Linux containers are great for local development environments, quickly testing stuff, and much more. Nowadays everybody talks Docker, but Docker might be an overkill in terms of complexity and learning curve. There's a lightweight alternative: Linux containers built with LXD.
There are two major differences between Docker containers and LXD containers:
- LXD containers are persistent by default. Things you change inside containers are kept.
- Docker containers normally run a single process. LXD doesn't have this limitation.
In fact, LXD container are much more like traditional VMs. They are a good bet e.g. for simple local development environments. There are caveats for sure:
- The ecosystem is much smaller, e.g. there's a lack of orchestration tools
- The technology is still young, and might be a moving target.
LXW is a simple wrapper for LXD's command line interface, lxc. It's no replacement, but a small addition to make some things easier, e.g. mounting host folders inside containers, and sharing file access rights. In fact, it just uses plain lxc commands and some shell script magic to achieve this goal.
LXW uses preconfigured LXD images to spin up containers. So for example you might use a LXD stock image, start a container, orchestrate it for your needs and publish it as a new local image. So you might end up with some local base images like 'drupal-7', 'nodejs', whatever.
That's the point where LXW comes in:
Using your custom images, you'll spin up new containers for your projects in no time. LXW uses your current folder as container name, so it might go like this:
- Your project is located in ~/projects/someproject
- The source files are located in ~/projects/someproject/source
- You want to use a customized local image named 'nodejs'
- Inside your folder, just create a new container using LXW:
lxw create nodejs, this gives you a container named "someproject" - Share your source folder using LXW:
lxw mount code ./source /var/www/html - Start the container:
lxw start - Open a shell:
lxw shell
And so on, you get it. If you need some examples on how to create custom local images, take a look at this project
The wrapper scripts needs LXD installed and configured. While it might work on many Linux distributions, it has been tested on current Ubuntu releases only. Stock images for LXD containers are located on the LXD image server It's your part to create suitable custom images for use with LXW.
Instructions for installing LXD can be found here
Installing LXW is simple: just copy the script to /usr/local/bin, naming it 'lxw' and make it executable:
sudo mv lxw.sh /user/local/bin/lxw
sudo chmod +x /usr/local/bin/lxw
Create a container using a local or remote image, start it and enter the shell
Examples:
lxw launch images:alpine/3.8
lxw launch mylocalimage
Create a container using a local or remote image
Examples:
lxw create images:alpine/3.8
lxw create mylocalimage
Start the container
Restart the container
Stop (shutdown) the container
Destroy the container. Displays a confirmation message and deletes the container. All data outside of shared folders will get lost.
Share a folder on the host system with the container. Both the host user and the user inside the container get full access rights. Arguments:
- alias - a custom name for the share, as there can be multiple ones
- host_path - The path on the host system (relative or absolute)
- container_path - The path inside the container (must be absolute)
Example:
lxw mount code ./source /var/www/html
Unmounts a shared folder using the alias
Example:
lxw unmount code
Open a shell inside the container, using the default shell configured inside the container.
Run a single shell command inside the container. For now it's not possible to run multiple commands.
Examples:
lxw exec apk --version
lxw exec ls /etc -al
Display the current status of the container, including the IP
List containers created by LXW
Display the current ip address of the container
Show usage instructions