Merge ~cjwatson/launchpad-layers:turnip-base-nagios-avoid-comma into launchpad-layers:main

[Colin Watson]

turnip-base: Avoid comma in Nagios service description

On production, the comma caused Nagios to fail to parse the collected configuration with errors such as:

  Error: Could not find a service matching host name 'lp-prodstack-git-juju-f2a69b-prod-launchpad-git-17' and description 'Git E2E git://git.launchpad.net/launchpad - hint: check nfs-ganesha.service if all appservers are bad' (config file '/etc/nagios3/conf.d/servicegroups/prompt-critical.cfg', starting on line 2)
  Error: Could not expand member services specified in servicegroup (config file '/etc/nagios3/conf.d/servicegroups/prompt-critical.cfg', starting on line 2)

[Ines Almeida (ines-almeida)]

What an odd peculiarity. LGTM

review: Approve

[Jürgen Gmach (jugmac00)]

Nice catch!

review: Approve

diff --git a/turnip-base/lib/charms/turnip/base.py b/turnip-base/lib/charms/turnip/base.py
index 7eb96c6..55fc056 100644
--- a/turnip-base/lib/charms/turnip/base.py
+++ b/turnip-base/lib/charms/turnip/base.py
@@ -340,9 +340,18 @@ def add_nagios_e2e_checks(nagios):
         nagios.add_check(
             [os.path.join(nrpe_dir(), "check_git_refs"), url],
             name=f"check_turnip_git_refs_{i}",
+            # This ends up in service_description, and
+            # https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/3/en/objectdefinitions.html#service
+            # mentions some restrictions on allowed characters here: "This
+            # directive is used to define the description of the service,
+            # which may contain spaces, dashes, and colons (semicolons,
+            # apostrophes, and quotation marks should be avoided)."  Commas
+            # aren't explicitly mentioned either way, but Nagios seems to
+            # fail to parse the configuration when we include them, so take
+            # care to avoid them.
             description=(
                 "Git E2E {} - hint: check nfs-ganesha.service if all "
-                "appservers are bad, otherwise check "
+                "appservers are bad or otherwise check "
                 "srv-turnip-data.mount"
             ).format(url),
             context=config["nagios_context"],