Add OpenTelemetry types and handlers (#348)

Author: klauspost

opentelemetry.go

@@ -0,0 +1,136 @@
+// Copyright (c) 2015-2025 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+package madmin
+
+import (
+	"context"
+	"crypto/rsa"
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/minio/madmin-go/v4/estream"
+)
+
+//go:generate msgp $GOFILE
+
+//msgp:replace TraceType with:uint64
+
+// ServiceTelemetryOpts is a request to add following types to tracing.
+type ServiceTelemetryOpts struct {
+	// Types to add to tracing.
+	Types TraceType `json:"types"`
+
+	// Public cert to encrypt stream.
+	PubCert []byte
+
+	// Sample rate to set for this filter.
+	// If <=0 or >=1 no sampling will be performed
+	// and all hits will be traced.
+	SampleRate float64 `json:"sampleRate"`
+
+	// Disable sampling and only do tracing when a trace id is set on incoming request.
+	ParentOnly bool `json:"parentOnly"`
+
+	// Tag adds a `custom.tag` field to all traces triggered by this.
+	TagKV map[string]string `json:"tags"`
+
+	// On incoming HTTP types, only trigger if substring is in request.
+	HTTPFilter struct {
+		Func      string            `json:"funcFilter"`
+		UserAgent string            `json:"userAgent"`
+		Header    map[string]string `json:"header"`
+	} `json:"httpFilter"`
+}
+
+//msgp:ignore ServiceTelemetry
+
+// ServiceTelemetry holds http telemetry spans, serialized and compressed.
+type ServiceTelemetry struct {
+	SpanMZ []byte // Serialized and Compressed spans.
+	Err    error  // Any error that occurred
+}
+
+// ServiceTelemetryStream - gets raw stream for service telemetry.
+func (adm AdminClient) ServiceTelemetryStream(ctx context.Context, opts ServiceTelemetryOpts) (io.ReadCloser, error) {
+	bopts, err := json.Marshal(opts)
+	if err != nil {
+		return nil, err
+	}
+	reqData := requestData{
+		relPath: adminAPIPrefixV4 + "/telemetry",
+		content: bopts,
+	}
+	// Execute GET to call trace handler
+	resp, err := adm.executeMethod(ctx, http.MethodPost, reqData)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		closeResponse(resp)
+		return nil, httpRespToErrorResponse(resp)
+	}
+
+	return resp.Body, nil
+}
+
+// ServiceTelemetry - perform trace request and return individual packages.
+// If options contains a public key the private key must be provided.
+// If context is canceled the function will return.
+func (adm AdminClient) ServiceTelemetry(ctx context.Context, opts ServiceTelemetryOpts, dst chan<- ServiceTelemetry, pk *rsa.PrivateKey) {
+	defer close(dst)
+	resp, err := adm.ServiceTelemetryStream(ctx, opts)
+	if err != nil {
+		dst <- ServiceTelemetry{Err: err}
+		return
+	}
+	dec, err := estream.NewReader(resp)
+	if err != nil {
+		dst <- ServiceTelemetry{Err: err}
+		return
+	}
+	if pk != nil {
+		dec.SetPrivateKey(pk)
+	}
+	for {
+		st, err := dec.NextStream()
+		if err != nil {
+			dst <- ServiceTelemetry{Err: err}
+			return
+		}
+		if ctx.Err() != nil {
+			return
+		}
+		block, err := io.ReadAll(st)
+		if err == nil && len(block) == 0 {
+			// Ignore 0 sized blocks.
+			continue
+		}
+		if ctx.Err() != nil {
+			return
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case dst <- ServiceTelemetry{SpanMZ: block, Err: err}:
+			if err != nil {
+				return
+			}
+		}
+	}
+}