main.go

// socle is a read-only web host for local git repositories:
// browsing of committed state at refs, and anonymous fetch over smart HTTP.
// Nothing in it can write to a repo.
package main

import (
	"flag"
	"log"
	"net/http"
	"os"
	"time"

	"vitrine/display"
)

func main() {
	configPath := flag.String("config", "", "path to the socle config file (required; there is no default location)")
	listen := flag.String("listen", ":8080", "listen address")
	themeSeed := flag.String("theme-seed", "", "theme name override (default: first dot-segment of the hostname)")
	flag.Parse()
	if *configPath == "" {
		log.Fatal("socle: the -config flag is required")
	}
	seed := *themeSeed
	if seed == "" {
		hostname, err := os.Hostname()
		if err != nil {
			log.Fatalf("socle: cannot determine hostname for theming (use -theme-seed to bypass): %v", err)
		}
		seed = display.HostLabel(hostname)
	}
	cfg, err := loadConfig(*configPath)
	if err != nil {
		log.Fatal("socle: ", err)
	}
	repos, warnings := openAll(cfg)
	for _, w := range warnings {
		log.Print("socle: ", w)
	}
	srv := newServer(repos, display.NewTheme(seed))

	// Config changes apply live: reloads are fail-stable
	// (any problem logs loudly and the old repo set keeps serving),
	// while startup above stays fail-closed as ever.
	watchConfig(*configPath, 5*time.Second, func() {
		reloadConfig(srv, *configPath)
	})

	log.Printf("socle: serving %d repos on %s", len(repos), *listen)
	log.Fatal(http.ListenAndServe(*listen, srv))
}

// reloadConfig loads the config file and swaps the server's repo set to it.
// Fail-stable, unlike startup: a config that cannot be loaded (parse or validation
// failure) or that yields not one openable repo is rejected loudly and the previous
// set keeps serving -- a showcase must not go dark from one typo mid-edit.
// Per-repo open failures are the same warning-and-skip as at startup.
func reloadConfig(srv *server, path string) {
	cfg, err := loadConfig(path)
	if err != nil {
		log.Printf("socle: config reload REJECTED, keeping previous repos: %v", err)
		return
	}
	repos, warnings := openAll(cfg)
	for _, w := range warnings {
		log.Print("socle: ", w)
	}
	if len(repos) == 0 {
		log.Printf("socle: config reload REJECTED, keeping previous repos: no configured repo could be opened")
		return
	}
	srv.setRepos(repos)
	log.Printf("socle: config reloaded: %d repos", len(repos))
}