v0.16.0 - 2026-04-04

Check the release notes in discussions.

Added

• K8s transformer plugins to be able to customize the k8s resulting objects without depending on current Prometheys operator Rule CR.
• sloth.dev/k8stransform/prom-operator-prometheus-rule/v1 K8s transformer plugin.
• Users can now create multiple K8s objects as the output of the SLO generated rules.
• Sloth lib support for K8s transformer plugins using WriteResultAsK8sObjects.
• New server command that serves the new UI.
• UI: Service listing and searching.
• UI: SLO listing, searching and filtered by service.
• UI: SLO details with stats, alerts state, SLI chart and budged burn in period chart.
• UI: Support SLO grouped by labels.
• UI: Redirect unmarshaled ID of grouped SLO labels to proper SLO ID.
• UI: Support service list sort by name and alert status.
• UI: Support alert firing, burning over budget and budget consumed in period SLO filtering on SLO listing.
• Update to Kubernetes v1.35.
• validate command will check for SLO duplicates (disable with --ignore-slo-duplicates).

Changed

• Sloth now uses a dynamic unstructured plugin (sloth.dev/k8stransform/prom-operator-prometheus-rule/v1) to create and manage the prometheus operator Rule K8s CRs.
• BREAKING: Plugin loader will ignore directories starting with ...

Added

• K8s transformer plugins to be able to customize the k8s resulting objects without depending on current Prometheys operator Rule CR.
• sloth.dev/k8stransform/prom-operator-prometheus-rule/v1 K8s transformer plugin.
• Users can now create multiple K8s objects as the output of the SLO generated rules.
• Sloth lib support for K8s transformer plugins using WriteResultAsK8sObjects.
• New server command that serves the new UI.
• UI: Service listing and searching.
• UI: SLO listing, searching and filtered by service.
• UI: SLO details with stats, alerts state, SLI chart and budged burn in period chart.
• UI: Support SLO grouped by labels.
• UI: Redirect unmarshaled ID of grouped SLO labels to proper SLO ID.
• UI: Support service list sort by name and alert status.
• UI: Support alert firing, burning over budget and budget consumed in period SLO filtering on SLO listing.
• Update to Kubernetes v1.35.
• validate command will check for SLO duplicates (disable with --ignore-slo-duplicates).

Changed

• Sloth now uses a dynamic unstructured plugin (sloth.dev/k8stransform/prom-operator-prometheus-rule/v1) to create and manage the prometheus operator Rule K8s CRs.
• BREAKING: Plugin loader will ignore directories starting with ...

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v0.16.0 - 2026-04-04

Check the release notes in discussions .

Added

• K8s transformer plugins to be able to customize the k8s resulting objects without depending on current Prometheys operator Rule CR.

• sloth.dev/k8stransform/prom-operator-prometheus-rule/v1 K8s transformer plugin.

• Users can now create multiple K8s objects as the output of the SLO generated rules.

• Sloth lib support for K8s transformer plugins using WriteResultAsK8sObjects .

• New server command that serves the new UI.

• UI: Service listing and searching.

• UI: SLO listing, searching and filtered by service.

• UI: SLO details with stats, alerts state, SLI chart and budged burn in period chart.

• UI: Support SLO grouped by labels.

• UI: Redirect unmarshaled ID of grouped SLO labels to proper SLO ID.

• UI: Support service list sort by name and alert status.

• UI: Support alert firing, burning over budget and budget consumed in period SLO filtering on SLO listing.

• Update to Kubernetes v1.35.

• validate command will check for SLO duplicates (disable with --ignore-slo-duplicates ).

Changed

• Sloth now uses a dynamic unstructured plugin ( sloth.dev/k8stransform/prom-operator-prometheus-rule/v1 ) to create and manage the prometheus operator Rule K8s CRs.

• BREAKING: Plugin loader will ignore directories starting with .. .

Check out the announcement

v0.15.0 - 2025-10-31

Added

• Sloth SLO generation can be used as a Go library in github.com/slok/sloth/pkg/lib.
• Sloth lib PrometheusSLOGenerator with GenerateFromSlothV1 to generate SLOs based on Sloth v1 spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromK8sV1 to generate SLOs based on Kubernetes Sloth v1 spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromOpenSLOV1Alpha to generate SLOs based on OpenSLO v1Alpha spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromRaw to generate SLOs based on any raw string spec.
• Sloth lib WriteResultAsPrometheusStd helper method to write generated SLO results into standard Prometheus rules YAML.
• Sloth lib WriteResultAsK8sPrometheusOperator helper method to write generated SLO results into Prometheus operator rules YAML.
• The resulting SLO Prometheus rule group name can be customized by SLO plugins.
• SLO plugins have the ability to add extra Prometheus Rule groups.

Changed

• The CLI commands generate and validate use the public Sloth Go library.

Added

• Sloth SLO generation can be used as a Go library in github.com/slok/sloth/pkg/lib.
• Sloth lib PrometheusSLOGenerator with GenerateFromSlothV1 to generate SLOs based on Sloth v1 spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromK8sV1 to generate SLOs based on Kubernetes Sloth v1 spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromOpenSLOV1Alpha to generate SLOs based on OpenSLO v1Alpha spec.
• Sloth lib PrometheusSLOGenerator with GenerateFromRaw to generate SLOs based on any raw string spec.
• Sloth lib WriteResultAsPrometheusStd helper method to write generated SLO results into standard Prometheus rules YAML.
• Sloth lib WriteResultAsK8sPrometheusOperator helper method to write generated SLO results into Prometheus operator rules YAML.
• The resulting SLO Prometheus rule group name can be customized by SLO plugins.
• SLO plugins have the ability to add extra Prometheus Rule groups.

Changed

• The CLI commands generate and validate use the public Sloth Go library.

Check the announcement here

v0.14.0

Highlights

Added

• Add contrib plugin directory and CODEOWNERS policies.
• Contrib plugin: /internal/plugin/slo/contrib/info_labels_v1/.
• Allow github.com/VictoriaMetrics/metricsql module in SLO plugins.
• Contrib plugin: sloth.dev/contrib/validate_victoria_metrics/v1.
• Contrib plugin: sloth.dev/contrib/rule_intervals/v1.
• Contrib plugin: sloth.dev/contrib/error_budget_exhausted_alert/v1.
• Contrib plugin: sloth.dev/contrib/denominator_corrected_rules/v1.
• Add --slo-plugins and -s flag (validate) to be able to declare SLO plugins at cmd level, these plugins will be applied to all SLOs.
• Add --disable-default-slo-plugins flag (validate) to be able to disable default Sloth SLO plugins.

Changed

• Update chat git sync to v4.5.0

Detailed and Autogenerated

What's Changed

• Release Helm chart for Sloth v0.13.0 by @slok in #665
• Add info_labels_v1 contrib SLO plugin by @slok in #667
• Add Victoria metrics SLO validator plugin by @slok in #668
• Simplify victoria metrics validator SLO plugin by @slok in #669
• Increase integration tests in k8s eventual consistency waits by @slok in #672
• build(deps): bump github.com/prometheus/prometheus from 0.305.0 to 0.306.0 by @dependabot[bot] in #673
• Add rule intervals SLO plugin by @slok in #671
• feat: error budget exhausted plugin by @wbollock in #670
• Port denominator corrected feature as SLO plugin by @slok in #674
• Relax stale issues by @slok in #676
• Update deps by @slok in #677
• Improve conventions by @slok in #679
• Add optimized rules to denominator corrected plugin by @slok in #681
• chore: tiny markdown heading fix by @wbollock in #682
• Update deps by @slok in #688
• Add app level SLO plugins support on validate cmd by @slok in #689
• build(deps): bump github.com/prometheus-operator/prometheus-operator/pkg/client from 0.86.0 to 0.86.1 by @dependabot[bot] in #691
• Bump v0.14.0 by @slok in #692

Full Changelog: v0.13.0...v0.14.0

Added

• Add contrib plugin directory and CODEOWNERS policies.
• Contrib plugin: /internal/plugin/slo/contrib/info_labels_v1/.
• Allow github.com/VictoriaMetrics/metricsql module in SLO plugins.
• Contrib plugin: sloth.dev/contrib/validate_victoria_metrics/v1.
• Contrib plugin: sloth.dev/contrib/rule_intervals/v1.
• Contrib plugin: sloth.dev/contrib/error_budget_exhausted_alert/v1.
• Contrib plugin: sloth.dev/contrib/denominator_corrected_rules/v1.
• Add --slo-plugins and -s flag (validate) to be able to declare SLO plugins at cmd level, these plugins will be applied to all SLOs.
• Add --disable-default-slo-plugins flag (validate) to be able to disable default Sloth SLO plugins.

Changed

• Update chat git sync to v4.5.0

This is a big one 😆 (check https://github.com/slok/sloth/discussions/664)

Highlights

Changed

• Split image registry and repository in Helm chart
• ⚠️(BREAKING) Internally Sloth (not k8s) prometheusServiceLevel uses k8s k8s.io/apimachinery/pkg/util/yaml lib for unmarshaling YAML instead of gopkg.in/yaml.v2.
• Core SLO validation and SLO rules generation migrated to SLO plugins.
• ⚠️(BREAKING) --sli-plugins-path, --slo-plugins-path, -m args and it's env vars SLOTH_SLI_PLUGINS_PATHand SLOTH_SLO_PLUGINS_PATH have been removed in favor or --plugins-path, -p and it's env var SLOTH_PLUGINS_PATH that discovers and loads SLI and SLO plugins with a single flag.
• Simplify validation and improve validation message by using custom logic instead of go-playground/validator.
• ⚠️(BREAKING) --disable-optimized-rules flag and associated env var has been removed.**
• (BREAKING) Helm chart has removed the option for disabling optimized rules.
• Update to Kubernetes v1.34.
• Update to Go v1.25.

Added

• Sloth domain models can be imported in Go apps using github.com/slok/sloth/pkg/common/model.
• Sloth conventions can be imported in Go apps using github.com/slok/sloth/pkg/common/conventions.
• Sloth SLO validation logic can be imported in Go apps using github.com/slok/sloth/pkg/common/validation.
• A new SLO rule generation plugin system has been added to be able to change/extend the SLO rule generation process.
• SLO plugins can be loaded from FS directories recursively using --plugins-path in the commands.
• SLO plugins have a priority value to be able to order in the execution chain.
• Sloth regular (non-k8s) prometheus/v1 API support for SLO plugins at SLO group level and per SLO level.
• Sloth K8s CRD sloth.slok.dev/v1/PrometheusServiceLevel API support for SLO plugins at SLO group level and per SLO level.
• Allow overriding previous declared SLO plugins (includes defaults) at SLO group and SLO level.
• SLO plugins can access env vars and use OS/exec by default.
• Allow github.com/caarlos0/env/v11 module in SLO plugins.
• Add --slo-plugins and -s flag (generate and k8s controller) to be able to declare SLO plugins at cmd level, these plugins will be applied to all SLOs.
• Add --disable-default-slo-plugins flag (generate and k8s controller) to be able to disable default Sloth SLO plugins.
• Helm chart supports node selector.

Details (Per PR and autogenerated)

What's Changed

• Prepare deployoment manifests release for v0.12.0 by @slok in #556
• Add Stale CI to autoclose issues and PRs by @slok in #559
• Start moving models to an importable own package by @slok in #561
• Move more to conventions and utils to be importable by @slok in #562
• Move sli plugins loader and reader to independent packages by @slok in #563
• Move prom SLO IO writer to storage package by @slok in #564
• Move merge label to utils by @slok in #565
• Move sloth prom spec loader to storage package by @slok in #566
• Move open SLO spec loader to storage package by @slok in #567
• build(deps): bump github.com/go-playground/validator/v10 from 10.25.0 to 10.26.0 by @dependabot[bot] in #568
• Split image registry and repository from Helm chart by @QuantumEnigmaa in #491
• Move K8s YAML and CR loaders to storage package by @slok in #569
• Add a middle domain model for prom rules by @slok in #570
• Move apiserver storage to storage package by @slok in #571
• Move kubernetes logic to their own packages in storage by @slok in #572
• Add SLO generation as a chain of processors by @slok in #573
• build(deps): bump golang from 1.24.1-alpine to 1.24.2-alpine in /docker/prod by @dependabot[bot] in #574
• Add SLO rule generation plugin system by @slok in #575
• Add intervals to prom rule models by @slok in #576
• Add SLO plugin and SLO plugin repository on domain layer by @slok in #577
• Add missing SLO plugin unit test usage on domain app by @slok in #578
• Add priority to have SLO plugins execution order in the chain by @slok in #579
• Update project status on readme by @slok in #580
• Add debug core SLO plugin by @slok in #581
• build(deps): bump github.com/prometheus/client_golang from 1.21.1 to 1.22.0 by @dependabot[bot] in #583
• Add support for SLO plugins on default (non-k8s) sloth prometheus service level spec by @slok in #584
• Move SLO validation to an SLO plugin by @slok in #585
• Add the original SLO group source information to the plugin request by @slok in #586
• fix: update go version go.mod by @wbollock in #588
• Aggregate SLO and SLI plugin file loader into a single repo that discovers both and change flags to improve usage by @slok in #589
• Migrate to mockery v3 by @slok in #590
• build(deps): bump sigs.k8s.io/structured-merge-diff/v4 from 4.6.0 to 4.7.0 by @dependabot[bot] in #592
• Add support for SLO plugins on Kubernetes API by @slok in #591
• Fix naming on k8s plugin example by @slok in #593
• Add overridePrevious as a way of resetting the declared previous chain by @slok in #595
• build(deps): bump github.com/prometheus-operator/prometheus-operator/pkg/client from 0.81.0 to 0.82.0 by @dependabot[bot] in #597
• Simplify and improve validator by @slok in #600
• Remove not optimized SLI rule generation flag by @slok in #601
• Pass default plugins as a chain by @slok in #603
• Support env vars on SLO plugins by @slok in #604
• Allow SLO plugins at application level using cmd flags by @slok in #605
• Add SLO plugin readmes by @slok in #606
• Fix readme on validate plugin by @slok in #609
• build(deps): bump golang from 1.24.2-alpine to 1.24.3-alpine in /docker/prod by @dependabot[bot] in #612
• [FEAT] add helm chart nodeselector property by @pgmrey in #613
• Allow disabling default plugins using a cmd flag on CLI and k8s controller modes by @slok in #614
• Update Prometheus dep to v3.4.0 by @slok in #619
• build(deps): bump github.com/prometheus/common from 0.63.0 to 0.64.0 by @dependabot[bot] in #617
• Update to Kubernetes v1.33 by @slok in #620
• Update prom operator dependencies by @slok in #622
• build(deps): bump github.com/prometheus/prometheus from 0.304.0 to 0.304.1 by @dependabot[bot] in #625
• build(deps): bump golang from 1.24.3-alpine to 1.24.4-alpine in /docker/prod by @dependabot[bot] in #627
• build(deps): bump github.com/prometheus/common from 0.64.0 to 0.65.0 by @dependabot[bot] in #632
• build(deps): bump github.com/oklog/run from 1.1.0 to 1.2.0 by @dependabot[bot] in #636
• Update deps and add support for go 1.25 and k8s 1.34 by @slok in #662
• Prepare for v0.13.0 by @slok in #663

New Contributors

• @QuantumEnigmaa made their first contribution in #491
• @wbollock made their first contribution in #588
• @pgmrey made their first contribution in #613

Full Changelog: v0.12.0...v0.13.0

Changed

• Split image registry and repository in Helm chart
• (BREAKING) Internally Sloth (not k8s) prometheusServiceLevel uses k8s k8s.io/apimachinery/pkg/util/yaml lib for unmarshaling YAML instead of gopkg.in/yaml.v2.
• Core SLO validation and SLO rules generation migrated to SLO plugins.
• (BREAKING) --sli-plugins-path, --slo-plugins-path, -m args and it's env vars SLOTH_SLI_PLUGINS_PATHand SLOTH_SLO_PLUGINS_PATH have been removed in favor or --plugins-path, -p and it's env var SLOTH_PLUGINS_PATH that discovers and loads SLI and SLO plugins with a single flag.
• Simplify validation and improve validation message by using custom logic instead of go-playground/validator.
• (BREAKING) --disable-optimized-rules flag and associated env var has been removed.
• (BREAKING) Helm chart has removed the option for disabling optimized rules.
• Update to Kubernetes v1.34.
• Update to Go v1.25.

Added

• Sloth domain models can be imported in Go apps using github.com/slok/sloth/pkg/common/model.
• Sloth conventions can be imported in Go apps using github.com/slok/sloth/pkg/common/conventions.
• Sloth SLO validation logic can be imported in Go apps using github.com/slok/sloth/pkg/common/validation.
• A new SLO rule generation plugin system has been added to be able to change/extend the SLO rule generation process.
• SLO plugins can be loaded from FS directories recursively using --plugins-path in the commands.
• SLO plugins have a priority value to be able to order in the execution chain.
• Sloth regular (non-k8s) prometheus/v1 API support for SLO plugins at SLO group level and per SLO level.
• Sloth K8s CRD sloth.slok.dev/v1/PrometheusServiceLevel API support for SLO plugins at SLO group level and per SLO level.
• Allow overriding previous declared SLO plugins (includes defaults) at SLO group and SLO level.
• SLO plugins can access env vars and use OS/exec by default.
• Allow github.com/caarlos0/env/v11 module in SLO plugins.
• Add --slo-plugins and -s flag (generate and k8s controller) to be able to declare SLO plugins at cmd level, these plugins will be applied to all SLOs.
• Add --disable-default-slo-plugins flag (generate and k8s controller) to be able to disable default Sloth SLO plugins.
• Helm chart supports node selector.

v0.12.0 - 2025-03-27

Container image: docker pull ghcr.io/slok/sloth:v0.12.0

Added

• Add ApplyConfig utils for Kubernetes lib clients.

Changed

• Update to Go 1.24.
• Update to Kubernetes v1.32.
• Update all other dependencies to latest versions.
• Migrate deployment manifests git-sync to v4.

Fixes

• Allow spec files with CRLF.
• Helm chart tolerations

Changed

• Optimized SLI recording rules now have the same labels as the non-optimized ones, avoiding promtool check warnings.
• Update to Go 1.19.
• Update to Kubernetes v1.25.
• sloth_window is ignored in alerts reducing the noise of refiring alerts.