| package middleware // import "github.com/docker/docker/api/server/middleware" |
| |
| import ( |
| "context" |
| "fmt" |
| "net/http" |
| "runtime" |
| |
| "github.com/docker/docker/api/server/httputils" |
| "github.com/docker/docker/api/types/versions" |
| ) |
| |
| // 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, |
| } |
| } |
| |
| type versionUnsupportedError struct { |
| version, minVersion, maxVersion string |
| } |
| |
| func (e versionUnsupportedError) Error() string { |
| if e.minVersion != "" { |
| return fmt.Sprintf("client version %s is too old. Minimum supported API version is %s, please upgrade your client to a newer version", e.version, e.minVersion) |
| } |
| return fmt.Sprintf("client version %s is too new. Maximum supported API version is %s", e.version, e.maxVersion) |
| } |
| |
| func (e versionUnsupportedError) InvalidParameter() {} |
| |
| // 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 { |
| w.Header().Set("Server", fmt.Sprintf("Docker/%s (%s)", v.serverVersion, runtime.GOOS)) |
| w.Header().Set("API-Version", v.defaultVersion) |
| w.Header().Set("OSType", runtime.GOOS) |
| |
| apiVersion := vars["version"] |
| if apiVersion == "" { |
| apiVersion = v.defaultVersion |
| } |
| if versions.LessThan(apiVersion, v.minVersion) { |
| return versionUnsupportedError{version: apiVersion, minVersion: v.minVersion} |
| } |
| if versions.GreaterThan(apiVersion, v.defaultVersion) { |
| return versionUnsupportedError{version: apiVersion, maxVersion: v.defaultVersion} |
| } |
| ctx = context.WithValue(ctx, httputils.APIVersionKey{}, apiVersion) |
| return handler(ctx, w, r, vars) |
| } |
| |
| } |