fixup: handle err and lint

Signed-off-by: Todd Baert <todd.baert@dynatrace.com>

Author: toddbaert

core/pkg/telemetry/builder.go

@@ -147,7 +147,11 @@ func buildTransportCredentials(_ context.Context, cfg CollectorConfig) (credenti
 			RootCAs:    capool,
 			MinVersion: tls.VersionTLS13,
 			GetCertificate: func(chi *tls.ClientHelloInfo) (*tls.Certificate, error) {
-				return reloader.GetCertificate()
+				certs, err := reloader.GetCertificate()
+				if err != nil {
+					return nil, fmt.Errorf("failed to reload certs: %w", err)
+				}
+				return certs, nil
 			},
 		}
 

flagd/cmd/start.go

@@ -75,7 +75,8 @@ func init() {
 	flags.StringP(otelCertPathFlagName, "D", "", "tls certificate path to use with OpenTelemetry collector")
 	flags.StringP(otelKeyPathFlagName, "K", "", "tls key path to use with OpenTelemetry collector")
 	flags.StringP(otelCAPathFlagName, "A", "", "tls certificate authority path to use with OpenTelemetry collector")
-	flags.DurationP(otelReloadIntervalFlagName, "I", time.Hour, "how long between reloading the otel tls certificate from disk")
+	flags.DurationP(otelReloadIntervalFlagName, "I", time.Hour, "how long between reloading the otel tls certificate"+
+		"from disk")
 
 	_ = viper.BindPFlag(corsFlagName, flags.Lookup(corsFlagName))
 	_ = viper.BindPFlag(logFormatFlagName, flags.Lookup(logFormatFlagName))

flagd/pkg/certreloader/certreloader.go

@@ -13,15 +13,15 @@ type Config struct {
 	ReloadInterval time.Duration
 }
 
-type certReloader struct {
+type CertReloader struct {
 	cert       *tls.Certificate
 	mu         sync.RWMutex
 	nextReload time.Time
 	Config
 }
 
-func NewCertReloader(config Config) (*certReloader, error) {
-	reloader := certReloader{
+func NewCertReloader(config Config) (*CertReloader, error) {
+	reloader := CertReloader{
 		Config: config,
 	}
 
@@ -36,7 +36,7 @@ func NewCertReloader(config Config) (*certReloader, error) {
 	return &reloader, nil
 }
 
-func (r *certReloader) GetCertificate() (*tls.Certificate, error) {
+func (r *CertReloader) GetCertificate() (*tls.Certificate, error) {
 	now := time.Now()
 	// Read locking here before we do the time comparison
 	// If a reload is in progress this will block and we will skip reloading in the current
@@ -59,8 +59,8 @@ func (r *certReloader) GetCertificate() (*tls.Certificate, error) {
 	return r.cert, nil
 }
 
-func (c *certReloader) loadCertificate() (tls.Certificate, error) {
-	newCert, err := tls.LoadX509KeyPair(c.CertPath, c.KeyPath)
+func (r *CertReloader) loadCertificate() (tls.Certificate, error) {
+	newCert, err := tls.LoadX509KeyPair(r.CertPath, r.KeyPath)
 	if err != nil {
 		return tls.Certificate{}, fmt.Errorf("failed to load key pair: %w", err)
 	}

flagd/pkg/certreloader/certreloader_test.go

@@ -186,16 +186,22 @@ func generateValidCertificate(t *testing.T) (*bytes.Buffer, *bytes.Buffer) {
 
 	// pem encode
 	caPEM := new(bytes.Buffer)
-	pem.Encode(caPEM, &pem.Block{
+	err = pem.Encode(caPEM, &pem.Block{
 		Type:  "CERTIFICATE",
 		Bytes: caBytes,
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	caPrivKeyPEM := new(bytes.Buffer)
-	pem.Encode(caPrivKeyPEM, &pem.Block{
+	err = pem.Encode(caPrivKeyPEM, &pem.Block{
 		Type:  "RSA PRIVATE KEY",
 		Bytes: x509.MarshalPKCS1PrivateKey(caPrivKey),
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// set up our server certificate
 	cert := &x509.Certificate{
@@ -228,16 +234,22 @@ func generateValidCertificate(t *testing.T) (*bytes.Buffer, *bytes.Buffer) {
 	}
 
 	certPEM := new(bytes.Buffer)
-	pem.Encode(certPEM, &pem.Block{
+	err = pem.Encode(certPEM, &pem.Block{
 		Type:  "CERTIFICATE",
 		Bytes: certBytes,
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	certPrivKeyPEM := new(bytes.Buffer)
-	pem.Encode(certPrivKeyPEM, &pem.Block{
+	err = pem.Encode(certPrivKeyPEM, &pem.Block{
 		Type:  "RSA PRIVATE KEY",
 		Bytes: x509.MarshalPKCS1PrivateKey(certPrivKey),
 	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	return certPEM, certPrivKeyPEM
 }
@@ -272,15 +284,20 @@ func generateValidCertificateFiles(t *testing.T) (string, string, func()) {
 func copyFile(src, dst string) error {
 	data, err := os.ReadFile(src)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to load key pair: %w", err)
 	}
 
-	return os.WriteFile(dst, data, 0o777)
+	err = os.WriteFile(dst, data, 0o0600)
+	if err != nil {
+		return fmt.Errorf("failed to load key pair: %w", err)
+	}
+	return nil
 }
 
 func randString(n int) string {
 	const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
 	bytes := make([]byte, n)
+	//nolint:errcheck
 	rand.Read(bytes)
 	for i, b := range bytes {
 		bytes[i] = alphanum[b%byte(len(alphanum))]