmpl(self, get_base_dir, get_templates_dir, write_file):
         get_templates_dir.return_value = os.path.join(
             os.path.dirname(__file__), '..', 'templates')
+        get_base_dir.return_value = '/etc/telegraf'
 
         reactive.telegraf.render_postgresql_tmpl([
             {'replica': 'master',
@@ -104,10 +112,12 @@ class TestPostgreSQL(unittest.TestCase):
 
     @patch('charmhelpers.core.host.write_file')
     @patch('reactive.telegraf.get_templates_dir')
-    def test_render_postgresql_tmpl_extra_options(self, get_templates_dir,
+    @patch('reactive.telegraf.get_base_dir')
+    def test_render_postgresql_tmpl_extra_options(self, get_base_dir, get_templates_dir,
                                                   write_file):
         get_templates_dir.return_value = os.path.join(
             os.path.dirname(__file__), '..', 'templates')
+        get_base_dir.return_value = '/etc/telegraf'
 
         pg_extra_opts = {
             "tagexclude": ["server"],
@@ -144,8 +154,10 @@ class TestPostgreSQL(unittest.TestCase):
 
     @patch('os.unlink')
     @patch('os.path.exists')
-    def test_render_postgresql_tmpl_no_context(self, exists, unlink):
+    @patch('reactive.telegraf.get_base_dir')
+    def test_render_postgresql_tmpl_no_context(self, get_base_dir, exists, unlink):
         exists.return_value = False
+        get_base_dir.return_value = '/etc/telegraf'
         reactive.telegraf.render_postgresql_tmpl([])
         exists.assert_called_once_with(
             '/etc/telegraf/telegraf.d/postgresql.conf'
diff --git a/unit_tests/test_telegraf.py b/unit_tests/test_telegraf.py
index b4860ac..71af731 100644
--- a/unit_tests/test_telegraf.py
+++ b/unit_tests/test_telegraf.py
@@ -46,18 +46,19 @@ from reactive import telegraf
 UNIT_TESTS_DIR = os.path.dirname(os.path.abspath(__file__))
 UNIT_TESTS_DATA_DIR = os.path.join(UNIT_TESTS_DIR, 'data')
 
+
 @pytest.fixture(autouse=True)
 def setup(monkeypatch, tmpdir):
     monkeypatch.setitem(os.environ, 'JUJU_UNIT_NAME', 'telegraf/0')
     monkeypatch.setitem(os.environ, 'JUJU_MODEL_NAME', 'telegraf-test-model')
     monkeypatch.setattr(telegraf, 'get_remote_unit_name', lambda: 'remote-unit/0')
-    monkeypatch.setattr(telegraf, 'exec_timeout_supported', lambda: True)
     # mock this to avoid permission errors
     monkeypatch.setattr(telegraf, 'update_sysstat_config_with_sdac_xall', lambda: True)
     monkeypatch.setattr(telegraf.hookenv, 'status_set', lambda status, msg: None)
     monkeypatch.setattr(telegraf.hookenv, 'log', lambda msg, **kw: None)
     monkeypatch.setattr(telegraf.host, 'service_resume', lambda svc: None)
     monkeypatch.setattr(telegraf.host, 'service_reload', lambda svc: None)
+    monkeypatch.setattr(telegraf.host, 'service_pause', lambda svc: None)
 
     # patch host.write for non-root
     user = getpass.getuser()
@@ -113,7 +114,7 @@ def temp_charm_dir(monkeypatch, tmpdir):
 def temp_config_dir(monkeypatch, tmpdir):
     base_dir = tmpdir.mkdir("etc_telegraf")
     base_dir.mkdir(telegraf.CONFIG_DIR)
-    monkeypatch.setattr(telegraf, 'BASE_DIR', base_dir.strpath)
+    monkeypatch.setattr(telegraf, 'DEB_BASE_DIR', base_dir.strpath)
 
 
 @pytest.fixture(autouse=True)
@@ -127,7 +128,7 @@ def config(monkeypatch, temp_charm_dir):
 
 # utilities
 def base_dir():
-    return py.path.local(telegraf.BASE_DIR)
+    return py.path.local(telegraf.DEB_BASE_DIR)
 
 
 def configs_dir():
@@ -872,24 +873,6 @@ def test_exec_input_leader_no_more(mocker, monkeypatch):
     assert not configs_dir().join('exec.conf').exists()
 
 
-def test_exec_input_no_timeout_support(mocker, monkeypatch):
-    interface = mocker.Mock(spec=RelationBase)
-    interface.commands = mocker.Mock()
-    commands = [{'commands': ['/srv/bin/test.sh', '/bin/true'],
-                 'data_format': 'json',
-                 'timeout': '5s',
-                 'run_on_this_unit': True}]
-    interface.commands.return_value = commands
-    expected = """
-[[inputs.exec]]
-  commands = ['/srv/bin/test.sh', '/bin/true']
-  data_format = "json"
-"""
-    monkeypatch.setattr(telegraf, 'exec_timeout_supported', lambda: False)
-    telegraf.exec_input(interface)
-    assert configs_dir().join('exec.conf').read().strip() == expected.strip()
-
-
 def test_exec_input_departed(mocker, monkeypatch):
     configs_dir().join('exec.conf').write('empty')
     relations = [1]
@@ -969,7 +952,7 @@ def test_basic_config(mocker, monkeypatch, config):
     bus.dispatch()
     assert 'telegraf.configured' in bus.get_states().keys()
     assert base_dir().join('telegraf.conf').exists()
-    service_restart.assert_called_once_with('telegraf')
+    service_restart.assert_called_once_with(telegraf.DEB_SERVICE)
     check_prometheus_port.assert_called_once_with('prometheus_output', 9103)
 
 
@@ -984,7 +967,7 @@ def test_config_no_prometheus(mocker, monkeypatch, config):
     bus.dispatch()
     assert 'telegraf.configured' in bus.get_states().keys()
     assert base_dir().join('telegraf.conf').exists()
-    service_restart.assert_called_once_with('telegraf')
+    service_restart.assert_called_once_with(telegraf.DEB_SERVICE)
     assert not check_prometheus_port.called
 
 
@@ -996,7 +979,7 @@ def test_config_changed_apt(mocker, monkeypatch, config):
     set_flag('apt.installed.telegraf')
     set_flag('config.changed')
     bus.dispatch()
-    service_restart.assert_called_once_with('telegraf')
+    service_restart.assert_called_once_with(telegraf.DEB_SERVICE)
 
 
 def test_config_changed_extra_options(mocker, monkeypatch, config):
@@ -1004,7 +987,7 @@ def test_config_changed_extra_options(mocker, monkeypatch, config):
     monkeypatch.setattr(telegraf.host, 'service_running',
                         lambda n: True)
     mocker.patch('reactive.telegraf.check_prometheus_port')
-    set_flag('telegraf.installed')
+    set_flag('apt.telegraf.installed')
     set_flag('plugins.haproxy.configured')
     config.save()
     config.load_previous()
@@ -1013,7 +996,7 @@ def test_config_changed_extra_options(mocker, monkeypatch, config):
     set_flag('config.changed')
     bus.dispatch()
     assert 'plugins.haproxy.configured' not in bus.get_states().keys()
-    service_restart.assert_called_once_with('telegraf')
+    service_restart.assert_called_once_with(telegraf.DEB_SERVICE)
 
 
 def test_config_changed_extra_plugins(mocker, monkeypatch, config):
@@ -1021,7 +1004,7 @@ def test_config_changed_extra_plugins(mocker, monkeypatch, config):
     monkeypatch.setattr(telegraf.host, 'service_running',
                         lambda n: True)
     mocker.patch('reactive.telegraf.check_prometheus_port')
-    set_flag('telegraf.installed')
+    set_flag('apt.telegraf.installed')
     assert not configs_dir().join('extra_plugins.conf').exists()
     config.save()
     config.load_previous()
@@ -1037,7 +1020,7 @@ def test_config_changed_extra_plugins(mocker, monkeypatch, config):
     bus.dispatch()
     assert configs_dir().join('extra_plugins.conf').exists()
     assert configs_dir().join('extra_plugins.conf').read() == config['extra_plugins']
-    service_restart.assert_called_with('telegraf')
+    service_restart.assert_called_with(telegraf.DEB_SERVICE)
 
 
 def test_restart_on_output_plugin_relation_departed(mocker, monkeypatch, config):
@@ -1056,7 +1039,7 @@ def test_restart_on_output_plugin_relation_departed(mocker, monkeypatch, config)
         return_value={"ingress_addresses": ["1.2.3.4"]})
     config['prometheus_output_port'] = ''
     bus.discover()
-    set_flag('telegraf.installed')
+    set_flag('snap.telegraf.installed')
     set_flag('telegraf.configured')
     interface = mocker.Mock(spec=RelationBase)
     interface.configure = mocker.Mock()
@@ -1065,7 +1048,7 @@ def test_restart_on_output_plugin_relation_departed(mocker, monkeypatch, config)
     # dispatch, file should be gone and telegraf restarted.
     bus.dispatch()
     assert not configs_dir().join('prometheus-client.conf').exists()
-    service_restart.assert_called_with('telegraf')
+    service_restart.assert_called_with(telegraf.DEB_SERVICE)
 
 
 def test_upgrade_charm(mocker):
@@ -1074,10 +1057,12 @@ def test_upgrade_charm(mocker):
     list_plugins.return_value = ['foo', 'bar']
     telegraf.upgrade_charm()
     clear_flag.assert_any_call('telegraf.configured')
+    clear_flag.assert_any_call('telegraf.apt.configured')
+    clear_flag.assert_any_call('telegraf.snap.configured')
     clear_flag.assert_any_call('plugins.foo.configured')
     clear_flag.assert_any_call('plugins.bar.configured')
     clear_flag.assert_any_call('extra_plugins.configured')
-    assert clear_flag.call_count == 4
+    assert clear_flag.call_count == 6
 
 
 def test_get_socket_listener_port(monkeypatch, config):