feat(config): add HTTP basic auth for metrics

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/config/metrics.go

@@ -12,6 +12,7 @@ import (
 var (
 	ErrInvalidMetricsConfig          = errors.New("config: invalid metrics configuration")
 	ErrInvalidMetricsTLSConfig       = errors.New("config: invalid metrics TLS configuration")
+	ErrInvalidMetricsBasicAuthConfig = errors.New("config: invalid metrics basic auth configuration")
 	ErrNoMetricsBind                 = errors.New("config.Metrics: must define bind")
 	ErrNoMetricsNetwork              = errors.New("config.Metrics: must define network")
 	ErrNoMetricsSocketMode           = errors.New("config.Metrics: must define socket mode when using unix sockets")
@@ -22,6 +23,8 @@ var (
 	ErrInvalidMetricsTLSKeypair      = errors.New("config.Metrics.TLS: keypair is invalid")
 	ErrInvalidMetricsCACertificate   = errors.New("config.Metrics.TLS: invalid CA certificate")
 	ErrCantReadFile                  = errors.New("config: can't read required file")
+	ErrNoMetricsBasicAuthUsername    = errors.New("config.Metrics.BasicAuth: must define username")
+	ErrNoMetricsBasicAuthPassword    = errors.New("config.Metrics.BasicAuth: must define password")
 )
 
 type Metrics struct {
@@ -29,6 +32,7 @@ type Metrics struct {
 	Network    string            `json:"network" yaml:"network"`
 	SocketMode string            `json:"socketMode" yaml:"socketMode"`
 	TLS        *MetricsTLS       `json:"tls" yaml:"tls"`
+	BasicAuth  *MetricsBasicAuth `json:"basicAuth" yaml:"basicAuth"`
 }
 
 func (m *Metrics) Valid() error {
@@ -62,6 +66,12 @@ func (m *Metrics) Valid() error {
 		}
 	}
 
+	if m.BasicAuth != nil {
+		if err := m.BasicAuth.Valid(); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
 	if len(errs) != 0 {
 		return errors.Join(ErrInvalidMetricsConfig, errors.Join(errs...))
 	}
@@ -131,3 +141,26 @@ func canReadFile(fname string) error {
 
 	return nil
 }
+
+type MetricsBasicAuth struct {
+	Username string `json:"username" yaml:"username"`
+	Password string `json:"password" yaml:"password"`
+}
+
+func (mba *MetricsBasicAuth) Valid() error {
+	var errs []error
+
+	if mba.Username == "" {
+		errs = append(errs, ErrNoMetricsBasicAuthUsername)
+	}
+
+	if mba.Password == "" {
+		errs = append(errs, ErrNoMetricsBasicAuthPassword)
+	}
+
+	if len(errs) != 0 {
+		return errors.Join(ErrInvalidMetricsBasicAuthConfig, errors.Join(errs...))
+	}
+
+	return nil
+}

lib/config/metrics_test.go

@@ -157,6 +157,79 @@ func TestMetricsValid(t *testing.T) {
 			},
 			err: ErrInvalidMetricsCACertificate,
 		},
+		{
+			name: "basic auth credentials set",
+			input: &Metrics{
+				Bind:    ":9090",
+				Network: "tcp",
+				BasicAuth: &MetricsBasicAuth{
+					Username: "admin",
+					Password: "hunter2",
+				},
+			},
+		},
+		{
+			name: "invalid basic auth config",
+			input: &Metrics{
+				Bind:      ":9090",
+				Network:   "tcp",
+				BasicAuth: &MetricsBasicAuth{},
+			},
+			err: ErrInvalidMetricsBasicAuthConfig,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.input.Valid(); !errors.Is(err, tt.err) {
+				t.Logf("wanted error: %v", tt.err)
+				t.Logf("got error:    %v", err)
+				t.Error("validation failed")
+			}
+		})
+	}
+}
+
+func TestMetricsBasicAuthValid(t *testing.T) {
+	for _, tt := range []struct {
+		name  string
+		input *MetricsBasicAuth
+		err   error
+	}{
+		{
+			name: "both set",
+			input: &MetricsBasicAuth{
+				Username: "admin",
+				Password: "hunter2",
+			},
+		},
+		{
+			name:  "empty username and password",
+			input: &MetricsBasicAuth{},
+			err:   ErrInvalidMetricsBasicAuthConfig,
+		},
+		{
+			name: "missing username",
+			input: &MetricsBasicAuth{
+				Password: "hunter2",
+			},
+			err: ErrNoMetricsBasicAuthUsername,
+		},
+		{
+			name: "missing password",
+			input: &MetricsBasicAuth{
+				Username: "admin",
+			},
+			err: ErrNoMetricsBasicAuthPassword,
+		},
+		{
+			name:  "missing both surfaces wrapper error",
+			input: &MetricsBasicAuth{},
+			err:   ErrNoMetricsBasicAuthUsername,
+		},
+		{
+			name:  "missing both surfaces password error",
+			input: &MetricsBasicAuth{},
+			err:   ErrNoMetricsBasicAuthPassword,
+		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
 			if err := tt.input.Valid(); !errors.Is(err, tt.err) {