Add zstd compression to SAPM receiver and exporter (open-telemetry#23257)

- Updated github.com/signalfx/sapm-proto to v0.13.0
- Added "compression" config setting to sapm exporter
- Added tests to verify various compression settings for sapm receiver
and exporter.

Author: tigrannajaryan

.chloggen/sapm-exporter-zstd.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: sapmexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: sapm exporter now supports `compression` config option to specify either gzip or zstd compression to use.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23257]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

.chloggen/sapm-receiver-zstd.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: sapmreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: sapm receiver now accepts requests in compressed with zstd.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23257]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

exporter/sapmexporter/README.md

@@ -48,6 +48,11 @@ during final translation.  Intended to be used in tandem with identical configur
 - `timeout` (default = 5s): Is the timeout for every attempt to send data to the backend.
 - `log_detailed_response` (default = `false`): Option to log detailed response from Splunk APM.
 In addition to setting this option to `true`, debug logging at the Collector level needs to be enabled.
+- `compression`: Compression method to use for outgoing SAPM requests. Can be one of
+  "gzip", "zstd" or be unspecified. If unspecified then "gzip" compression is used unless
+  `disable_compression` option is set to true.
+- `disable_compression` (default = `false`): If set to true the outgoing requests are not
+  compressed and `compression` option is ignored.
 
 In addition, this exporter offers queued retry which is enabled by default.
 Information about queued retry configuration parameters can be found

exporter/sapmexporter/config.go

@@ -5,6 +5,7 @@ package sapmexporter // import "github.com/open-telemetry/opentelemetry-collecto
 
 import (
 	"errors"
+	"fmt"
 	"net/url"
 
 	sapmclient "github.com/signalfx/sapm-proto/client"
@@ -35,9 +36,13 @@ type Config struct {
 	// MaxConnections is used to set a limit to the maximum idle HTTP connection the exporter can keep open.
 	MaxConnections uint `mapstructure:"max_connections"`
 
-	// Disable GZip compression.
+	// Disable compression. If set to true then Compression field is ignored.
 	DisableCompression bool `mapstructure:"disable_compression"`
 
+	// Compression method to use (gzip or zstd). Ignored if DisableCompression=true.
+	// If unspecified defaults to gzip.
+	Compression string `mapstructure:"compression"`
+
 	// Log detailed response from trace ingest.
 	LogDetailedResponse bool `mapstructure:"log_detailed_response"`
 
@@ -56,6 +61,17 @@ func (c *Config) Validate() error {
 	if err != nil {
 		return err
 	}
+
+	switch c.Compression {
+	// Valid compression methods.
+	case "", // no compression
+		string(sapmclient.CompressionMethodGzip),
+		string(sapmclient.CompressionMethodZstd):
+
+	default:
+		return fmt.Errorf("invalid compression %q", c.Compression)
+	}
+
 	return nil
 }
 
@@ -85,5 +101,9 @@ func (c *Config) clientOptions() []sapmclient.Option {
 		opts = append(opts, sapmclient.WithDisabledCompression())
 	}
 
+	if c.Compression != "" {
+		opts = append(opts, sapmclient.WithCompressionMethod(sapmclient.CompressionMethod(c.Compression)))
+	}
+
 	return opts
 }

exporter/sapmexporter/config_test.go

@@ -101,6 +101,12 @@ func TestInvalidConfig(t *testing.T) {
 	invalidURLErr := invalid.Validate()
 	require.Error(t, invalidURLErr)
 
+	invalid = Config{
+		Endpoint:    "http://localhost",
+		Compression: "nosuchcompression",
+	}
+	assert.Error(t, invalid.Validate())
+
 	invalid = Config{
 		Endpoint: "abcd1234",
 		QueueSettings: exporterhelper.QueueSettings{

exporter/sapmexporter/exporter_test.go

@@ -4,14 +4,18 @@
 package sapmexporter
 
 import (
+	"compress/gzip"
 	"context"
 	"crypto/rand"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	"github.com/jaegertracing/jaeger/model"
+	"github.com/klauspost/compress/zstd"
+	splunksapm "github.com/signalfx/sapm-proto/gen"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/exporter/exportertest"
@@ -210,3 +214,115 @@ func TestSAPMClientTokenUsageAndErrorMarshalling(t *testing.T) {
 		})
 	}
 }
+
+func decompress(body io.Reader, compression string) ([]byte, error) {
+	switch compression {
+	case "":
+		return io.ReadAll(body)
+	case "gzip":
+		reader, err := gzip.NewReader(body)
+		if err != nil {
+			return nil, err
+		}
+		return io.ReadAll(reader)
+	case "zstd":
+		reader, err := zstd.NewReader(body)
+		if err != nil {
+			return nil, err
+		}
+		return io.ReadAll(reader)
+	}
+	return nil, fmt.Errorf("unknown compression %q", compression)
+}
+
+func TestCompression(t *testing.T) {
+	tests := []struct {
+		name                     string
+		configDisableCompression bool
+		configCompression        string
+		receivedCompression      string
+	}{
+		{
+			name:                     "unspecified config",
+			configCompression:        "",
+			configDisableCompression: false,
+			receivedCompression:      "gzip",
+		},
+		{
+			name:                     "gzip",
+			configCompression:        "gzip",
+			configDisableCompression: false,
+			receivedCompression:      "gzip",
+		},
+		{
+			name:                     "zstd",
+			configCompression:        "zstd",
+			configDisableCompression: false,
+			receivedCompression:      "zstd",
+		},
+		{
+			name:                     "disable compression and unspecified method",
+			configDisableCompression: true,
+			configCompression:        "",
+			receivedCompression:      "",
+		},
+		{
+			name:                     "disable compression and specify gzip",
+			configDisableCompression: true,
+			configCompression:        "gzip",
+			receivedCompression:      "",
+		},
+		{
+			name:                     "disable compression and specify zstd",
+			configDisableCompression: true,
+			configCompression:        "zstd",
+			receivedCompression:      "",
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(
+			tt.name, func(t *testing.T) {
+				tracesReceived := false
+				server := httptest.NewServer(
+					http.HandlerFunc(
+						func(w http.ResponseWriter, r *http.Request) {
+							compression := r.Header.Get("Content-Encoding")
+							assert.EqualValues(t, compression, tt.receivedCompression)
+
+							payload, err := decompress(r.Body, compression)
+							require.NoError(t, err)
+
+							var sapm splunksapm.PostSpansRequest
+							err = sapm.Unmarshal(payload)
+							require.NoError(t, err)
+
+							w.WriteHeader(200)
+							tracesReceived = true
+						},
+					),
+				)
+				defer func() {
+					assert.True(t, tracesReceived, "Test server never received traces.")
+				}()
+				defer server.Close()
+
+				cfg := &Config{
+					Endpoint:           server.URL,
+					DisableCompression: tt.configDisableCompression,
+					Compression:        tt.configCompression,
+				}
+				params := exportertest.NewNopCreateSettings()
+
+				se, err := newSAPMExporter(cfg, params)
+				assert.Nil(t, err)
+				assert.NotNil(t, se, "failed to create trace exporter")
+
+				trace, testTraceErr := buildTestTrace()
+				require.NoError(t, testTraceErr)
+				err = se.pushTraceData(context.Background(), trace)
+				require.NoError(t, err)
+			},
+		)
+	}
+}

exporter/sapmexporter/go.mod

@@ -5,6 +5,7 @@ go 1.19
 require (
 	github.com/cenkalti/backoff/v4 v4.2.1
 	github.com/jaegertracing/jaeger v1.41.0
+	github.com/klauspost/compress v1.16.5
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/splunk v0.79.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/batchperresourceattr v0.79.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/jaeger v0.79.0

receiver/sapmreceiver/go.mod

@@ -5,6 +5,7 @@ go 1.19
 require (
 	github.com/gorilla/mux v1.8.0
 	github.com/jaegertracing/jaeger v1.41.0
+	github.com/klauspost/compress v1.16.5
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/common v0.79.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/splunk v0.79.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/translator/jaeger v0.79.0
@@ -31,7 +32,6 @@ require (
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/klauspost/compress v1.16.5 // indirect
 	github.com/knadh/koanf v1.5.0 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect