api: Create `/status/tsdb/blocks` endpoint.

this endpoint serves blocks data to the client.

Signed-off-by: sujal shah <sujalshah28092004@gmail.com>

cmd/prometheus/main.go

@@ -1755,6 +1755,21 @@ func (s *readyStorage) CleanTombstones() error {
 	return tsdb.ErrNotReady
 }
 
+// BlockMetas implements the api_v1.TSDBAdminStats and api_v2.TSDBAdmin interfaces.
+func (s *readyStorage) BlockMetas() ([]tsdb.BlockMeta, error) {
+	if x := s.get(); x != nil {
+		switch db := x.(type) {
+		case *tsdb.DB:
+			return db.BlockMetas(), nil
+		case *agent.DB:
+			return nil, agent.ErrUnsupported
+		default:
+			panic(fmt.Sprintf("unknown storage type %T", db))
+		}
+	}
+	return nil, tsdb.ErrNotReady
+}
+
 // Delete implements the api_v1.TSDBAdminStats and api_v2.TSDBAdmin interfaces.
 func (s *readyStorage) Delete(ctx context.Context, mint, maxt int64, ms ...*labels.Matcher) error {
 	if x := s.get(); x != nil {

docs/querying/api.md

@@ -1355,6 +1355,64 @@ curl http://localhost:9090/api/v1/status/tsdb
 }
 ```
 
+*New in v3.6.0*
+
+### TSDB Blocks
+
+**NOTE**: This endpoint is **experimental** and might change in the future. The endpoint name and the exact format of the returned data may change between Prometheus versions. The **exact metadata returned** by this endpoint is an implementation detail and may change in future Prometheus versions.
+
+The following endpoint returns the list of currently loaded TSDB blocks and their metadata.
+
+```
+GET /api/v1/status/tsdb/blocks
+```
+
+This endpoint returns the following information for each block:
+
+- `ulid`: Unique ID of the block.
+- `minTime`: Minimum timestamp (in milliseconds) of the block.
+- `maxTime`: Maximum timestamp (in milliseconds) of the block.
+- `stats`:
+  - `numSeries`: Number of series in the block.
+  - `numSamples`: Number of samples in the block.
+  - `numChunks`: Number of chunks in the block.
+- `compaction`:
+  - `level`: The compaction level of the block.
+  - `sources`: List of ULIDs of source blocks used to compact this block.
+- `version`: The block version.
+
+
+```bash
+curl http://localhost:9090/api/v1/status/tsdb/blocks
+```
+
+```json
+{
+  "status": "success",
+  "data": {
+    "blocks": [
+      {
+        "ulid": "01JZ8JKZY6XSK3PTDP9ZKRWT60",
+        "minTime": 1750860620060,
+        "maxTime": 1750867200000,
+        "stats": {
+          "numSamples": 13701,
+          "numSeries": 716,
+          "numChunks": 716
+        },
+        "compaction": {
+          "level": 1,
+          "sources": [
+            "01JZ8JKZY6XSK3PTDP9ZKRWT60"
+          ]
+        },
+        "version": 1
+      }
+    ]
+  }
+}
+```
+
 *New in v2.15*
 
 ### WAL Replay Stats

tsdb/db.go

@@ -1074,6 +1074,16 @@ func (db *DB) Dir() string {
 	return db.dir
 }
 
+// BlockMetas returns the list of metadata for all blocks.
+func (db *DB) BlockMetas() []BlockMeta {
+	blocks := db.Blocks()
+	metas := make([]BlockMeta, 0, len(blocks))
+	for _, b := range blocks {
+		metas = append(metas, b.Meta())
+	}
+	return metas
+}
+
 func (db *DB) run(ctx context.Context) {
 	defer close(db.donec)
 

web/api/v1/api.go

@@ -186,6 +186,7 @@ type TSDBAdminStats interface {
 	Snapshot(dir string, withHead bool) error
 	Stats(statsByLabelName string, limit int) (*tsdb.Stats, error)
 	WALReplayStatus() (tsdb.WALReplayStatus, error)
+	BlockMetas() ([]tsdb.BlockMeta, error)
 }
 
 type QueryOpts interface {
@@ -404,6 +405,7 @@ func (api *API) Register(r *route.Router) {
 	r.Get("/status/buildinfo", wrap(api.serveBuildInfo))
 	r.Get("/status/flags", wrap(api.serveFlags))
 	r.Get("/status/tsdb", wrapAgent(api.serveTSDBStatus))
+	r.Get("/status/tsdb/blocks", wrapAgent(api.serveTSDBBlocks))
 	r.Get("/status/walreplay", api.serveWALReplayStatus)
 	r.Get("/notifications", api.notifications)
 	r.Get("/notifications/live", api.notificationsSSE)
@@ -1740,6 +1742,19 @@ func TSDBStatsFromIndexStats(stats []index.Stat) []TSDBStat {
 	return result
 }
 
+func (api *API) serveTSDBBlocks(_ *http.Request) apiFuncResult {
+	blockMetas, err := api.db.BlockMetas()
+	if err != nil {
+		return apiFuncResult{nil, &apiError{errorInternal, fmt.Errorf("error getting block metadata: %w", err)}, nil, nil}
+	}
+
+	return apiFuncResult{
+		data: map[string][]tsdb.BlockMeta{
+			"blocks": blockMetas,
+		},
+	}
+}
+
 func (api *API) serveTSDBStatus(r *http.Request) apiFuncResult {
 	limit := 10
 	if s := r.FormValue("limit"); s != "" {

web/api/v1/api_test.go

@@ -15,6 +15,7 @@ package v1
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -31,6 +32,7 @@ import (
 	"time"
 
 	jsoniter "github.com/json-iterator/go"
+	"github.com/oklog/ulid/v2"
 	"github.com/prometheus/client_golang/prometheus"
 	config_util "github.com/prometheus/common/config"
 	"github.com/prometheus/common/model"
@@ -3793,10 +3795,15 @@ func assertAPIResponseMetadataLen(t *testing.T, got interface{}, expLen int) {
 }
 
 type fakeDB struct {
-	err error
+	err        error
+	blockMetas []tsdb.BlockMeta
 }
 
-func (f *fakeDB) CleanTombstones() error                                         { return f.err }
+func (f *fakeDB) CleanTombstones() error { return f.err }
+
+func (f *fakeDB) BlockMetas() ([]tsdb.BlockMeta, error) {
+	return f.blockMetas, nil
+}
 func (f *fakeDB) Delete(context.Context, int64, int64, ...*labels.Matcher) error { return f.err }
 func (f *fakeDB) Snapshot(string, bool) error                                    { return f.err }
 func (f *fakeDB) Stats(statsByLabelName string, limit int) (_ *tsdb.Stats, retErr error) {
@@ -4122,6 +4129,45 @@ func TestRespondSuccess_DefaultCodecCannotEncodeResponse(t *testing.T) {
 	require.JSONEq(t, `{"status":"error","errorType":"not_acceptable","error":"cannot encode response as application/default-format"}`, string(body))
 }
 
+func TestServeTSDBBlocks(t *testing.T) {
+	blockMeta := tsdb.BlockMeta{
+		ULID:    ulid.MustNew(ulid.Now(), nil),
+		MinTime: 0,
+		MaxTime: 1000,
+		Stats: tsdb.BlockStats{
+			NumSeries: 10,
+		},
+	}
+
+	db := &fakeDB{
+		blockMetas: []tsdb.BlockMeta{blockMeta},
+	}
+
+	api := &API{
+		db: db,
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/status/tsdb/blocks", nil)
+	w := httptest.NewRecorder()
+
+	result := api.serveTSDBBlocks(req)
+
+	json.NewEncoder(w).Encode(result.data)
+
+	resp := w.Result()
+	defer resp.Body.Close()
+
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	var resultData struct {
+		Blocks []tsdb.BlockMeta `json:"blocks"`
+	}
+	err := json.NewDecoder(resp.Body).Decode(&resultData)
+	require.NoError(t, err)
+	require.Len(t, resultData.Blocks, 1)
+	require.Equal(t, blockMeta, resultData.Blocks[0])
+}
+
 func TestRespondError(t *testing.T) {
 	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		api := API{}

web/web_test.go

@@ -52,6 +52,10 @@ type dbAdapter struct {
 	*tsdb.DB
 }
 
+func (a *dbAdapter) BlockMetas() ([]tsdb.BlockMeta, error) {
+	return a.DB.BlockMetas(), nil
+}
+
 func (a *dbAdapter) Stats(statsByLabelName string, limit int) (*tsdb.Stats, error) {
 	return a.Head().Stats(statsByLabelName, limit), nil
 }
@@ -569,6 +573,7 @@ func TestAgentAPIEndPoints(t *testing.T) {
 		"/query_range":                 {http.MethodGet, http.MethodPost},
 		"/query_exemplars":             {http.MethodGet, http.MethodPost},
 		"/status/tsdb":                 {http.MethodGet},
+		"/status/tsdb/blocks":          {http.MethodGet},
 		"/alerts":                      {http.MethodGet},
 		"/rules":                       {http.MethodGet},
 		"/admin/tsdb/delete_series":    {http.MethodPost, http.MethodPut},