docker · silvin-lubecki · Jun 30, 2020 · Jun 29, 2020
diff --git a/cli/command/container/exec.go b/cli/command/container/exec.go
@@ -27,10 +27,14 @@ type execOptions struct {
 	workdir     string
 	container   string
 	command     []string
+	envFile     opts.ListOpts
 }
 
 func newExecOptions() execOptions {
-	return execOptions{env: opts.NewListOpts(opts.ValidateEnv)}
+	return execOptions{
+		env:     opts.NewListOpts(opts.ValidateEnv),
+		envFile: opts.NewListOpts(nil),
+	}
 }
 
 // NewExecCommand creates a new cobra.Command for `docker exec`
@@ -59,14 +63,20 @@ func NewExecCommand(dockerCli command.Cli) *cobra.Command {
 	flags.BoolVarP(&options.privileged, "privileged", "", false, "Give extended privileges to the command")
 	flags.VarP(&options.env, "env", "e", "Set environment variables")
 	flags.SetAnnotation("env", "version", []string{"1.25"})
+	flags.Var(&options.envFile, "env-file", "Read in a file of environment variables")
+	flags.SetAnnotation("env-file", "version", []string{"1.25"})
 	flags.StringVarP(&options.workdir, "workdir", "w", "", "Working directory inside the container")
 	flags.SetAnnotation("workdir", "version", []string{"1.35"})
 
 	return cmd
 }
 
 func runExec(dockerCli command.Cli, options execOptions) error {
-	execConfig := parseExec(options, dockerCli.ConfigFile())
+	execConfig, err := parseExec(options, dockerCli.ConfigFile())
+	if err != nil {
+		return err
+	}
+
 	ctx := context.Background()
 	client := dockerCli.Client()
 
@@ -185,30 +195,35 @@ func getExecExitStatus(ctx context.Context, client apiclient.ContainerAPIClient,
 
 // parseExec parses the specified args for the specified command and generates
 // an ExecConfig from it.
-func parseExec(opts execOptions, configFile *configfile.ConfigFile) *types.ExecConfig {
+func parseExec(execOpts execOptions, configFile *configfile.ConfigFile) (*types.ExecConfig, error) {
 	execConfig := &types.ExecConfig{
-		User:       opts.user,
-		Privileged: opts.privileged,
-		Tty:        opts.tty,
-		Cmd:        opts.command,
-		Detach:     opts.detach,
-		Env:        opts.env.GetAll(),
-		WorkingDir: opts.workdir,
+		User:       execOpts.user,
+		Privileged: execOpts.privileged,
+		Tty:        execOpts.tty,
+		Cmd:        execOpts.command,
+		Detach:     execOpts.detach,
+		WorkingDir: execOpts.workdir,
+	}
+
+	// collect all the environment variables for the container
+	var err error
+	if execConfig.Env, err = opts.ReadKVEnvStrings(execOpts.envFile.GetAll(), execOpts.env.GetAll()); err != nil {
+		return nil, err
 	}
 
 	// If -d is not set, attach to everything by default
-	if !opts.detach {
+	if !execOpts.detach {
 		execConfig.AttachStdout = true
 		execConfig.AttachStderr = true
-		if opts.interactive {
+		if execOpts.interactive {
 			execConfig.AttachStdin = true
 		}
 	}
 
-	if opts.detachKeys != "" {
-		execConfig.DetachKeys = opts.detachKeys
+	if execOpts.detachKeys != "" {
+		execConfig.DetachKeys = execOpts.detachKeys
 	} else {
 		execConfig.DetachKeys = configFile.DetachKeys
 	}
-	return execConfig
+	return execConfig, nil
 }
diff --git a/cli/command/container/exec_test.go b/cli/command/container/exec_test.go
@@ -3,6 +3,7 @@ package container
 import (
 	"context"
 	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/docker/cli/cli"
@@ -13,17 +14,26 @@ import (
 	"github.com/pkg/errors"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
+	"gotest.tools/v3/fs"
 )
 
 func withDefaultOpts(options execOptions) execOptions {
 	options.env = opts.NewListOpts(opts.ValidateEnv)
+	options.envFile = opts.NewListOpts(nil)
 	if len(options.command) == 0 {
 		options.command = []string{"command"}
 	}
 	return options
 }
 
 func TestParseExec(t *testing.T) {
+	content := `ONE=1
+TWO=2
+	`
+
+	tmpFile := fs.NewFile(t, t.Name(), fs.WithContent(content))
+	defer tmpFile.Remove()
+
 	testcases := []struct {
 		options    execOptions
 		configFile configfile.ConfigFile
@@ -102,14 +112,51 @@ func TestParseExec(t *testing.T) {
 				Detach:     true,
 			},
 		},
+		{
+			expected: types.ExecConfig{
+				Cmd:          []string{"command"},
+				AttachStdout: true,
+				AttachStderr: true,
+				Env:          []string{"ONE=1", "TWO=2"},
+			},
+			options: func() execOptions {
+				o := withDefaultOpts(execOptions{})
+				o.envFile.Set(tmpFile.Path())
+				return o
+			}(),
+		},
+		{
+			expected: types.ExecConfig{
+				Cmd:          []string{"command"},
+				AttachStdout: true,
+				AttachStderr: true,
+				Env:          []string{"ONE=1", "TWO=2", "ONE=override"},
+			},
+			options: func() execOptions {
+				o := withDefaultOpts(execOptions{})
+				o.envFile.Set(tmpFile.Path())
+				o.env.Set("ONE=override")
+				return o
+			}(),
+		},
 	}
 
 	for _, testcase := range testcases {
-		execConfig := parseExec(testcase.options, &testcase.configFile)
+		execConfig, err := parseExec(testcase.options, &testcase.configFile)
+		assert.NilError(t, err)
 		assert.Check(t, is.DeepEqual(testcase.expected, *execConfig))
 	}
 }
 
+func TestParseExecNoSuchFile(t *testing.T) {
+	execOpts := withDefaultOpts(execOptions{})
+	execOpts.envFile.Set("no-such-env-file")
+	execConfig, err := parseExec(execOpts, &configfile.ConfigFile{})
+	assert.ErrorContains(t, err, "no-such-env-file")
+	assert.Check(t, os.IsNotExist(err))
+	assert.Check(t, execConfig == nil)
+}
+
 func TestRunExec(t *testing.T) {
 	var testcases = []struct {
 		doc           string

@@ -1604,6 +1604,10 @@ _docker_container_exec() {
 			__docker_nospace
 			return
 			;;
+		--env-file)
+			_filedir
+			return
+			;;
 		--user|-u)
 			__docker_complete_user_group
 			return
@@ -1615,7 +1619,7 @@ _docker_container_exec() {
 
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--detach -d --detach-keys --env -e --help --interactive -i --privileged -t --tty -u --user --workdir -w" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--detach -d --detach-keys --env -e --env-file --help --interactive -i --privileged -t --tty -u --user --workdir -w" -- "$cur" ) )
 			;;
 		*)
 			__docker_complete_containers_running

diff --git a/contrib/completion/zsh/_docker b/contrib/completion/zsh/_docker
@@ -750,6 +750,7 @@ __docker_container_subcommand() {
                 $opts_attach_exec_run_start \
                 "($help -d --detach)"{-d,--detach}"[Detached mode: leave the container running in the background]" \
                 "($help)*"{-e=,--env=}"[Set environment variables]:environment variable: " \
+                "($help)*--env-file=[Read environment variables from a file]:environment file:_files" \
                 "($help -i --interactive)"{-i,--interactive}"[Keep stdin open even if not attached]" \
                 "($help)--privileged[Give extended Linux capabilities to the command]" \
                 "($help -t --tty)"{-t,--tty}"[Allocate a pseudo-tty]" \

@@ -15,6 +15,7 @@ Options:
   -d, --detach         Detached mode: run command in the background
       --detach-keys    Override the key sequence for detaching a container
   -e, --env=[]         Set environment variables
+      --env-file       Read in a file of environment variables
       --help           Print usage
   -i, --interactive    Keep STDIN open even if not attached
       --privileged     Give extended privileges to the command