commands/env: Add

Author: rajivr

commands/env.go

@@ -0,0 +1,275 @@
+package commands
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"text/template"
+
+	"github.com/docker/machine/commands/mcndirs"
+	"github.com/docker/machine/libmachine"
+	"github.com/docker/machine/libmachine/check"
+	"github.com/docker/machine/libmachine/log"
+	"github.com/docker/machine/libmachine/shell"
+)
+
+const (
+	envTmpl = `{{ .Prefix }}DOCKER_TLS_VERIFY{{ .Delimiter }}{{ .DockerTLSVerify }}{{ .Suffix }}{{ .Prefix }}DOCKER_HOST{{ .Delimiter }}{{ .DockerHost }}{{ .Suffix }}{{ .Prefix }}DOCKER_CERT_PATH{{ .Delimiter }}{{ .DockerCertPath }}{{ .Suffix }}{{ .Prefix }}DOCKER_MACHINE_NAME{{ .Delimiter }}{{ .MachineName }}{{ .Suffix }}{{ if .ComposePathsVar }}{{ .Prefix }}COMPOSE_CONVERT_WINDOWS_PATHS{{ .Delimiter }}true{{ .Suffix }}{{end}}{{ if .NoProxyVar }}{{ .Prefix }}{{ .NoProxyVar }}{{ .Delimiter }}{{ .NoProxyValue }}{{ .Suffix }}{{end}}{{ .UsageHint }}`
+)
+
+var (
+	errImproperUnsetEnvArgs = errors.New("Error: Expected no machine name when the -u flag is present")
+	defaultUsageHinter      UsageHintGenerator
+	runtimeOS               = func() string { return runtime.GOOS }
+)
+
+func init() {
+	defaultUsageHinter = &EnvUsageHintGenerator{}
+}
+
+type ShellConfig struct {
+	Prefix          string
+	Delimiter       string
+	Suffix          string
+	DockerCertPath  string
+	DockerHost      string
+	DockerTLSVerify string
+	UsageHint       string
+	MachineName     string
+	NoProxyVar      string
+	NoProxyValue    string
+	ComposePathsVar bool
+}
+
+func cmdEnv(c CommandLine, api libmachine.API) error {
+	var (
+		err      error
+		shellCfg *ShellConfig
+	)
+
+	// Ensure that log messages always go to stderr when this command is
+	// being run (it is intended to be run in a subshell)
+	log.SetOutWriter(os.Stderr)
+
+	if c.Bool("unset") {
+		shellCfg, err = shellCfgUnset(c, api)
+		if err != nil {
+			return err
+		}
+	} else {
+		shellCfg, err = shellCfgSet(c, api)
+		if err != nil {
+			return err
+		}
+	}
+
+	return executeTemplateStdout(shellCfg)
+}
+
+func shellCfgSet(c CommandLine, api libmachine.API) (*ShellConfig, error) {
+	if len(c.Args()) > 1 {
+		return nil, ErrExpectedOneMachine
+	}
+
+	target, err := targetHost(c, api)
+	if err != nil {
+		return nil, err
+	}
+
+	host, err := api.Load(target)
+	if err != nil {
+		return nil, err
+	}
+
+	dockerHost, _, err := check.DefaultConnChecker.Check(host, c.Bool("swarm"))
+	if err != nil {
+		return nil, fmt.Errorf("Error checking TLS connection: %s", err)
+	}
+
+	userShell, err := getShell(c.String("shell"))
+	if err != nil {
+		return nil, err
+	}
+
+	shellCfg := &ShellConfig{
+		DockerCertPath:  filepath.Join(mcndirs.GetMachineDir(), host.Name),
+		DockerHost:      dockerHost,
+		DockerTLSVerify: "1",
+		UsageHint:       defaultUsageHinter.GenerateUsageHint(userShell, os.Args),
+		MachineName:     host.Name,
+	}
+
+	if c.Bool("no-proxy") {
+		ip, err := host.Driver.GetIP()
+		if err != nil {
+			return nil, fmt.Errorf("Error getting host IP: %s", err)
+		}
+
+		noProxyVar, noProxyValue := findNoProxyFromEnv()
+
+		// add the docker host to the no_proxy list idempotently
+		switch {
+		case noProxyValue == "":
+			noProxyValue = ip
+		case strings.Contains(noProxyValue, ip):
+		//ip already in no_proxy list, nothing to do
+		default:
+			noProxyValue = fmt.Sprintf("%s,%s", noProxyValue, ip)
+		}
+
+		shellCfg.NoProxyVar = noProxyVar
+		shellCfg.NoProxyValue = noProxyValue
+	}
+
+	if runtimeOS() == "windows" {
+		shellCfg.ComposePathsVar = true
+	}
+
+	switch userShell {
+	case "fish":
+		shellCfg.Prefix = "set -gx "
+		shellCfg.Suffix = "\";\n"
+		shellCfg.Delimiter = " \""
+	case "powershell":
+		shellCfg.Prefix = "$Env:"
+		shellCfg.Suffix = "\"\n"
+		shellCfg.Delimiter = " = \""
+	case "cmd":
+		shellCfg.Prefix = "SET "
+		shellCfg.Suffix = "\n"
+		shellCfg.Delimiter = "="
+	case "tcsh":
+		shellCfg.Prefix = "setenv "
+		shellCfg.Suffix = "\";\n"
+		shellCfg.Delimiter = " \""
+	case "emacs":
+		shellCfg.Prefix = "(setenv \""
+		shellCfg.Suffix = "\")\n"
+		shellCfg.Delimiter = "\" \""
+	default:
+		shellCfg.Prefix = "export "
+		shellCfg.Suffix = "\"\n"
+		shellCfg.Delimiter = "=\""
+	}
+
+	return shellCfg, nil
+}
+
+func shellCfgUnset(c CommandLine, api libmachine.API) (*ShellConfig, error) {
+	if len(c.Args()) != 0 {
+		return nil, errImproperUnsetEnvArgs
+	}
+
+	userShell, err := getShell(c.String("shell"))
+	if err != nil {
+		return nil, err
+	}
+
+	shellCfg := &ShellConfig{
+		UsageHint: defaultUsageHinter.GenerateUsageHint(userShell, os.Args),
+	}
+
+	if c.Bool("no-proxy") {
+		shellCfg.NoProxyVar, shellCfg.NoProxyValue = findNoProxyFromEnv()
+	}
+
+	switch userShell {
+	case "fish":
+		shellCfg.Prefix = "set -e "
+		shellCfg.Suffix = ";\n"
+		shellCfg.Delimiter = ""
+	case "powershell":
+		shellCfg.Prefix = `Remove-Item Env:\\`
+		shellCfg.Suffix = "\n"
+		shellCfg.Delimiter = ""
+	case "cmd":
+		shellCfg.Prefix = "SET "
+		shellCfg.Suffix = "\n"
+		shellCfg.Delimiter = "="
+	case "emacs":
+		shellCfg.Prefix = "(setenv \""
+		shellCfg.Suffix = ")\n"
+		shellCfg.Delimiter = "\" nil"
+	case "tcsh":
+		shellCfg.Prefix = "unsetenv "
+		shellCfg.Suffix = ";\n"
+		shellCfg.Delimiter = ""
+	default:
+		shellCfg.Prefix = "unset "
+		shellCfg.Suffix = "\n"
+		shellCfg.Delimiter = ""
+	}
+
+	return shellCfg, nil
+}
+
+func executeTemplateStdout(shellCfg *ShellConfig) error {
+	t := template.New("envConfig")
+	tmpl, err := t.Parse(envTmpl)
+	if err != nil {
+		return err
+	}
+
+	return tmpl.Execute(os.Stdout, shellCfg)
+}
+
+func getShell(userShell string) (string, error) {
+	if userShell != "" {
+		return userShell, nil
+	}
+	return shell.Detect()
+}
+
+func findNoProxyFromEnv() (string, string) {
+	// first check for an existing lower case no_proxy var
+	noProxyVar := "no_proxy"
+	noProxyValue := os.Getenv("no_proxy")
+
+	// otherwise default to allcaps HTTP_PROXY
+	if noProxyValue == "" {
+		noProxyVar = "NO_PROXY"
+		noProxyValue = os.Getenv("NO_PROXY")
+	}
+	return noProxyVar, noProxyValue
+}
+
+type UsageHintGenerator interface {
+	GenerateUsageHint(string, []string) string
+}
+
+type EnvUsageHintGenerator struct{}
+
+func (g *EnvUsageHintGenerator) GenerateUsageHint(userShell string, args []string) string {
+	cmd := ""
+	comment := "#"
+
+	dockerMachinePath := args[0]
+	if strings.Contains(dockerMachinePath, " ") || strings.Contains(dockerMachinePath, `\`) {
+		args[0] = fmt.Sprintf("\"%s\"", dockerMachinePath)
+	}
+
+	commandLine := strings.Join(args, " ")
+
+	switch userShell {
+	case "fish":
+		cmd = fmt.Sprintf("eval (%s)", commandLine)
+	case "powershell":
+		cmd = fmt.Sprintf("& %s | Invoke-Expression", commandLine)
+	case "cmd":
+		cmd = fmt.Sprintf("\t@FOR /f \"tokens=*\" %%i IN ('%s') DO @%%i", commandLine)
+		comment = "REM"
+	case "emacs":
+		cmd = fmt.Sprintf("(with-temp-buffer (shell-command \"%s\" (current-buffer)) (eval-buffer))", commandLine)
+		comment = ";;"
+	case "tcsh":
+		cmd = fmt.Sprintf("eval `%s`", commandLine)
+		comment = ":"
+	default:
+		cmd = fmt.Sprintf("eval $(%s)", commandLine)
+	}
+
+	return fmt.Sprintf("%s Run this command to configure your shell: \n%s %s\n", comment, comment, cmd)
+}