| package middleware |
| |
| import ( |
| "fmt" |
| "net/http" |
| "runtime" |
| |
| "github.com/docker/engine-api/types/versions" |
| "golang.org/x/net/context" |
| ) |
| |
| type badRequestError struct { |
| error |
| } |
| |
| func (badRequestError) HTTPErrorStatusCode() int { |
| return http.StatusBadRequest |
| } |
| |
| // VersionMiddleware is a middleware that |
| // validates the client and server versions. |
| type VersionMiddleware struct { |
| serverVersion string |
| defaultVersion string |
| minVersion string |
| } |
| |
| // NewVersionMiddleware creates a new VersionMiddleware |
| // with the default versions. |
| func NewVersionMiddleware(s, d, m string) VersionMiddleware { |
| return VersionMiddleware{ |
| serverVersion: s, |
| defaultVersion: d, |
| minVersion: m, |
| } |
| } |
| |
| // WrapHandler returns a new handler function wrapping the previous one in the request chain. |
| func (v VersionMiddleware) WrapHandler(handler func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error) func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error { |
| return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error { |
| apiVersion := vars["version"] |
| if apiVersion == "" { |
| apiVersion = v.defaultVersion |
| } |
| |
| if versions.GreaterThan(apiVersion, v.defaultVersion) { |
| return badRequestError{fmt.Errorf("client is newer than server (client API version: %s, server API version: %s)", apiVersion, v.defaultVersion)} |
| } |
| if versions.LessThan(apiVersion, v.minVersion) { |
| return badRequestError{fmt.Errorf("client version %s is too old. Minimum supported API version is %s, please upgrade your client to a newer version", apiVersion, v.minVersion)} |
| } |
| |
| header := fmt.Sprintf("Docker/%s (%s)", v.serverVersion, runtime.GOOS) |
| w.Header().Set("Server", header) |
| ctx = context.WithValue(ctx, "api-version", apiVersion) |
| return handler(ctx, w, r, vars) |
| } |
| |
| } |