MM-10702 Moving plugins to use hashicorp go-plugin. (#8978)

* Moving plugins to use hashicorp go-plugin.

* Tweaks from feedback.

1 files changed, 45 insertions, 0 deletions

diff --git a/vendor/github.com/hashicorp/go-plugin/protocol.go b/vendor/github.com/hashicorp/go-plugin/protocol.go
new file mode 100644
index 000000000..0cfc19e52
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-plugin/protocol.go
@@ -0,0 +1,45 @@
+package plugin
+
+import (
+	"io"
+	"net"
+)
+
+// Protocol is an enum representing the types of protocols.
+type Protocol string
+
+const (
+	ProtocolInvalid Protocol = ""
+	ProtocolNetRPC  Protocol = "netrpc"
+	ProtocolGRPC    Protocol = "grpc"
+)
+
+// ServerProtocol is an interface that must be implemented for new plugin
+// protocols to be servers.
+type ServerProtocol interface {
+	// Init is called once to configure and initialize the protocol, but
+	// not start listening. This is the point at which all validation should
+	// be done and errors returned.
+	Init() error
+
+	// Config is extra configuration to be outputted to stdout. This will
+	// be automatically base64 encoded to ensure it can be parsed properly.
+	// This can be an empty string if additional configuration is not needed.
+	Config() string
+
+	// Serve is called to serve connections on the given listener. This should
+	// continue until the listener is closed.
+	Serve(net.Listener)
+}
+
+// ClientProtocol is an interface that must be implemented for new plugin
+// protocols to be clients.
+type ClientProtocol interface {
+	io.Closer
+
+	// Dispense dispenses a new instance of the plugin with the given name.
+	Dispense(string) (interface{}, error)
+
+	// Ping checks that the client connection is still healthy.
+	Ping() error
+}