moby/rcli/tcp.go
Solomon Hykes c59fff422f gofmt
2013-03-09 19:44:09 -08:00

69 lines
1.6 KiB
Go

package rcli
import (
"bufio"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"log"
"net"
)
// Connect to a remote endpoint using protocol `proto` and address `addr`,
// issue a single call, and return the result.
// `proto` may be "tcp", "unix", etc. See the `net` package for available protocols.
func Call(proto, addr string, args ...string) (*net.TCPConn, error) {
cmd, err := json.Marshal(args)
if err != nil {
return nil, err
}
conn, err := net.Dial(proto, addr)
if err != nil {
return nil, err
}
if _, err := fmt.Fprintln(conn, string(cmd)); err != nil {
return nil, err
}
return conn.(*net.TCPConn), nil
}
// Listen on `addr`, using protocol `proto`, for incoming rcli calls,
// and pass them to `service`.
func ListenAndServe(proto, addr string, service Service) error {
listener, err := net.Listen(proto, addr)
if err != nil {
return err
}
log.Printf("Listening for RCLI/%s on %s\n", proto, addr)
defer listener.Close()
for {
if conn, err := listener.Accept(); err != nil {
return err
} else {
go func() {
if err := Serve(conn, service); err != nil {
log.Printf("Error: " + err.Error() + "\n")
fmt.Fprintf(conn, "Error: "+err.Error()+"\n")
}
conn.Close()
}()
}
}
return nil
}
// Parse an rcli call on a new connection, and pass it to `service` if it
// is valid.
func Serve(conn io.ReadWriter, service Service) error {
r := bufio.NewReader(conn)
var args []string
if line, err := r.ReadString('\n'); err != nil {
return err
} else if err := json.Unmarshal([]byte(line), &args); err != nil {
return err
} else {
return call(service, ioutil.NopCloser(r), conn, args...)
}
return nil
}