Howto install Bitwarden in a LXC container (e.g. Proxmox)

January 13, 2019

As many of you know me, I’m quite serious about security and therefore a believer in the theory that a service which is not reachable (e.g. from the Internet) cannot be attacked as easily as one that it. Looking at password managers this makes choosing not that easy. Sure there is Keepass and the descendants, but they have the problem that the security is based solely on the master password and the end device security. Knowing friends that use Google Drive for syncing the password file between their devices, I looked at that option, but it was not right for me (e.g. Browser integration, 2FA, …).

Password managers like Lastpass or 1Password are also not the right solution for me. Yes, I believe that their crypto is good, and they never see the passwords of their users, but the 2FA is only as good as the lost password/2FA reset feature is. I’ve read and seen to many attacks on that to rely on it.

All of this leads to Bitwarden, it provides the same level of functionality as Lastpass or 1Password but is OpenSource and can be hosted on my own server. Not opening it up to Internet and using it from remote only via VPN (which I have anyway) make for a real small attack surface. This blog post shows how I installed it within a Proxmox LXC container, which I did to isolated it from other stuff and therefore there are no dependencies, if I need to upgrade something. I don’t like to install anything on the Proxmox host itself. As this is my first try, and I run into a problem with an unprivileged container and docker within it, this setup works currently only with a privileged container. I know this is not that good, but in this case it is a risk I can accept. If you find a solution to get it running in an unprivileged container please send me an email or write a comment.

LXC container

After creating the LXC container (2Gb RAM, >5GB HD) with Debian 9, don’t start the container at once. You need to add following to /etc/modules-load.d/modules.conf

aufs
overlay

And if you don’t want to boot load the modules with

modprobe aufs
modprobe overlay


If you don’t do this your installation will get gigantic (over 30gb). Now we just need to add following to /etc/pve/lxc/<vid>.conf

#insert docker part below
lxc.apparmor.profile: unconfined
lxc.cgroup.devices.allow: a
lxc.cap.drop:

Now you can start the container and enter it, we’ll check later if all was correct, but we need docker for this.

Docker and Docker Composer

Some requirements for docker

apt install apt-transport-https ca-certificates curl gnupg2 software-properties-common

and now we can add the repository for docker

curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add -
add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable"

and now we can install it with

apt-get update apt-get install docker-ce

The Docker Composer which is shipped with Debian is too old to work with this docker, so we need following:

curl -L "https://github.com/docker/compose/releases/download/1.23.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
chmod +x /usr/local/bin/docker-compose

and add /usr/local/bin/ to the path variable by adding

PATH=/usr/local/bin:$PATH

to .bashrc and calling it directly in the bash to get it set without starting a new bash instance. I know that a package would be better, couldn’t find one, so this is a temporary solution. If someone finds a better one, leave it in the comments below.

Now we need to check if the overlay stuff is working by calling docker info and hopefully you get also overlay2 as storage driver:

Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 0
Server Version: 18.06.1-ce
Storage Driver: overlay2
Backing Filesystem: extfs
Supports d_type: true
Native Overlay Diff: true
Logging Driver: json-file

Bitwarden

Now we just need following:

curl -s -o bitwarden.sh https://raw.githubusercontent.com/bitwarden/core/master/scripts/bitwarden.sh
chmod +x bitwarden.sh
./bitwarden.sh install
./bitwarden.sh start
./bitwarden.sh updatedb

And now you’re done, you’ve your own password manager server which also supports Google Authenticator (Time-based One-time Password Algorithm (TOTP) as second factor. Maybe I’ll write a blogpost how to setup a Yubikey as 2FA (desktop and mobile) later.