[env] Add --env and --env-file flags (#1353)

## Summary

Adds `--env` and `--env-file` flags that can be used with `run` `shell`
and `services`

If both flags are specified they are merged with `--env` taking
precedence.

environment variables passed in with flags take the highest level of
precedence, replacing any env variables set by nix, devbox.json, or
plugins.

TODO: The flag code is a bit brittle and repetitive, I think we can
consolidate the common flag registration.

## How was it tested?

```
devbox run -e FOO=BAR echo \$FOO
devbox services up -e HTTPD_PORT=8083
```

Author: mikeland73

examples/servers/apache/devbox.lock

@@ -3,8 +3,9 @@
   "packages": {
     "apacheHttpd@latest": {
       "last_modified": "2023-05-01T16:53:22Z",
+      "plugin_version": "0.0.2",
       "resolved": "github:NixOS/nixpkgs/8670e496ffd093b60e74e7fa53526aa5920d09eb#apacheHttpd",
       "version": "2.4.57"
     }
   }
-}
+}

go.mod

@@ -45,6 +45,8 @@ require (
 	gopkg.in/yaml.v3 v3.0.1
 )
 
+require github.com/joho/godotenv v1.5.1
+
 require (
 	github.com/bahlo/generic-list-go v0.2.0 // indirect
 	github.com/buger/jsonparser v1.1.1 // indirect

go.sum

@@ -129,6 +129,8 @@ github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9Y
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
 github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=

internal/boxcli/env.go

@@ -0,0 +1,48 @@
+// Copyright 2023 Jetpack Technologies Inc and contributors. All rights reserved.
+// Use of this source code is governed by the license in the LICENSE file.
+
+package boxcli
+
+import (
+	"path/filepath"
+
+	"github.com/joho/godotenv"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+// to be composed into xyzCmdFlags structs
+type envFlag struct {
+	env     map[string]string
+	envFile string
+}
+
+func (f *envFlag) register(cmd *cobra.Command) {
+	cmd.PersistentFlags().StringToStringVarP(
+		&f.env, "env", "e", nil, "environment variables to set in the devbox environment",
+	)
+	cmd.PersistentFlags().StringVar(
+		&f.envFile, "env-file", "", "path to a file containing environment variables to set in the devbox environment",
+	)
+}
+
+func (f *envFlag) Env(path string) (map[string]string, error) {
+	envs := map[string]string{}
+	var err error
+	if f.envFile != "" {
+		envPath := f.envFile
+		if !filepath.IsAbs(envPath) {
+			envPath = filepath.Join(path, envPath)
+		}
+		envs, err = godotenv.Read(envPath)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+	}
+
+	for k, v := range f.env {
+		envs[k] = v
+	}
+
+	return envs, nil
+}

internal/boxcli/run.go

@@ -20,6 +20,7 @@ import (
 )
 
 type runCmdFlags struct {
+	envFlag
 	config      configFlags
 	pure        bool
 	listScripts bool
@@ -43,6 +44,7 @@ func runCmd() *cobra.Command {
 		},
 	}
 
+	flags.envFlag.register(command)
 	flags.config.register(command)
 	command.Flags().BoolVar(
 		&flags.pure, "pure", false, "If this flag is specified, devbox runs the script in an isolated environment inheriting almost no variables from the current environment. A few variables, in particular HOME, USER and DISPLAY, are retained.")
@@ -90,11 +92,16 @@ func runScriptCmd(cmd *cobra.Command, args []string, flags runCmdFlags) error {
 	debug.Log("script: %s", script)
 	debug.Log("script args: %v", scriptArgs)
 
+	env, err := flags.Env(path)
+	if err != nil {
+		return err
+	}
 	// Check the directory exists.
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    path,
 		Writer: cmd.ErrOrStderr(),
 		Pure:   flags.pure,
+		Env:    env,
 	})
 	if err != nil {
 		return redact.Errorf("error reading devbox.json: %w", err)

internal/boxcli/services.go

@@ -11,6 +11,7 @@ import (
 )
 
 type servicesCmdFlags struct {
+	envFlag
 	config configFlags
 }
 
@@ -92,6 +93,7 @@ func servicesCmd() *cobra.Command {
 		},
 	}
 
+	flags.envFlag.register(servicesCommand)
 	flags.config.registerPersistent(servicesCommand)
 	serviceUpFlags.register(upCommand)
 	serviceStopFlags.register(stopCommand)
@@ -116,8 +118,13 @@ func listServices(cmd *cobra.Command, flags servicesCmdFlags) error {
 }
 
 func startServices(cmd *cobra.Command, services []string, flags servicesCmdFlags) error {
+	env, err := flags.Env(flags.config.path)
+	if err != nil {
+		return err
+	}
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    flags.config.path,
+		Env:    env,
 		Writer: cmd.ErrOrStderr(),
 	})
 	if err != nil {
@@ -133,8 +140,13 @@ func stopServices(
 	servicesFlags servicesCmdFlags,
 	flags serviceStopFlags,
 ) error {
+	env, err := servicesFlags.Env(servicesFlags.config.path)
+	if err != nil {
+		return err
+	}
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    servicesFlags.config.path,
+		Env:    env,
 		Writer: cmd.ErrOrStderr(),
 	})
 	if err != nil {
@@ -151,8 +163,13 @@ func restartServices(
 	services []string,
 	flags servicesCmdFlags,
 ) error {
+	env, err := flags.Env(flags.config.path)
+	if err != nil {
+		return err
+	}
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    flags.config.path,
+		Env:    env,
 		Writer: cmd.ErrOrStderr(),
 	})
 	if err != nil {
@@ -168,8 +185,13 @@ func startProcessManager(
 	servicesFlags servicesCmdFlags,
 	flags serviceUpFlags,
 ) error {
+	env, err := servicesFlags.Env(servicesFlags.config.path)
+	if err != nil {
+		return err
+	}
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:                      servicesFlags.config.path,
+		Env:                      env,
 		CustomProcessComposeFile: flags.processComposeFile,
 		Writer:                   cmd.ErrOrStderr(),
 	})

internal/boxcli/shell.go

@@ -16,6 +16,7 @@ import (
 )
 
 type shellCmdFlags struct {
+	envFlag
 	config   configFlags
 	printEnv bool
 	pure     bool
@@ -42,13 +43,19 @@ func shellCmd() *cobra.Command {
 		&flags.pure, "pure", false, "If this flag is specified, devbox creates an isolated shell inheriting almost no variables from the current environment. A few variables, in particular HOME, USER and DISPLAY, are retained.")
 
 	flags.config.register(command)
+	flags.envFlag.register(command)
 	return command
 }
 
 func runShellCmd(cmd *cobra.Command, flags shellCmdFlags) error {
+	env, err := flags.Env(flags.config.path)
+	if err != nil {
+		return err
+	}
 	// Check the directory exists.
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    flags.config.path,
+		Env:    env,
 		Pure:   flags.pure,
 		Writer: cmd.ErrOrStderr(),
 	})

internal/boxcli/shellenv.go

@@ -12,6 +12,7 @@ import (
 )
 
 type shellEnvCmdFlags struct {
+	envFlag
 	config      configFlags
 	runInitHook bool
 	install     bool
@@ -45,17 +46,23 @@ func shellEnvCmd() *cobra.Command {
 		&flags.pure, "pure", false, "If this flag is specified, devbox creates an isolated environment inheriting almost no variables from the current environment. A few variables, in particular HOME, USER and DISPLAY, are retained.")
 
 	flags.config.register(command)
+	flags.envFlag.register(command)
 
 	command.AddCommand(shellEnvOnlyPathWithoutWrappersCmd())
 
 	return command
 }
 
 func shellEnvFunc(cmd *cobra.Command, flags shellEnvCmdFlags) (string, error) {
+	env, err := flags.Env(flags.config.path)
+	if err != nil {
+		return "", err
+	}
 	box, err := devbox.Open(&devopt.Opts{
 		Dir:    flags.config.path,
 		Writer: cmd.ErrOrStderr(),
 		Pure:   flags.pure,
+		Env:    env,
 	})
 	if err != nil {
 		return "", err

internal/impl/devbox.go

@@ -53,6 +53,7 @@ const (
 
 type Devbox struct {
 	cfg                      *devconfig.Config
+	env                      map[string]string
 	lockfile                 *lock.File
 	nix                      nix.Nixer
 	projectDir               string
@@ -84,6 +85,7 @@ func Open(opts *devopt.Opts) (*Devbox, error) {
 
 	box := &Devbox{
 		cfg:                      cfg,
+		env:                      opts.Env,
 		nix:                      &nix.Nix{},
 		projectDir:               projectDir,
 		pluginManager:            plugin.NewManager(),
@@ -881,6 +883,10 @@ func (d *Devbox) computeNixEnv(ctx context.Context, usePrintDevEnvCache bool) (m
 		env["XDG_DATA_DIRS"] = JoinPathLists(env["XDG_DATA_DIRS"], os.Getenv("XDG_DATA_DIRS"))
 	}
 
+	for k, v := range d.env {
+		env[k] = v
+	}
+
 	return env, d.addHashToEnv(env)
 }
 

internal/impl/devopt/devboxopts.go

@@ -7,6 +7,7 @@ import (
 type Opts struct {
 	AllowInsecureAdds        bool
 	Dir                      string
+	Env                      map[string]string
 	Pure                     bool
 	IgnoreWarnings           bool
 	CustomProcessComposeFile string