package plugin import ( "errors" "fmt" "io/ioutil" "log" "net" "net/rpc" "os" "os/signal" "runtime" "strconv" "sync/atomic" tfrpc "github.com/hashicorp/terraform/rpc" ) // The APIVersion is outputted along with the RPC address. The plugin // client validates this API version and will show an error if it doesn't // know how to speak it. const APIVersion = "1" // The "magic cookie" is used to verify that the user intended to // actually run this binary. If this cookie isn't present as an // environmental variable, then we bail out early with an error. const MagicCookieKey = "TF_PLUGIN_MAGIC_COOKIE" const MagicCookieValue = "d602bf8f470bc67ca7faa0386276bbdd4330efaf76d1a219cb4d6991ca9872b2" func Serve(svc interface{}) error { // First check the cookie if os.Getenv(MagicCookieKey) != MagicCookieValue { fmt.Fprintf(os.Stderr, "This binary is a Terraform plugin. These are not meant to be\n" + "executed directly. Please execute `terraform`, which will load\n" + "any plugins automatically.\n") os.Exit(1) } // Create the server to serve our interface server := rpc.NewServer() // Register the service name, err := tfrpc.Register(server, svc) if err != nil { return err } // Register a listener so we can accept a connection listener, err := serverListener() if err != nil { return err } defer listener.Close() // Output the address and service name to stdout log.Printf("Plugin address: %s %s\n", listener.Addr().Network(), listener.Addr().String()) fmt.Printf("%s|%s|%s|%s\n", APIVersion, listener.Addr().Network(), listener.Addr().String(), name) os.Stdout.Sync() // Accept a connection log.Println("Waiting for connection...") conn, err := listener.Accept() if err != nil { log.Printf("Error accepting connection: %s\n", err.Error()) return err } // Eat the interrupts ch := make(chan os.Signal, 1) signal.Notify(ch, os.Interrupt) go func() { var count int32 = 0 for { <-ch newCount := atomic.AddInt32(&count, 1) log.Printf( "Received interrupt signal (count: %d). Ignoring.", newCount) } }() // Serve a single connection log.Println("Serving a plugin connection...") server.ServeConn(conn) return nil } func serverListener() (net.Listener, error) { if runtime.GOOS == "windows" { return serverListener_tcp() } return serverListener_unix() } func serverListener_tcp() (net.Listener, error) { minPort, err := strconv.ParseInt(os.Getenv("TF_PLUGIN_MIN_PORT"), 10, 32) if err != nil { return nil, err } maxPort, err := strconv.ParseInt(os.Getenv("TF_PLUGIN_MAX_PORT"), 10, 32) if err != nil { return nil, err } for port := minPort; port <= maxPort; port++ { address := fmt.Sprintf("127.0.0.1:%d", port) listener, err := net.Listen("tcp", address) if err == nil { return listener, nil } } return nil, errors.New("Couldn't bind plugin TCP listener") } func serverListener_unix() (net.Listener, error) { tf, err := ioutil.TempFile("", "tf-plugin") if err != nil { return nil, err } path := tf.Name() // Close the file and remove it because it has to not exist for // the domain socket. if err := tf.Close(); err != nil { return nil, err } if err := os.Remove(path); err != nil { return nil, err } return net.Listen("unix", path) }