docker common containers

Quick Project: Splitting Docker Compose Projects

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Way back in the when I first started using Docker in earnest, I wrote about my web hosting stack. Recently, this has undergone an upgrade as I’m working on a new website which will be served from the same server. I took the opportunity to split the system up into multiple docker-compose projects, which makes deployment of further sites much easier. It allows me to manage the common containers from one docker-compose project and then each of the sites from their own project. This will be of further use in future as I move towards deploying these with Ansible.

The Approach

My basic approach here is to move my two common containers (my Traefik container and SMTP forwarder) into their own project. This project will create a couple of networks for interfacing to the containers from other projects. To create these networks I add the following to my common project docker-compose.yml:

networks:
  gateway:
    name: 'gateway'
  smtp:
    name: 'smtp'

Here I create two networks as per normal. The key is to give them a proper name, rather than the auto generated one that would be assigned by Docker. This will enable us to address them easily from our other projects. We then assign these to our common containers:

services:
  traefik:
    image: traefik:2.1
    command:
      ...
    volumes:
      ...
    ports:
      - "80:80"
      - "443:443"
      - "127.0.0.1:8080:8080"
    networks:
      gateway:
        aliases:
          # add hostnames you might want to refer to this container by
          - example.com
    restart: always

  postfix:
    image: boky/postfix
    ports:
      ...
    environment:
      ...
    volumes:
      ...
    networks:
      smtp:
        aliases:
          - postfix
    restart: always

Here I simply assign the relevant network to each container. The aliases section allows other containers on these networks to find our common containers by whatever name we specify. In the case of the postfix container this is to connect via SMTP. For the traefik container, adding hostnames which internal apps my need to refer to can help (for example with the WordPress loopback test).

External Projects

With this in place, the other applications can be moved out into their own projects. For each one we need to access the gateway and smtp networks in order to have access to our common services. These are accessed as external networks via the docker-compose.yaml file for our project:

networks:
  gateway:
    external: true
  smtp:
    external: true

We then go ahead and add our services to access these networks:

services:
  varnish:
    image: wodby/varnish:latest
    depends_on:
      - wordpress
    environment:
      ...
    labels:
      - 'traefik.enable=true'
      - "traefik.docker.network=gateway"
      ...
    networks:
      - gateway
      - cache
    restart: always

  wordpress:
    image: wordpress:latest
    depends_on:
      - mariadb
    environment:
      ...
    volumes:
      ...
    networks:
      smtp:
      cache:
      database:
    restart: always

Here I add my varnish cache, as per my previous article. The key thing here is to specify the label traefik.docker.network=gateway to allow Traefik to reliably discover the container. We then also make sure the container is added to the gateway network. I’ve also added a WordPress container, which is on the smtp network. This will allow sending of email from WordPress via the SMTP forwarder.

Conclusion

This is a pretty simple approach for better management of my increasingly complex web stack. As I mentioned earlier that the next step will be to deploy these projects via Ansible. In this case the common containers will become part of a role which can be used across my infrastructure.

The splitting out of the apps into their own projects has enabled me to duplicate my current WordPress+Varnish+Mariadb setup for the new site I’m working on. There will be more info to come about that site as soon as I am ready to share!

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rss-bridge

Reconnecting the Web with RSS-Bridge

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I’ve mentioned before that I’m a big fan of RSS as a medium for consuming my daily news and for following the blogs of others. However, there are an increasing number of websites that don’t provide an RSS feed (or at least don’t advertise a feed if one exists). Luckily for us there is an awesome piece of self-hosted software which aims to fill in the gaps left by these missing feeds – RSS-bridge.

My use case for this was twofold. First I wanted to follow some sites for which I couldn’t find RSS feeds, specifically The Guardian. Second, I wanted to get updates from some local groups, who only have a Facebook page. Obviously, I don’t actually want to actually check in to Facebook to do this, that would be intolerable. RSS-Bridge fills both these needs.

Installation

There are several public instances of RSS-bridge available, but of course I wanted to host my own. Doing so is extremely easy with Docker. I added the following to my docker-compose.yml file on the server in question:

services:
  rss-bridge:
    image: rssbridge/rss-bridge:latest
    volumes:
      - /mnt/docker-data/rss-bridge/whitelist.txt:/app/whitelist.txt
    labels:
      - 'traefik.enable=true'
      - "traefik.http.middlewares.rssbridge_redirect.redirectscheme.scheme=https"
      - "traefik.http.routers.rssbridge_insecure.rule=Host(`rssbridge.example.com`)"
      - "traefik.http.routers.rssbridge_insecure.entrypoints=web"
      - "traefik.http.routers.rssbridge_insecure.middlewares=rssbridge_redirect@docker"
      - "traefik.http.routers.rssbridge.rule=Host(`rssbridge.example.com`)"
      - "traefik.http.routers.rssbridge.entrypoints=websecure"
      - "traefik.http.routers.rssbridge.tls.certresolver=mydnschallenge"
      - "traefik.http.services.rssbridge.loadbalancer.server.port=80"
    networks:
      - external
    restart: always

This uses Traefik, with my internal HTTPS setup to serve the bridge over HTTPS. You can also set up authentication for the bridge if you like. This isn’t really required unless you are hosting the bridge on a publicly available URL and would rather keep it private. I elected not to bother with authentication, since mine is on my internal network. It should also be noted that the bridge is totally stateless. All the parameters are sent in the URL, so there is no data to protect.

Grabbing Feeds

You’ll see above that we mounted a text file called whitelist.txt inside the container. This contains a list of all the bridges you want to use, from the full list of bridges. Here’s mine:

FacebookBridge
TheGuardianBridge
TwitterBridge
YoutubeBridge

I’ll demonstrate the use of a couple of these below, but it’s pretty simple. First up TheGuardianBridge, just select the section of the site you are interested in and click a button – couldn’t be easier!

rss-bridge
Super simple!

I like to use the HTML button so that I can see that the bridge is working right there in the browser. You can then grab the (M)RSS or Atom links directly from the resulting page:

rss-bridge
The resulting feed page

I’m also going to grab a feed of my local council news from their Facebook page, using the FacebookBridge:

rss-bridge
The Facebook Bridge

Here we just enter the name of the page or user we are interested in. There is another dialogue below this for groups, but I haven’t tried that yet. I assume this only works for public pages, since it doesn’t ask for any login credentials. Of course, when we click through we are greeted by our feed:

rss-bridge
The resultant Facebook feed

The Twitter bridge works similarly. I haven’t had much luck with the Youtube bridge, but I’m already using a well known trick to get RSS feeds of my favourite Youtube channels.

Setting Up Email Notifications

So far, this has all been very easy. Let’s step it up (just a little) and get notified when one of our feeds gets updated. I’m using this to be notified of events and goings on in my local area via some of the Facebook feeds. This closes the loop quite nicely and takes “social media” back to the promise it had in the early days.

To do this I’m using a tool called rss2email. This is a brilliant little tool, which I actually used as my primary RSS reader for some years, until I got too many feeds to get through all the emails! I’m glad to press it back into service for this.

I elected not to install rss2email in Docker, since I couldn’t find a nicely updated image and didn’t fancy building my own. It’s also kind of a personal tool, so fits nicely in a Unix user account as a cron job. On Ubuntu rss2email can be installed via APT:

$ sudo apt install rss2email

Next it’s best to follow the official documentation to get it up and running. You’ll need some access to an SMTP server to be able to send mail. One place where the documentation seems to differ is in enabling SMTP, where I had to use the line email-protocol = smtp rather than the use-smtp specified in the docs.

Once this is all set up you can add your feeds like so:

$ r2e add FeedName https://rss-bridge.example.com/.....

Of course you can add non-RSS-bridge feeds too. Just add whatever feeds you’d like to receive notifications on!

The last thing is to schedule this as a cron job:

14  *  *   *   *     /usr/local/bin/log-output "/usr/bin/r2e run"

I’m using the wrapper script I’ve mentioned previously. Done!

Conclusion

This has been a really simple project (by my standards). Everything went according to plan, which almost never happens! Regardless, I’m very happy with the result and it’s something I’ll continue to make use of every day.

RSS-Bridge fills a much needed hole in the modern web. With the dominance of the big social media platforms and increasing “appification”, we’ve lost the real promise of the web to be an open and connected platform. RSS-bridge brings back at least some of this.

The addition of rss2email fulfils the hopes I had for social networks in the early days – that they would become notification platforms for events/people/things in the world around us. Instead, they’ve become locked down walled gardens which force you to use their app or website in order to engage with what’s going on.

Technology should come to us, on our own terms and via whatever medium we choose. This makes projects like RSS-Bridge, rss2email and the myriad of RSS readers out there incredibly important for those who refuse to be locked inside the gardens, but still require access to the information contained within.

If you liked this post and want to see more, please consider subscribing to the mailing list (below) or the RSS feed. You can also follow me on Twitter. If you want to show your appreciation, feel free to buy me a coffee.

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restic rsync backups

Centralised Backups With Restic and Rsync

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In my recent post on synchronising ZFS snapshots from remote servers, I mentioned that I had being using rsync for the same purpose. This is part of my larger overall backup strategy with restic. It was brought to my attention recently that I hadn’t actually written up my backup approach. This post will rectify that!

The key requirement of my system was to have something that would work across multiple systems, without being too difficult to maintain. I also wanted it to scale to new systems easily as my self-hosting infrastructure inevitably continues to grow. Of course, I had the usual requirements of local and off site backups, with the off site copy suitably secured. Restic fits the bill quite nicely for secure local and remote backups, but has no way to synchronise multiple systems unless you set it up on each system individually.

Backup Architecture

I’ve architected my backups as a centralised system, where the relevant data from each satellite system is propagated to a central server and then backed up to various end points from there. This architecture was chosen because it was reasonably easy for me to setup and maintain and actually results in more copies of the data since it has to be copied to the backup server first.

restic rsync backups
They say a picture is worth a thousand words…

As you can see from the diagram the synchronisation from the remote systems to the backup server is done via rsync. This is done in a pull fashion. The backup server connects to each machine in turn and pulls down the files to be backed up to it’s local cache.

The second stage is a backup using restic to both a locally connected external hard drive and to the cloud (in this case Backblaze B2). I’ll cover each of these steps in the following sections.

Synchronising Remote Machines with Rsync

The first step is to synchronise the relevant files on the remote machines via rsync. When I say remote machines here, I specifically mean machines which are not the central backup server. These could be remote cloud machines, hosts on the local network or VMs hosted on the same machine. In my case it’s all three, since I run the backups on my main home server.

For each machine I want to synchronise, I have a script looking like this:

#!/bin/bash

HOST=<REMOTE HOSTNAME>
PORT=22
USER=backup
SSH_KEY="/storage/data/backup/keys/backup_key"

BASE_DEST=/storage/data/backup/$HOST

LOG_DIR=/storage/data/backup/logs
LOG_FILE=$LOG_DIR/rsync-$HOST.log

function do_rsync() {
    echo "Starting rsync job for $HOST:$1 at $(date '+%Y-%m-%d %H:%M:%S')..." >> $LOG_FILE 2>&1
    echo >> $LOG_FILE 2>&1

    mkdir -p $BASE_DEST$1 >> $LOG_FILE 2>&1
    /usr/bin/rsync -avP --delete -e "ssh -p $PORT -i $SSH_KEY" $USER@$HOST:$1 $BASE_DEST$1 >> $LOG_FILE 2>&1

    echo >> $LOG_FILE 2>&1
    echo "Job finished at $(date '+%Y-%m-%d %H:%M:%S')." >> $LOG_FILE 2>&1
}

mkdir -p $LOG_DIR

do_rsync <DIRECTORY 1>
do_rsync <DIRECTORY 2>
...

Here we start with some basic configuration, including the hostname, port, user and SSH key to use to connect to the remote host. I then configure the local destination directory, which is located on my main ZFS mirror. I also configure where the logs will be stored.

We then get into the main function of the script, called do_rsync. This sets up the logging environment and does the actual rsync transfer with the options we’ve specified. It takes as an argument the remote directory to backup (which obviously must be readable by the user in question).

We then close out the script by ensuring the log directory exists and then calling the do_rsync function for the directories we are interested in. Looking at the backup scripts now it would actually be good to factor out the common functionality here into a helper script. This could then be sourced by all of the host specific scripts. I also need to move this into git which will happen with my continued migration to Ansible.

A Note About Security

Obviously, with the rsync client logging in to the remote system automatically via SSH it’s good to restrict what this can do. To this end, the SSH key is locked down so that the only command that can be run is that executed by the rsync client. This is done via the ~/.ssh/authorized_keys file:

command="/usr/bin/rsync --server --sender -vlogDtpre.is . ${SSH_ORIGINAL_COMMAND//* \//\/}",no-pty,no-agent-forwarding,no-port-forwarding,no-X11-forwarding ssh-rsa .....

These backup scripts are run from cron and spread throughout the day so as not to overlap with each other, in an effort to even out the traffic on the network. I’m not really happy with this part of the solution, it might just be better to run the whole lot in sequence.

Local Restic Backups

The next step in the process is to run the backup to the locally connected external drive with restic. This backup is run over all the previously synced data as well as data from the local machine, such as the contents of my Nextcloud server and media collection.

This backup is achieved with the following script:

#!/bin/bash
set -e

######## START CONFIG ########
DISK_UUID="<DISK UUID>"
#GLOBAL_FLAGS="-q"
MOUNT_POINT=/mnt/backup
export RESTIC_REPOSITORY=$MOUNT_POINT/restic/storage
export RESTIC_PASSWORD_FILE=/root/restic-local.pass
######## END CONFIG ########

echo "Starting backup process at $(date '+%Y-%m-%d %H:%M:%S')."

# check for the backup disk and mount it
if [ ! -e /dev/disk/by-uuid/$DISK_UUID ]; then
    echo "Backup disk not found!" >&2
    exit 1
fi
echo "Mounting backup disk..."
mount -t ext4 /dev/disk/by-uuid/$DISK_UUID $MOUNT_POINT

# pre-backup check
echo "Performing pre-backup check..."
restic $GLOBAL_FLAGS check

# perform backups
echo "Performing backups..."
restic $GLOBAL_FLAGS backup /storage/data/nextcloud
restic $GLOBAL_FLAGS backup /storage/data/backup
restic $GLOBAL_FLAGS backup /storage/music
restic $GLOBAL_FLAGS backup /storage/media
# add any other directories here...

# post-backup check
echo "Performing post backup check..."
restic $GLOBAL_FLAGS check

# clean up old snapshots
echo "Cleaning up old snapshots..."
restic $GLOBAL_FLAGS forget -d 7 -w 4 -m 6 -y 2 --prune

# final check
echo "Performing final backup check..."
restic $GLOBAL_FLAGS check

# unmount backup disk
echo "Unmounting backup disk..."
umount $MOUNT_POINT

echo "Backups completed at $(date '+%Y-%m-%d %H:%M:%S')."
exit 0

This script is pretty simple, despite the wall of commands. First we have some configuration in which I specify the UUID of the external disk and the mount point of the disk. This is done because the disk is kept unmounted when not in use. The path to the restic repository, relative to the mount point and the path to the password file are also specified.

We then move into checking for and mounting the external disk. The first restic command performs a check on the repository to make sure all is well, before getting into the backups for the directories we are interested in. This is followed by another check to make sure that went OK.

I then run a restic forget command to prune old snapshots. Currently I’m keeping the last 7 days of backups, 4 weekly backups, 6 monthly backups and 2 yearly backups! I run a final restic check before unmounting the external disk.

This script is run once a day from cron. I use the following command to reduce the priority of the backup script and avoid interfering with the normal operation of the server:

/usr/bin/nice -n 19 /usr/bin/ionice -c2 -n7 /storage/data/backup/restic-local.sh >> /storage/data/backup/logs/restic-local.log

Remote Restic Backups

The final stage in this process is a separate backup to the cloud. As mentioned before I use Backblaze’s B2 service for this since it seems to be about the cheapest around. I’ve been reasonably happy with it so far at least.

#!/bin/bash
set -e

######## START CONFIG ########
B2_CONFIG=/root/b2_creds.sh
#GLOBAL_FLAGS="-q"
export RESTIC_REPOSITORY="<MY B2 REPO>"
export RESTIC_PASSWORD_FILE=/root/restic-remote-b2.pass
######## END CONFIG ########

echo "Starting backup process at $(date '+%Y-%m-%d %H:%M:%S')."

# load b2 config
source $B2_CONFIG

# pre-backup check
echo "Performing pre-backup check..."
restic $GLOBAL_FLAGS check

# perform backups
echo "Performing backups..."
restic $GLOBAL_FLAGS backup /storage/data/nextcloud
restic $GLOBAL_FLAGS backup /storage/data/backup
restic $GLOBAL_FLAGS backup /storage/music
# This costs to much to backup, but it's not the end of the world
# if I lose a load of DVD rips!
#restic $GLOBAL_FLAGS backup /storage/media

# post-backup check
echo "Performing post backup check..."
restic $GLOBAL_FLAGS check

# clean up old snapshots
echo "Cleaning up old snapshots..."
restic $GLOBAL_FLAGS forget -w 8 -m 12 -y 2 --prune

# final check
echo "Performing final backup check..."
restic $GLOBAL_FLAGS check

echo "Backups completed at $(date '+%Y-%m-%d %H:%M:%S')."
exit 0

This looks very similar to the previous script, but differs in the configuration. First I specify the file where I keep my B2 credentials, to be sourced later. This file is of the form:

export B2_ACCOUNT_ID="<MY ACCOUNT ID>"
export B2_ACCOUNT_KEY="<MY ACCOUNT KEY>"

I then set the RESTIC_REPOSITORY and RESTIC_PASSWORD_FILE variables as before. In this case the repository is of the form b2:bucketname:path/to/repo.

The snapshot retention policy here is different, with 8 weekly backups, 12 monthly backups and 2 yearly backups retained. This is mostly because I only run this backup once per week – the backup script will actually take more than 24 hours to run with all the checking and forgetting thrown in! The script is run from cron with the same nice/ionice combination as the local backup.

Conclusion

With all that in place, I have a pretty comprehensive backup system. The system stores at least 3 copies of any data (live, local backup, remote backup) and in the case of remote systems 4 copies (live, backup server cache, local backup, remote backup). The main issue I have with this setup currently is the use of the local external disk, which I don’t like being connected to the same server. Hopefully I’ll be moving this to another machine in my next round of server upgrades.

I also don’t really like the reliance on the cloud, even though I’ve got no complaints about the B2 service. My ideal system would probably be an SBC based system located at the home of someone with a fast, non-data capped internet connection. Ideally this person would also live on a different continent! I could then run a Minio server in place of the B2 service. This would probably end up cheaper in the long run, since I’m paying nearly $10/month for the current service.

One last piece of sage advice: TEST YOUR BACKUPS! They are worth nothing if you don’t know they are working. I’ve done a couple of test restores with this system, but I’m probably due for another one.

What’s your backup routine like? Got improvements for my system? Feel free to share them in the comments.

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ansible roles

Automating My Infrastructure with Ansible and Gitlab CI: Part 3 – SSH Keys and Dotfiles

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This is the third post in a series, you can find the first two installments here and here.

Having recently reinstalled on both of my client machines, I took the opportunity to rotate my SSH keys. Luckily I backed up the old keys before doing this, so I didn’t lock myself out of anything. However, it did leave me having to update the authorized_keys files on all my servers (about 15 at last count). Of course there is a better way than doing this all manually, so cue some Ansible automation!

While I was at it I decided it would be nice to deploy my dotfiles across all my machines. I’ve had them stored in a git repo for some time and manage them with GNU Stow. However, I would never get around to deploying the repo onto new machines and installing all the relevant tools. Writing the Ansible automation to do this was pretty tricky, but I got there in the end. I also added my client machines to my Ansible inventory so that they get the same setup deployed to them.

Getting Started

For those who haven’t read the previous installments in this series, all the code for this article is going in my main ansible-infrastructure repo on GitLab.

I started out by installing some base packages that I would need for the rest of the steps. This is complicated slightly by having different distributions on different machines. The servers are all running Ubuntu or Debian (usually in the form of Raspbian or Proxmox), whilst the clients are running Manjaro (i.e. Archlinux). This is easily dealt with in Ansible by way of a set of checks against ansible_distribution:

- hosts: all
  tasks:
    - name: Install common apt packages
      become: true
      when: ansible_distribution == 'Debian' or ansible_distribution == 'Ubuntu'
      apt:
        pkg:
          - vim
          - git
          - tmux
          - htop
          - dnsutils
          - ack-grep
          - stow
          - zsh
          - build-essential
          - python-dev
          - python3-dev
          - cmake
          - curl

    - name: Install common pacman packages
      become: true
      when: ansible_distribution == 'Archlinux'
      pacman:
        name:
          - vim
          - git
          - tmux
          - htop
          - bind-tools
          - ack
          - stow
          - zsh
          - cmake
          - clang
          - curl

You’ll see here that some of the packages are named differently in the different distros. We also need to use different package management modules for each.

It should be noted that I didn’t start out with this full list, but instead just added a few basics (e.g. git, vim, etc) and added more as I encountered the need for them. You’ll also notice that I take the opportunity to install any nice utilities that I like to have everywhere, such as htop and dig (provided by dnsutils/bind-tools).

Deploying SSH Keys

Deploying the SSH keys turned out to be fairly trivial, despite being the main task that I wanted to accomplish here. This is thanks to the excellent authorized_key module in Ansible:

- name: Set up authorized keys
  become: true
  authorized_key:
    user: '{{ admin_user }}'
    state: present
    key: '{{ item }}'
  with_file:
    - public_keys/aragorn.pub
    - public_keys/arathorn.pub
    - public_keys/work.pub
    - public_keys/phone.pub

Here I add a set of four keys from the repository, by way of the with_file clause in Ansible. I copied all the public keys into the playbooks/files/public_keys directory for ease of access. This also makes it easy to rotate keys as we’ll see below.

I set the user to add the keys to a custom variable called admin_user. This variable is set to a default value at the top of my inventory file and then overriden it for certain hosts or groups. For example I use the standard pi user on my Raspberry Pis, so the variable is set to pi for the rpis group. This ensures that the keys always get installed for the right user.

I also wanted to remove the old keys from my machines, which is pretty straightforward:

- name: Remove old authorized keys
  become: true
  authorized_key:
    user: '{{ admin_user }}'
    state: absent
    key: '{{ item }}'
  with_file:
    - public_keys/riker.pub.deprecated

Now if I want to rotate keys in future, I’ll just add the new key to the repository, rename the old key to remind myself that it’s no longer in use and update the file lists in these tags. Done!

A Minor Detour

I haven’t mentioned so far this article that all of this is running through the Gitlab CI pipeline I built in my original post. In fact this is most likely going to be a GitLab CI article, without much GitLab CI stuff. That’s because the previous pipeline has been working brilliantly.

However, one issue has been the speed. Making changes, committing, pushing and waiting for the pipeline to complete takes quite a long time. It was pretty frustrating given the number of iterations I needed to get this right!

I noticed that it took quite a while each time to install Ansible and Ansible Lint in the containers and that this was done twice for each pipeline. Given my recent success with custom Docker images, I built a quick image containing the tools I needed (with a 3 line Dockerfile!). I was able to quickly copy over the previous docker build pipeline and get this building via CI. All I then had to do was update the images used in my main pipeline and remove the old installation commands. Boom, much faster!

You can check out my Ansible image on GitLab and pull it with the command:

$ docker pull registry.gitlab.com/robconnolly/docker-ansible

I haven’t set up a periodic build for this yet, but I’m intending that this image will be automatically updated on a weekly basis.

Deploying My Dotfiles

My dotfiles are deployed from a private repository on my internal Gitea instance. So far I haven’t published them as they contain quite a few unredacted details of my network. In order to deploy them I generated a new SSH key and added it as a deploy key to the project in Gitea.

ansible dotfiles
Deploy keys in Gitea are added in the project Settings->Deploy Keys

I then encrypted the private key with Ansible vault (I added the public key to the repo too, in case I need it again in future):

$ ansible-vault encrypt playbooks/files/dotfiles_deploy_key

I then copy the private key to each of the machines which need it:

- hosts: all,!cloud,!rpis
  serial: 2
  tasks:
    - name: Copy deploy key
      become: true
      become_user: "{{ admin_user }}"
      copy:
        src: dotfiles_deploy_key
        dest: "/home/{{ admin_user }}/.dotfiles_deploy_key"
        owner: "{{ admin_user }}"
        group: "{{ admin_user }}"
        mode: 0600

You’ll note that the above is in a new play to the previous steps. That’s because I wanted to restrict which machines get my dotfiles. The cloud machined currently can’t access my Gitea instance, since I still need to deploy my OpenVPN setup to some of them. The Raspberry Pis have trouble with some of the later steps in the setup, so I’ve skipped them too for now. I’m also running this two hosts at a time, because of the compilation step (see below).

The next step is to simply clone the repository with the Ansible git module:

- name: Clone dotfiles repo
  become: true
  become_user: "{{ admin_user }}"
  git:
    repo: "{{ dotfiles_repo }}"
    dest: "/home/{{ admin_user }}/dotfiles"
    version: master
    accept_hostkey: true
    ssh_opts: "-i /home/{{ admin_user }}/.dotfiles_deploy_key"

The dotfiles_repo variable host the URL to clone the repository from and is again defined in my encrypted inventory file. I use the ssh_opts clause to set the key for git to use.

You’ll note that the tasks above all use become_user to switch to the admin_user. In order to get this to work on some of my hosts I had to set allow_world_readable_tmpfiles to true. This has some security implications, so you might want to tread carefully, if you have potentially untrustworthy users on your systems. It seemed to work without this set on Ubuntu based systems, but those with a pure Debian base had issues.

Running Stow

The next step was to unstow a few of the newly deployed files. For this we can use the command module and with_items:

- name: Unstow dotfiles
  become: true
  become_user: "{{ admin_user }}"
  command:
    chdir: "/home/{{ admin_user }}/dotfiles"
    cmd: "stow {{ item.name }}"
    creates: "{{ item.file }}"
  with_items:
    - { name: ssh, file: "/home/{{ admin_user }}/.ssh/config"}
    - { name: vim, file: "/home/{{ admin_user }}/.vimrc"}
    - { name: tmux, file: "/home/{{ admin_user }}/.tmux.conf"}

In the items list here I pass a dictionary of names and filenames. This is so that Ansible can use one of the files which should be created to know if it needs to run the command. These are accessed with the item.variable notation in the templates. I really like the templating in Ansible!

Dealing With Vim Plugins

My Vim config contains a load of plugins, which I manage with Vundle. Installing these should be pretty simple, but it confused me for ages because the command always seemed to fail (with no output!), even when I could see it working on the command line. As it turns out, the command will exit with a return code of one even when it is successful! You can see why I was confused! In the end I came up with:

- name: Install vundle
  become: true
  become_user: "{{ admin_user }}"
  git:
    repo: https://github.com/VundleVim/Vundle.vim.git
    dest: "/home/{{ admin_user }}/.vim/bundle/Vundle.vim"
    version: master

- name: Install vim plugins
  become: true
  become_user: "{{ admin_user }}"
  shell:
    cmd: 'vim -E -s -c "source /home/{{ admin_user }}/.vimrc" -c PluginInstall -c qa || touch /home/{{ admin_user }}/.vim/plugins_installed'
    creates: "/home/{{ admin_user }}/.vim/plugins_installed"

I ended up using the shell module from Ansible to create a file when the installation completes. This file is used as the check in Ansible for whether it should run the command again. The || operator has to be used here (rather than &&) due to the weird return code. This does however have the effect of changing the overall return code to zero, which makes Ansible happy.

The final step here is compiling the YouCompleteMe plugin, which is just running another command:

- name: Build ycm_core
  become: true
  become_user: "{{ admin_user }}"
  command:
    cmd: "./install.py --clang-completer {% if ansible_distribution == 'Archlinux' %}--system-libclang{% endif %}"
    chdir: "/home/{{ admin_user }}/.vim/bundle/YouCompleteMe"
    creates: "/home/{{ admin_user }}/.vim/bundle/YouCompleteMe/third_party/ycmd/ycm_core.so"
  environment:
    YCM_CORES: 1

You’ll see above that the command is different on Arch based systems, since I use the system libclang there to work around a compile issue. I also define the YCM_CORES environment variable. This limits the number of cores to one, which seems to stop the build running out of memory on small virtual machines!

Deploying Oh-My-Zsh

The final piece to this increasingly complex puzzle is installing Oh-My-Zsh to give me a nice Zsh environment. This is again accomplished with the shell module:

- name: Install oh-my-zsh
  become: true
  become_user: "{{ admin_user }}"
  shell:
    cmd: sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" "" --unattended
    creates: "/home/{{ admin_user }}/.oh-my-zsh"
  register: ohmyzsh

You’ll see here that I register a variable containing the status of this task. This is used in the next step to delete the default zshrc that the installer will create for us:

- name: Remove default zshrc
  become: true
  become_user: "{{ admin_user }}"
  file:
    name: "/home/{{ admin_user }}/.zshrc"
    state: absent
  when: ohmyzsh.changed

I then unstow my Zsh config as before:

- name: Unstow zsh config
  become: true
  become_user: "{{ admin_user }}"
  command:
    chdir: "/home/{{ admin_user }}/dotfiles"
    cmd: "stow zsh"
    creates: "/home/{{ admin_user }}/.zshrc"

This process is probably ripe for simplification, since I assume the installer wouldn’t overwrite an existing zshrc. If I unstowed the Zsh config earlier I could probably remove the file deletion, but I haven’t tried this to see if it works.

The absolute last step, is to switch the default shell for admin_user over to Zsh:

- name: Change shell to zsh
  become: true
  user:
    name: "{{ admin_user }}"
    shell: /usr/bin/zsh

Done!

Conclusion

Phew! That comes out as a pretty epic playbook. I’ve opted to keep this all in my common playbook for now since it’s getting run against every machine, along with my previous roles. I may split it up later however, if it becomes useful to do so.

The playbook works really well now and it’s nice to have the same environment on every machine. I also really like the centralised SSH key management, which solves a real issue for me.

One improvement I would like to make would be around the syncing of changes to the dotfiles repository to all the machines. This could be as simple as deploying a cron job to git pull that repository periodically, but I’d rather have it react to changes in to repo. I could move the repository to GitLab and run a pipeline which would deploy it, but this would mean duplicating my Ansible inventory (and keeping two copies up to date). I’m wondering if a webhook could be used to trigger the main CI pipeline?

I’m interested to know if anyone out there has solved similar problems in a different way. Please let me know in the comments!

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x2go manjaro

Remote Workstation with x2go and Manjaro Linux

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I’ve been running a very under-powered and increasingly ancient laptop, a ThinkPad X131e, for several years. It’s been upgraded over time with an SSD and a replacement battery. For my requirements this is mostly OK, since my workload mostly consists of a web browser and terminal windows and it runs my preferred desktop (KDE Plasma Desktop) just fine. Since my server performs the majority of my computing I haven’t really been limited by this. However, every now and then I need to run a couple of apps which just bring it to a halt as it thrashes around trying to swap. Clearly 4GB of RAM is not enough to run modern applications.

I actually do have another desktop computer, but my use of it recently has been limited to the odd DVD rip. This was mainly due to having to switch the mouse, keyboard and monitor over from my work machine in order to use it in the limited space which is my home office. I could have probably remedied this with a KVM switch, but somehow I never got around to it. I was also not enthused about spending my evenings sitting in the same office I’ve just been working in all day. So that computer sat gathering dust for the most part.

That was until I came across a post about using x2go to create a remote workstation after musing whether this would be possible. I decided to do the same, since I had the hardware already available to make it work.

A (Semi) Failed Experiment

Initially I did a few tests with local VMs to see if x2go was going to work with KDE, since I’d seen mixed reports about this. The good news is that it works pretty well (at least for basic remote desktop, I’ll come to some of the problems below). The bad news is that my preferred desktop distro – KDE Neon – didn’t work well. First of all I couldn’t install the client on my laptop due to a dependency issue in APT. Secondly, although the desktop worked fine I was unable to suspend the session due to some Systemd/D-BUS issue. So I tried another distro. I’d heard good things about Manjaro and the KDE edition works great with x2go (both client and server). It also has a really nice default theme!

I also wanted the remote desktop to run as a VM on the machine, under Proxmox, so that I could potentially switch distros easily or create extra VMs for other purposes. I spent quite a bit of time configuring this only to find a few issues. The first was that I couldn’t get the host machine to pass through the internal DVD drive to the VM which was a deal breaker. The second was that suspending the VM and shutting down the host was pretty clunky and prone to just hang for no reason. As I added this machine in a cluster with my other host, the cluster would also lose quorum when the host went down. This causes lots of things to fail, including VM backups on the remaining host.

Back to Bare Metal

I decided to abandon the VM approach for now and go with a bare metal install to see if I can work with the remote desktop system. It wasn’t a complete loss, since I got a chance to try out the newly updated clustering in Proxmox, which will be relevant when I convert my existing Ubuntu server over.

The bare metal install of Manjaro was pretty boring (which is a good thing, installing a Linux distro should be boring and stable!). One thing I noticed was that I wasn’t able to manually set up LVM from the GUI installer. I could create volume groups, but it wouldn’t let me add partitions to them! As far as I understand Manjaro Architect lets you do this. I played with this a bit later when installing Manjaro on my Laptop, but opted to go with the default encrypted system option from the GUI installer. If I ever come to reinstall on the desktop machine, I’ll look at Manjaro Architect further.

Saving Power

Since this machine won’t be in use all the time, I wanted to shut it down and power it up remotely. I also wanted my x2go session to be persistent so I could pick up where I left off. For this reason I opted to use hibernate coupled with wake-on-LAN.

Configuring the wake-on-LAN took a little while. Even after enabling it in the BIOS and configuring network manager, it still didn’t work. It turned out that it was being disabled by TLP. After fixing that it worked fine.

The next problem was that I wanted to power the system up and down via a switch in Home Assistant. This was difficult as the Home Automation system is on a different subnet to the machine in question. I opted in the end to run the WOL command from my pfSense firewall over SSH. The following HASS configuration gave me the switch I was looking for:

shell_command:
  desktop_power_on: "ssh -i /config/id_rsa -o 'StrictHostKeyChecking=no' home-assistant@<my_firewall> -- '-i <subnet broadcast address> <mac address>'"
  desktop_power_off: "ssh -i /config/id_rsa -o 'StrictHostKeyChecking=no' <user>@<my_desktop>"

binary_sensor:
  - platform: ping
    name: "Desktop Computer State"
    host: <desktop ip>
    count: 1
    scan_interval: 5

switch:
  - platform: template
    switches:
      desktop_computer_power:
        value_template: "{{ is_state('binary_sensor.desktop_computer_state', 'on') }}"
        turn_on:
          service: shell_command.desktop_power_on
        turn_off:
          service: shell_command.desktop_power_off

This requires a bit of setup on both the firewall and the desktop machines. First I created a user in pfSense with the relevant permissions to log in via SSH. I then added the following to the authorised SSH keys field:

command="wol $SSH_ORIGINAL_COMMAND",no-port-forwarding,no-x11-forwarding,no-agent-forwarding ssh-rsa .....

This basically allows the SSH key to only run the wol command and to pass through the original command as arguments to it. You’ll note that in the power on command above, only the arguments are specified. This means that I can send WOL packets to any machine on the network, but the key can’t do anything else.

There is a similar bit of configuration on the desktop machine:

command="systemctl hibernate",no-port-forwarding,no-x11-forwarding,no-agent-forwarding ssh-rsa ....

This restricts the key to only running the systemctl hibernate command.

With that in place I have a nice switch in my HASS GUI to power up and down the machine. I can also automate it to power up and down under certain conditions if I wish.

x2go manjaro
The resulting power switch in HASS

Setting Up x2go

Since Manjaro is based on Arch Linux, I just installed the x2goserver package on my desktop and the x2goclient package on my laptop.

x2go is fairly trivial to set up, requiring only the enabling of X11 forwarding in the SSH daemon on the server side, just follow the instructions to do this.

x2go manjaro
My x2go Session Preferences

In order to connect to a KDE desktop running on the server, we need to set up a profile in the x2go client. The main thing here is to set the session type to “Custom desktop” with the command startplasma-x11 (the KDE session type doesn’t work for some reason). Obviously you also need to set the address of the machine to log in to. I also found that I needed to set the path to my SSH key in order to have it be used by the client.

The Finished Product

The final product is pretty nice. I can remotely boot my desktop machine from my laptop or phone. I then connect with x2go from my laptop and get to work! My previous session will be restored if there is one, meaning I can just pick up where I left off. The connection to the remote system is excellent, with no noticeable delay. So far I’ve only tested this over my local wifi, but that will be 97% of it’s usage anyway. There is some tearing when moving windows and some graphical issues when the x2go session window gets resized, but these resolve themselves after a few seconds.

x2go manjaro
My full remote desktop in all it’s glory!

One wrinkle is shared folders, which are supposed to be supported by x2go, but currently seem to be broken. I get an error message, similar to that described here when I try to mount one. Apparently that bug is fixed, but I guess the version containing the fix hasn’t been released yet. If the new version doesn’t land soon I’ll probably try and work around it with SSHFS+some scripting. For now it’s not too much of an issue, all my files are now on the desktop anyway!

I also don’t see any sound devices on the remote system, but I haven’t tried playing sound to see if it’s working. I tend not to listen to music or watch movies on my laptop anyway and I can still do this locally if need be.

Conclusion

Overall, I’m pretty happy with this setup. It’s not perfect, but it is nice to have easier access to my other machine. I still have a lot of setup to do at both ends to make this work better and to make the remote machine feel like home, but it’s getting there.

I’m not sure if I’ll run this setup full time yet or just for certain applications. I’ve decided to upgrade the RAM in both systems as well as my server, so we’ll see how the balance of local vs remote falls out after doing that! I’m also eyeing a Pinebook Pro as a potential replacement laptop.

I really like Manjaro as a distro. It’s not quite as polished a KDE experience as KDE Neon is, but it’s getting there. I like the Arch base – I’ve been a fan of Arch since my very first experience with it (CAUTION: very old post!), but I just couldn’t get on with it as a main driver. Manjaro gives you a nice experience out of the box with the power to tweak as much as you like.

I’ll be sure to update on any further progress with fixing some of the issues I’ve encountered with this project. In the meantime, if anyone has solutions/workarounds to the shared folder issue, please leave a comment. Bye for now!

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