fix(internal/telemetry): run TestNoEmptyHeaders only when we are runn…

…ing in the right environment

ddtrace/tracer/transport_test.go

@@ -396,3 +396,30 @@ func TestWithUDS(t *testing.T) {
 	assert.Len(rt.reqs, 1)
 	assert.Equal(hits, 2)
 }
+
+func TestExternalEnvironment(t *testing.T) {
+	t.Setenv("DD_EXTERNAL_ENV", "it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759")
+	assert := assert.New(t)
+	found := false
+	srv := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, r *http.Request) {
+		extEnv := r.Header.Get("Datadog-External-Env")
+		if extEnv == "" {
+			return
+		}
+		assert.Equal("it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759", extEnv)
+		found = true
+	}))
+	defer srv.Close()
+
+	u, err := url.Parse(srv.URL)
+	assert.NoError(err)
+	c := &http.Client{}
+	trc := newTracer(WithAgentTimeout(2), WithAgentAddr(u.Host), WithHTTPClient(c))
+	defer trc.Stop()
+
+	p, err := encode(getTestTrace(1, 1))
+	assert.NoError(err)
+	_, err = trc.config.transport.send(p)
+	assert.NoError(err)
+	assert.True(found)
+}

internal/env.go

@@ -134,6 +134,7 @@ func BoolVal(val string, def bool) bool {
 	return v
 }
 
+// ExternalEnvironment returns the value of the DD_EXTERNAL_ENV environment variable.
 func ExternalEnvironment() string {
 	return os.Getenv("DD_EXTERNAL_ENV")
 }

internal/telemetry/client_test.go

@@ -11,13 +11,15 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"runtime"
 	"sort"
 	"sync"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 
+	"gopkg.in/DataDog/dd-trace-go.v1/internal"
 	logging "gopkg.in/DataDog/dd-trace-go.v1/internal/log"
 )
 
@@ -439,11 +441,18 @@ func Test_heartbeatInterval(t *testing.T) {
 }
 
 func TestNoEmptyHeaders(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip("skipping test on non-linux OS")
+	}
+	if internal.EntityID() == "" || internal.ContainerID() == "" {
+		t.Skip("skipping test when entity ID and container ID are not available")
+	}
 	c := &client{}
 	req := c.newRequest(RequestTypeAppStarted)
 	assertNotEmpty := func(header string) {
 		headers := *req.Header
 		vals := headers[header]
+		assert.Greater(t, len(vals), 0, "header %s should not be empty", header)
 		for _, v := range vals {
 			assert.NotEmpty(t, v, "%s header should not be empty", header)
 		}