server: organize error types (#9465)

Co-authored-by: Bruce MacDonald <brucewmacdonald@gmail.com>

server/download.go

@@ -29,8 +29,9 @@ import (
 const maxRetries = 6
 
 var (
-	errMaxRetriesExceeded = errors.New("max retries exceeded")
-	errPartStalled        = errors.New("part stalled")
+	errMaxRetriesExceeded   = errors.New("max retries exceeded")
+	errPartStalled          = errors.New("part stalled")
+	errMaxRedirectsExceeded = errors.New("maximum redirects exceeded (10) for directURL")
 )
 
 var blobDownloadManager sync.Map
@@ -236,7 +237,7 @@ func (b *blobDownload) run(ctx context.Context, requestURL *url.URL, opts *regis
 
 			newOpts.CheckRedirect = func(req *http.Request, via []*http.Request) error {
 				if len(via) > 10 {
-					return errors.New("maximum redirects exceeded (10) for directURL")
+					return errMaxRedirectsExceeded
 				}
 
 				// if the hostname is the same, allow the redirect

server/images.go

@@ -35,6 +35,7 @@ var (
 	errCapabilityCompletion = errors.New("completion")
 	errCapabilityTools      = errors.New("tools")
 	errCapabilityInsert     = errors.New("insert")
+	errInsecureProtocol     = errors.New("insecure protocol http")
 )
 
 type Capability string
@@ -479,7 +480,7 @@ func PushModel(ctx context.Context, name string, regOpts *registryOptions, fn fu
 	fn(api.ProgressResponse{Status: "retrieving manifest"})
 
 	if mp.ProtocolScheme == "http" && !regOpts.Insecure {
-		return errors.New("insecure protocol http")
+		return errInsecureProtocol
 	}
 
 	manifest, _, err := GetManifest(mp)
@@ -543,7 +544,7 @@ func PullModel(ctx context.Context, name string, regOpts *registryOptions, fn fu
 	}
 
 	if mp.ProtocolScheme == "http" && !regOpts.Insecure {
-		return errors.New("insecure protocol http")
+		return errInsecureProtocol
 	}
 
 	fn(api.ProgressResponse{Status: "pulling manifest"})

server/modelpath.go

@@ -31,9 +31,10 @@ const (
 
 var (
 	ErrInvalidImageFormat  = errors.New("invalid image format")
+	ErrInvalidDigestFormat = errors.New("invalid digest format")
 	ErrInvalidProtocol     = errors.New("invalid protocol scheme")
 	ErrInsecureProtocol    = errors.New("insecure protocol http")
-	ErrInvalidDigestFormat = errors.New("invalid digest format")
+	ErrModelPathInvalid    = errors.New("invalid model path")
 )
 
 func ParseModelPath(name string) ModelPath {
@@ -73,8 +74,6 @@ func ParseModelPath(name string) ModelPath {
 	return mp
 }
 
-var errModelPathInvalid = errors.New("invalid model path")
-
 func (mp ModelPath) GetNamespaceRepository() string {
 	return fmt.Sprintf("%s/%s", mp.Namespace, mp.Repository)
 }

server/routes.go

@@ -777,7 +777,7 @@ func (s *Server) ShowHandler(c *gin.Context) {
 func GetModelInfo(req api.ShowRequest) (*api.ShowResponse, error) {
 	name := model.ParseName(req.Model)
 	if !name.IsValid() {
-		return nil, errModelPathInvalid
+		return nil, ErrModelPathInvalid
 	}
 	name, err := getExistingName(name)
 	if err != nil {