Merge ~peter-sabaini/charm-grafana:implement-manual-upgrade into charm-grafana:master

[Peter Sabaini]

Upgrade support

[Alvaro Uria (aluria)]

I've added a few comments inline

[Alvaro Uria (aluria)]

In case we want to collect all channels and versions:
>>> dict([(channel[0], channel[1]) for channel in [i.strip().split() for i in subprocess.check_output(["snap", "info", "grafana"]).decode("utf-8", errors="replace").partition("channels:")[-1].splitlines() if i.find("/") != -1]])
{'latest/stable:': '6.7.4', 'latest/candidate:': '6.7.4', 'latest/beta:': '6.7.4', 'latest/edge:': '6.7.4', '7/stable:': '7.0.3', '7/candidate:': '7.0.3', '7/beta:': '7.0.3', '7/edge:': '7.0.3', '6/stable:': '6.7.4', '6/candidate:': '6.7.4', '6/beta:': '6.7.4', '6/edge:': '6.7.4', '5/stable:': '5.0.0', '5/candidate:': '^', '5/beta:': '^', '5/edge:': '^'}

[Peter Sabaini (peter-sabaini)]

Hey, thanks for the valuable feedback, one question below though:

On 08.06.20 17:55, Alvaro Uria wrote:
> I've added a few comments inline
>
> Diff comments:
>
>> diff --git a/lib/charms/layer/grafana.py b/lib/charms/layer/grafana.py
>> index 1ddd431..bcc7977 100644
>> --- a/lib/charms/layer/grafana.py
>> +++ b/lib/charms/layer/grafana.py
>> @@ -90,3 +99,54 @@ def download_file(url, proxies=None, prefix="grafana-", suffix=".deb"):
>> if chunk:
>> f.write(chunk)
>> return path
>> +
>> +
>> +def parse_snap_major_version(channel):
>> + for codename in SNAP_CODENAME_MAP.keys():
>> + if channel.startswith(codename):
>> + return SNAP_CODENAME_MAP[codename]
>> + try:
>> + major_ver = int(channel.partition("/")[0])
>> + except ValueError:
>> + return -1
>> + return major_ver
>> +
>> +
>> +def check_snap_channel(snap_name, channel):
>> + """Check if given channel could be configured
>> +
>> + Set unit status accordingly, and return a status code:
>> +
>> + -1: Invalid channel
>> + 0: Channel configurable, needs manual upgrade
>> + 1: Channel unchanged
>> + 2: Would result in downgrade
>> + """
>> + installed_ver = parse_snap_major_version(
>> + snap.get_installed_channel(snap_name)
>
> This causes IndexError if the snap is not installed (because "tracking:" does not exist in the output of "snap info grafana").
> OTOH, SNAP_CODENAME_MAP says "latest" is "7", but "latest/stable" is v6.7.4 (so "6" should be returned).
>
>> + )
>> + new_ver = parse_snap_major_version(channel)
>
> if "6/stable" is shared, "6" will be returned.
> if "latest/edge" is shared, 6 would also need to be returned.
> if "7/stable" is shared, "6" will be returned.

Not sure I understand -- this should be True:

  parse_snap_major_version("7/stable") == 7

> if "edge" is shared, "6" should be returned (I guess, when no "/" exists, "latest/" should be added as prefix).
>
>> +
>> + if new_ver == -1:
>> + msg = "Invalid snap channel: {}".format(channel)
>> + status_set("blocked", msg)
>> + log(msg)
>> + return -1
>> + if installed_ver == new_ver:
>> + log("Channel version unchanged: {}".format(installed_ver))
>> + return 1
>
> What if a minor version exists? We had to upgrade from v6.7.3 to v6.7.4 because of a security vuln.
>
>> + if installed_ver <= new_ver:
>> + msg = (
>> + "PACKAGE UPGRADE REQUIRES MANUAL INTERVENTION: see {} for "
>> + "more info"
>> + ).format(VERSION_CHANGE_URL)
>> + status_set("blocked", msg)
>> + log(msg)
>> + return 0
>> + msg = (
>> + "PACKAGE DOWNGRADES ARE NOT SUPPORTED BY THIS CHARM - to clear "
>> + "this message, set config 'snap_channel' to '{}/stable'"
>> + ).format(installed_ver)
>> + status_set("blocked", msg)
>> + log(msg)
>> + return 2
>
>

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

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

[Paul Goins (vultaire)]

2 comments, one is from our face-to-face discussion and the other is a small thing which caught my eye.

review: Needs Fixing

[Peter Sabaini (peter-sabaini)]

Hi,

as discussed I'm catching snap_channel="latest.*" now, and blocking changes in config or relation when the charm got blocked due to channel updates.

cheers,
peter.

[Paul Goins (vultaire)]

A few quick comments added.

[Peter Sabaini (peter-sabaini)]

Thanks Paul. After talking to Jeremy I've also changed the behaviour such that minor refreshes will get auto-installed instead of blocking for manual upgrade

[Paul Goins (vultaire)]

I think this looks okay, however I noticed one mismatch re: the default channel. Please review the diff comments.

If this delta was intentional, consider this a +1 from me. Otherwise, please change as necessary.

[Peter Sabaini (peter-sabaini)]

On 23.06.20 10:19, Paul Goins wrote:
> I think this looks okay, however I noticed one mismatch re: the default channel. Please review the diff comments.
>
> If this delta was intentional, consider this a +1 from me. Otherwise, please change as necessary.

Yes, the update for the config default is intentional. Rationale is that we used to default to 6/x track as there were some uncertainties around performance, but that has been resolved since.

Thanks for the review!

> Diff comments:
>
>> diff --git a/config.yaml b/config.yaml
>> index 8788be1..69d0116 100644
>> --- a/config.yaml
>> +++ b/config.yaml
>> @@ -187,11 +187,12 @@ options:
>> package will be installed using apt-get.
>> If set to "snap", snap package will be installed
>> snap_channel:
>> - default: "stable"
>> + default: "7/stable"
>
> I just want to check on this - here we're changing the default to 7/stable (instead of implicitly latest/stable), but in the version lookup table, "stable" resolves to 6 rather than 7. Is this intentional?
>
>> type: string
>> description: |
>> - If install_method is set to "snap" this option controlls channel name.
>> - Supported values are: "stable", "candidate", "beta" and "edge"
>> + If install_method is set to "snap" this option controls channel name being used.
>> +
>> + Note: a) changing this option will not automatically upgrade snaps -- see the do-upgrade action for this, b) downgrading snaps is unsupported, and c) using the track symbolic name "latest" is also unsupported (use an explicit track name instead, e.g. "7/stable")
>> external_network:
>> default: "ext_net"
>> type: string
>
>

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

Change cannot be self approved, setting status to needs review.

diff --git a/README.md b/README.md
index bd6e7b8..c9a1323 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-#Overview
+# Overview
 
 This charm provides the latest stable version of Grafana.
 
-#Usage
+# Usage
 
     juju deploy grafana
     juju add-relation prometheus:grafana-source grafana:grafana-source
@@ -15,7 +15,7 @@ To retrieve autogenerated password run:
 
     juju run-action --wait grafana/0 get-admin-password
 
-#Actions
+# Actions
 
 This charm supports importing dashboards, simply run:
 
@@ -33,7 +33,7 @@ There is also an action to create an API key, run:
 
 where the keyrole is one of Viewer, Editor, Read Only Editor or Admin.
 
-##User Management Actions
+## User Management Actions
 
 Currently user management is only implemented to manipulate users in the default
 organisation.
@@ -69,7 +69,14 @@ To delete a user, you simply run:
     juju run-action --wait grafana/0 delete-user login=john
 
 
-#Auth proxy
+## Upgrade action
+
+To perform an upgrade after changing `snap_channel` an upgrade action must be run:
+
+    juju run-action --wait grafana/0 do-upgrade
+
+
+# Auth proxy
 
 If deployed behind a reverse proxy, you can configure Grafana to let
 it handle authentication by enabled auth-proxy.
@@ -92,7 +99,7 @@ and `anonymous=true` is set, those paths will be accessible (view only) to
 non-authenticated users.
 
 
-#Development
+# Development
 
 Explicitly set `JUJU_REPOSITORY`:
 
@@ -109,7 +116,7 @@ Assemble the charm:
 
     charm build
 
-#Contact Information
+# Contact Information
 
 Author: Alvaro Uria <[e-mail]>, Jacek Nykis <[e-mail]>
 Report bugs at: https://bugs.launchpad.net/grafana-charm
diff --git a/actions.yaml b/actions.yaml
index b90282b..71de777 100644
--- a/actions.yaml
+++ b/actions.yaml
@@ -77,3 +77,6 @@ change-user-role:
       description: New role to use, one of Viewer, Editor, Read Only Editor or Admin
   required: [login, new-role]
   additionalProperties: false
+do-upgrade:
+  description: Perform an upgrade
+
diff --git a/actions/do-upgrade b/actions/do-upgrade
new file mode 100755
index 0000000..edb0eb9
--- /dev/null
+++ b/actions/do-upgrade
@@ -0,0 +1,63 @@
+#!/usr/local/sbin/charm-env python3
+# Performs an upgrade
+
+import sys
+
+from charmhelpers import fetch
+from charmhelpers.core.hookenv import (
+    config,
+    function_fail,
+    function_set,
+    status_set,
+)
+from charms.layer import snap
+from charms.reactive import remove_state
+
+
+sys.path.append("lib")
+
+from charms.layer.grafana import ChangeStatus, check_snap_channel
+
+
+SNAP_NAME = "grafana"
+PACKAGES = ["grafana"]
+
+
+def snap_upgrade(channel):
+    if not snap.is_installed(SNAP_NAME):
+        # Only upgrade if snap is in fact installed
+        function_fail("Snap not installed, can't upgrade")
+        return
+    result = check_snap_channel(SNAP_NAME, channel)
+    if result == ChangeStatus.UPGRADE:
+        snap.install(
+            SNAP_NAME, channel=channel, force_dangerous=False,
+        )
+        function_set({"result": "Upgraded, channel {}".format(channel)})
+        status_set("active", "Ready")
+        remove_state("grafana.change-block")
+    elif result == ChangeStatus.UNCHANGED:
+        function_fail("Nothing to upgrade")
+    elif result == ChangeStatus.DOWNGRADE:
+        function_fail("Abort: would result in downgrade")
+    elif result == ChangeStatus.INVALID:
+        function_fail("Invalid channel {}".format(channel))
+    elif result == ChangeStatus.LATEST:
+        function_fail('"latest" track unsuported, revert channel config')
+
+
+def apt_upgrade():
+    fetch.apt_install(PACKAGES, fatal=True)
+    function_set({"result": "Upgraded package"})
+
+
+def main():
+    cfg = config()
+    if cfg["install_method"] == "snap":
+        snap_upgrade(cfg["snap_channel"])
+    else:  # apt method
+        apt_upgrade()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/config.yaml b/config.yaml
index 8788be1..69d0116 100644
--- a/config.yaml
+++ b/config.yaml
@@ -187,11 +187,12 @@ options:
         package will be installed using apt-get.
         If set to "snap", snap package will be installed
   snap_channel:
-    default: "stable"
+    default: "7/stable"
     type: string
     description: |
-        If install_method is set to "snap" this option controlls channel name.
-        Supported values are: "stable", "candidate", "beta" and "edge"
+        If install_method is set to "snap" this option controls channel name being used.
+        
+        Note: a) changing this option will not automatically upgrade snaps -- see the do-upgrade action for this, b) downgrading snaps is unsupported, and c) using the track symbolic name "latest" is also unsupported (use an explicit track name instead, e.g. "7/stable")
   external_network:
     default: "ext_net"
     type: string
diff --git a/lib/charms/layer/grafana.py b/lib/charms/layer/grafana.py
index 1ddd431..9853dc2 100644
--- a/lib/charms/layer/grafana.py
+++ b/lib/charms/layer/grafana.py
@@ -1,5 +1,5 @@
 #!/usr/bin/python3
-
+import enum
 import json
 import tempfile
 import subprocess
@@ -10,7 +10,24 @@ from charmhelpers.core import unitdata
 from charmhelpers.core.hookenv import (
     config,
     log,
+    status_set,
 )
+from charms.layer import snap
+
+
+class ChangeStatus(enum.Enum):
+    LATEST = -2
+    INVALID = -1
+    UPGRADE = 0
+    UNCHANGED = 1
+    DOWNGRADE = 2
+
+
+VERSION_CHANGE_URL = "<url>"
+SNAP_CODENAME_MAP = {
+    "latest": -2,  # special case: we do not allow changes to the latest track
+    "stable": 6,
+}
 
 
 def get_admin_password():
@@ -90,3 +107,72 @@ def download_file(url, proxies=None, prefix="grafana-", suffix=".deb"):
                 if chunk:
                     f.write(chunk)
     return path
+
+
+def parse_snap_major_version(channel):
+    for codename in SNAP_CODENAME_MAP.keys():
+        if channel.startswith(codename):
+            return SNAP_CODENAME_MAP[codename]
+    try:
+        major_ver = int(channel.partition("/")[0])
+    except ValueError:
+        return -1
+    return major_ver
+
+
+def check_snap_channel(snap_name, channel):
+    """Check if given channel could be configured
+
+    Set unit status accordingly, and return a status code from
+    the ChangeStatus enum:
+
+    LATEST: Specified "latest" track which we prohibit
+    INVALID: Invalid channel
+    UPGRADE: Channel configurable, needs manual upgrade
+    UNCHANGED: Channel unchanged
+    DOWNGRADE: Would result in downgrade of major version
+    """
+    installed_ver = parse_snap_major_version(
+        snap.get_installed_channel(snap_name)
+    )
+    new_ver = parse_snap_major_version(channel)
+    is_refresh_available = snap.is_refresh_available(snap_name)
+    if new_ver == -2:
+        msg = (
+            'The "latest" track is not supported; revert the channel config '
+            "change to unblock"
+        )
+        status_set("blocked", msg)
+        log(msg)
+        return ChangeStatus.LATEST
+    if new_ver == -1:
+        msg = "Invalid snap channel: {}".format(channel)
+        status_set("blocked", msg)
+        log(msg)
+        return ChangeStatus.INVALID
+    if installed_ver == new_ver and not is_refresh_available:
+        status_set("active", "Ready")
+        log("Channel version unchanged: {}".format(installed_ver))
+        return ChangeStatus.UNCHANGED
+    if installed_ver == new_ver and is_refresh_available:
+        msg = "Snap is being refreshed"
+        status_set("maintenance", msg)
+        log(msg)
+        snap.refresh(snap_name)
+        status_set("active", "Refresh complete")
+        return ChangeStatus.UNCHANGED
+    if installed_ver < new_ver:
+        msg = (
+            "PACKAGE UPGRADE REQUIRES MANUAL INTERVENTION: see {} for "
+            "more info"
+        ).format(VERSION_CHANGE_URL)
+        status_set("blocked", msg)
+        log(msg)
+        return ChangeStatus.UPGRADE
+    msg = (
+        "PACKAGE DOWNGRADES ARE NOT SUPPORTED BY THIS CHARM - to clear "
+        "this message, set config 'snap_channel' to '{}/stable'"
+    ).format(installed_ver)
+    status_set("blocked", msg)
+    log(msg)
+    return ChangeStatus.DOWNGRADE
diff --git a/reactive/grafana.py b/reactive/grafana.py
index d12a2c6..c64743a 100644
--- a/reactive/grafana.py
+++ b/reactive/grafana.py
@@ -18,6 +18,8 @@ from charmhelpers.core import (
 from charmhelpers.core.templating import render
 from charms.layer import snap
 from charms.layer.grafana import (
+    ChangeStatus,
+    check_snap_channel,
     download_file,
     get_admin_password,
     get_deb_package_version,
@@ -171,6 +173,7 @@ def data_path():
 
 @when("grafana.installed")
 @when("config.changed.install_plugins")
+@when_not("grafana.change-block")
 def install_plugins():
     data_dir = data_path()
     if not data_dir:
@@ -210,6 +213,7 @@ def install_plugins():
 
 
 @hook("upgrade-charm")
+@when_not("grafana.change-block")
 def upgrade_charm():
     hookenv.status_set(
         "maintenance",
@@ -222,17 +226,7 @@ def upgrade_charm():
 
 @hook("config-changed")
 def config_changed():
-    remove_state("grafana.configured")
     config = hookenv.config()
-    if config.changed("dashboards_backup_schedule") or config.changed(
-        "dashboards_backup_dir"
-    ):
-        remove_state("grafana.backup.configured")
-    if config.changed("admin_password") or config.changed("nagios_context"):
-        remove_state("grafana.admin_password.set")
-    if config.changed("install_file") and config.get("install_file"):
-        remove_state("grafana.installed")
-
     if (
         config.changed("snap_channel")
         and config["snap_channel"]
@@ -241,14 +235,31 @@ def config_changed():
     ):
         # NOTE(aluria): install_method change (apt -> snap, and viceversa)
         # is not supported. However, snap channel change support was missing
-        snap.install(
-            SNAP_NAME, channel=config["snap_channel"], force_dangerous=False,
-        )
-        hookenv.log(
-            "{} snap channel updated to {}".format(
-                SNAP_NAME, config["snap_channel"]
+        if snap.is_installed(SNAP_NAME):
+            # Check if we should upgrade
+            status = check_snap_channel(SNAP_NAME, config["snap_channel"])
+            if status == ChangeStatus.UNCHANGED:
+                remove_state("grafana.change-block")
+            else:
+                set_state("grafana.change-block")
+            # We don't need to re-setup so bail out
+            return
+        else:
+            # Install from requested channel
+            snap.install(
+                SNAP_NAME,
+                channel=config["snap_channel"],
+                force_dangerous=False,
             )
-        )
+    remove_state("grafana.configured")
+    if config.changed("dashboards_backup_schedule") or config.changed(
+        "dashboards_backup_dir"
+    ):
+        remove_state("grafana.backup.configured")
+    if config.changed("admin_password") or config.changed("nagios_context"):
+        remove_state("grafana.admin_password.set")
+    if config.changed("install_file") and config.get("install_file"):
+        remove_state("grafana.installed")
 
 
 def check_ports(new_port):
@@ -327,6 +338,7 @@ def add_backup_api_keys():
 
 @when("grafana.installed")
 @when_not("grafana.configured")
+@when_not("grafana.change-block")
 def setup_grafana():
     kv = unitdata.kv()
     source = kv.get("install_method")
@@ -358,6 +370,7 @@ def setup_grafana():
 
 @when("grafana.started")
 @when_not("grafana.backup.configured")
+@when_not("grafana.change-block")
 def setup_backup_shedule():
     # copy script, create cronjob, ensure directory exists
 
@@ -395,6 +408,7 @@ def setup_backup_shedule():
 
 @when("grafana.configured")
 @when_not("grafana.started")
+@when_not("grafana.change-block")
 def restart_grafana():
     kv = unitdata.kv()
     source = kv.get("install_method")
@@ -424,6 +438,7 @@ def restart_grafana():
 
 @when("grafana.started")
 @when("nrpe-external-master.available")
+@when_not("grafana.change-block")
 def update_nrpe_config(svc):
     kv = unitdata.kv()
     source = kv.get("install_method")
@@ -458,6 +473,7 @@ def wipe_nrpe_checks():
 @when("grafana.started")
 @when("grafana-source.available")
 @when("grafana.admin_password.set")
+@when_not("grafana.change-block")
 def configure_sources(relation):
     sources = relation.datasources()
     gf_adminpasswd = get_admin_password()
@@ -908,6 +924,7 @@ def get_main_org_id():
 
 @when("grafana.started")
 @when_not("grafana.admin_password.set")
+@when_not("grafana.change-block")
 def check_adminuser():
     """Create Adminuser if not existing.
 
@@ -990,6 +1007,7 @@ def hpwgen(passwd, salt):
 
 
 @when("grafana.started", "endpoint.dashboards.requests")
+@when_not("grafana.change-block")
 def import_dashboards(dashboards):
     for request in dashboards.new_requests:
         try:
diff --git a/tests/functional/tests/bundles/bionic-snap.yaml b/tests/functional/tests/bundles/bionic-snap.yaml
index f34416b..a14fd81 100644
--- a/tests/functional/tests/bundles/bionic-snap.yaml
+++ b/tests/functional/tests/bundles/bionic-snap.yaml
@@ -4,6 +4,7 @@ applications:
     num_units: 1
     options:
       install_method: snap
+      snap_channel: 6/stable
   ceph-mon:
     charm: cs:ceph-mon
     num_units: 1
diff --git a/tests/functional/tests/bundles/focal-snap.yaml b/tests/functional/tests/bundles/focal-snap.yaml
index d824b05..79ac514 100644
--- a/tests/functional/tests/bundles/focal-snap.yaml
+++ b/tests/functional/tests/bundles/focal-snap.yaml
@@ -4,6 +4,7 @@ applications:
     num_units: 1
     options:
       install_method: snap
+      snap_channel: 6/stable
   ceph-mon:
     charm: cs:ceph-mon
     num_units: 1
diff --git a/tests/functional/tests/test_grafana.py b/tests/functional/tests/test_grafana.py
index c9bbd72..5f452d9 100644
--- a/tests/functional/tests/test_grafana.py
+++ b/tests/functional/tests/test_grafana.py
@@ -30,6 +30,10 @@ class BaseGrafanaTest(unittest.TestCase):
         )
         cls.grafana_ip = model.get_app_ips(cls.application_name)[0]
 
+    def get_unit_status(self, unit):
+        u = model.get_unit_from_name(unit)
+        return u.workload_status_message
+
 
 class CharmOperationTest(BaseGrafanaTest):
     """Verify operations."""
@@ -93,7 +97,7 @@ class CharmOperationTest(BaseGrafanaTest):
         content = result.get("Stdout")
         self.assertTrue(expected_nrpe_check in content)
 
-    def test_grafana_imported_dashboards(self):
+    def test_10_grafana_imported_dashboards(self):
         """Check that Grafana dashboards expected are there"""
         action = model.run_action(
             self.lead_unit_name, "get-admin-password", raise_on_failure=True,
@@ -123,7 +127,7 @@ class CharmOperationTest(BaseGrafanaTest):
             )
         )
 
-    def test_grafana_create_user(self):
+    def test_12_grafana_create_user(self):
         """Run the create-user action."""
         params = {
             "name": "FooUser",
@@ -145,3 +149,66 @@ class CharmOperationTest(BaseGrafanaTest):
         )
         self.assertTrue(req.status_code == 200)
         self.assertTrue("name" in req.json())
+
+
+class SnappedGrafanaTest(BaseGrafanaTest):
+    def test_50_snap_upgrade(self):
+        """Test a snap upgrade from 6 to 7"""
+        model.set_application_config(
+            self.application_name, {"snap_channel": "7/stable"}
+        )
+        model.block_until_unit_wl_status(self.lead_unit_name, "blocked")
+        model.block_until_all_units_idle()
+        status_message = self.get_unit_status(self.lead_unit_name)
+        self.assertTrue(
+            "PACKAGE UPGRADE REQUIRES MANUAL INTERVENTION" in status_message
+        )
+        action = model.run_action(self.lead_unit_name, "do-upgrade")
+        self.assertEqual(action.data["status"], "completed")
+        self.assertTrue("Upgraded" in action.data["results"]["result"])
+
+    def test_51_snap_downgrade_block(self):
+        """Test that after the previous upgrade, downgrades are blocked"""
+        model.set_application_config(
+            self.application_name, {"snap_channel": "6/stable"}
+        )
+        model.block_until_unit_wl_status(self.lead_unit_name, "blocked")
+        model.block_until_all_units_idle()
+        status_message = self.get_unit_status(self.lead_unit_name)
+        self.assertTrue(
+            "PACKAGE DOWNGRADES ARE NOT SUPPORTED" in status_message
+        )
+        model.set_application_config(  # unblock unit again
+            self.application_name, {"snap_channel": "7/stable"}
+        )
+        model.block_until_all_units_idle()
+        downgrade_cmd = "sudo snap refresh grafana --channel=6/stable"
+        model.run_on_unit(self.lead_unit_name, downgrade_cmd)
+        model.set_application_config(  # set it back to 6
+            self.application_name, {"snap_channel": "6/stable"}
+        )
+        model.block_until_all_units_idle()
+
+    def test_52_latest(self):
+        """Test: track 'latest' is blocked"""
+        model.set_application_config(
+            self.application_name, {"snap_channel": "latest/stable"}
+        )
+        model.block_until_unit_wl_status(self.lead_unit_name, "blocked")
+        model.block_until_all_units_idle()
+        status_message = self.get_unit_status(self.lead_unit_name)
+        self.assertTrue(
+            'The "latest" track is not supported; revert ' in status_message
+        )
+        model.set_application_config(  # unblock unit again
+            self.application_name, {"snap_channel": "6/stable"}
+        )
+        model.block_until_all_units_idle()
+
+
+class AptGrafanaTest(BaseGrafanaTest):
+    def test_50_apt_upgrade(self):
+        """Test an apt upgrade"""
+        action = model.run_action(self.lead_unit_name, "do-upgrade")
+        self.assertEqual(action.data["status"], "completed")
+        self.assertTrue("Upgraded" in action.data["results"]["result"])
diff --git a/tests/functional/tests/tests.yaml b/tests/functional/tests/tests.yaml
index c7da132..56abe83 100644
--- a/tests/functional/tests/tests.yaml
+++ b/tests/functional/tests/tests.yaml
@@ -1,16 +1,21 @@
 charm_name: grafana
 gate_bundles:
-  - focal
-  - bionic
-  - xenial
-  - bionic-snap
-  - focal-snap
+  - model_apt_install: focal
+  - model_apt_install: bionic
+  - model_apt_install: xenial
+  - model_snap_install: bionic-snap
+  - model_snap_install: focal-snap
 smoke_bundles:
-  - bionic
+  - model_snap_install: bionic-snap
 dev_bundles:
-  - bionic
+  - model_snap_install: bionic-snap
 tests:
-  - tests.test_grafana.CharmOperationTest
+  - model_snap_install:
+      - tests.test_grafana.CharmOperationTest
+      - tests.test_grafana.SnappedGrafanaTest
+  - model_apt_install:
+      - tests.test_grafana.CharmOperationTest
+      - tests.test_grafana.AptGrafanaTest
 target_deploy_status:
   grafana:
     workload-status-message: Started
diff --git a/tests/unit/test_grafana.py b/tests/unit/test_grafana.py
index 0b8e749..57e730d 100644
--- a/tests/unit/test_grafana.py
+++ b/tests/unit/test_grafana.py
@@ -1,7 +1,13 @@
 from os.path import isfile
+from unittest import mock
+import sys
 import unittest
 
-from charms.layer.grafana import (
+
+sys.modules["charms.layer.snap"] = mock.Mock()
+
+
+from charms.layer.grafana import (  # noqa E402
     download_file,
     get_cmd_output,
     get_deb_package_version,
diff --git a/tox.ini b/tox.ini
index b5cb33b..486c489 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 skipsdist=True
-envlist = unit, functional
+envlist = unit, functional, func-smoke
 skip_missing_interpreters = True
 
 [testenv]
@@ -31,6 +31,12 @@ changedir = {toxinidir}/tests/functional
 commands = functest-run-suite --keep-model
 deps = -r{toxinidir}/tests/functional/requirements.txt
 
+[testenv:func-smoke]
+changedir = {toxinidir}/tests/functional
+commands =
+    functest-run-suite --keep-model --smoke
+deps = -r{toxinidir}/tests/functional/requirements.txt
+
 [testenv:lint]
 commands =
     black --check --line-length 79 reactive lib tests