fix golint issues in zrpc (#531)

zrpc/internal/auth/auth.go

@@ -13,6 +13,7 @@ import (
 
 const defaultExpiration = 5 * time.Minute
 
+// An Authenticator is used to authenticate the rpc requests.
 type Authenticator struct {
 	store  *redis.Redis
 	key    string
@@ -20,6 +21,7 @@ type Authenticator struct {
 	strict bool
 }
 
+// NewAuthenticator returns an Authenticator.
 func NewAuthenticator(store *redis.Redis, key string, strict bool) (*Authenticator, error) {
 	cache, err := collection.NewCache(defaultExpiration)
 	if err != nil {
@@ -34,6 +36,7 @@ func NewAuthenticator(store *redis.Redis, key string, strict bool) (*Authenticat
 	}, nil
 }
 
+// Authenticate authenticates the given ctx.
 func (a *Authenticator) Authenticate(ctx context.Context) error {
 	md, ok := metadata.FromIncomingContext(ctx)
 	if !ok {

zrpc/internal/auth/credential.go

@@ -6,11 +6,13 @@ import (
 	"google.golang.org/grpc/metadata"
 )
 
+// A Credential is used to authenticate.
 type Credential struct {
 	App   string
 	Token string
 }
 
+// GetRequestMetadata gets the request metadata.
 func (c *Credential) GetRequestMetadata(context.Context, ...string) (map[string]string, error) {
 	return map[string]string{
 		appKey:   c.App,
@@ -18,10 +20,12 @@ func (c *Credential) GetRequestMetadata(context.Context, ...string) (map[string]
 	}, nil
 }
 
+// RequireTransportSecurity always returns false.
 func (c *Credential) RequireTransportSecurity() bool {
 	return false
 }
 
+// ParseCredential parses credential from given ctx.
 func ParseCredential(ctx context.Context) Credential {
 	var credential Credential