Merge ~tcuthbert/charm-telegraf:master into charm-telegraf:master

[Thomas Cuthbert]

Workaround for LP#1910974: telegraf haproxy input broken with Juju >= 2.8.7

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

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

[Junien F (axino)]

Some questions inline

[Haw Loeung (hloeung)]

I think the best solution here is to update the haproxy[1] and content-cache[2] to pass through the listen address for haproxy statistics, they both already pass through the username, password, and port. Then have the telegraf charm check the presence of this and use it if it's something other than 0.0.0.0. If it doesn't exist, try work it out with the existing code (rel["private-address"] and hookenv.unit_private_ip()).

For the HAProxy charm, it defaults to statistics on 0.0.0.0 so why it doesn't appear broken with the latest Juju version - localhost or private-address, HAProxy statistics will answer on both interfaces. For the Content-cache charm, it configures statistics to listen on 127.0.0.1.

[1]https://bazaar.launchpad.net/~haproxy-team/charm-haproxy/trunk/view/head:/hooks/hooks.py#L1437
[2]https://git.launchpad.net/~hloeung/content-cache-charm/tree/reactive/content_cache.py#n483

[Thomas Cuthbert (tcuthbert)]

> I think the best solution here is to update the haproxy[1] and content-
> cache[2] to pass through the listen address for haproxy statistics, they both
> already pass through the username, password, and port. Then have the telegraf
> charm check the presence of this and use it if it's something other than
> 0.0.0.0. If it doesn't exist, try work it out with the existing code (rel
> ["private-address"] and hookenv.unit_private_ip()).
>
> For the HAProxy charm, it defaults to statistics on 0.0.0.0 so why it doesn't
> appear broken with the latest Juju version - localhost or private-address,
> HAProxy statistics will answer on both interfaces. For the Content-cache
> charm, it configures statistics to listen on 127.0.0.1.
>
> [1]https://bazaar.launchpad.net/~haproxy-team/charm-
> haproxy/trunk/view/head:/hooks/hooks.py#L1437
> [2]https://git.launchpad.net/~hloeung/content-cache-
> charm/tree/reactive/content_cache.py#n483

okay I've updated, see https://code.launchpad.net/~tcuthbert/content-cache-charm/+git/content-cache-charm/+merge/396233 also.

[Thomas Cuthbert (tcuthbert)]

comment inline

[Thomas Cuthbert (tcuthbert)]

comment inline mk2

[Haw Loeung (hloeung)]

LGTM, but let's see what BootStack reviewers say.

review: Approve (+1)

[Peter Sabaini (peter-sabaini)]

Approve lgtm

review: Approve

[Xav Paice (xavpaice)]

LGTM

review: Approve

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

Change successfully merged at revision bc10de9a5a8c0e07f101bf5664fda6d6b7c076df

diff --git a/src/reactive/telegraf.py b/src/reactive/telegraf.py
index c0b9e0c..e106ee4 100644
--- a/src/reactive/telegraf.py
+++ b/src/reactive/telegraf.py
@@ -910,9 +910,7 @@ def haproxy_input(haproxy):
                 enabled = False
         if not enabled:
             continue
-        addr = rel["private-address"]
-        if addr == hookenv.unit_private_ip():
-            addr = "localhost"
+        addr = rel.get("listener-address", rel["private-address"])
         port = rel["port"]
         user = rel["user"]
         password = rel.get("password", None)
diff --git a/src/tests/unit/test_telegraf.py b/src/tests/unit/test_telegraf.py
index afc3625..2cfbdc8 100644
--- a/src/tests/unit/test_telegraf.py
+++ b/src/tests/unit/test_telegraf.py
@@ -879,7 +879,15 @@ def test_haproxy_input(monkeypatch, config):
     telegraf.haproxy_input("test")
     expected = """
 [[inputs.haproxy]]
-  servers = ["http://foo:bar@localhost:1234"]
+  servers = ["http://foo:bar@1.2.3.4:1234"]
+"""
+    assert configs_dir().join("haproxy.conf").read().strip() == expected.strip()
+
+    relations[0]["listener-address"] = "127.0.0.1"
+    telegraf.haproxy_input("test")
+    expected = """
+[[inputs.haproxy]]
+  servers = ["http://foo:bar@127.0.0.1:1234"]
 """
     assert configs_dir().join("haproxy.conf").read().strip() == expected.strip()