libnetwork/client/client.go

116 lines
3.0 KiB
Go

package client
import (
"fmt"
"io"
"io/ioutil"
"net/http"
"reflect"
"strings"
flag "github.com/docker/libnetwork/client/mflag"
)
// CallFunc provides environment specific call utility to invoke backend functions from UI
type CallFunc func(string, string, interface{}, map[string][]string) (io.ReadCloser, http.Header, int, error)
// NetworkCli is the UI object for network subcmds
type NetworkCli struct {
out io.Writer
err io.Writer
call CallFunc
}
// NewNetworkCli is a convenient function to create a NetworkCli object
func NewNetworkCli(out, err io.Writer, call CallFunc) *NetworkCli {
return &NetworkCli{
out: out,
err: err,
call: call,
}
}
// getMethod is Borrowed from Docker UI which uses reflection to identify the UI Handler
func (cli *NetworkCli) getMethod(args ...string) (func(string, ...string) error, bool) {
camelArgs := make([]string, len(args))
for i, s := range args {
if len(s) == 0 {
return nil, false
}
camelArgs[i] = strings.ToUpper(s[:1]) + strings.ToLower(s[1:])
}
methodName := "Cmd" + strings.Join(camelArgs, "")
method := reflect.ValueOf(cli).MethodByName(methodName)
if !method.IsValid() {
return nil, false
}
return method.Interface().(func(string, ...string) error), true
}
// Cmd is borrowed from Docker UI and acts as the entry point for network UI commands.
// network UI commands are designed to be invoked from multiple parent chains
func (cli *NetworkCli) Cmd(chain string, args ...string) error {
if len(args) > 2 {
method, exists := cli.getMethod(args[:3]...)
if exists {
return method(chain+" "+args[0]+" "+args[1], args[3:]...)
}
}
if len(args) > 1 {
method, exists := cli.getMethod(args[:2]...)
if exists {
return method(chain+" "+args[0], args[2:]...)
}
}
if len(args) > 0 {
method, exists := cli.getMethod(args[0])
if !exists {
return fmt.Errorf("%s: '%s' is not a %s command. See '%s --help'", chain, args[0], chain, chain)
}
return method(chain, args[1:]...)
}
flag.Usage()
return nil
}
// Subcmd is borrowed from Docker UI and performs the same function of configuring the subCmds
func (cli *NetworkCli) Subcmd(chain, name, signature, description string, exitOnError bool) *flag.FlagSet {
var errorHandling flag.ErrorHandling
if exitOnError {
errorHandling = flag.ExitOnError
} else {
errorHandling = flag.ContinueOnError
}
flags := flag.NewFlagSet(name, errorHandling)
flags.Usage = func() {
flags.ShortUsage()
flags.PrintDefaults()
}
flags.ShortUsage = func() {
options := ""
if signature != "" {
signature = " " + signature
}
if flags.FlagCountUndeprecated() > 0 {
options = " [OPTIONS]"
}
fmt.Fprintf(cli.out, "\nUsage: %s %s%s%s\n\n%s\n\n", chain, name, options, signature, description)
flags.SetOutput(cli.out)
}
return flags
}
func readBody(stream io.ReadCloser, hdr http.Header, statusCode int, err error) ([]byte, int, error) {
if stream != nil {
defer stream.Close()
}
if err != nil {
return nil, statusCode, err
}
body, err := ioutil.ReadAll(stream)
if err != nil {
return nil, -1, err
}
return body, statusCode, nil
}