ixvick/rest-server

Rest Server is a high performance HTTP server that implements restic's REST backend API.

Rest Server

Rest Server is a high performance HTTP server that implements restic's REST backend API. It provides secure and efficient way to backup data remotely, using restic backup client via the rest: URL.

Requirements

Rest Server requires Go 1.14 or higher to build. The only tested compiler is the official Go compiler. Building server with gccgo may work, but is not supported.

The required version of restic backup client to use with rest-server is v0.7.1 or higher.

Build

For building the rest-server binary run CGO_ENABLED=0 go build -o rest-server ./cmd/rest-server

Docker

Build image

The docker image build process will build a fresh version of the rest-server and package that into a usable container.

To build the binary along with the container run:

docker build -t restic/rest-server:latest .

Pull image

docker pull restic/rest-server

Usage

To learn how to use restic backup client with REST backend, please consult restic manual.

$ rest-server --help

Run a REST server for use with restic

Usage:
  rest-server [flags]

Flags:
      --append-only          enable append only mode
      --cpu-profile string   write CPU profile to file
      --debug                output debug messages
  -h, --help                 help for rest-server
      --listen string        listen address (default ":8000")
      --log string           log HTTP requests in the combined log format
      --max-size int         the maximum size of the repository in bytes
      --no-auth              disable .htpasswd authentication
      --no-verify-upload     do not verify the integrity of uploaded data. DO NOT enable unless the rest-server runs on a very low-power device
      --path string          data directory (default "/tmp/restic")
      --private-repos        users can only access their private repo
      --prometheus           enable Prometheus metrics
      --prometheus-no-auth   disable auth for Prometheus /metrics endpoint
      --tls                  turn on TLS support
      --tls-cert string      TLS certificate path
      --tls-key string       TLS key path
  -v, --version              version for rest-server

By default the server persists backup data in the OS temporary directory (/tmp/restic on Linux/BSD and others, in %TEMP%\\restic in Windows, etc). If rest-server is launched using the default path, all backups will be lost. To start the server with a custom persistence directory and with authentication disabled:

rest-server --path /user/home/backup --no-auth

To authenticate users (for access to the rest-server), the server supports using a .htpasswd file to specify users. You can create such a file at the root of the persistence directory by executing the following command (note that you need the htpasswd program from Apache's http-tools). In order to append new user to the file, just omit the -c argument. Only bcrypt and SHA encryption methods are supported, so use -B (very secure) or -s (insecure by today's standards) when adding/changing passwords.

htpasswd -B -c .htpasswd username

If you want to disable authentication, you must add the --no-auth flag. If this flag is not specified and the .htpasswd cannot be opened, rest-server will refuse to start.

NOTE: In older versions of rest-server (up to 0.9.7), this flag does not exist and the server disables authentication if .htpasswd is missing or cannot be opened.

By default the server uses HTTP protocol. This is not very secure since with Basic Authentication, user name and passwords will be sent in clear text in every request. In order to enable TLS support just add the --tls argument and add a private and public key at the root of your persistence directory. You may also specify private and public keys by --tls-cert and --tls-key.

Signed certificate is normally required by the restic backend, but if you just want to test the feature you can generate unsigned keys with the following commands:

openssl req -newkey rsa:2048 -x509 -keyout private_key -out public_key -days 365 -addext "subjectAltName = IP:127.0.0.1,DNS:yourdomain.com"

Omit the IP:127.0.0.1 if you don't need your server be accessed via SSH Tunnels. No need to change default values in the openssl dialog, hitting enter every time is sufficient. To access this server via restic use --cacert public_key, meaning with a self-signed certificate you have to distribute your public_key file to every restic client.

The --append-only mode allows creation of new backups but prevents deletion and modification of existing backups. This can be useful when backing up systems that have a potential of being hacked.

To prevent your users from accessing each others' repositories, you may use the --private-repos flag which grants access only when a subdirectory with the same name as the user is specified in the repository URL. For example, user "foo" using the repository URLs rest:https://foo:pass@host:8000/foo or rest:https://foo:pass@host:8000/foo/ would be granted access, but the same user using repository URLs rest:https://foo:pass@host:8000/ or rest:https://foo:pass@host:8000/foobar/ would be denied access. Users can also create their own subrepositories, like /foo/bar/.

Rest Server uses exactly the same directory structure as local backend, so you should be able to access it both locally and via HTTP, even simultaneously.

Systemd

There's an example systemd service file included with the source, so you can get Rest Server up & running as a proper Systemd service in no time. Before installing, adapt paths and options to your environment.

Docker

By default, image uses authentication. To turn it off, set environment variable DISABLE_AUTHENTICATION to any value.

Persistent data volume is located to /data.

Start server

docker run -p 8000:8000 -v /my/data:/data --name rest_server restic/rest-server

It's suggested to set a container name to more easily manage users (see next section).

You can set environment variable OPTIONS to any extra flags you'd like to pass to rest-server.

Manage users

Add user

docker exec -it rest_server create_user myuser

or

docker exec -it rest_server create_user myuser mypassword

Delete user

docker exec -it rest_server delete_user myuser

Prometheus support and Grafana dashboard

The server can be started with --prometheus to expose Prometheus metrics at /metrics. If authentication is enabled, this endpoint requires authentication for the 'metrics' user, but this can be overridden with the --prometheus-no-auth flag.

This repository contains an example full stack Docker Compose setup with a Grafana dashboard in examples/compose-with-grafana/.

Why use Rest Server?

Compared to the SFTP backend, the REST backend has better performance, especially so if you can skip additional crypto overhead by using plain HTTP transport (restic already properly encrypts all data it sends, so using HTTPS is mostly about authentication).

But, even if you use HTTPS transport, the REST protocol should be faster and more scalable, due to some inefficiencies of the SFTP protocol (everything needs to be transferred in chunks of 32 KiB at most, each packet needs to be acknowledged by the server).

One important safety feature that Rest Server adds is the optional ability to run in append-only mode. This prevents an attacker from wiping your server backups when access is gained to the server being backed up.

Finally, the Rest Server implementation is really simple and as such could be used on the low-end devices, no problem. Also, in some cases, for example behind corporate firewalls, HTTP/S might be the only protocol allowed. Here too REST backend might be the perfect option for your backup needs.

Contributors

Contributors are welcome, just open a new issue / pull request.