Rest Server - gokrazy

This repository contains the package and gokrazy application for Restic's Rest Server

Disk Setup

Before running the rest-server we need to setup the disk so that it can be used directly.

Directory

We need a directory inside the external disk which can be used. for example we can use a directory named restic/ which will have all the named directories by username and other configurations.

cd /run/media/username/diskname
mkdir restic/

Authentication

If rest-server is used in authentication mode the directory should have .htpasswd file with bcrypt hashed password. This can be carried out by running following command

touch restic/.htpasswd
htpasswd -B restic/.htpasswd username

For all the users needed for authentication we can repeat the last command.

gokrazy Setup

gokrazy does not support mounting a disk directly, so this project wraps the original arm64 binary of restic's rest-server into /usr/local/bin with mount options.

Before we begin, we setup the directory where we can keep package files for gokrazy.

go mod init rpi4-gorilla                # this is an arbitrary name

go get development.thatwebsite.xyz/gokrazy/restic-rest-server@latest
go get github.com/restic/[email protected]

The gokr-packer will need to add these two packages in the list.

gokr-packer -hostname rpi4-gorilla.local \
  -update=yes -serial_console=disabled \
  github.com/gokrazy/breakglass \
  github.com/gokrazy/serial-busybox \
  github.com/restic/rest-server/cmd/rest-server \
  development.thatwebsite.xyz/gokrazy/util-linux \
  development.thatwebsite.xyz/gokrazy/restic-rest-server

We don't want rest-server to start directly, so we disable it using dontstart.txt.

mkdir -p dontstart/github.com/restic/rest-server/cmd/rest-server
touch dontstart/github.com/restic/rest-server/cmd/rest-server/dontstart.txt

Mount Specifications

This program uses three environment variables for this specification

• MNT_SOURCE: source device for mounting.
• MNT_TARGET: target directory where the device should be mounted.
• MNT_FSTYPE: filesystem type of the device, e.g. exfat, ext4, vfat, etc...

To use these variables there needs to be the following file in the directory where the gokr-packer command is being run.

# in the same directory as go.mod

mkdir -p env/development.thatwebsite.xyz/gokrazy/restic-rest-server/
cat << EOF > env/development.thatwebsite.xyz/gokrazy/restic-rest-server/env.txt
MNT_SOURCE=/dev/sda1
MNT_TARGET=/perm/rest-server
MNT_FSTYPE=exfat
EOF

Flags

This program transparently passes all arguments to rest-server command and also the stdout/stderr from it, so the flags or arguments which we want to pass will be actually going in to rest-server

To add flags we can just create flags.txt same as the env.txt

mkdir -p flags/development.thatwebsite.xyz/gokrazy/restic-rest-server/
cat < EOF > flags/development.thatwebsite.xyz/gokrazy/restic-rest-server/flags.txt
--path
/perm/rest-server/restic

Here we are defining where the root of the rest-server should be available. Also in case if there's need to add more arguments/flags just add it in this file separated by new lines.

Enabling Private Access to repositories

Other flags can be --private-repos which enables authentication and prevents anyone accessing the repository without basic auth.

Enabling Prometheus Metrics

Passing --prometheus enables the Prometheus /metrics endpoint, but if that is used with --private-repos a new user should be created with name metrics to access the endpoint.

Other options

In some cases the command/program will run before the /perm/ directory is mounted and that will make it fail and retry after a second. To avoid that, we can have a delay in startup using waitforclock feature.

mkdir -p waitforclock/development.thatwebsite.xyz/gokrazy/restic-rest-server/
touch waitforclock/development.thatwebsite.xyz/gokrazy/restic-rest-server/waitforclock.txt

These commands will actually instruct gokrazy to start the rest-server only after the NTP has synced the clock, which from my observations is also after mounting the /perm/ directory.