Update dskit to support loading runtime configs from HTTP endpoints (#15052)

#### What this PR does

Update dskit to get grafana/dskit#926.

That change lets the runtimeconfig Manager load configuration from
`http://` and `https://` URLs in addition to local files, so
`-runtime-config.file` now accepts URLs. It also adds the
`-runtime-config.http-client-timeout` flag (default `30s`) for the HTTP
fetch timeout.

#### Which issue(s) this PR fixes or relates to

N/A

#### Checklist

- [ ] Tests updated.
- [x] Documentation added.
- [x] `CHANGELOG.md` updated - the order of entries should be
`[CHANGE]`, `[FEATURE]`, `[ENHANCEMENT]`, `[BUGFIX]`. If changelog entry
is not needed, please add the `changelog-not-needed` label to the PR.
- [ ]
[`about-versioning.md`](https://github.com/grafana/mimir/blob/main/docs/sources/mimir/configure/about-versioning.md)
updated with experimental features.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Changes runtime-config loading to perform HTTP requests and adds new
timeout/metrics, which can affect startup/reload behavior and introduce
network-related failure modes.
> 
> **Overview**
> **Runtime config loading now supports remote sources.**
`-runtime-config.file` can point to `http://`/`https://` URLs as well as
local files, via a new provider abstraction in the vendored `dskit`
runtimeconfig manager.
> 
> Adds `-runtime-config.http-client-timeout` (default `30s`) and a
`runtime_config_http_request_duration_seconds` metric for HTTP fetch
latency, and updates generated config/help docs plus `CHANGELOG.md`
accordingly.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
1dd09da. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: colega

CHANGELOG.md

@@ -34,6 +34,7 @@
 * [CHANGE] Ingest storage: The `cortex_ingest_storage_writer_latency_seconds` metric now tracks the latency to write an incoming request to all Kafka partitions in a single call, instead of tracking latency individually for each partition. #14898
 * [CHANGE] Ingest storage: deprecated `-ingest-storage.kafka.write-clients` CLI flag. The flag is now ignored and Mimir always uses a single Kafka write client. The flag will be removed in Mimir 3.3. #14903
 * [CHANGE] Alertmanager: `-alertmanager.grafana-alertmanager-idle-grace-period` renamed to `-alertmanager.strict-initialization-idle-grace-period`. #14960
+* [FEATURE] Runtime config: Support loading configuration from `http://` and `https://` URLs in addition to local files via `-runtime-config.file`. Added `-runtime-config.http-client-timeout` (default `30s`) to control the HTTP fetch timeout. #15052
 * [FEATURE] Distributor: Derive limits based on tenant metadata. Supported limits are `max_active_series_per_user`, `ingestion_rate`, `ingestion_burst_size`, `ingestion_burst_factor`, `otel_metric_suffixes_enabled`, `name_validation_scheme` and `otel_translation_strategy`. #14289
 * [FEATURE] Distributor: add `cortex_distributor_request_body_compression_ratio` histogram that tracks the compression of write requests. #14232
 * [FEATURE] Distributor: add `-distributor.otel-label-name-underscore-sanitization` and `-distributor.otel-label-name-preserve-underscores` that control sanitization of underscores during OTLP translation. #13133

cmd/mimir/config-descriptor.json

@@ -18683,11 +18683,22 @@
           "kind": "field",
           "name": "file",
           "required": false,
-          "desc": "Comma separated list of yaml files with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.",
+          "desc": "Comma separated list of yaml files or URLs with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.",
           "fieldValue": null,
           "fieldDefaultValue": "",
           "fieldFlag": "runtime-config.file",
           "fieldType": "string"
+        },
+        {
+          "kind": "field",
+          "name": "http_client_timeout",
+          "required": false,
+          "desc": "HTTP client timeout when fetching runtime config from URLs.",
+          "fieldValue": null,
+          "fieldDefaultValue": 30000000000,
+          "fieldFlag": "runtime-config.http-client-timeout",
+          "fieldType": "duration",
+          "fieldCategory": "advanced"
         }
       ],
       "fieldValue": null,

cmd/mimir/help-all.txt.tmpl

@@ -3282,7 +3282,9 @@ Usage of ./cmd/mimir/mimir:
   -ruler.tenant-shard-size int
     	The tenant's shard size when sharding is used by ruler. Value of 0 disables shuffle sharding for the tenant, and tenant rules will be sharded across all ruler replicas.
   -runtime-config.file comma-separated-list-of-strings
-    	Comma separated list of yaml files with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.
+    	Comma separated list of yaml files or URLs with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.
+  -runtime-config.http-client-timeout duration
+    	HTTP client timeout when fetching runtime config from URLs. (default 30s)
   -runtime-config.reload-period duration
     	How often to check runtime config files. (default 10s)
   -server.cluster-validation.additional-labels comma-separated-list-of-strings

cmd/mimir/help.txt.tmpl

@@ -840,7 +840,7 @@ Usage of ./cmd/mimir/mimir:
   -ruler.tenant-shard-size int
     	The tenant's shard size when sharding is used by ruler. Value of 0 disables shuffle sharding for the tenant, and tenant rules will be sharded across all ruler replicas.
   -runtime-config.file comma-separated-list-of-strings
-    	Comma separated list of yaml files with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.
+    	Comma separated list of yaml files or URLs with the configuration that can be updated at runtime. Runtime config files will be merged from left to right.
   -server.create-new-traces
     	Creates new traces for each call rather than continuing the existing trace. A span link is used to allow navigation to the parent trace. Only works when using Open-Telemetry tracing.
   -server.grpc-collect-max-streams-by-conn

docs/sources/mimir/configure/configuration-parameters/index.md

@@ -342,11 +342,16 @@ runtime_config:
   # CLI flag: -runtime-config.reload-period
   [period: <duration> | default = 10s]
 
-  # Comma separated list of yaml files with the configuration that can be
-  # updated at runtime. Runtime config files will be merged from left to right.
+  # Comma separated list of yaml files or URLs with the configuration that can
+  # be updated at runtime. Runtime config files will be merged from left to
+  # right.
   # CLI flag: -runtime-config.file
   [file: <string> | default = ""]
 
+  # (advanced) HTTP client timeout when fetching runtime config from URLs.
+  # CLI flag: -runtime-config.http-client-timeout
+  [http_client_timeout: <duration> | default = 30s]
+
 # The memberlist block configures the Gossip memberlist.
 [memberlist: <memberlist>]
 

go.mod

@@ -17,7 +17,7 @@ require (
 	github.com/golang/snappy v1.0.0
 	github.com/google/gopacket v1.1.19
 	github.com/gorilla/mux v1.8.1
-	github.com/grafana/dskit v0.0.0-20260413135140-f8fd8e188362
+	github.com/grafana/dskit v0.0.0-20260417113503-29a3c41c2ad7
 	github.com/grafana/e2e v0.1.2-0.20260309174126-b5393d4e610f
 	github.com/hashicorp/golang-lru v1.0.2 // indirect
 	github.com/influxdata/influxdb/v2 v2.8.0

go.sum

@@ -585,8 +585,8 @@ github.com/gosimple/slug v1.1.1 h1:fRu/digW+NMwBIP+RmviTK97Ho/bEj/C9swrCspN3D4=
 github.com/gosimple/slug v1.1.1/go.mod h1:ER78kgg1Mv0NQGlXiDe57DpCyfbNywXXZ9mIorhxAf0=
 github.com/grafana-tools/sdk v0.0.0-20220919052116-6562121319fc h1:PXZQA2WCxe85Tnn+WEvr8fDpfwibmEPgfgFEaC87G24=
 github.com/grafana-tools/sdk v0.0.0-20220919052116-6562121319fc/go.mod h1:AHHlOEv1+GGQ3ktHMlhuTUwo3zljV3QJbC0+8o2kn+4=
-github.com/grafana/dskit v0.0.0-20260413135140-f8fd8e188362 h1:hE4cSWYfhmUV1RBGm+caOF7QhYDVX9VTfNuhH5yZvTQ=
-github.com/grafana/dskit v0.0.0-20260413135140-f8fd8e188362/go.mod h1:6zFIzal2FCd0JC1pE0ZTb2ftC0Jr/zsQR4zRNRdDfZA=
+github.com/grafana/dskit v0.0.0-20260417113503-29a3c41c2ad7 h1:5LLRUYS/OUhGoaxY0x+6vUDtKgtlB4kLp3k9vQxcYjM=
+github.com/grafana/dskit v0.0.0-20260417113503-29a3c41c2ad7/go.mod h1:6zFIzal2FCd0JC1pE0ZTb2ftC0Jr/zsQR4zRNRdDfZA=
 github.com/grafana/e2e v0.1.2-0.20260309174126-b5393d4e610f h1:gxaqz5StufMU078tWFuf8CUi4PZtITBxjM2TZV7NOFw=
 github.com/grafana/e2e v0.1.2-0.20260309174126-b5393d4e610f/go.mod h1:KFvJP5m5GQ837CN7rUbWIiPdw1JZgeRJTEyp2O5U0is=
 github.com/grafana/go-yaml/v3 v3.0.0-20260130164322-e3c24e8f4c87 h1:Op5/Kd8Ae90IC7Ow+CNwGo/oq87cJX2iE+U8Dw4a8Bc=

operations/mimir/mimir-flags-defaults.json

@@ -1328,6 +1328,7 @@
   "alertmanager-storage.local.path": "",
   "runtime-config.reload-period": 10000000000,
   "runtime-config.file": "",
+  "runtime-config.http-client-timeout": 30000000000,
   "memberlist.nodename": "",
   "memberlist.randomize-node-name": true,
   "memberlist.stream-timeout": 2000000000,