Added validation to avoid partial configuration for sigv4

pkg/remotewrite/config.go

@@ -3,6 +3,7 @@ package remotewrite
 import (
 	"crypto/tls"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"github.com/grafana/xk6-output-prometheus-remote/pkg/sigv4"
 	"net/http"
@@ -123,6 +124,14 @@ func (conf Config) RemoteConfig() (*remote.HTTPConfig, error) {
 		hc.TLSConfig.Certificates = []tls.Certificate{cert}
 	}
 
+	if isSigV4PartiallyConfigured(conf.SigV4Region, conf.SigV4AccessKey, conf.SigV4SecretKey) {
+		return nil, errors.New(
+			"sigv4 seems to be partially configured. All of " +
+				"K6_PROMETHEUS_RW_SIGV4_REGION, K6_PROMETHEUS_RW_SIGV4_ACCESS_KEY, K6_PROMETHEUS_RW_SIGV4_SECRET_KEY " +
+				"must all be set. Unset all to bypass sigv4",
+		)
+	}
+
 	if conf.SigV4Region.Valid && conf.SigV4AccessKey.Valid && conf.SigV4SecretKey.Valid {
 		hc.SigV4 = &sigv4.Config{
 			Region:             conf.SigV4Region.String,
@@ -429,3 +438,12 @@ func parseArg(text string) (Config, error) {
 
 	return c, nil
 }
+
+func isSigV4PartiallyConfigured(region, accessKey, secretKey null.String) bool {
+	hasRegion := region.Valid && len(strings.TrimSpace(region.String)) != 0
+	hasAccessID := accessKey.Valid && len(strings.TrimSpace(accessKey.String)) != 0
+	hasSecretAccessKey := secretKey.Valid && len(strings.TrimSpace(secretKey.String)) != 0
+	// either they are all set, or all not set. False if partial
+	isComplete := (hasRegion && hasAccessID && hasSecretAccessKey) || (!hasRegion && !hasAccessID && !hasSecretAccessKey)
+	return !isComplete
+}

pkg/sigv4/tripper.go

@@ -14,31 +14,32 @@ type Tripper struct {
 
 type Config struct {
 	Region             string
-	AwsSecretAccessKey string
 	AwsAccessKeyID     string
+	AwsSecretAccessKey string
 }
 
-func NewRoundTripper(config *Config, next http.RoundTripper) (*Tripper, error) {
-	if config == nil {
-		return nil, errors.New("can't initialize a sigv4 round tripper with nil config")
-	}
-
-	if len(strings.TrimSpace(config.Region)) == 0 {
-		return nil, errors.New("sigV4 config `Region` must be set")
+func (c *Config) validate() error {
+	if c == nil {
+		return errors.New("config should not be nil")
 	}
-
-	if len(strings.TrimSpace(config.AwsSecretAccessKey)) == 0 {
-		return nil, errors.New("sigV4 config `AwsSecretAccessKey` must be set")
+	hasRegion := len(strings.TrimSpace(c.Region)) != 0
+	hasAccessID := len(strings.TrimSpace(c.AwsAccessKeyID)) != 0
+	hasSecretAccessKey := len(strings.TrimSpace(c.AwsSecretAccessKey)) != 0
+	if !hasRegion || !hasAccessID || !hasSecretAccessKey {
+		return errors.New("sigV4 config `Region`, `AwsAccessKeyID`, `AwsSecretAccessKey` must all be set")
 	}
+	return nil
+}
 
-	if len(strings.TrimSpace(config.AwsAccessKeyID)) == 0 {
-		return nil, errors.New("sigV4 config `AwsAccessKeyID` must be set")
+func NewRoundTripper(config *Config, next http.RoundTripper) (*Tripper, error) {
+	if err := config.validate(); err != nil {
+		return nil, err
 	}
 
 	if next == nil {
 		next = http.DefaultTransport
 	}
-	
+
 	tripper := &Tripper{
 		config: config,
 		next:   next,

pkg/sigv4/tripper_test.go

@@ -43,3 +43,52 @@ func TestTripper_request_includes_required_headers(t *testing.T) {
 
 	client.Do(req)
 }
+
+func TestConfig_Validation(t *testing.T) {
+	testCases := []struct {
+		shouldError bool
+		arg         *Config
+	}{
+		{
+			shouldError: false,
+			arg: &Config{
+				Region:             "us-east1",
+				AwsAccessKeyID:     "someAccessKey",
+				AwsSecretAccessKey: "someSecretKey",
+			},
+		},
+		{
+			shouldError: true,
+			arg:         nil,
+		},
+		{
+			shouldError: true,
+			arg: &Config{
+				Region: "us-east1",
+			},
+		},
+		{
+			shouldError: true,
+			arg: &Config{
+				Region:         "us-east1",
+				AwsAccessKeyID: "someAccessKeyId",
+			},
+		},
+		{
+			shouldError: true,
+			arg: &Config{
+				AwsAccessKeyID:     "SomeAccessKey",
+				AwsSecretAccessKey: "SomeSecretKey",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		got := tc.arg.validate()
+		if tc.shouldError {
+			assert.Error(t, got)
+			continue
+		}
+		assert.NoError(t, got)
+	}
+}