This guide is useful if you intend to contribute on containerd. Thanks for your effort. Every contribution is very appreciated.
This doc includes:
To build the containerd
daemon, and the ctr
simple test client, the following build system dependencies are required:
- Go 1.13.x or above except 1.14.x
- Protoc 3.x compiler and headers (download at the Google protobuf releases page)
- Btrfs headers and libraries for your distribution. Note that building the btrfs driver can be disabled via the build tag
no_btrfs
, removing this dependency.
First you need to setup your Go development environment. You can follow this
guideline How to write go code and at the
end you have go
command in your PATH
.
You need git
to checkout the source code:
git clone https://github.com/containerd/containerd
For proper results, install the protoc
release into /usr/local
on your build system. For example, the following commands will download and install the 3.11.4 release for a 64-bit Linux host:
wget -c https://github.com/protocolbuffers/protobuf/releases/download/v3.11.4/protoc-3.11.4-linux-x86_64.zip
sudo unzip protoc-3.11.4-linux-x86_64.zip -d /usr/local
containerd
uses Btrfs it means that you
need to satisfy these dependencies in your system:
- CentOS/Fedora:
yum install btrfs-progs-devel
- Debian/Ubuntu:
apt-get install btrfs-progs libbtrfs-dev
- Debian(before Buster)/Ubuntu(before 19.10):
apt-get install btrfs-tools
- Debian(before Buster)/Ubuntu(before 19.10):
At this point you are ready to build containerd
yourself!
Runc is the default container runtime used by containerd
and is required to
run containerd. While it is okay to download a runc
binary and install that on
the system, sometimes it is necessary to build runc directly when working with
container runtime development. Make sure to follow the guidelines for versioning
in RUNC.md for the best results.
containerd
uses make
to create a repeatable build flow. It means that you
can run:
cd containerd
make
This is going to build all the project binaries in the ./bin/
directory.
You can move them in your global path, /usr/local/bin
with:
sudo make install
The install prefix can be changed by passing the PREFIX
variable (defaults
to /usr/local
).
Note: if you set one of these vars, set them to the same values on all make stages (build as well as install).
If you want to prepend an additional prefix on actual installation (eg. packaging or chroot install),
you can pass it via DESTDIR
variable:
sudo make install DESTDIR=/tmp/install-x973234/
The above command installs the containerd
binary to /tmp/install-x973234/usr/local/bin/containerd
The current DESTDIR
convention is supported since containerd v1.6.
Older releases was using DESTDIR
for a different purpose that is similar to PREFIX
.
When making any changes to the gRPC API, you can use the installed protoc
compiler to regenerate the API generated code packages with:
make generate
Note: Several build tags are currently available:
no_cri
: A build tag disables building Kubernetes CRI support into containerd. See here for build tags of CRI plugin.- snapshotters (alphabetical order)
no_aufs
: A build tag disables building the aufs snapshot driver.no_btrfs
: A build tag disables building the Btrfs snapshot driver.no_devmapper
: A build tag disables building the device mapper snapshot driver.no_zfs
: A build tag disables building the ZFS snapshot driver.For example, adding
BUILDTAGS=no_btrfs
to your environment before calling the binaries Makefile target will disable the btrfs driver within the containerd Go build.
Vendoring of external imports uses the Go Modules. You need
to use go mod
command to modify the dependencies. After modifition, you should run go mod tidy
and go mod vendor
to ensure the go.mod
, go.sum
files and vendor
directory are up to date.
Changes to these files should become a single commit for a PR which relies on vendored updates.
Please refer to RUNC.md for the currently supported version of runc
that is used by containerd.
You can build static binaries by providing a few variables to make
:
make EXTRA_FLAGS="-buildmode pie" \
EXTRA_LDFLAGS='-linkmode external -extldflags "-fno-PIC -static"' \
BUILDTAGS="netgo osusergo static_build"
Note:
- static build is discouraged
- static containerd binary does not support loading shared object plugins (
*.so
)
The following instructions assume you are at the parent directory of containerd source directory.
You can build containerd
via a Linux-based Docker container.
You can build an image from this Dockerfile
:
FROM golang
RUN apt-get update && \
apt-get install -y libbtrfs-dev
Let's suppose that you built an image called containerd/build
. From the
containerd source root directory you can run the following command:
docker run -it \
-v ${PWD}/containerd:/go/src/github.com/containerd/containerd \
-e GOPATH=/go \
-w /go/src/github.com/containerd/containerd containerd/build sh
This mounts containerd
repository
You are now ready to build:
make && make install
To have complete core container runtime, you will need both containerd
and runc
. It is possible to build both of these via Docker container.
You can use git
to checkout runc
:
git clone https://github.com/opencontainers/runc
We can build an image from this Dockerfile
:
FROM golang
RUN apt-get update && \
apt-get install -y libbtrfs-dev libseccomp-dev
In our Docker container we will build runc
build, which includes
seccomp, SELinux,
and AppArmor support. Seccomp support
in runc requires libseccomp-dev
as a dependency (AppArmor and SELinux support
do not require external libraries at build time). Refer to RUNC.md
in the docs directory to for details about building runc, and to learn about
supported versions of runc
as used by containerd.
Let's suppose you build an image called containerd/build
from the above Dockerfile. You can run the following command:
docker run -it --privileged \
-v /var/lib/containerd \
-v ${PWD}/runc:/go/src/github.com/opencontainers/runc \
-v ${PWD}/containerd:/go/src/github.com/containerd/containerd \
-e GOPATH=/go \
-w /go/src/github.com/containerd/containerd containerd/build sh
This mounts both runc
and containerd
repositories in our Docker container.
From within our Docker container let's build containerd
:
cd /go/src/github.com/containerd/containerd
make && make install
These binaries can be found in the ./bin
directory in your host.
make install
will move the binaries in your $PATH
.
Next, let's build runc
:
cd /go/src/github.com/opencontainers/runc
make && make install
For further details about building runc, refer to RUNC.md in the docs directory.
When working with ctr
, the simple test client we just built, don't forget to start the daemon!
containerd --config config.toml
During the automated CI the unit tests and integration tests are run as part of the PR validation. As a developer you can run these tests locally by using any of the following Makefile
targets:
make test
: run all non-integration tests that do not requireroot
privilegesmake root-test
: run all non-integration tests which requireroot
make integration
: run all tests, including integration tests and those which requireroot
.TESTFLAGS_PARALLEL
can be used to control parallelism. For example,TESTFLAGS_PARALLEL=1 make integration
will lead a non-parallel execution. The default value ofTESTFLAGS_PARALLEL
is 8.
To execute a specific test or set of tests you can use the go test
capabilities
without using the Makefile
targets. The following examples show how to specify a test
name and also how to use the flag directly against go test
to run root-requiring tests.
# run the test <TEST_NAME>:
go test -v -run "<TEST_NAME>" .
# enable the root-requiring tests:
go test -v -run . -test.root
Example output from directly running go test
to execute the TestContainerList
test:
sudo go test -v -run "TestContainerList" . -test.root
INFO[0000] running tests against containerd revision=f2ae8a020a985a8d9862c9eb5ab66902c2888361 version=v1.0.0-beta.2-49-gf2ae8a0
=== RUN TestContainerList
--- PASS: TestContainerList (0.00s)
PASS
ok github.com/containerd/containerd 4.778s
In addition to go test
-based testing executed via the Makefile
targets, the containerd-stress
tool is available and built with the all
or binaries
targets and installed during make install
.
With this tool you can stress a running containerd daemon for a specified period of time, selecting a concurrency level to generate stress against the daemon. The following command is an example of having five workers running for two hours against a default containerd gRPC socket address:
containerd-stress -c 5 -t 120
For more information on this tool's options please run containerd-stress --help
.
Bucketbench is an external tool which can be used to drive load against a container runtime, specifying a particular set of lifecycle operations to run with a specified amount of concurrency. Bucketbench is more focused on generating performance details than simply inducing load against containerd.
Bucketbench differs from the containerd-stress
tool in a few ways:
- Bucketbench has support for testing the Docker engine, the
runc
binary, and containerd 0.2.x (viactr
) and 1.0 (via the client library) branches. - Bucketbench is driven via configuration file that allows specifying a list of lifecycle operations to execute. This can be used to generate detailed statistics per-command (e.g. start, stop, pause, delete).
- Bucketbench generates detailed reports and timing data at the end of the configured test run.
More details on how to install and run bucketbench
are available at the GitHub project page.