fix: implement config-export hook

This will allow dropping many of the "source config/functions" calls littered over the codebase. Plugin triggers are the way to perform cross-plugin communication :)

plugins/config/functions.go

@@ -0,0 +1,38 @@
+package config
+
+import "fmt"
+
+func export(appName string, global bool, merged bool, format string) error {
+	appName, err := getAppNameOrGlobal(appName, global)
+	if err != nil {
+		return err
+	}
+
+	env := getEnvironment(appName, merged)
+	exportType := ExportFormatExports
+	suffix := "\n"
+
+	exportTypes := map[string]ExportFormat{
+		"exports":          ExportFormatExports,
+		"envfile":          ExportFormatEnvfile,
+		"docker-args":      ExportFormatDockerArgs,
+		"docker-args-keys": ExportFormatDockerArgsKeys,
+		"shell":            ExportFormatShell,
+		"pretty":           ExportFormatPretty,
+		"json":             ExportFormatJSON,
+		"json-list":        ExportFormatJSONList,
+	}
+
+	exportType, ok := exportTypes[format]
+	if !ok {
+		return fmt.Errorf("Unknown export format: %v", format)
+	}
+
+	if exportType == ExportFormatShell {
+		suffix = " "
+	}
+
+	exported := env.Export(exportType)
+	fmt.Print(exported + suffix)
+	return nil
+}