From 779f980451d20079b34812f7006f2d7230738ad0 Mon Sep 17 00:00:00 2001
From: csepp <raingloom@riseup.net>
Date: Wed, 3 Nov 2021 21:14:54 +0100
Subject: [PATCH] add extra config file option to yggdrasil command

This is useful in Guix and Nix, because one config file can come
from the world-readable store and another can be placed directly
into /etc with much stricter permissions.
---
 cmd/yggdrasil/main.go | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/cmd/yggdrasil/main.go b/cmd/yggdrasil/main.go
index 58b8230..b9df98a 100644
--- a/cmd/yggdrasil/main.go
+++ b/cmd/yggdrasil/main.go
@@ -43,11 +43,12 @@ type node struct {
 	admin     *admin.AdminSocket
 }
 
-func readConfig(log *log.Logger, useconf bool, useconffile string, normaliseconf bool) *config.NodeConfig {
+func readConfig(log *log.Logger, useconf bool, useconffile string, extraconffile string, normaliseconf bool) *config.NodeConfig {
 	// Use a configuration file. If -useconf, the configuration will be read
 	// from stdin. If -useconffile, the configuration will be read from the
 	// filesystem.
 	var conf []byte
+	var extraconf []byte
 	var err error
 	if useconffile != "" {
 		// Read the file from the filesystem
@@ -59,6 +60,21 @@ func readConfig(log *log.Logger, useconf bool, useconffile string, normaliseconf
 	if err != nil {
 		panic(err)
 	}
+	if extraconffile != "" {
+		extraconf, err = ioutil.ReadFile(extraconffile);
+	}
+	if err != nil {
+		panic(err)
+	}
+	// Generate a new configuration - this gives us a set of sane defaults -
+	// then parse the configuration we loaded above on top of it. The effect
+	// of this is that any configuration item that is missing from the provided
+	// configuration will use a sane default.
+	cfg := defaults.GenerateConfig()
+	var confs [2][]byte
+	confs[0]=conf
+	confs[1]=extraconf
+	for _, conf := range confs { if len(conf)>0 {
 	// If there's a byte order mark - which Windows 10 is now incredibly fond of
 	// throwing everywhere when it's converting things into UTF-16 for the hell
 	// of it - remove it and decode back down into UTF-8. This is necessary
@@ -72,11 +88,6 @@ func readConfig(log *log.Logger, useconf bool, useconffile string, normaliseconf
 			panic(err)
 		}
 	}
-	// Generate a new configuration - this gives us a set of sane defaults -
-	// then parse the configuration we loaded above on top of it. The effect
-	// of this is that any configuration item that is missing from the provided
-	// configuration will use a sane default.
-	cfg := defaults.GenerateConfig()
 	var dat map[string]interface{}
 	if err := hjson.Unmarshal(conf, &dat); err != nil {
 		panic(err)
@@ -136,6 +147,7 @@ func readConfig(log *log.Logger, useconf bool, useconffile string, normaliseconf
 	if err = mapstructure.Decode(dat, &cfg); err != nil {
 		panic(err)
 	}
+	}}
 	return cfg
 }
 
@@ -192,6 +204,7 @@ type yggArgs struct {
 	getaddr       bool
 	getsnet       bool
 	useconffile   string
+        extraconffile string
 	logto         string
 	loglevel      string
 }
@@ -200,6 +213,7 @@ func getArgs() yggArgs {
 	genconf := flag.Bool("genconf", false, "print a new config to stdout")
 	useconf := flag.Bool("useconf", false, "read HJSON/JSON config from stdin")
 	useconffile := flag.String("useconffile", "", "read HJSON/JSON config from specified file path")
+	extraconffile := flag.String("extraconffile", "", "extra (usually private) HJSON/JSON config from specified file path")
 	normaliseconf := flag.Bool("normaliseconf", false, "use in combination with either -useconf or -useconffile, outputs your configuration normalised")
 	confjson := flag.Bool("json", false, "print configuration from -genconf or -normaliseconf as JSON instead of HJSON")
 	autoconf := flag.Bool("autoconf", false, "automatic mode (dynamic IP, peer with IPv6 neighbors)")
@@ -213,6 +227,7 @@ func getArgs() yggArgs {
 		genconf:       *genconf,
 		useconf:       *useconf,
 		useconffile:   *useconffile,
+                extraconffile: *extraconffile,
 		normaliseconf: *normaliseconf,
 		confjson:      *confjson,
 		autoconf:      *autoconf,
@@ -265,7 +280,7 @@ func run(args yggArgs, ctx context.Context, done chan struct{}) {
 		cfg = defaults.GenerateConfig()
 	case args.useconffile != "" || args.useconf:
 		// Read the configuration from either stdin or from the filesystem
-		cfg = readConfig(logger, args.useconf, args.useconffile, args.normaliseconf)
+		cfg = readConfig(logger, args.useconf, args.useconffile, args.extraconffile, args.normaliseconf)
 		// If the -normaliseconf option was specified then remarshal the above
 		// configuration and print it back to stdout. This lets the user update
 		// their configuration file with newly mapped names (like above) or to
-- 
2.33.1