munin does not depend on libcache-cache-perl

[Hannes Roest]

munin does not depend on libcache-cache-perl even though it maybe should for the mysql plugins that are delivered (but not installed) by default. This surprises the user in an unpleasant way and the error message is also not immediately helpful. Thus either adding libcache-cache-perl to the dependencies or having a more intuitive way of explaining errors might be helpful.

running

# uname -a
Linux 2.6.32-36-server #79-Ubuntu SMP Tue Nov 8 22:44:38 UTC 2011 x86_64 GNU/Linux
# cat /etc/issue
Ubuntu 10.04.3 LTS \n \l

# dpkg -l | grep munin
ii munin 1.4.4-1ubuntu1 network-wide graphing framework (grapher/gat
ii munin-common 1.4.4-1ubuntu1 network-wide graphing framework (common)
ii munin-node 1.4.4-1ubuntu1 network-wide graphing framework (node)

[Daniel Hahler (blueyed)]

Can you please provide an example plugin which fails and how (error message)?
Thanks.

[Stevel (stevel-launchpad)]

The mysql_ plugin from the munin-node package fails.

Steps to reproduce:
- Install munin-node. Make sure that libcache-cache-perl is not installed yet.
- Run /usr/share/munin/plugins/myqsl_ suggest

Expected result: a list of possible symlink names to make (in /etc/munin/plugins).

Actual result: Missing dependency Cache::Cache at /usr/share/munin/plugins/mysql_ line 716.

Workaround: install libcache-cache-perl.
The same plugin also lists libdbd-mysql-perl as a dependency.

Both packages are in the suggests-list of the package now.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mikkel Kirkgaard Nielsen (mikini)]

This is still an issue on 14.04 where you'll need to hunt and install packages libcache-{perl,cache-perl} before the mysql_ plugin is satisfied.

At least this is noted by a suggests in the most recent package releases; https://launchpad.net/ubuntu/zesty/amd64/munin-plugins-core/2.0.33-1

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.3 LTS
Release: 14.04
Codename: trusty

$ munin-node-configure --suggest
Plugin | Used | Suggestions
------ | ---- | -----------
...
mysql_ | no | no [Missing dependency Cache::Cache]
...
$ apt install libcache-{perl,cache-perl}
...
$ munin-node-configure --suggest
Plugin | Used | Suggestions
------ | ---- | -----------
...
mysql_ | no | yes (+bin_relay_log +commands +connections +files_tables +innodb_bpool +innodb_bpool_act +innodb_insert_buf +innodb_io +innodb_io_pend +innodb_log +innodb_rows +innodb_semaphores +innodb_tnx +myisam_indexes +network_traffic +qcache +qcache_mem +replication +select_types +slow +sorts +table_locks +tmp_tables)
...

[Christian Ehrhardt  (paelzer)]

Hi Mikkel,
you are reviving long forgotten bugs :-).
The suggest actually is there a long time - back before Precise even.

That was added in:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=698078

The reasoning to only do suggests (and not harder dependencies) is in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=697861#10

As of today munin-plugins-extra still is not split (and it would increase the maintenance burden).
Yet it is a long time ago, you might consider opening a bug with Debian and linking it here to discuss the issue more generally once more.

OTOH I understand your pain needing to install those on top to get it working, so clearly I'm not marking invalid or such.