package wrapper import ( "context" "reflect" "strings" "github.com/micro/go-micro/v2/auth" "github.com/micro/go-micro/v2/client" "github.com/micro/go-micro/v2/debug/stats" "github.com/micro/go-micro/v2/debug/trace" "github.com/micro/go-micro/v2/errors" "github.com/micro/go-micro/v2/metadata" "github.com/micro/go-micro/v2/server" ) type fromServiceWrapper struct { client.Client // headers to inject headers metadata.Metadata } var ( HeaderPrefix = "Micro-" ) func (f *fromServiceWrapper) setHeaders(ctx context.Context) context.Context { // don't overwrite keys return metadata.MergeContext(ctx, f.headers, false) } func (f *fromServiceWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error { ctx = f.setHeaders(ctx) return f.Client.Call(ctx, req, rsp, opts...) } func (f *fromServiceWrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) { ctx = f.setHeaders(ctx) return f.Client.Stream(ctx, req, opts...) } func (f *fromServiceWrapper) Publish(ctx context.Context, p client.Message, opts ...client.PublishOption) error { ctx = f.setHeaders(ctx) return f.Client.Publish(ctx, p, opts...) } // FromService wraps a client to inject service and auth metadata func FromService(name string, c client.Client) client.Client { return &fromServiceWrapper{ c, metadata.Metadata{ HeaderPrefix + "From-Service": name, }, } } // HandlerStats wraps a server handler to generate request/error stats func HandlerStats(stats stats.Stats) server.HandlerWrapper { // return a handler wrapper return func(h server.HandlerFunc) server.HandlerFunc { // return a function that returns a function return func(ctx context.Context, req server.Request, rsp interface{}) error { // execute the handler err := h(ctx, req, rsp) // record the stats stats.Record(err) // return the error return err } } } type traceWrapper struct { client.Client name string trace trace.Tracer } func (c *traceWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error { newCtx, s := c.trace.Start(ctx, req.Service()+"."+req.Endpoint()) s.Type = trace.SpanTypeRequestOutbound err := c.Client.Call(newCtx, req, rsp, opts...) if err != nil { s.Metadata["error"] = err.Error() } // finish the trace c.trace.Finish(s) return err } // TraceCall is a call tracing wrapper func TraceCall(name string, t trace.Tracer, c client.Client) client.Client { return &traceWrapper{ name: name, trace: t, Client: c, } } // TraceHandler wraps a server handler to perform tracing func TraceHandler(t trace.Tracer) server.HandlerWrapper { // return a handler wrapper return func(h server.HandlerFunc) server.HandlerFunc { // return a function that returns a function return func(ctx context.Context, req server.Request, rsp interface{}) error { // don't store traces for debug if strings.HasPrefix(req.Endpoint(), "Debug.") { return h(ctx, req, rsp) } // get the span newCtx, s := t.Start(ctx, req.Service()+"."+req.Endpoint()) s.Type = trace.SpanTypeRequestInbound err := h(newCtx, req, rsp) if err != nil { s.Metadata["error"] = err.Error() } // finish t.Finish(s) return err } } } type authWrapper struct { client.Client auth func() auth.Auth } func (a *authWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error { // parse the options var options client.CallOptions for _, o := range opts { o(&options) } // check to see if the authorization header has already been set. // We dont't override the header unless the ServiceToken option has // been specified or the header wasn't provided if _, ok := metadata.Get(ctx, "Authorization"); ok && !options.ServiceToken { return a.Client.Call(ctx, req, rsp, opts...) } // if auth is nil we won't be able to get an access token, so we execute // the request without one. aa := a.auth() if aa == nil { return a.Client.Call(ctx, req, rsp, opts...) } // set the namespace header if it has not been set (e.g. on a service to service request) if _, ok := metadata.Get(ctx, "Micro-Namespace"); !ok { ctx = metadata.Set(ctx, "Micro-Namespace", aa.Options().Issuer) } // check to see if we have a valid access token aaOpts := aa.Options() if aaOpts.Token != nil && !aaOpts.Token.Expired() { ctx = metadata.Set(ctx, "Authorization", auth.BearerScheme+aaOpts.Token.AccessToken) return a.Client.Call(ctx, req, rsp, opts...) } // call without an auth token return a.Client.Call(ctx, req, rsp, opts...) } // AuthClient wraps requests with the auth header func AuthClient(auth func() auth.Auth, c client.Client) client.Client { return &authWrapper{c, auth} } // AuthHandler wraps a server handler to perform auth func AuthHandler(fn func() auth.Auth) server.HandlerWrapper { return func(h server.HandlerFunc) server.HandlerFunc { return func(ctx context.Context, req server.Request, rsp interface{}) error { // get the auth.Auth interface a := fn() // Check for debug endpoints which should be excluded from auth if strings.HasPrefix(req.Endpoint(), "Debug.") { return h(ctx, req, rsp) } // Extract the token if the header is present. We will inspect the token regardless of if it's // present or not since noop auth will return a blank account upon Inspecting a blank token. var token string if header, ok := metadata.Get(ctx, "Authorization"); ok { // Ensure the correct scheme is being used if !strings.HasPrefix(header, auth.BearerScheme) { return errors.Unauthorized(req.Service(), "invalid authorization header. expected Bearer schema") } // Strip the bearer scheme prefix token = strings.TrimPrefix(header, auth.BearerScheme) } // Inspect the token and decode an account account, _ := a.Inspect(token) // Extract the namespace header ns, ok := metadata.Get(ctx, "Micro-Namespace") if !ok { ns = a.Options().Issuer ctx = metadata.Set(ctx, "Micro-Namespace", ns) } // Check the issuer matches the services namespace. TODO: Stop allowing go.micro to access // any namespace and instead check for the server issuer. if account != nil && account.Issuer != ns && account.Issuer != "go.micro" { return errors.Forbidden(req.Service(), "Account was not issued by %v", ns) } // construct the resource res := &auth.Resource{ Type: "service", Name: req.Service(), Endpoint: req.Endpoint(), } // Verify the caller has access to the resource err := a.Verify(account, res, auth.VerifyContext(ctx)) if err != nil && account != nil { return errors.Forbidden(req.Service(), "Forbidden call made to %v:%v by %v", req.Service(), req.Endpoint(), account.ID) } else if err != nil { return errors.Unauthorized(req.Service(), "Unauthorized call made to %v:%v", req.Service(), req.Endpoint()) } // There is an account, set it in the context if account != nil { ctx = auth.ContextWithAccount(ctx, account) } // The user is authorised, allow the call return h(ctx, req, rsp) } } } type cacheWrapper struct { cacheFn func() *client.Cache client.Client } // Call executes the request. If the CacheExpiry option was set, the response will be cached using // a hash of the metadata and request as the key. func (c *cacheWrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error { // parse the options var options client.CallOptions for _, o := range opts { o(&options) } // if the client doesn't have a cacbe setup don't continue cache := c.cacheFn() if cache == nil { return c.Client.Call(ctx, req, rsp, opts...) } // if the cache expiry is not set, execute the call without the cache if options.CacheExpiry == 0 { return c.Client.Call(ctx, req, rsp, opts...) } // if the response is nil don't call the cache since we can't assign the response if rsp == nil { return c.Client.Call(ctx, req, rsp, opts...) } // check to see if there is a response cached, if there is assign it if r, ok := cache.Get(ctx, &req); ok { val := reflect.ValueOf(rsp).Elem() val.Set(reflect.ValueOf(r).Elem()) return nil } // don't cache the result if there was an error if err := c.Client.Call(ctx, req, rsp, opts...); err != nil { return err } // set the result in the cache cache.Set(ctx, &req, rsp, options.CacheExpiry) return nil } // CacheClient wraps requests with the cache wrapper func CacheClient(cacheFn func() *client.Cache, c client.Client) client.Client { return &cacheWrapper{cacheFn, c} } type staticClient struct { address string client.Client } func (s *staticClient) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error { return s.Client.Call(ctx, req, rsp, append(opts, client.WithAddress(s.address))...) } func (s *staticClient) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) { return s.Client.Stream(ctx, req, append(opts, client.WithAddress(s.address))...) } // StaticClient sets an address on every call func StaticClient(address string, c client.Client) client.Client { return &staticClient{address, c} }