Merge ~sajoupa/charm-telegraf:prometheus-client-default-port-9103 into charm-telegraf:master

[Barry Price]

when related with prometheus-client, if prometheus_output_port is unset, use :9103 by default instead of 9126

[Laurent Sesquès (sajoupa)]

pre-req MP: https://code.launchpad.net/~sajoupa/charm-telegraf/+git/telegraf-charm/+merge/397010

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

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

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

Unable to determine commit message from repository - please click "Set commit message" and enter the commit message manually.

[Haw Loeung (hloeung)]

LGTM

review: Approve (+1)

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

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

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

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

[Haw Loeung (hloeung)]

LGTM

review: Approve (+1)

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

Failed to merge change (unable to merge source repository due to conflicts), setting status to needs review.

Unmerged commits

ea55458... by Laurent Sesquès on 2021-01-27

when related with prometheus-client, if prometheus_output_port is unset, use :9103 by default instead of 9126

diff --git a/src/reactive/telegraf.py b/src/reactive/telegraf.py
index 82cf10e..a17ceea 100644
--- a/src/reactive/telegraf.py
+++ b/src/reactive/telegraf.py
@@ -1269,7 +1269,12 @@ def configure_prometheus_client_with_relation(prometheus):
         "Configuring prometheus_client output plugin, with prometheus-client relation",
         level=hookenv.DEBUG,
     )
-    port = get_prometheus_port() or "9126"
+    if get_prometheus_port():
+        port = get_prometheus_port()
+    else:
+        # We have a relation with prometheus, but removed the port number config.
+        # Default to 9103.
+        port = "9103"
     # We'll iterate through the prometheus-client relation counterparts,
     # inform them of our address so that they scrape it, and get their egress subnets
     # so that we can allow them
diff --git a/src/tests/unit/test_telegraf.py b/src/tests/unit/test_telegraf.py
index d1ecd6b..433a03e 100644
--- a/src/tests/unit/test_telegraf.py
+++ b/src/tests/unit/test_telegraf.py
@@ -837,7 +837,7 @@ outputs:
   namedrop = ["aerospike*"]
   [outputs.prometheus_client.tagpass]
     cpu = ["cpu0"]"""
-    config_file = os.path.join(base_dir(), "telegraf.d", "prometheus_client.conf")
+    config_file = base_dir().join("telegraf.d", "prometheus_client.conf")
     assert expected in config_file.read()
 
 
@@ -1150,14 +1150,14 @@ def test_prometheus_client_output(mocker, monkeypatch, config):
     telegraf.configure_prometheus_client_with_relation(interface)
     expected = """
     [[outputs.prometheus_client]]
-  listen = ":9126"
+  listen = ":9103"
 """
     assert (
         configs_dir().join("prometheus_client.conf").read().strip() == expected.strip()
     )
     network_get_primary_address.assert_called_once_with("prometheus-client")
     interface.configure.assert_called_once_with(
-        "9126", hostname="foo", private_address="foo"
+        "9103", hostname="foo", private_address="foo"
     )