New format for custom HTTP headers (#147)

A new format for passing custom HTTP headers using the same syntax as used by InfluxDB output in k6 core.

Author: codebien

pkg/remotewrite/config.go

@@ -180,7 +180,9 @@ func GetConsolidatedConfig(jsonRawConf json.RawMessage, env map[string]string, _
 }
 
 func parseEnvs(env map[string]string) (Config, error) {
-var c Config
+c := Config{
+Headers: make(map[string]string),
+}
 
 getEnvBool := func(env map[string]string, name string) (null.Bool, error) {
 if v, vDefined := env[name]; vDefined {
@@ -231,12 +233,19 @@ func parseEnvs(env map[string]string) (Config, error) {
 
 envHeaders := getEnvMap(env, "K6_PROMETHEUS_RW_HEADERS_")
 for k, v := range envHeaders {
-if c.Headers == nil {
-c.Headers = make(map[string]string)
-}
 c.Headers[k] = v
 }
 
+if headers, headersDefined := env["K6_PROMETHEUS_RW_HTTP_HEADERS"]; headersDefined {
+for _, kvPair := range strings.Split(headers, ",") {
+header := strings.Split(kvPair, ":")
+if len(header) != 2 {
+return c, fmt.Errorf("the provided header (%s) does not respect the expected format <header key>:<value>", kvPair)
+}
+c.Headers[header[0]] = header[1]
+}
+}
+
 if b, err := getEnvBool(env, "K6_PROMETHEUS_RW_TREND_AS_NATIVE_HISTOGRAM"); err != nil {
 return c, err
 } else if b.Valid {

pkg/remotewrite/config_test.go

@@ -255,8 +255,15 @@ func TestOptionHeaders(t *testing.T) {
 env map[string]string
 jsonRaw json.RawMessage
 }{
-"JSON": {jsonRaw: json.RawMessage(`{"headers":{"X-MY-HEADER1":"hval1","X-MY-HEADER2":"hval2"}}`)},
-"Env": {env: map[string]string{"K6_PROMETHEUS_RW_HEADERS_X-MY-HEADER1": "hval1", "K6_PROMETHEUS_RW_HEADERS_X-MY-HEADER2": "hval2"}},
+"JSON": {jsonRaw: json.RawMessage(
+`{"headers":{"X-MY-HEADER1":"hval1","X-MY-HEADER2":"hval2","X-Scope-OrgID":"my-org-id","another-header":"true","empty":""}}`)},
+"Env": {env: map[string]string{
+"K6_PROMETHEUS_RW_HEADERS_X-MY-HEADER1": "hval1",
+"K6_PROMETHEUS_RW_HEADERS_X-MY-HEADER2": "hval2",
+// it assert that the new method using HTTP_HEADERS overwrites it
+"K6_PROMETHEUS_RW_HEADERS_X-Scope-OrgID": "my-org-id-old-method",
+"K6_PROMETHEUS_RW_HTTP_HEADERS": "X-Scope-OrgID:my-org-id,another-header:true,empty:",
+}},
 //nolint:gocritic
 //"Arg": {arg: "headers.X-MY-HEADER1=hval1,headers.X-MY-HEADER2=hval2"},
 }
@@ -266,8 +273,11 @@ func TestOptionHeaders(t *testing.T) {
 InsecureSkipTLSVerify: null.BoolFrom(false),
 PushInterval: types.NullDurationFrom(5 * time.Second),
 Headers: map[string]string{
-"X-MY-HEADER1": "hval1",
-"X-MY-HEADER2": "hval2",
+"X-MY-HEADER1": "hval1",
+"X-MY-HEADER2": "hval2",
+"X-Scope-OrgID": "my-org-id",
+"another-header": "true",
+"empty": "",
 },
 TrendStats: []string{"p(99)"},
 StaleMarkers: null.BoolFrom(false),