[usm] service discovery, fetch only target environment variables from /proc

pkg/collector/corechecks/servicediscovery/apm/detect.go

@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/servicediscovery/language"
+	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/servicediscovery/targetenvs"
 	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/servicediscovery/usm"
 	"github.com/DataDog/datadog-agent/pkg/network/go/bininspect"
 	"github.com/DataDog/datadog-agent/pkg/util/kernel"
@@ -37,6 +38,21 @@ const (
 	Injected Instrumentation = "injected"
 )
 
+const (
+	// ddTraceGoPrefix is the prefix of the dd-trace-go symbols. The symbols we
+	// are looking for are for example
+	// "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer.init". We use a prefix
+	// without the version number instead of a specific symbol name in an
+	// attempt to make it future-proof.
+	ddTraceGoPrefix = "gopkg.in/DataDog/dd-trace-go"
+	// ddTraceGoMaxLength is the maximum length of the dd-trace-go symbols which
+	// we look for. The max length is an optimization in bininspect to avoid
+	// reading unnecesssary symbols.  As of writing, most non-internal symbols
+	// in dd-trace-go are under 100 chars. The tracer.init example above at 51
+	// chars is one of the shortest.
+	ddTraceGoMaxLength = 100
+)
+
 type detector func(pid int, args []string, envs map[string]string, contextMap usm.DetectorContextMap) Instrumentation
 
 var (
@@ -51,36 +67,12 @@ var (
 	nodeAPMCheckRegex = regexp.MustCompile(`"dd-trace"`)
 )
 
-// JavaDetectorEnvs list of environment variables used for Java detection
-var JavaDetectorEnvs = []string{
-	// These are the environment variables that are used to pass options to the JVM
-	"JAVA_TOOL_OPTIONS",
-	"_JAVA_OPTIONS",
-	"JDK_JAVA_OPTIONS",
-	// I'm pretty sure these won't be necessary, as they should be parsed before the JVM sees them
-	// but there's no harm in including them
-	"JAVA_OPTIONS",
-	"CATALINA_OPTS",
-	"JDPA_OPTS",
-}
-
-const (
-	// EnvCoreClrEnableProfiling - environment variable specific to .net application
-	EnvCoreClrEnableProfiling = "CORECLR_ENABLE_PROFILING"
-)
-
-// DotNetDetectorEnvs list of environment variables used for .net detection
-var DotNetDetectorEnvs = []string{
-	EnvCoreClrEnableProfiling,
-}
-
 // Detect attempts to detect the type of APM instrumentation for the given service.
 func Detect(pid int, args []string, envs map[string]string, lang language.Language, contextMap usm.DetectorContextMap) Instrumentation {
 	// first check to see if the DD_INJECTION_ENABLED is set to tracer
-	if isInjected(envs) {
+	if targetenvs.TracerInjectionEnabled(envs) {
 		return Injected
 	}
-
 	// different detection for provided instrumentation for each
 	if detect, ok := detectorMap[lang]; ok {
 		return detect(pid, args, envs, contextMap)
@@ -89,36 +81,9 @@ func Detect(pid int, args []string, envs map[string]string, lang language.Langua
 	return None
 }
 
-func isInjected(envs map[string]string) bool {
-	if val, ok := envs["DD_INJECTION_ENABLED"]; ok {
-		parts := strings.Split(val, ",")
-		for _, v := range parts {
-			if v == "tracer" {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-const (
-	// ddTraceGoPrefix is the prefix of the dd-trace-go symbols. The symbols we
-	// are looking for are for example
-	// "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer.init". We use a prefix
-	// without the version number instead of a specific symbol name in an
-	// attempt to make it future-proof.
-	ddTraceGoPrefix = "gopkg.in/DataDog/dd-trace-go"
-	// ddTraceGoMaxLength is the maximum length of the dd-trace-go symbols which
-	// we look for. The max length is an optimization in bininspect to avoid
-	// reading unnecesssary symbols.  As of writing, most non-internal symbols
-	// in dd-trace-go are under 100 chars. The tracer.init example above at 51
-	// chars is one of the shortest.
-	ddTraceGoMaxLength = 100
-)
-
 // goDetector detects APM instrumentation for Go binaries by checking for
 // the presence of the dd-trace-go symbols in the ELF. This only works for
-// unstripped binaries.
+// non stripped binaries.
 func goDetector(pid int, _ []string, _ map[string]string, _ usm.DetectorContextMap) Instrumentation {
 	exePath := kernel.HostProc(strconv.Itoa(pid), "exe")
 
@@ -240,13 +205,10 @@ func javaDetector(_ int, args []string, envs map[string]string, _ usm.DetectorCo
 		}
 	}
 	// also don't instrument if the javaagent is there in the environment variable JAVA_TOOL_OPTIONS and friends
-	for _, name := range JavaDetectorEnvs {
-		if val, ok := envs[name]; ok {
-			if strings.Contains(val, "-javaagent:") && strings.Contains(val, "dd-java-agent.jar") {
-				return Provided
-			}
-		}
+	if targetenvs.FindJava(envs) {
+		return Provided
 	}
+
 	return None
 }
 
@@ -278,10 +240,8 @@ func dotNetDetectorFromMapsReader(reader io.Reader) Instrumentation {
 //
 // 785c8a400000-785c8aaeb000 r--s 00000000 fc:06 12762267 /home/foo/.../publish/Datadog.Trace.dll
 func dotNetDetector(pid int, _ []string, envs map[string]string, _ usm.DetectorContextMap) Instrumentation {
-	for _, name := range DotNetDetectorEnvs {
-		if val, ok := envs[name]; ok && val == "1" {
-			return Provided
-		}
+	if targetenvs.DotNetEnabled(envs) {
+		return Provided
 	}
 
 	mapsPath := kernel.HostProc(strconv.Itoa(pid), "maps")

pkg/collector/corechecks/servicediscovery/apm/detect_nix_test.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/servicediscovery/targetenvs"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -31,21 +32,21 @@ func TestInjected(t *testing.T) {
 		{
 			name: "injected",
 			envs: map[string]string{
-				"DD_INJECTION_ENABLED": "tracer",
+				targetenvs.EnvInjectionEnabled: "tracer",
 			},
 			result: true,
 		},
 		{
 			name: "one of injected",
 			envs: map[string]string{
-				"DD_INJECTION_ENABLED": "service_name,tracer",
+				targetenvs.EnvInjectionEnabled: "service_name,tracer",
 			},
 			result: true,
 		},
 		{
 			name: "not injected but with env variable",
 			envs: map[string]string{
-				"DD_INJECTION_ENABLED": "service_name",
+				targetenvs.EnvInjectionEnabled: "service_name",
 			},
 		},
 		{
@@ -54,7 +55,7 @@ func TestInjected(t *testing.T) {
 	}
 	for _, d := range data {
 		t.Run(d.name, func(t *testing.T) {
-			result := isInjected(d.envs)
+			result := targetenvs.TracerInjectionEnabled(d.envs)
 			assert.Equal(t, d.result, result)
 		})
 	}
@@ -86,7 +87,7 @@ func Test_javaDetector(t *testing.T) {
 			name: "CATALINA_OPTS",
 			args: []string{"java"},
 			envs: map[string]string{
-				"CATALINA_OPTS": "-javaagent:dd-java-agent.jar",
+				targetenvs.EnvJavaDetectorCatalinaOpts: "-javaagent:dd-java-agent.jar",
 			},
 			result: Provided,
 		},
@@ -176,7 +177,7 @@ func Test_pythonDetector(t *testing.T) {
 func TestDotNetDetector(t *testing.T) {
 	for _, test := range []struct {
 		name   string
-		env    map[string]string
+		envs   map[string]string
 		maps   string
 		result Instrumentation
 	}{
@@ -186,15 +187,15 @@ func TestDotNetDetector(t *testing.T) {
 		},
 		{
 			name: "profiling disabled",
-			env: map[string]string{
-				"CORECLR_ENABLE_PROFILING": "0",
+			envs: map[string]string{
+				targetenvs.EnvDotNetDetector: "0",
 			},
 			result: None,
 		},
 		{
 			name: "profiling enabled",
-			env: map[string]string{
-				"CORECLR_ENABLE_PROFILING": "1",
+			envs: map[string]string{
+				targetenvs.EnvDotNetDetector: "1",
 			},
 			result: Provided,
 		},
@@ -218,8 +219,8 @@ func TestDotNetDetector(t *testing.T) {
 		},
 		{
 			name: "in maps, env misleading",
-			env: map[string]string{
-				"CORECLR_ENABLE_PROFILING": "0",
+			envs: map[string]string{
+				targetenvs.EnvDotNetDetector: "0",
 			},
 			maps: `
 785c8a400000-785c8aaeb000 r--s 00000000 fc:06 12762267                   /home/foo/hello/bin/release/net8.0/linux-x64/publish/Datadog.Trace.dll
@@ -230,7 +231,7 @@ func TestDotNetDetector(t *testing.T) {
 		t.Run(test.name, func(t *testing.T) {
 			var result Instrumentation
 			if test.maps == "" {
-				result = dotNetDetector(0, nil, test.env, nil)
+				result = dotNetDetector(0, nil, test.envs, nil)
 			} else {
 				result = dotNetDetectorFromMapsReader(strings.NewReader(test.maps))
 			}

pkg/collector/corechecks/servicediscovery/impl_linux_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/DataDog/datadog-agent/pkg/collector/corechecks/servicediscovery/targetenvs"
 	"github.com/golang/mock/gomock"
 	gocmp "github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
@@ -165,7 +166,7 @@ func cmpEvents(a, b *event) bool {
 func Test_linuxImpl(t *testing.T) {
 	host := "test-host"
 	cfgYaml := `ignore_processes: ["ignore-1", "ignore-2"]`
-	t.Setenv("DD_DISCOVERY_ENABLED", "true")
+	t.Setenv(targetenvs.EnvDiscoveryEnabled, "true")
 
 	type checkRun struct {
 		servicesResp *model.ServicesResponse