Forbid invalid relabel configurations

[grobie]

This produces an empty label name

# config
relabel_configs:
- source_labels: [__address__]

# result
node_boot_time{="localhost:9100",instance="localhost:9100",job="node"}

I guess a configuration with either just source_labels or just target_label or any other config not having the minimum set of attributes set should be rejected.

[hashmap]

@grobie I'm not an expert in relabeling, all my knowledge comes from @brian-brazil PromCon talk. I've implemented a draft of this fix based on https://prometheus.io/docs/operating/configuration/#<relabel_config>:

• source_labels must be defined
• target_label must be defined if action is replace or hashmod

However I found some counterexamples in conf.good.yml which is good by definition, right?

• https://github.com/prometheus/prometheus/blob/master/config/testdata/conf.good.yml#L49
• https://github.com/prometheus/prometheus/blob/master/config/testdata/conf.good.yml#L87

Am I missing something?

[brian-brazil]

It is valid to not have source labels.

[hashmap]

@brian-brazil in any case or in some particular? In https://prometheus.io/docs/operating/configuration/#<relabel_config> only labelmap looks unclear to me, the rest should require source labels

[brian-brazil]

Replace doesn't require source_labels either.

[fabxc]

Omitting the source labels allows you to attach new labels. That's not
useful for target relabellings but can be elsewhere in general.

On Mon, Aug 29, 2016, 3:12 PM Alexey Miroshkin notifications@github.com
wrote:

@brian-brazil https://github.com/brian-brazil in any case or in some
particular? In https://prometheus.io/docs/operating/configuration/# only
labelmap looks unclear to me, the rest should require source labels

—
You are receiving this because you are subscribed to this thread.
Reply to this email directly, view it on GitHub
#1900 (comment),
or mute the thread
https://github.com/notifications/unsubscribe-auth/AEuA8mi1eQc1AxUPsxlxsBPtGpgAI9heks5qktrDgaJpZM4JnFRn
.

[brian-brazil]

That's useful for target relabelling, as you might want to add something static that's not from SD.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.