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fix(alloy): scrape all alloy pod targets on the Alloy HTTP port - #90
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This was referenced Oct 16, 2026
Pod discovery makes one scrape target for each declared container port. It makes a target on port 80 for containers that declare no port, such as config-reloader. Alloy does not listen on port 80, so the config-reloader target is always down. Set the prometheus.io/port annotation on the Alloy pod to the Alloy HTTP port by default. Operators no longer need to set it in their own values.
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October 16, 2026 15:35
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Appreciate the follow-up here! |
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Summary
Set
prometheus.io/port: "12345"on the Alloy pod by default.Review of coder/dogfood#702 (v0.8.0 bump) asked for dogfood settings to become chart defaults. Dogfood sets this annotation in its own values. Source: https://github.com/coder/dogfood/pull/702#pullrequestreview-5547941289
Why
Pod discovery makes one scrape target for each declared container port. It makes a target on port 80 for containers that declare no port. Alloy listens on 12345, not 80, so
up{job="<ns>/alloy/config-reloader"}is always 0. The annotation points every target of the pod at the Alloy HTTP port.Test
Kind cluster tested, baseline is
mainwith default values.up{pod=~"alloy.*"}mainalloy/alloy= 1,alloy/config-reloader= 0alloy/alloy= 1,alloy/config-reloader= 1Method:
helm upgradewith the local chart, wait for the DaemonSet rollout, query Prometheus.Notes
config-reloadertarget now scrapes Alloy's own/metrics. Its series are a copy of thealloyjob under anotherjoblabel. Raised in https://github.com/coder/dogfood/pull/702#discussion_r4286919738 and left as is.alloy.alloy.listenPort. Helm values cannot reference each other, so a comment records this.compiled/resources.yamlregenerated withmake build.