[config] first cut of config rewritten in golang

still to do:
* Rework disk format to be okay with quotes
* Fix Dockerfile deployments
* Dedup code in the subcommands
* Add --encode
* Add deploytests for the new stuff
* Restore some log messages (should I make some helpers in common?)
* Restore some functions that may be used by 3d-party plugins

plugins/config/src/subcommands/export/export.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	common "github.com/dokku/dokku/plugins/common"
+	"github.com/dokku/dokku/plugins/config/src/configenv"
+)
+
+// print the environment to stdout
+func main() {
+	args := flag.NewFlagSet("config:export", flag.ExitOnError)
+	global := args.Bool("global", false, "--global: use the global environment")
+	envfile := args.Bool("envfile", false, "--envfile: export as envfile rather than bash exports")
+	args.Parse(os.Args[2:])
+
+	appName := args.Arg(0)
+	if appName == "" && !*global {
+		common.LogFail("Please specify an app or --global")
+	}
+
+	if *global {
+		if appName != "" {
+			common.LogFail("Trailing argument: " + appName)
+		}
+		appName = "--global"
+	}
+
+	env, err := configenv.NewFromTarget(appName)
+	if err != nil {
+		common.LogFail(err.Error())
+	}
+	if *envfile {
+		fmt.Println(env.EnvfileString())
+	} else {
+		fmt.Println(env.ExportfileString())
+	}
+}

plugins/config/src/subcommands/get/get.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	common "github.com/dokku/dokku/plugins/common"
+	"github.com/dokku/dokku/plugins/config/src/configenv"
+)
+
+// get the given entries from the specified environment
+func main() {
+	args := flag.NewFlagSet("config:get", flag.ExitOnError)
+	global := args.Bool("global", false, "--global: use the global environment")
+	args.Parse(os.Args[2:])
+	appName := args.Arg(0)
+	nextArg := 0
+	if appName == "" && !*global {
+		common.LogFail("Please specify an app or --global")
+	}
+
+	if *global {
+		appName = "--global"
+	} else {
+		nextArg = 1
+	}
+
+	env, err := configenv.NewFromTarget(appName)
+	if err != nil {
+		common.LogFail(err.Error())
+	}
+
+	if args.NArg() > nextArg+1 {
+		common.LogFail(fmt.Sprintf("Unexpected argument(s): %v", args.Args()[nextArg+1:]))
+	}
+	key := args.Arg(nextArg)
+	fmt.Printf("%s", env.GetDefault(key, ""))
+}

plugins/config/src/subcommands/set/set.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"flag"
+
+	"strings"
+
+	"os"
+
+	common "github.com/dokku/dokku/plugins/common"
+	"github.com/dokku/dokku/plugins/config/src/configenv"
+)
+
+// set the given entries from the specified environment
+func main() {
+	args := flag.NewFlagSet("config:set", flag.ExitOnError)
+	global := args.Bool("global", false, "--global: use the global environment")
+	noRestart := args.Bool("no-restart", false, "--no-restart: no restart")
+	args.Parse(os.Args[2:])
+	shouldRestart := !*global && !*noRestart
+	var nextArg = 0
+	appName := args.Arg(0)
+	if appName == "" && !*global {
+		common.LogFail("Please specify an app or --global")
+	}
+
+	if *global {
+		appName = "--global"
+	} else {
+		nextArg = 1
+	}
+
+	env, err := configenv.NewFromTarget(appName)
+	if err != nil {
+		common.LogFail(err.Error())
+	}
+
+	var changed = false
+	entries := args.Args()[nextArg:]
+	for _, e := range entries {
+		//log
+		parts := strings.SplitN(e, "=", 2)
+		if len(parts) == 1 {
+			common.LogFail("Invalid env pair: " + e)
+		}
+		env.Set(parts[0], parts[1])
+		changed = true
+	}
+
+	if changed {
+		//log
+		env.Write()
+		args := append([]string{appName, "set"}, entries...)
+		common.PlugnTrigger("post-config-update", args...)
+	}
+
+	if shouldRestart && env.GetBoolDefault("DOKKU_APP_RESTORE", true) {
+		cmd := common.NewTokenizedShellCmd("dokku", "ps:restart", appName)
+		cmd.Execute()
+	}
+}

plugins/config/src/subcommands/unset/unset.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"flag"
+	"os"
+
+	common "github.com/dokku/dokku/plugins/common"
+	"github.com/dokku/dokku/plugins/config/src/configenv"
+)
+
+//unset the given entries from the given environment
+func main() {
+	args := flag.NewFlagSet("config:unset", flag.ExitOnError)
+	global := args.Bool("global", false, "--global: use the global environment")
+	noRestart := args.Bool("no-restart", false, "--no-restart: no restart")
+	args.Parse(os.Args[2:])
+	shouldRestart := !*global && !*noRestart
+	var nextArg = 0
+	appName := args.Arg(0)
+	if appName == "" && !*global {
+		common.LogFail("Please specify an app or --global")
+	}
+
+	if *global {
+		appName = "--global"
+	} else {
+		nextArg = 1
+	}
+
+	env, err := configenv.NewFromTarget(appName)
+	if err != nil {
+		common.LogFail(err.Error())
+	}
+
+	var changed = false
+	keys := args.Args()[nextArg:]
+	for _, k := range keys {
+		//log
+		env.Unset(k)
+		changed = true
+	}
+
+	if changed {
+		//log
+		env.Write()
+		args := append([]string{appName, "unset"}, keys...)
+		common.PlugnTrigger("post-config-update", args...)
+	}
+
+	if shouldRestart && env.GetBoolDefault("DOKKU_APP_RESTORE", true) {
+		cmd := common.NewTokenizedShellCmd("dokku", "ps:restart", appName)
+		cmd.Execute()
+	}
+}