A fast and low-memory footprint OCI Container Runtime fully written in C.
crun conforms to the OCI Container Runtime specifications (https://github.com/opencontainers/runtime-spec).
The user documentation is available here.
If you are looking for a static build, take a look at the instructions here.
Why another implementation?
While most of the tools used in the Linux containers ecosystem are written in Go, I believe C is a better fit for a lower level tool like a container runtime. runc, the most used implementation of the OCI runtime specs written in Go, re-execs itself and use a module written in C for setting up the environment before the container process starts.
crun aims to be also usable as a library that can be easily included in programs without requiring an external process for managing OCI containers.
crun is faster than runc and has a much lower memory footprint.
This is the elapsed time on my machine for running sequentially 100
containers, the containers run
|100 /bin/true (no network namespace)||0:05.70||0:10.95||-47.9%|
|100 /bin/true (new network namespace)||0:06.16||0:11.17||-44.8%|
On Fedora these dependencies are required for the build:
dnf install -y make python git gcc automake autoconf libcap-devel \ systemd-devel yajl-devel libseccomp-devel libselinux-devel \ go-md2man glibc-static python3-libmount libtool
apt-get install -y make git gcc build-essential pkgconf libtool \ libsystemd-dev libcap-dev libseccomp-dev libyajl-dev libselinux1-dev \ go-md2man libtool autoconf python3
Unless you are also building the Python bindings, Python is needed only by libocispec to generate the C parser at build time, it won't be used afterwards.
Once all the dependencies are installed:
./autogen.sh && ./configure make sudo make install