github.com/kaisenlinux/docker.io@v0.0.0-20230510090727-ea55db55fac7/libnetwork/client/client.go (about)

     1  package client
     2  
     3  import (
     4  	"fmt"
     5  	"io"
     6  	"io/ioutil"
     7  	"net/http"
     8  	"reflect"
     9  	"strings"
    10  
    11  	flag "github.com/docker/libnetwork/client/mflag"
    12  )
    13  
    14  // CallFunc provides environment specific call utility to invoke backend functions from UI
    15  type CallFunc func(string, string, interface{}, map[string][]string) (io.ReadCloser, http.Header, int, error)
    16  
    17  // NetworkCli is the UI object for network subcmds
    18  type NetworkCli struct {
    19  	out  io.Writer
    20  	err  io.Writer
    21  	call CallFunc
    22  }
    23  
    24  // NewNetworkCli is a convenient function to create a NetworkCli object
    25  func NewNetworkCli(out, err io.Writer, call CallFunc) *NetworkCli {
    26  	return &NetworkCli{
    27  		out:  out,
    28  		err:  err,
    29  		call: call,
    30  	}
    31  }
    32  
    33  // getMethod is Borrowed from Docker UI which uses reflection to identify the UI Handler
    34  func (cli *NetworkCli) getMethod(args ...string) (func(string, ...string) error, bool) {
    35  	camelArgs := make([]string, len(args))
    36  	for i, s := range args {
    37  		if len(s) == 0 {
    38  			return nil, false
    39  		}
    40  		camelArgs[i] = strings.ToUpper(s[:1]) + strings.ToLower(s[1:])
    41  	}
    42  	methodName := "Cmd" + strings.Join(camelArgs, "")
    43  	method := reflect.ValueOf(cli).MethodByName(methodName)
    44  	if !method.IsValid() {
    45  		return nil, false
    46  	}
    47  	return method.Interface().(func(string, ...string) error), true
    48  }
    49  
    50  // Cmd is borrowed from Docker UI and acts as the entry point for network UI commands.
    51  // network UI commands are designed to be invoked from multiple parent chains
    52  func (cli *NetworkCli) Cmd(chain string, args ...string) error {
    53  	if len(args) > 2 {
    54  		method, exists := cli.getMethod(args[:3]...)
    55  		if exists {
    56  			return method(chain+" "+args[0]+" "+args[1], args[3:]...)
    57  		}
    58  	}
    59  	if len(args) > 1 {
    60  		method, exists := cli.getMethod(args[:2]...)
    61  		if exists {
    62  			return method(chain+" "+args[0], args[2:]...)
    63  		}
    64  	}
    65  	if len(args) > 0 {
    66  		method, exists := cli.getMethod(args[0])
    67  		if !exists {
    68  			return fmt.Errorf("%s: '%s' is not a %s command. See '%s --help'", chain, args[0], chain, chain)
    69  		}
    70  		return method(chain, args[1:]...)
    71  	}
    72  	flag.Usage()
    73  	return nil
    74  }
    75  
    76  // Subcmd is borrowed from Docker UI and performs the same function of configuring the subCmds
    77  func (cli *NetworkCli) Subcmd(chain, name, signature, description string, exitOnError bool) *flag.FlagSet {
    78  	var errorHandling flag.ErrorHandling
    79  	if exitOnError {
    80  		errorHandling = flag.ExitOnError
    81  	} else {
    82  		errorHandling = flag.ContinueOnError
    83  	}
    84  	flags := flag.NewFlagSet(name, errorHandling)
    85  	flags.Usage = func() {
    86  		flags.ShortUsage()
    87  		flags.PrintDefaults()
    88  	}
    89  	flags.ShortUsage = func() {
    90  		options := ""
    91  		if signature != "" {
    92  			signature = " " + signature
    93  		}
    94  		if flags.FlagCountUndeprecated() > 0 {
    95  			options = " [OPTIONS]"
    96  		}
    97  		fmt.Fprintf(cli.out, "\nUsage: %s %s%s%s\n\n%s\n\n", chain, name, options, signature, description)
    98  		flags.SetOutput(cli.out)
    99  	}
   100  	return flags
   101  }
   102  
   103  func readBody(stream io.ReadCloser, hdr http.Header, statusCode int, err error) ([]byte, int, error) {
   104  	if stream != nil {
   105  		defer stream.Close()
   106  	}
   107  	if err != nil {
   108  		return nil, statusCode, err
   109  	}
   110  	body, err := ioutil.ReadAll(stream)
   111  	if err != nil {
   112  		return nil, -1, err
   113  	}
   114  	return body, statusCode, nil
   115  }