Prometheus Files

Prometheus now offers a distroless Docker image variant alongside the default busybox image. The distroless variant provides enhanced security with a minimal base image, uses UID/GID 65532 (nonroot) instead of nobody, and removes the VOLUME declaration. Both variants are available with -busybox and -distroless tag suffixes (e.g., prom/prometheus:latest-busybox, prom/prometheus:latest-distroless). The busybox image remains the default with no suffix for backwards compatibility (e.g., prom/prometheus:latest points to the busybox variant).

For users migrating existing named volumes from the busybox image to the distroless variant, the ownership can be adjusted with:

docker run --rm -v prometheus-data:/prometheus alpine chown -R 65532:65532 /prometheus

Then, the container can be started with the old volume with:

docker run -v prometheus-data:/prometheus prom/prometheus:latest-distroless

User migrating from bind mounts might need to ajust permissions too, depending on their setup.

• [CHANGE] Alerting: Add alertmanager dimension to following metrics: prometheus_notifications_dropped_total, prometheus_notifications_queue_capacity, prometheus_notifications_queue_length. [#16355]
• [CHANGE] UI: Hide expanded alert annotations by default, enabling more information density on the /alerts page. [#17611]
• [FEATURE] AWS SD: Add MSK Role. [#17600]
• [FEATURE] PromQL: Add fill() / fill_left() / fill_right() binop modifiers for specifying default values for missing series. [#17644]
• [FEATURE] Web: Add OpenAPI 3.2 specification for the HTTP API at /api/v1/openapi.yaml. [#17825]
• [FEATURE] Dockerfile: Add distroless image variant using UID/GID 65532 and no VOLUME declaration. Busybox image remains default. [#17876]
• [FEATURE] Web: Add on-demand wall time profiling under <URL>/debug/pprof/fgprof. [#18027]
• [ENHANCEMENT] PromQL: Add more detail to histogram quantile monotonicity info annotations. [#15578]
• [ENHANCEMENT] Alerting: Independent alertmanager sendloops. [#16355]
• [ENHANCEMENT] TSDB: Experimental support for early compaction of stale series in the memory with configurable threshold stale_series_compaction_threshold in the config file. [#16929]
• [ENHANCEMENT] Service Discovery: Service discoveries are now removable from the Prometheus binary through the Go build tag remove_all_sd and individual service discoveries can be re-added with the build tags enable_<sd name>_sd. Users can build a custom Prometheus with only the necessary SDs for a smaller binary size. [#17736]
• [ENHANCEMENT] Promtool: Support promql syntax features promql-duration-expr and promql-extended-range-selectors. [#17926]
• [PERF] PromQL: Avoid unnecessary label extraction in PromQL functions. [#17676]
• [PERF] PromQL: Improve performance of regex matchers like .*-.*-.*. [#17707]
• [PERF] OTLP: Add label caching for OTLP-to-Prometheus conversion to reduce allocations and improve latency. [#17860]
• [PERF] API: Compute /api/v1/targets/relabel_steps in a single pass instead of re-running relabeling for each prefix. [#17969]
• [PERF] tsdb: Optimize LabelValues intersection performance for matchers. [#18069]
• [BUGFIX] PromQL: Prevent query strings containing only UTF-8 continuation bytes from crashing Prometheus. [#17735]
• [BUGFIX] Web: Fix missing X-Prometheus-Stopping header for /-/ready endpoint in NotReady state. [#17795]
• [BUGFIX] PromQL: Fix PromQL info() function returning empty results when filtering by a label that exists on both the input metric and target_info. [#17817]
• [BUGFIX] TSDB: Fix a bug during exemplar buffer grow/shrink that could cause exemplars to be incorrectly discarded. [#17863]
• [BUGFIX] UI: Fix broken graph display after page reload, due to broken Y axis min encoding/decoding. [#17869]
• [BUGFIX] TSDB: Fix memory leaks in buffer pools by clearing reference fields (Labels, Histogram pointers, metadata strings) before returning buffers to pools. [#17879]
• [BUGFIX] PromQL: info function: fix series without identifying labels not being returned. [#17898]
• [BUGFIX] OTLP: Filter __name__ from OTLP attributes to prevent duplicate labels. [#17917]
• [BUGFIX] TSDB: Fix division by zero when computing stale series ratio with empty head. [#17952]
• [BUGFIX] OTLP: Fix potential silent data loss for sum metrics. [#17954]
• [BUGFIX] PromQL: Fix smoothed interpolation across counter resets. [#17988]
• [BUGFIX] PromQL: Fix panic with @ modifier on empty ranges. [#18020]
• [BUGFIX] PromQL: Fix avg_over_time for a single native histogram. [#18058]