fix: alertmanager slack templating bug by heliapb · Pull Request #8299 · prometheus-operator/prometheus-operator

heliapb · 2026-01-20T15:54:15Z

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Closes: ##8291

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simonpasquier · 2026-01-20T16:58:40Z

pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go

 }

 // URL represents a valid URL
-// +kubebuilder:validation:Pattern=`^https?://.+$`


hmm I'd rather change the type of the Slack URL field?

Hi I understand, my main concern is this can affect other templated variables that's why I made the change. But I guess then should I just undo the url changes done in
#8235 right?

slashpai · 2026-01-20T17:08:55Z

This PR should be against release-0.88 right?

heliapb · 2026-01-20T17:18:03Z

This PR should be against release-0.88 right?

yes thanks @slashpai - fixed the branch

simonpasquier

I'm currently checking if we have other PRs that we'd need to revert...

simonpasquier · 2026-01-21T13:19:17Z

pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go

 }

 // URL represents a valid URL
-// +kubebuilder:validation:Pattern=`^https?://.+$`


simonpasquier · 2026-01-21T13:42:04Z

Affected receivers other than Slack which support templated URLs:

Webhook pkg/alertmanager: add URL validation for Webhook receiver #8229 => fix: implement template URL validations #8307
PagerDuty (clientURL and image + link hrefs) Feat: Add validations for PagerDuty Receiver in Alertmanager Config CR #8113
Pushover (url field) Feat: Add Validations to Pushover Receiver in Alertmanager Config CR #8239
Rocket Chat (icon URL + action URLs but the main url field is fine) feat: add support for rocketchat reciever in AlertManagerConfig CRD #7328
SNS Feat: Add validations to SNS Receiver in Alertmanager Config CR #8217

And this is not accounting for the additional validation/sanitization happening on the generated configuration...

simonpasquier · 2026-01-21T13:49:02Z

I suggest that we do the reverts step by step so let's keep this one to fix the slack config.

heliapb · 2026-01-21T13:54:08Z

I suggest that we do the reverts step by step so let's keep this one to fix the slack config.

ok got it, I'll revert the slack one, give me a few mins

heliapb · 2026-01-21T14:49:14Z

Ok undo the url changes, I'm guessing the others related to // +kubebuilder:validation:MinItems=1 from the #8235 should be fine

heliapb · 2026-01-21T14:49:45Z

pkg/alertmanager: add URL validation for Webhook receiver pkg/alertmanager: add URL validation for Webhook receiver #8229

Will try to pick on webhook next: #8306

simonpasquier · 2026-01-21T16:30:41Z

@heliapb can you sign the commit(s)?

heliapb · 2026-01-21T16:33:36Z

@heliapb can you sign the commit(s)?

Hum thought I had, reseted and pushed again.

simonpasquier · 2026-01-21T16:33:59Z

for some reason, the signatures can't be verified

heliapb · 2026-01-21T16:39:04Z

for some reason, the signatures can't be verified

😕 - going to try to fix on my side

heliapb · 2026-01-21T17:03:34Z

for some reason, the signatures can't be verified

😕 - going to try to fix on my side

@simonpasquier fixed

pkg/apis/monitoring/v1beta1/conversion_from.go

pkg/apis/monitoring/v1beta1/conversion_to.go

simonpasquier · 2026-01-22T08:36:51Z

pkg/alertmanager/amcfg.go

 		out.APIURL = url
 	}

-	if ptr.Deref(in.TitleLink, "") != "" {


should be kept?

Hum this was added https://github.com/nutmos/prometheus-operator/blob/b1f2020818a034f52f06469b527192f555732d30/pkg/alertmanager/amcfg.go#L927 but I guess I can adjust to the proper type now, done

simonpasquier · 2026-01-22T12:44:13Z

thanks!

…r to v0.89.0 ##### [\`v0.89.0\`](https://github.com/prometheus-operator/prometheus-operator/releases/tag/v0.89.0) - \[ENHANCEMENT] Add `hostNetwork` field to the `Alertmanager` CRD. [#8281](prometheus-operator/prometheus-operator#8281) - \[ENHANCEMENT] Add the `crds` and `full-crds` commands to the operator's binary. [#8251](prometheus-operator/prometheus-operator#8251) - \[ENHANCEMENT] Report deprecated field usage in the `Reconciled` condition type. [#8236](prometheus-operator/prometheus-operator#8236) - \[ENHANCEMENT] Avoid unnecessary reconciliation upon creation of the `ThanosRuler` StatefulSet. [#8347](prometheus-operator/prometheus-operator#8347) - \[ENHANCEMENT] Add `bodySizeLimit` to the ScrapeConfig CRD. [#8348](prometheus-operator/prometheus-operator#8348) - \[ENHANCEMENT] Support `http_headers` field in the Alertmanager Secret. [#8357](prometheus-operator/prometheus-operator#8357) - \[ENHANCEMENT] Add the `-kubelet-http-metrics` flag to enable/disable the HTTP metrics port in the Kubelet endpoint (default=enabled). [#8350](prometheus-operator/prometheus-operator#8350) - \[ENHANCEMENT] Include `operator.prometheus.io/version` annotation in the full version of CRDs. [#8279](prometheus-operator/prometheus-operator#8279) - \[BUGFIX] Validate VictorOps global configuration in the `Alertmanager` CRD. [#8020](prometheus-operator/prometheus-operator#8020) - \[BUGFIX] Validate Jira global configuration in the `Alertmanager` CRD. [#8265](prometheus-operator/prometheus-operator#8265) - \[BUGFIX] Validate VictorOps receiver's URL in the `AlertmanagerConfig` CRD. [#8258](prometheus-operator/prometheus-operator#8258) - \[BUGFIX] Validate Webex receiver's URL in the `AlertmanagerConfig` CRD. [#8255](prometheus-operator/prometheus-operator#8255) - \[BUGFIX] Validate Jira receiver's URL configuration in the `AlertmanagerConfig` CRD. [#8230](prometheus-operator/prometheus-operator#8230) - \[BUGFIX] Validate OpsGenie receiver configuration in the `AlertmanagerConfig` CRD. [#8267](prometheus-operator/prometheus-operator#8267) - \[BUGFIX] Validate WeChat receiver configuration in the `AlertmanagerConfig` CRD. [#8271](prometheus-operator/prometheus-operator#8271) - \[BUGFIX] Validate SNS receiver configuration in the `AlertmanagerConfig` CRD. [#8217](prometheus-operator/prometheus-operator#8217) - \[BUGFIX] Validate Webex global configuration in the `Alertmanager` CRD. [#7979](prometheus-operator/prometheus-operator#7979) - \[BUGFIX] Validate Telegram global configuration in the `Alertmanager` CRD. [#8268](prometheus-operator/prometheus-operator#8268) - \[BUGFIX] Restore statefulset's labels if the creation fails with AlreadyExists. [#8343](prometheus-operator/prometheus-operator#8343) - \[BUGFIX] Fix potential panic due to informer cache races. [#8310](prometheus-operator/prometheus-operator#8310) - \[BUGFIX] Support probers defined with IPv6 addresses in the `Probe` CRD. [#8354](prometheus-operator/prometheus-operator#8354) - \[BUGFIX] Prevent group and repeat intervals with zero duration from breaking Alertmanager. [#8126](prometheus-operator/prometheus-operator#8126) - \[BUGFIX] Propagate all supported RocketChat attributes for `AlertmanagerConfig` CRD. [#8016](prometheus-operator/prometheus-operator#8016) - \[BUGFIX] Add URL validation for WeChat receiver. [#8256](prometheus-operator/prometheus-operator#8256) - \[BUGFIX] Add URL validation for SNS receiver. [#8259](prometheus-operator/prometheus-operator#8259) - \[BUGFIX] Fix GCE service discovery for the `ScrapeConfig` CRD. [#8284](prometheus-operator/prometheus-operator#8284) - \[BUGFIX] Avoid stale conditions in `Alertmanager`, `ThanosRuler`, `Prometheus` and `PrometheusAgent` resources. [#8304](prometheus-operator/prometheus-operator#8304) - \[BUGFIX] Fix race condition when updating rule ConfigMaps. [#8290](prometheus-operator/prometheus-operator#8290) - \[BUGFIX] Fix race condition when patching finalizers. [#8323](prometheus-operator/prometheus-operator#8323) - \[BUGFIX] Reconcile `ScrapeConfig` resources when namespace selection changes. [#8334](prometheus-operator/prometheus-operator#8334) --- ##### [\`v0.88.1\`](https://github.com/prometheus-operator/prometheus-operator/releases/tag/v0.88.1) - \[BUGFIX] Validate `webhookURL` secret for `MSTeams` receiver in `AlertmanagerConfig` CRD. [#8294](prometheus-operator/prometheus-operator#8294) - \[BUGFIX] Revert maximum version check for `EC2/Lightsail` SD in `ScrapeConfig` CRD. [#8308](prometheus-operator/prometheus-operator#8308) - \[BUGFIX] Relax URL validation in `Slack` receiver in AlertmanagerConfig CRD to support Go templates. [#8299](prometheus-operator/prometheus-operator#8299) [#8331](prometheus-operator/prometheus-operator#8331) - \[BUGFIX] Relax URL validation in `PagerDuty` in AlertmanagerConfig CRD to support Go templates. [#8319](prometheus-operator/prometheus-operator#8319) - \[BUGFIX] Relax URL validation in `WebhookConfig` in AlertmanagerConfig CRD to support Go templates. [#8307](prometheus-operator/prometheus-operator#8307) [#8317](prometheus-operator/prometheus-operator#8317) - \[BUGFIX] Relax URL validation in `RocketChat` receiver in AlertmanagerConfig CRD to support Go templates. [#8318](prometheus-operator/prometheus-operator#8318) - \[BUGFIX] Relax URL validation in `Pushover` receiver in AlertmanagerConfig CRD to support Go templates. [#8307](prometheus-operator/prometheus-operator#8307) [#8316](prometheus-operator/prometheus-operator#8316)

heliapb requested a review from a team as a code owner January 20, 2026 15:54

pull-request-size bot added the size/M label Jan 20, 2026

heliapb mentioned this pull request Jan 20, 2026

Slack action url validation rejects templated URLs in AlertmanagerConfig since prometheus-operator 0.88 #8291

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simonpasquier reviewed Jan 20, 2026

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heliapb changed the base branch from main to release-0.88 January 20, 2026 17:14

pull-request-size bot added size/XXL and removed size/M labels Jan 20, 2026

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heliapb reopened this Jan 20, 2026

heliapb force-pushed the fix/am_slack_templating branch from 95bdd0f to be1a492 Compare January 20, 2026 17:24

pull-request-size bot added size/M and removed size/XXL labels Jan 20, 2026

slashpai mentioned this pull request Jan 21, 2026

chore: cut v0.88.1 #8303

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simonpasquier reviewed Jan 21, 2026

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simonpasquier mentioned this pull request Jan 21, 2026

add URL validation for SNS receiver #8259

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heliapb force-pushed the fix/am_slack_templating branch from be1a492 to 361200f Compare January 21, 2026 14:47

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simonpasquier approved these changes Jan 21, 2026

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heliapb force-pushed the fix/am_slack_templating branch from 361200f to 455c941 Compare January 21, 2026 16:33

heliapb force-pushed the fix/am_slack_templating branch 4 times, most recently from a1a0624 to b6f2f56 Compare January 21, 2026 17:01

heliapb requested a review from simonpasquier January 21, 2026 17:13

zeritti mentioned this pull request Jan 21, 2026

[kube-prometheus-stack] - crd-alertmanagerconfigs.yaml slackConfigs.actions.URL pattern issue prometheus-community/helm-charts#6503

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simonpasquier reviewed Jan 22, 2026

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heliapb force-pushed the fix/am_slack_templating branch from b6f2f56 to 383e123 Compare January 22, 2026 10:17

fix: am slack templating issue

0808755

heliapb force-pushed the fix/am_slack_templating branch from 383e123 to 0808755 Compare January 22, 2026 10:21

simonpasquier approved these changes Jan 22, 2026

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simonpasquier merged commit b093b0b into prometheus-operator:release-0.88 Jan 22, 2026
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heliapb deleted the fix/am_slack_templating branch January 22, 2026 12:46

simonpasquier mentioned this pull request Jan 23, 2026

Various regressions in v0.88.0 #8315

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heliapb commented Jan 20, 2026

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