LXC Security

The upside being that we do consider those containers to be root-safe and so, as long as you keep on top of kernel security issues, those containers are safe. If this flag is 0 (default), then the container will not bestarted if the kernel lacks the apparmor mount features, so that aregression after a kernel upgrade will be detected. To start thecontainer under partial apparmor protection, set this flag to 1. Note that sharing pid namespaces between system containers willlikely not work with most init systems. Will mount a proc filesystem under the container's /proc,regardless of where the root filesystem comes from.

If it aborts further down the line, the previous configuration (for example, about storage) has already been applied. You probably mean lxd init (and not lxc init, which creates a container but does not launch it). It is this user’s opinion that all “green field” (new user/new server) deployments looking at LXC or LXD as a solution should, in 99% of cases, just use LXD. This is especially true if your container host OS is Ubuntu 16.04 or later; you’ll have the most secure, most streamlined experience on this specific OS distro/version combo. The download template will show you a list of distributions, versions, and architectures to choose from. A good example would be "ubuntu", "focal" (20.04 LTS), and "amd64".

Comparing LXD vs. LXC

With that done, the last step is to create an LXC configuration file. If you start a container, you can explore the uid range in use as seen from the host side compared to the uid range as seen from the container side. For safe keeping, create a backup of the original LXC default.conf file. After allowing the host some time to reboot and signing back into the host's shell, we see that the container is running and has the autostart property set to 1. Suppose we have already created and started a container named mycontainer as described above.

In the unified cgroup hierarchy the implementation of the devicecontroller has completely changed. Instead of files to read from andwrite to a eBPF program ofBPF_PROG_TYPE_CGROUP_DEVICE can be attached to acgroup. Even though the kernel implementation has changed completelyLXC tries to allow for the same semantics to be followed in the legacydevice cgroup and the unified eBPF-based device controller. Thefollowing paragraphs explain the semantics for the unified eBPF-baseddevice controller.

The goal of LXC is to create an environment as close as possible to a standard Linux installation but without the need for a separate kernel. First of all, you need to make sure your user has a uid and gid map defined in /etc/subuid and /etc/subgid. On Ubuntu systems, a default allocation of uids and gids is given to every new user on the system, so lxc coin you should already have one.

All commands support lxc-start syntax

• With that done, the last step is to create an LXC configuration file.
• In version 2, the policy may be denylist or allowlist,supports per-rule and per-policy default actions, and supportsper-architecture system call resolution from textual names.
• LXC containers are often considered as something in the middle between a chroot and a full fledged virtual machine.
• This is especially true if your container host OS is Ubuntu 16.04 or later; you’ll have the most secure, most streamlined experience on this specific OS distro/version combo.
• LXC inherits cgroup limits from its parent, on my Linux distribution, there are no real limits set.

This adds support for mount propagation (private, shared, slave, unbindable, rprivate, rshared, rslave, runbindable) to mount entries specified via lxc.mount.entry and lxc.mount.fstab. This is the result of over 6 months of intense work since the LXC 2.1.0 releaseThis is the third LTS release for the LXC project and will be supported until June 2023. IMHO, along the lines of this post/article, another useful one (or two) would be to list some typical use cases for choosing either lxc or lxd. I personally don’t some of the decisions made with LXD and how lxc init is working.

CONSOLE DEVICES LOCATION

• Standard output from the hooks is logged at debug level.Standard error is not logged, but can be captured by thehook redirecting its standard error to standard output.
• A hook to be run in the host’s namespace after the container has been setup, and immediately before starting the container init.
• Unprivileged containers (default) should be perfectly safe as apparmor only acts as a safety net there with the user namespace acting as the main security barrier.
• Code cleanups have been performed widely across the codebase based on our written down coding style.

Note that sharing pid namespaces will likely not work with most initsystems. Note that when mounting a filesystem from animage file or block device the third field (fs_vfstype)cannot be auto as withmount(8)but must be explicitly specified. Standard output from the script is logged at debug level.Standard error is not logged, but can be captured by thehook redirecting its standard error to standard output. That is, containers which offer anenvironment as close as possible as the one you'd get from a VM butwithout the overhead that comes with running a separate kernel andsimulating all the hardware. For migration optimization features like pre-copy or post-copy migration the support cannot be determined by simply looking at the CRIU version.

Removed support for all legacy configuration keys

Thisis resilient to block device backed filesystems as well ascontainer cloning. Whether this information is provided in the form of environmentvariables or as arguments to the script depends on the value oflxc.hook.version. If set to 1 then information isprovided in the form of environment variables.

The 1st is that i’m mostly interested personally in doing system level things with containers. The 2nd is the i am wanting to learn about containers the way i would have learned had i not been misdirected away when they first came out years ago. I would have learned lxc 1st because at one time that’s all there was. And somewhere in their i want to also learn the API in terms of programming in C and in Python. And they might well be confusing to typical users who only learn lxd (or Docker).

force property for cgroup mounts specified via lxc.mount.auto

LXD doesn’t require apparmor, it will happily run on systems that have it missing or disabled. This means, once you’ve earned the “Basic” badge, you can edit this post to improve it. If you see an error, or want to add different perspectives or resources, please feel free – but try to keep it on the topic of LXD vs. LXC. For detailed specifics or how-tos for a specific product (LXC or LXD), you are encouraged to create your own Wiki articles. Other releases will typically be maintained on a best effort basis which typically means until the next stable release is out.

This site is protected by reCAPTCHA Enterprise and the Google Privacy Policy and Terms of Service apply. Juan Carlos Fresnadillo directed the pilot and executive produces with Basgallo and Escape Artists Productions. The current LTS release is Incus 6.0 and is supported until June 2029. The Incus project was created by Aleksa Sarai as a community driven alternative to Canonical's LXD.Today, it's led and maintained by many of the same people that once created LXD.

The “defaults” for things like storage path is an absolute pain to change, and should be looked at. It’s generally a bad idea to mix and match LXC and LXD on the same system, in my opinion, because you are likely to get confused, or LXC and LXD might get themselves confused with sharing resources like namespaces, etc. I am not aware of any good use case for using both, so you should really decide on which one to use, and stick with it. It’s basically an alternative to LXC’s tools and distribution template systemwith the added features that come from being controllable over the network.