Alert rule validation error

[gangsta]

Hi,

Getting error while using puppet-prometheus

init.pp

  class { '::prometheus':
    version              => '2.0.0',
  }

Error shown below

==> prometheus: Error: Execution of '/usr/local/bin/promtool check rules /etc/prometheus/alert.rules20180110-5183-s8nrev' returned 1: Checking /etc/prometheus/alert.rules20180110-5183-s8nrev
==> prometheus:   FAILED:
==> prometheus: yaml: unmarshal errors:
==> prometheus:   line 1: cannot unmarshal !!seq into rulefmt.RuleGroups
==> prometheus: Error: /Stage[main]/Prometheus::Alerts/File[/etc/prometheus/alert.rules]/ensure: change from absent to file failed: Execution of '/usr/local/bin/promtool check rules /etc/prometheus/alert.rules20180110-5183-s8nrev' returned 1: Checking /etc/prometheus/alert.rules20180110-5183-s8nrev
==> prometheus:   FAILED:
==> prometheus: yaml: unmarshal errors:
==> prometheus:   line 1: cannot unmarshal !!seq into rulefmt.RuleGroups

probably something wrong here: https://github.com/voxpupuli/puppet-prometheus/blob/master/manifests/alerts.pp#L36

BR
Karen

[tuxmea]

Many thanks for the report. Can you check that the promtool check command works without errors on the new alert file?
I want to verify whether it is the promtool command or the alert file which causes the error.

[gangsta]

Hi @tuxmea ,

After getting above described error, I did ssh to vagrant box and added some simple alert.rules file to check promtool command . below copy of terminal .

[root@prometheus ~]# prometheus --version
prometheus, version 2.0.0 (branch: HEAD, revision: 0a74f98628a0463dddc90528220c94de5032d1a0)
  build user:       root@615b82cb36b6
  build date:       20171108-07:11:59
  go version:       go1.9.2
[root@prometheus ~]# cat /etc/prometheus/alert.rules 
groups:
- name: example
  rules:
  - alert: HighErrorRate
    expr: job:request_latency_seconds:mean5m{job="myjob"} > 0.5
    for: 10m
    labels:
      severity: page
    annotations:
      summary: High request latency
[root@prometheus ~]# /usr/local/bin/promtool check rules /etc/prometheus/alert.rules
Checking /etc/prometheus/alert.rules
  SUCCESS: 1 rules found

[root@prometheus ~]# echo $?
0
[root@prometheus ~]# 

BR
Karen

[gangsta]

definitely something wrong with alert.rules files . including '::prometheus' should work out of box . I`m wondering that something is wrong here

[gangsta]

content => $alerts.to_yaml, I think here converting is not working or we are providing wrong hash . but by default alert.rules is empty . if it`s empty?, validation should giving error .

[gangsta]

Found issue . As Far as alert.rule has no default value Validation of empty yaml file is giving above error . so either we should add some default alert.rules to module to get include ::prometheus working out of box , or we should add in Readme that without alertrules your going to get error . I`ll do in minutes pull to Readme file to add Hash to alert.rule >= prometheus2.0.0

[costela]

Empty hashes seem to work, while empty arrays don't:

$ ruby -e "require 'yaml'; puts {}.to_yaml" | promtool check rules /dev/stdin
Checking /dev/stdin
  SUCCESS: 0 rules found

$ ruby -e "require 'yaml'; puts [].to_yaml" | promtool check rules /dev/stdin
Checking /dev/stdin
  FAILED:
yaml: unmarshal errors:
  line 1: cannot unmarshal !!seq into rulefmt.RuleGroups

So we can just change the default to {}. People using 1.* and not providing alert rules would still get a noop, while those providing rules would see no change, since they would override the default.

[gangsta]

Hi @costela ,
Thats a good one , it will solve include ::prometheus without any param , otherwise we should define some alert rules , From me +
Greetings