restic plugin for Caddy

example.Caddyfile

example.com

# specifying an empty root is not strictly necessary but not a bad
# idea if all you are serving on this site is the backups
root empty_www/

# authentication is required when using the Caddy plugin;
# this line assumes all requests are protected
basicauth / user pass

# enable restic for all requests, and store repos in /mnt/backup
restic / /home/matt/mybackups

# All valid restic syntaxes:
#
# restic
# 	This enables restic for all requests and uses the default data path
#
# restic /backups
#	This enables restic for all requests to /backups with default data path
#
# restic /backups /datapath
#	This enables restic for all requests to /backups and stores data in /datapath

restic.go

package restic

import (
	"net/http"
	"strings"

	"github.com/mholt/caddy/caddyhttp/httpserver"
)

type ResticHandler struct {
	Next          httpserver.Handler
	BasePath      string
	RestServerMux http.Handler
}

func (h ResticHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
	if !httpserver.Path(r.URL.Path).Matches(h.BasePath) {
		return h.Next.ServeHTTP(w, r)
	}

	// basic auth is required (some authentication is required, for obvious reasons)
	basicAuthUser, ok := r.Context().Value(httpserver.RemoteUserCtxKey).(string)
	if !ok || basicAuthUser == "" {
		return http.StatusForbidden, nil
	}

	// strip the base path from the request so that the restic mux can load
	// the repo relative to its Config.Path base path.
	r.URL.Path = strings.TrimPrefix(r.URL.Path, h.BasePath)
	if !strings.HasPrefix(r.URL.Path, "/") {
		r.URL.Path = "/" + r.URL.Path
	}

	// TODO: this doesn't return values so errors may not be handled properly. Oh well.
	h.RestServerMux.ServeHTTP(w, r)

	return 0, nil
}

setup.go

package restic

import (
	"github.com/mholt/caddy"
	"github.com/mholt/caddy/caddyhttp/httpserver"
	restserver "github.com/restic/rest-server"
)

func init() {
	caddy.RegisterPlugin("restic", caddy.Plugin{
		ServerType: "http",
		Action:     setup,
	})
}

func setup(c *caddy.Controller) error {
	var basePath string

	for c.Next() {
		if c.NextArg() {
			basePath = c.Val()
		}
		if c.NextArg() {
			restserver.Config.Path = c.Val()
		}
		if c.NextArg() {
			return c.ArgErr()
		}
	}

	if basePath == "" {
		basePath = "/"
	}

	cfg := httpserver.GetConfig(c)
	mid := func(next httpserver.Handler) httpserver.Handler {
		return ResticHandler{
			Next:          next,
			BasePath:      basePath,
			RestServerMux: restserver.NewMux(),
		}
	}
	cfg.AddMiddleware(mid)

	return nil
}