Ubuntu 18.04 LXD/LXC, ZFS, Docker, and Advanced Networking

Note on 2018.5.20: This is a first draft. This will undergo many revisions.

I used many, many other tutorials, blogs, and Q&A posts to assemble this. Relevant links are sprinkled throughout the guide.

This is a complete, step by step tutorial on configuring the following:

Ubuntu 18.04 install on a server with two NICs

One NIC for host traffic

Other NIC for LXC/Docker traffic

Plex, Sonarr, Radarr, Jackett in Docker on host

rTorrent, ruTorrent, Flood, and OpenVPN nested in Docker in LXC container on host

Topology from a visual perspective:

Topology from a CLI perspective:

will@ara:~$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 3bccf3d47433 linuxserver/radarr "/init" 5 hours ago Up 5 hours radarr cecc3e98ae8e linuxserver/sonarr "/init" 5 hours ago Up 5 hours sonarr 4137c943105c linuxserver/jackett "/init" 18 hours ago Up 18 hours jackett e5011d300ead plexinc/pms-docker "/init" 29 hours ago Up 29 hours (healthy) plex will@ara:~$ lxc list +---------+---------+----------------------+------+------------+-----------+ | NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS | +---------+---------+----------------------+------+------------+-----------+ | torrent | RUNNING | 172.17.0.1 (docker0) | | PERSISTENT | 0 | | | | 10.1.20.12 (eth0) | | | | +---------+---------+----------------------+------+------------+-----------+ will@ara:~$ lxc exec torrent bash root@torrent:~# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 71af0f693c10 binhex/arch-rtorrentvpn "/usr/bin/tini -- /b…" 19 hours ago Up 19 hours 0.0.0.0:3000->3000/tcp, 0.0.0.0:8118->8118/tcp, 0.0.0.0:9080->9080/tcp, 5000/tcp, 49160/tcp, 0.0.0.0:9443->9443/tcp, 49170/tcp torrent 1

INSTALL UBUNTU

At Filesystem Setup for 120GB SSD:

1. Leave bootloader partition alone

2. I gave 20GB to / partition

3. I gave 60GB to /home partition

4. I left the rest as free space so it can be used later in this guide for our ZFS pool

CREATE USER, ADD TO SUDO GROUP, SWITCH TO USER

adduser will

usermod -aG sudo will

su will

CONFIGURE HOST NETWORK INTERFACE

Get names of network interfaces

ip a

enp1s0f0 is for my host network

enp1s0f1 is for my container network

Edit the existing YAML file

sudo vim /etc/netplan/50-cloud-init.yaml

network: version: 2 ethernets: enp1s0f0: addresses: [10.1.20.24/24] gateway4: 10.1.20.1 nameservers: addresses: - 10.1.20.254 - 10.1.20.253 - 1.1.1.1 search: - paw.blue enp1s0f1: dhcp4: false # I don't think this bridge is necessary but I could be wrong # bridges: # br0: # interfaces: [enp1s0f1] # dhcp4: true 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 network: version: 2 ethernets: enp1s0f0: addresses: [10.1.20.24/24] gateway4: 10.1.20.1 nameservers: addresses: - 10.1.20.254 - 10.1.20.253 - 1.1.1.1 search: - paw.blue enp1s0f1: dhcp4: false # I don't think this bridge is necessary but I could be wrong # bridges: # br0: # interfaces: [enp1s0f1] # dhcp4: true

Apply changes

sudo netplan apply

Schedule script every boot to set the physical interface used for containers to be UP with PROMISC ON. This is necessary right now on Ubuntu 18.04 due to a bug documented here.

mkdir ~/scripts

echo "ip link set enp1s0f1 up && ip link set enp1s0f1 promisc on" > ~/scripts/enp1s0f1.sh

chmod +x ~/scripts/enp1s0f1.sh

The following command will write to crontab so that your script runs as root at boot.

This did not work with only the first sudo, so I threw a bunch of extra sudos in there to make it work. I don’t know if they are all necessary.

sudo crontab -u root -l | { sudo cat; sudo echo "@reboot /home/will/scripts/enp1s0f1.sh"; } | sudo crontab -

SET UNUSED INTERFACES DOWN

I have extra physical interfaces that I’m not using right now, so I’m shutting them down.

sudo ip link set en131s0f0 down

sudo ip link set en131s0f1 down

INTERFACE TROUBLESHOOTING

You can do the following to remove an IP from an interface. For example, I accidentally assigned 10.1.20.24/24 to enp1s0f1 but I want that IP on enp1s0f0 instead:

sudo ip address del 10.1.20.24/24 dev enp1s0f1

You can do the following to restart an interface:

sudo ip link set enp1s0f1 down && sudo ip link set enp1s0f1 up

If you need to fix 127.0.0.53 being in resolv.conf (this happened to me):

sudo rm -f /etc/resolv.conf

CREATE YOUR HOST UPGRADE SCRIPT

Create update script:

cd ~

vim update.sh

#/bin/bash time sudo apt update && sudo apt full-upgrade -y 1 2 3 #/bin/bash time sudo apt update && sudo apt full-upgrade -y

Make update script executable:

chmod +x update.sh

Run script to update. You can run this whenever you want to update.

./update.sh

Install whatever common packages you use:

sudo apt install tree unrar ncdu -y

INSTALL ZFS AND IMPORT ZFS POOL FROM HBA CONTROLLER

sudo apt install zfsutils-linux -y

zpool import

zpool import tank

Import zpools at boot. Not necessary if you reference the disk by-id when doing initial import as discussed here.

sudo systemctl enable zfs-import-cache

INSTALL AND CONFIGURE SAMBA

This section is entirely optional. I like being able to access my entire media ZFS pool from Windows.

Install Samba as described here.

sudo apt install -y samba

sudo nano /etc/samba/smb.conf

[tank] comment = ZFS Pool path = /tank read only = no guest only = no guest ok = no share modes = yes 1 2 3 4 5 6 7 8 9 10 11 12 13 [tank] comment = ZFS Pool path = /tank read only = no guest only = no guest ok = no share modes = yes

Turn SMB sharing on:

sudo zfs set sharesmb=on tank

Create Samba user and define password

sudo pdbedit -a will

Find out who owns the media folder

ls -l /tank/media

will@ara:~$ ls -l /tank/media total 499 drwxrwx--- 335 1420 1420 372 May 18 00:56 movies -rwxrwx--- 1 1420 1420 283648 Sep 18 2017 plexpy.db drwxrwx--- 5 1420 1420 16 Jan 25 19:03 radarr drwxrwx--- 2 1420 1420 2 Feb 18 01:36 security drwxrwx--- 5 1420 1420 16 Jan 25 19:01 sonarr drwxrwx--- 55 1420 1420 57 May 7 13:15 tv 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 will@ara:~$ ls -l /tank/media total 499 drwxrwx--- 335 1420 1420 372 May 18 00:56 movies -rwxrwx--- 1 1420 1420 283648 Sep 18 2017 plexpy.db drwxrwx--- 5 1420 1420 16 Jan 25 19:03 radarr drwxrwx--- 2 1420 1420 2 Feb 18 01:36 security drwxrwx--- 5 1420 1420 16 Jan 25 19:01 sonarr drwxrwx--- 55 1420 1420 57 May 7 13:15 tv

I don’t care about UID 1420, but I do want to name the GID 1420 group “media”

sudo groupadd media

sudo groupmod -g 1420 media

Observe changes:

will@ara:~$ ls -l /tank/media total 499 drwxrwx--- 335 1420 media 372 May 18 00:56 movies -rwxrwx--- 1 1420 media 283648 Sep 18 2017 plexpy.db drwxrwx--- 5 1420 media 16 Jan 25 19:03 radarr drwxrwx--- 2 1420 media 2 Feb 18 01:36 security drwxrwx--- 5 1420 media 16 Jan 25 19:01 sonarr drwxrwx--- 55 1420 media 57 May 7 13:15 tv 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 will@ara:~$ ls -l /tank/media total 499 drwxrwx--- 335 1420 media 372 May 18 00:56 movies -rwxrwx--- 1 1420 media 283648 Sep 18 2017 plexpy.db drwxrwx--- 5 1420 media 16 Jan 25 19:03 radarr drwxrwx--- 2 1420 media 2 Feb 18 01:36 security drwxrwx--- 5 1420 media 16 Jan 25 19:01 sonarr drwxrwx--- 55 1420 media 57 May 7 13:15 tv

Add myself to the media group and restart Samba

sudo adduser will media

sudo systemctl restart smbd nmbd

CONFIGURE LXC PROFILE TO USE MACVLAN

Run lxc without typing sudo every time:

sudo setfacl -m u:will:rwx ~/.config/lxc

Create and edit the YAML file:

lxc profile create lxcnet

lxc profile edit lxcnet

config: environment.TZ: "America/Chicago" description: Creates macvlan bridge for LXC containers devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic name: lxcnet used_by: [] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 config: environment.TZ: "America/Chicago" description: Creates macvlan bridge for LXC containers devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic name: lxcnet used_by: []

CREATE ZFS PARTITION ON LOCAL SSD

Find disk/partition to be used

sudo fdisk -l

Check lxc version. On 18.04 it’s 3.0.0 right now.

lxc info

Start configuration of LXC

sudo lxd init

will@ara:~$ sudo lxd init Would you like to use LXD clustering? (yes/no) [default=no]: Do you want to configure a new storage pool? (yes/no) [default=yes]: Name of the new storage pool [default=default]: lxd Name of the storage backend to use (btrfs, dir, lvm, zfs) [default=zfs]: Create a new ZFS pool? (yes/no) [default=yes]: Would you like to use an existing block device? (yes/no) [default=no]: yes Path to the existing block device: /dev/sdg4 Would you like to connect to a MAAS server? (yes/no) [default=no]: Would you like to create a new network bridge? (yes/no) [default=yes]: no Would you like to configure LXD to use an existing bridge or host interface? (yes/no) [default=no]: yes Name of the existing bridge or host interface: enp1s0f1 Is this interface connected to your MAAS server? (yes/no) [default=yes]: MAAS IPv4 subnet name for this interface (empty for no subnet): MAAS IPv6 subnet name for this interface (empty for no subnet): Would you like LXD to be available over the network? (yes/no) [default=no]: Would you like stale cached images to be updated automatically? (yes/no) [default=yes] Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]: yes config: {} cluster: null networks: [] storage_pools: - config: source: /dev/sdg4 description: "" name: lxd driver: zfs profiles: - config: {} description: "" devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic root: path: / pool: lxd type: disk name: default 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 will@ara:~$ sudo lxd init Would you like to use LXD clustering? (yes/no) [default=no]: Do you want to configure a new storage pool? (yes/no) [default=yes]: Name of the new storage pool [default=default]: lxd Name of the storage backend to use (btrfs, dir, lvm, zfs) [default=zfs]: Create a new ZFS pool? (yes/no) [default=yes]: Would you like to use an existing block device? (yes/no) [default=no]: yes Path to the existing block device: /dev/sdg4 Would you like to connect to a MAAS server? (yes/no) [default=no]: Would you like to create a new network bridge? (yes/no) [default=yes]: no Would you like to configure LXD to use an existing bridge or host interface? (yes/no) [default=no]: yes Name of the existing bridge or host interface: enp1s0f1 Is this interface connected to your MAAS server? (yes/no) [default=yes]: MAAS IPv4 subnet name for this interface (empty for no subnet): MAAS IPv6 subnet name for this interface (empty for no subnet): Would you like LXD to be available over the network? (yes/no) [default=no]: Would you like stale cached images to be updated automatically? (yes/no) [default=yes] Would you like a YAML "lxd init" preseed to be printed? (yes/no) [default=no]: yes config: {} cluster: null networks: [] storage_pools: - config: source: /dev/sdg4 description: "" name: lxd driver: zfs profiles: - config: {} description: "" devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic root: path: / pool: lxd type: disk name: default

The outcome of these steps is that the network configuration from the lxcnet profile is copied to the default profile, and the default profile is populated with the ZFS pool information.

You can see this with the following:

lxc profile show default

will@ara:~$ lxc profile show default config: {} description: "" devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic root: path: / pool: lxd type: disk name: default used_by: [] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 will@ara:~$ lxc profile show default config: {} description: "" devices: eth0: name: eth0 nictype: macvlan parent: enp1s0f1 type: nic root: path: / pool: lxd type: disk name: default used_by: []

INCREASE FILE AND INODE LIMITS

sudo vim /etc/sysctl.conf

fs.inotify.max_queued_events = 1048576 fs.inotify.max_user_instances = 1048576 fs.inotify.max_user_watches = 1048576 1 2 3 4 5 fs.inotify.max_queued_events = 1048576 fs.inotify.max_user_instances = 1048576 fs.inotify.max_user_watches = 1048576

sudo vim /etc/security/limits.conf

* soft nofile 100000 * hard nofile 100000 1 2 3 * soft nofile 100000 * hard nofile 100000

Now reboot:

sudo reboot

VERIFY HOST NETWORK, LXD NETWORK, AND ZFS

Observe your primary network interface matches what you set in /etc/netplan/00-netcfg.yaml

ip a

Note that a pool has been created with datasets:

sudo zfs list

CREATE AN LXC CONTAINER FOR TORRENT/VPN

Note, this is an empty Ubuntu 16.04 container. I’m naming it ‘torrent’

lxc launch ubuntu:xenial torrent

See that the container has started:

lxc list

Look for the MAC address in the container:

lxc config show --expanded torrent

In my case, I see the following:

volatile.eth0.hwaddr: 00:16:3e:e1:65:36

On my DHCP server, I create a new MAC reservation:

Name: torrent

IP: 10.1.20.12

MAC: 00:16:3e:e1:65:36

Enter the torrent container:

lxc exec torrent bash

Remove the dynamic IP so you can get the static one assigned

ip addr flush dev eth0

rm /var/lib/dhcp/dhclient.eth0.leases

dhclient -r; dhclient

You should see the DHCP-assigned static IP address:

ip a

Now exit the container

exit

root@torrent:~# exit exit will@ara:~$ 1 2 3 4 5 root@torrent:~# exit exit will@ara:~$

MOUNT HOST DIRECTORY INTO LXC CONTAINER

Stop it if it’s running:

lxc stop torrent

Make it privileged to avoid file ownership issues as noted here:

lxc config set torrent security.privileged true

Mount /tank/downloads to /downloads:

lxc config device add torrent downloads disk source=/tank/downloads path=/downloads

Allow Docker inside LXD container:

lxc config set torrent security.nesting true

CREATE NON-ROOT USER AND ASSIGN PRIVILEGES

Start the container and enter it:

lxc start torrent

lxc exec torrent bash

Create user in the container and assign permissions:

adduser will

usermod -aG sudo will

groupadd media

adduser will media

usermod -u 1420 will

groupmod -g 1420 media

Log into user and create command so you can run sudo as documented here:

su will

vim ~/.bashrc

alias sudo='sudo -S' 1 alias sudo='sudo -S'

Install the .bashrc:

source ~/.bashrc

INSTALL DOCKER IN LXC CONTAINER

Instructions pulled from here.

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

sudo apt update

sudo apt-get install -y docker-ce

Start it and enable it to start at boot:

sudo systemctl start docker

sudo systemctl enable docker

Let user do docker things without typing sudo:

sudo gpasswd -a will docker

sudo service docker restart

sudo systemctl enable docker

Leave and come back:

exit

su will

INSTALL PIA VPN AND TORRENT DOCKER IN LXC

Enter container if you aren’t already in it:

lxc exec torrent bash

Prepare host (LXC container) and create torrent config directory:

mkdir -p ~/torrent/config/openvpn

mkdir ~/torrent/openvpn_all

cd ~/torrent/openvpn_all

wget https://www.privateinternetaccess.com/openvpn/openvpn.zip

sudo apt install unzip

unzip openvpn.zip

Copy only the key, cert, and ovpn file you want to use:

cp *.crt ~/torrent/config/openvpn

cp *.pem ~/torrent/config/openvpn

cp US\ Midwest.ovpn ~/torrent/config/openvpn

Create and run torrent docker:

#/bin/bash docker run -d \ --cap-add=NET_ADMIN \ -p 9080:9080 \ -p 9443:9443 \ -p 8118:8118 \ -p 3000:3000 \ --name=torrent \ -v /home/will/torrent/config:/config \ -v /downloads:/downloads \ -v /etc/localtime:/etc/localtime:ro \ -e VPN_ENABLED=yes \ -e VPN_USER=yourusername \ -e VPN_PASS=yourpassword \ -e VPN_PROV=pia \ -e STRICT_PORT_FORWARD=no \ -e ENABLE_PRIVOXY=no \ -e ENABLE_FLOOD=both \ -e ENABLE_AUTODL_IRSSI=yes \ -e LAN_NETWORK=10.1.20.0/24 \ -e NAME_SERVERS=10.1.20.254,10.1.20.253,208.67.222.222,1.1.1.1 \ -e DEBUG=true \ -e PHP_TZ=America/Chicago \ -e UMASK=000 \ -e PUID=1420 \ -e PGID=1420 \ --restart=always \ binhex/arch-rtorrentvpn 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 #/bin/bash docker run -d \ --cap-add=NET_ADMIN \ -p 9080:9080 \ -p 9443:9443 \ -p 8118:8118 \ -p 3000:3000 \ --name=torrent \ -v /home/will/torrent/config:/config \ -v /downloads:/downloads \ -v /etc/localtime:/etc/localtime:ro \ -e VPN_ENABLED=yes \ -e VPN_USER=yourusername \ -e VPN_PASS=yourpassword \ -e VPN_PROV=pia \ -e STRICT_PORT_FORWARD=no \ -e ENABLE_PRIVOXY=no \ -e ENABLE_FLOOD=both \ -e ENABLE_AUTODL_IRSSI=yes \ -e LAN_NETWORK=10.1.20.0/24 \ -e NAME_SERVERS=10.1.20.254,10.1.20.253,208.67.222.222,1.1.1.1 \ -e DEBUG=true \ -e PHP_TZ=America/Chicago \ -e UMASK=000 \ -e PUID=1420 \ -e PGID=1420 \ --restart=always \ binhex/arch-rtorrentvpn

If you need to add a flag on the fly to a running container, here’s an example:

docker update --restart=always torrent

Troubleshooting Docker:

docker events&

docker start sonarr

docker logs 345fceb9d7589a51c6b2d40c4b84c2e7b4e23463a363a24d7bd47fffd3dec013

Enter a Docker container for troubleshooting:

docker exec -it torrent /bin/bash

INSTALL AND SET UP DOCKER ON HOST

Install Docker in Ubuntu 18.04:

curl -fsSL test.docker.com | sh

Create macvlan for hosts

docker network create -d macvlan \

--subnet=10.1.20.0/24 \

--gateway=10.1.20.1 \

-o parent=enp1s0f1 mvdock0

Create and run Plex container (source):

docker run -id \

--name plex \

--network=mvdock0 \

--ip=10.1.20.11 \

-h plex \

-e VERSION=latest \

-e TZ="America/Chicago" \

-e ADVERTISE_IP="http://plex.paw.blue:32400/" \

-e PLEX_UID=1420 -e PLEX_GID=1420 \

-v /tank/plexdata/config:/config \

-v /tank/media/tv:/tv \

-v /tank/media/movies:/movies \

-v /tank/media/education:/education \

-v /tank/transcode:/transcode \

plexinc/pms-docker

Sonarr:

docker run -d \

--name sonarr \

--network=mvdock0 \

--ip=10.1.20.15 \

-p 8989:8989 \

-e NAME_SERVERS=10.1.20.254,10.1.20.253,208.67.222.222,1.1.1.1 \

-e PUID=1420 -e PGID=1420 \

-e TZ=America/Chicago \

-e DEBUG=false \

-v /etc/localtime:/etc/localtime:ro \

-v /home/will/sonarr/config:/config \

-v /tank/downloads:/downloads \

-v /tank/media/tv:/tv \

--restart=always \

linuxserver/sonarr

Radarr:

docker run -d \

--name=radarr \

--network=mvdock0 \

--ip=10.1.20.16 \

-p 7878:7878 \

-e NAME_SERVERS=10.1.20.254,10.1.20.253,208.67.222.222,1.1.1.1 \

-e PGID=1420 -e PUID=1420 \

-e TZ=America/Chicago \

-v /etc/localtime:/etc/localtime:ro \

-v /home/will/radarr/config:/config \

-v /tank/downloads:/downloads \

-v /tank/media/movies:/movies \

--restart=always \

linuxserver/radarr

Jackett:

docker run -d \

--name=jackett \

--network=mvdock0 \

--ip=10.1.20.17 \

-p 9117:9117 \

-e NAME_SERVERS=10.1.20.254,10.1.20.253,208.67.222.222,1.1.1.1 \

-v /home/will/jackett/config:/config \

-v /tank/downloads:/downloads \

-e PGID=1420 -e PUID=1420 \

-e TZ=America/Chicago \

-v /etc/localtime:/etc/localtime:ro \

--restart=always \

linuxserver/jackett

DOCKER EXPERIMENTAL THINGS

If you want to use an ipvlan instead of a macvlan in Ubuntu 18.04, you will have to start docker in experimental mode.

Enabling experimental mode:

dockerd --experimental=true

Examples of layer 2 and layer 3 ipvlan networks:

docker network create -d ipvlan \ --subnet=10.1.20.0/24 \ -o ipvlan_mode=l3 \ -o parent=enp1s0f1 ipdock0 docker network create -d ipvlan \ --experimental=true \ --subnet=10.1.20.0/24 \ --gateway=10.1.20.1 \ -o ipvlan_mode=l2 ipvlan20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 docker network create -d ipvlan \ --subnet=10.1.20.0/24 \ -o ipvlan_mode=l3 \ -o parent=enp1s0f1 ipdock0 docker network create -d ipvlan \ --experimental=true \ --subnet=10.1.20.0/24 \ --gateway=10.1.20.1 \ -o ipvlan_mode=l2 ipvlan20

EXPLANATIONS ARE IN ORDER

Q: Why don’t you just run the vpn/torrent docker container on the host?

A: I tried to do that with the network=mvdock0 and ip flags, but it wasn’t working. I think it has something to do with the way the VPN is influencing the network connection. By making the vpn/torrent docker container use the “host” network and having the “host” actually be an LXC container, I can still ensure this traffic passes through enp1s0f1 on the physical host.

Q: Why not do all LXC or all Docker? Why mix and match?

A: First, so I could learn both. Second, Docker is so easy to get my applications up and running.

Third, my inspiration for this project was this amazing post by Jason Bayton, and I loved the idea of hosting LXC containers in ZFS. As it turns out, I only hosted one. But perhaps more soon!

SUMMARY

This took me many hours to assemble, as I had very little LXC or Docker experience before setting out on this journey. I’m sure people will point out many, many flaws in this tutorial. Please comment so that I can fix them!