Add a default path for the config file

Makefile

@@ -5,13 +5,18 @@ GOFLAGS ?=
 PREFIX ?= /usr/local
 BINDIR ?= bin
 MANDIR ?= share/man
+SYSCONFDIR ?= etc
+
+config_path := $(DESTDIR)/$(SYSCONFDIR)/soju/config
+goflags := $(GOFLAGS) \
+	-ldflags="-X 'git.sr.ht/~emersion/soju/config.DefaultPath=$(config_path)'"
 
 all: soju sojuctl doc/soju.1
 
 soju:
-	$(GO) build $(GOFLAGS) ./cmd/soju
+	$(GO) build $(goflags) ./cmd/soju
 sojuctl:
-	$(GO) build $(GOFLAGS) ./cmd/sojuctl
+	$(GO) build $(goflags) ./cmd/sojuctl
 doc/soju.1: doc/soju.1.scd
 	$(SCDOC) <doc/soju.1.scd >doc/soju.1
 
@@ -20,10 +25,10 @@ clean:
 install:
 	mkdir -p $(DESTDIR)$(PREFIX)/$(BINDIR)
 	mkdir -p $(DESTDIR)$(PREFIX)/$(MANDIR)/man1
-	mkdir -p $(DESTDIR)/etc/soju
+	mkdir -p $(DESTDIR)/$(SYSCONFDIR)/soju
 	mkdir -p $(DESTDIR)/var/lib/soju
 	cp -f soju sojuctl $(DESTDIR)$(PREFIX)/$(BINDIR)
 	cp -f doc/soju.1 $(DESTDIR)$(PREFIX)/$(MANDIR)/man1
-	[ -f $(DESTDIR)/etc/soju/config ] || cp -f config.in $(DESTDIR)/etc/soju/config
+	[ -f $(config_path) ] || cp -f config.in $(config_path)
 
 .PHONY: soju sojuctl clean install

cmd/soju/main.go

@@ -108,7 +108,7 @@ func loadConfig() (*config.Server, *soju.Config, error) {
 func main() {
 	var listen []string
 	flag.Var((*stringSliceFlag)(&listen), "listen", "listening address")
-	flag.StringVar(&configPath, "config", "", "path to configuration file")
+	flag.StringVar(&configPath, "config", config.DefaultPath, "path to configuration file")
 	flag.BoolVar(&debug, "debug", false, "enable debug logging")
 	flag.Parse()
 

cmd/sojuctl/main.go

@@ -31,7 +31,7 @@ func init() {
 
 func main() {
 	var configPath string
-	flag.StringVar(&configPath, "config", "", "path to configuration file")
+	flag.StringVar(&configPath, "config", config.DefaultPath, "path to configuration file")
 	flag.Parse()
 
 	var cfg *config.Server

config/config.go

@@ -11,6 +11,8 @@ import (
 	"git.sr.ht/~emersion/go-scfg"
 )
 
+var DefaultPath string
+
 type IPSet []*net.IPNet
 
 func (set IPSet) Contains(ip net.IP) bool {