1---
  2title: "LXD: Containers for Human Beings"
  3subtitle: "Docker's great and all, but I prefer the workflow of interacting with VMs"
  4date: 2023-08-11T16:30:00-04:00
  5categories:
  6  - Technology
  7tags:
  8  - Sysadmin
  9  - Containers
 10  - VMs
 11  - Docker
 12  - LXD
 13draft: true
 14rss_only: false
 15cover: ./cover.png
 16---
 17
 18This is a blog post version of a talk I presented at both Ubuntu Summit 2022 and
 19SouthEast LinuxFest 2023. The first was not recorded, but the second was and is
 20on [SELF's PeerTube instance.][selfpeertube] I apologise for the terrible, but
 21there's unfortunately nothing I can do about that.
 22
 23[selfpeertube]: https://peertube.linuxrocks.online/w/hjiTPHVwGz4hy9n3cUL1mq?start=1m
 24
 25{{< adm type="warn" >}}
 26
 27**Note:** Canonical has decided to [pull LXD out][lxd] from under the Linux
 28Containers entity and instead continue development under the Canonical brand.
 29The majority of the LXD creators and developers have congregated around
 30[Incus.][inc] I'll be keeping a close eye on the project and intend to migrate
 31as soon as there's an installable release.
 32
 33[lxd]: https://linuxcontainers.org/lxd/
 34[inc]: https://linuxcontainers.org/incus/
 35
 36{{< /adm >}}
 37
 38## The benefits of VMs and containers
 39
 40- **Isolation:** we don't want an attacker to get into our webserver and be able
 41  to gain access to our email server
 42- **Flexibility:** <abbr title="Virtual Machines">VMs</abbr> and containers only
 43  use the resources they've been given
 44- **Portability:** once set up and configured, VMs and containers can mostly be
 45  treated as black boxes; as long as the surrounding environment is similar to
 46  the previous in terms of communication, they can just be picked up and dropped
 47  on bare metal servers as necessary.
 48- **Density:**
 49- **Cleanliness:**
 50
 51## Virtual machines
 52
 53```goat
 54 .---------------------------------.
 55|  .-------.  .-------.  .-------. |
 56| | Guest  | | Guest  | | Guest  | |
 57| | OS     | | OS     | | OS     | |
 58| .---+---'  .---+---'  .---+---'  |
 59|  .--+----.  .--+----.  .--+----. |
 60| | Guest  | | Guest  | | Guest  | |
 61| | Kernel | | Kernel | | Kernel | |
 62| .---+---'  .---+---'  .---+---'  |
 63|  .--+----------+----------+----. |
 64| |          Hypervisor          | |
 65| .--------------+--------------'  |
 66|  .-------------+---------------. |
 67| |          Host Kernel         | |
 68| .-----------------------------'  |
 69.---------------------------------'
 70```
 71
 72## Containers
 73
 74```goat
 75       Application containers                 System containers
 76 .---------------------------------.   .------------------------------.
 77|  .-------.  .-------.  .-------. |  |  .------.  .------.  .------. |
 78| | App 01 | | App 02 | | App 03 | |  | | Guest | | Guest | | Guest | |
 79| '---+---'  '---+---'  '---+---'  |  | | OS    | | OS    | | OS    | |
 80|  .--+----------+----------+----. |  | '---+--'  '---+--'  '---+--'  |
 81| |          Hypervisor          | |  |  .--+---------+---------+---. |
 82| '--------------+--------------'  |  | |         Host Kernel       | |
 83|  .-------------+---------------. |  | '--------------------------'  |
 84| |          Host Kernel         | |  '------------------------------'
 85| '-----------------------------'  |
 86'---------------------------------'
 87```
 88
 89## When to use which
 90
 91### Virtual machines
 92
 93- Virtualising esoteric hardware
 94- Virtualising non-Linux operating systems (Windows, macOS)
 95- Completely isolating processes from one another with a decades-old, battle-tested technique
 96
 97{{< adm type="note" >}}
 98See Drew DeVault's blog post [_In praise of qemu_](https://earl.run/rmBs) for a great use of VMs
 99{{< /adm >}}
100
101### Application containers
102
103- Microservices
104- Extremely reproducible builds
105  - (NixOS.org would likely be a better fit though)
106- Dead-set on using cloud platforms with extreme scaling capabilities (AWS, GCP, etc.)
107- When the app you want to run is _only_ distributed as a Docker container and
108  the maintainers adamantly refuse to support any other deployment method
109  - (Docker does run in LXD 😉)
110
111### System containers
112
113- Anything not listed above 👍
114
115## Crash course to LXD
116
1171. Install snap following [Canonical's tutorial](https://earl.run/ZvUK)
118   - LXD is natively packaged for Arch and Alpine, but configuration can be a massive headache.
1192. `sudo snap install lxd`
1203. `lxd init`
1214. `lxc image copy images:debian/11 local: --alias deb-11`
1225. `lxc launch deb-11 container-name`
1236. `lxc shell container-name`