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author | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
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committer | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
commit | 6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005 (patch) | |
tree | 5564a47257bf6e85aaef711980c5b0fcb4d07dcc /vendor/github.com/hashicorp/go-plugin/server.go | |
parent | c042ffa460296587579aff54b157a5109e022f7e (diff) | |
parent | 1e1a5e5e85240f25c4faddcb24c5a29a915fe6e4 (diff) | |
download | chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.gz chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.bz2 chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.zip |
Merge branch 'plugins-2'
Diffstat (limited to 'vendor/github.com/hashicorp/go-plugin/server.go')
-rw-r--r-- | vendor/github.com/hashicorp/go-plugin/server.go | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/go-plugin/server.go b/vendor/github.com/hashicorp/go-plugin/server.go new file mode 100644 index 000000000..1e808b99e --- /dev/null +++ b/vendor/github.com/hashicorp/go-plugin/server.go @@ -0,0 +1,317 @@ +package plugin + +import ( + "crypto/tls" + "encoding/base64" + "errors" + "fmt" + "io/ioutil" + "log" + "net" + "os" + "os/signal" + "runtime" + "strconv" + "sync/atomic" + + "github.com/hashicorp/go-hclog" + + "google.golang.org/grpc" +) + +// CoreProtocolVersion is the ProtocolVersion of the plugin system itself. +// We will increment this whenever we change any protocol behavior. This +// will invalidate any prior plugins but will at least allow us to iterate +// on the core in a safe way. We will do our best to do this very +// infrequently. +const CoreProtocolVersion = 1 + +// HandshakeConfig is the configuration used by client and servers to +// handshake before starting a plugin connection. This is embedded by +// both ServeConfig and ClientConfig. +// +// In practice, the plugin host creates a HandshakeConfig that is exported +// and plugins then can easily consume it. +type HandshakeConfig struct { + // ProtocolVersion is the version that clients must match on to + // agree they can communicate. This should match the ProtocolVersion + // set on ClientConfig when using a plugin. + ProtocolVersion uint + + // MagicCookieKey and value are used as a very basic verification + // that a plugin is intended to be launched. This is not a security + // measure, just a UX feature. If the magic cookie doesn't match, + // we show human-friendly output. + MagicCookieKey string + MagicCookieValue string +} + +// ServeConfig configures what sorts of plugins are served. +type ServeConfig struct { + // HandshakeConfig is the configuration that must match clients. + HandshakeConfig + + // TLSProvider is a function that returns a configured tls.Config. + TLSProvider func() (*tls.Config, error) + + // Plugins are the plugins that are served. + Plugins map[string]Plugin + + // GRPCServer should be non-nil to enable serving the plugins over + // gRPC. This is a function to create the server when needed with the + // given server options. The server options populated by go-plugin will + // be for TLS if set. You may modify the input slice. + // + // Note that the grpc.Server will automatically be registered with + // the gRPC health checking service. This is not optional since go-plugin + // relies on this to implement Ping(). + GRPCServer func([]grpc.ServerOption) *grpc.Server + + // Logger is used to pass a logger into the server. If none is provided the + // server will create a default logger. + Logger hclog.Logger +} + +// Protocol returns the protocol that this server should speak. +func (c *ServeConfig) Protocol() Protocol { + result := ProtocolNetRPC + if c.GRPCServer != nil { + result = ProtocolGRPC + } + + return result +} + +// Serve serves the plugins given by ServeConfig. +// +// Serve doesn't return until the plugin is done being executed. Any +// errors will be outputted to os.Stderr. +// +// This is the method that plugins should call in their main() functions. +func Serve(opts *ServeConfig) { + // Validate the handshake config + if opts.MagicCookieKey == "" || opts.MagicCookieValue == "" { + fmt.Fprintf(os.Stderr, + "Misconfigured ServeConfig given to serve this plugin: no magic cookie\n"+ + "key or value was set. Please notify the plugin author and report\n"+ + "this as a bug.\n") + os.Exit(1) + } + + // First check the cookie + if os.Getenv(opts.MagicCookieKey) != opts.MagicCookieValue { + fmt.Fprintf(os.Stderr, + "This binary is a plugin. These are not meant to be executed directly.\n"+ + "Please execute the program that consumes these plugins, which will\n"+ + "load any plugins automatically\n") + os.Exit(1) + } + + // Logging goes to the original stderr + log.SetOutput(os.Stderr) + + logger := opts.Logger + if logger == nil { + // internal logger to os.Stderr + logger = hclog.New(&hclog.LoggerOptions{ + Level: hclog.Trace, + Output: os.Stderr, + JSONFormat: true, + }) + } + + // Create our new stdout, stderr files. These will override our built-in + // stdout/stderr so that it works across the stream boundary. + stdout_r, stdout_w, err := os.Pipe() + if err != nil { + fmt.Fprintf(os.Stderr, "Error preparing plugin: %s\n", err) + os.Exit(1) + } + stderr_r, stderr_w, err := os.Pipe() + if err != nil { + fmt.Fprintf(os.Stderr, "Error preparing plugin: %s\n", err) + os.Exit(1) + } + + // Register a listener so we can accept a connection + listener, err := serverListener() + if err != nil { + logger.Error("plugin init error", "error", err) + return + } + + // Close the listener on return. We wrap this in a func() on purpose + // because the "listener" reference may change to TLS. + defer func() { + listener.Close() + }() + + var tlsConfig *tls.Config + if opts.TLSProvider != nil { + tlsConfig, err = opts.TLSProvider() + if err != nil { + logger.Error("plugin tls init", "error", err) + return + } + } + + // Create the channel to tell us when we're done + doneCh := make(chan struct{}) + + // Build the server type + var server ServerProtocol + switch opts.Protocol() { + case ProtocolNetRPC: + // If we have a TLS configuration then we wrap the listener + // ourselves and do it at that level. + if tlsConfig != nil { + listener = tls.NewListener(listener, tlsConfig) + } + + // Create the RPC server to dispense + server = &RPCServer{ + Plugins: opts.Plugins, + Stdout: stdout_r, + Stderr: stderr_r, + DoneCh: doneCh, + } + + case ProtocolGRPC: + // Create the gRPC server + server = &GRPCServer{ + Plugins: opts.Plugins, + Server: opts.GRPCServer, + TLS: tlsConfig, + Stdout: stdout_r, + Stderr: stderr_r, + DoneCh: doneCh, + } + + default: + panic("unknown server protocol: " + opts.Protocol()) + } + + // Initialize the servers + if err := server.Init(); err != nil { + logger.Error("protocol init", "error", err) + return + } + + // Build the extra configuration + extra := "" + if v := server.Config(); v != "" { + extra = base64.StdEncoding.EncodeToString([]byte(v)) + } + if extra != "" { + extra = "|" + extra + } + + logger.Debug("plugin address", "network", listener.Addr().Network(), "address", listener.Addr().String()) + + // Output the address and service name to stdout so that core can bring it up. + fmt.Printf("%d|%d|%s|%s|%s%s\n", + CoreProtocolVersion, + opts.ProtocolVersion, + listener.Addr().Network(), + listener.Addr().String(), + opts.Protocol(), + extra) + os.Stdout.Sync() + + // 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) + logger.Debug("plugin received interrupt signal, ignoring", "count", newCount) + } + }() + + // Set our new out, err + os.Stdout = stdout_w + os.Stderr = stderr_w + + // Accept connections and wait for completion + go server.Serve(listener) + <-doneCh +} + +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("PLUGIN_MIN_PORT"), 10, 32) + if err != nil { + return nil, err + } + + maxPort, err := strconv.ParseInt(os.Getenv("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("", "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 + } + + l, err := net.Listen("unix", path) + if err != nil { + return nil, err + } + + // Wrap the listener in rmListener so that the Unix domain socket file + // is removed on close. + return &rmListener{ + Listener: l, + Path: path, + }, nil +} + +// rmListener is an implementation of net.Listener that forwards most +// calls to the listener but also removes a file as part of the close. We +// use this to cleanup the unix domain socket on close. +type rmListener struct { + net.Listener + Path string +} + +func (l *rmListener) Close() error { + // Close the listener itself + if err := l.Listener.Close(); err != nil { + return err + } + + // Remove the file + return os.Remove(l.Path) +} |