refactor: simplify env var passing by using a new config:export format

Also add a test for env vars during build time for pack-built applications.

plugins/builder-pack/builder-build

@@ -28,18 +28,11 @@ trigger-builder-pack-builder-build() {
 
   pushd "$SOURCECODE_WORK_DIR" &>/dev/null
 
-  ENV_ARGS_VALUES="$(config_export app "$APP" --format envfile --merged)"
-
-  while IFS= read -r line; do
-    ENV_ARGS="$ENV_ARGS--env ${line%=*} "
-  done <<< "$ENV_ARGS_VALUES"
-
+  ENV_ARGS=($(config_export app "$APP" --format pack --merged))
   eval "$(config_export app "$APP" --merged)"
 
   plugn trigger pre-build-pack "$APP" "$SOURCECODE_WORK_DIR"
-
-  eval "pack build "$IMAGE" --builder "$DOKKU_CNB_BUILDER" --path "$SOURCECODE_WORK_DIR" --default-process web "$ENV_ARGS""
-
+  pack build "$IMAGE" --builder "$DOKKU_CNB_BUILDER" --path "$SOURCECODE_WORK_DIR" --default-process web "${ENV_ARGS[@]}"
   docker-image-labeler --label=com.dokku.image-stage=build --label=com.dokku.app-name=$APP --label=org.label-schema.schema-version=1.0 --label=org.label-schema.vendor=dokku --label=dokku "$IMAGE"
 
   plugn trigger post-build-pack "$APP" "$SOURCECODE_WORK_DIR"

plugins/config/environment.go

@@ -26,7 +26,7 @@ const (
 	ExportFormatEnvfile
 	//ExportFormatDockerArgs format: --env KEY=VALUE args for docker
 	ExportFormatDockerArgs
-	//ExportFormatDockerArgsKeys format: --env KEY args for docker
+	//ExportFormatDockerArgsKeys format: --env=KEY args for docker
 	ExportFormatDockerArgsKeys
 	//ExportFormatShell format: env arguments for shell
 	ExportFormatShell
@@ -36,6 +36,8 @@ const (
 	ExportFormatJSON
 	//ExportFormatJSONList format: json output as a list of objects
 	ExportFormatJSONList
+	//ExportFormatPackArgKeys format: --env KEY args for pack
+	ExportFormatPackArgKeys
 )
 
 //Env is a representation for global or app environment
@@ -183,6 +185,8 @@ func (e *Env) Export(format ExportFormat) string {
 		return e.JSONString()
 	case ExportFormatJSONList:
 		return e.JSONListString()
+	case ExportFormatPackArgKeys:
+		return e.PackArgKeysAsString()
 	default:
 		common.LogFail(fmt.Sprintf("Unknown export format: %v", format))
 		return ""
@@ -244,6 +248,16 @@ func (e *Env) JSONListString() string {
 	return string(data)
 }
 
+//PackArgKeysAsString gets the contents of this Env in the form -env KEY --env...
+func (e *Env) PackArgKeysAsString() string {
+	keys := e.Keys()
+	entries := make([]string, len(keys))
+	for i, k := range keys {
+		entries[i] = fmt.Sprintf("%s%s", "--env ", k)
+	}
+	return strings.Join(entries, " ")
+}
+
 //ShellString gets the contents of this Env in the form "KEY='value' KEY2='value'"
 // for passing the environment in the shell
 func (e *Env) ShellString() string {

plugins/config/functions.go

@@ -13,14 +13,15 @@ func export(appName string, global bool, merged bool, format string) error {
 	suffix := "\n"
 
 	exportTypes := map[string]ExportFormat{
-		"exports":          ExportFormatExports,
-		"envfile":          ExportFormatEnvfile,
 		"docker-args":      ExportFormatDockerArgs,
 		"docker-args-keys": ExportFormatDockerArgsKeys,
-		"shell":            ExportFormatShell,
-		"pretty":           ExportFormatPretty,
+		"envfile":          ExportFormatEnvfile,
+		"exports":          ExportFormatExports,
 		"json":             ExportFormatJSON,
 		"json-list":        ExportFormatJSONList,
+		"pack":             ExportFormatPackArgKeys,
+		"pretty":           ExportFormatPretty,
+		"shell":            ExportFormatShell,
 	}
 
 	exportType, ok := exportTypes[format]

plugins/config/src/subcommands/subcommands.go

@@ -49,7 +49,7 @@ func main() {
 		args := flag.NewFlagSet("config:export", flag.ExitOnError)
 		global := args.Bool("global", false, "--global: use the global environment")
 		merged := args.Bool("merged", false, "--merged: merge app environment and global environment")
-		format := args.String("format", "exports", "--format: [ exports | envfile | docker-args | docker-args-keys | shell | pretty | json | json-list ] which format to export as)")
+		format := args.String("format", "exports", "--format: [ docker-args | docker-args-keys | exports | envfile | json | json-list | pack | pretty | shell ] which format to export as)")
 		args.Parse(os.Args[2:])
 		if !*global {
 			appName = args.Arg(0)

tests/apps/python/bin/pre_compile

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+echo "Build time env var SECRET_KEY=${SECRET_KEY}"

tests/unit/builder-pack.bats

@@ -15,6 +15,11 @@ teardown() {
 }
 
 @test "(builder-pack:set)" {
+  run /bin/bash -c "dokku config:set $TEST_APP SECRET_KEY=fjdkslafjdk"
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
   run /bin/bash -c "dokku builder:set $TEST_APP selected pack"
   echo "output: $output"
   echo "status: $status"
@@ -31,6 +36,7 @@ teardown() {
   assert_success
   assert_output_contains 'Building with buildpack 1' 0
   assert_output_contains 'Installing requirements with pip'
+  assert_output_contains "Build time env var SECRET_KEY=fjdkslafjdk"
 
   run /bin/bash -c "dokku builder-pack:set $TEST_APP projecttoml-path nonexistent.toml"
   echo "output: $output"