CARVIEW |
Containerd Quick Start
This document describes how to use containerd-shim-runsc-v1
with the
containerd runtime handler support on containerd
. This is a similar setup as
GKE Sandbox, other than the
platform configuration.
⚠️ Note: If you are using Kubernetes and set up your cluster using
kubeadm
you may run into issues. See the FAQ for details.
Requirements
- runsc and containerd-shim-runsc-v1: See the installation guide.
- containerd: See the containerd website for information on how to install containerd. Minimal version supported: 1.3.9 or 1.4.3.
Configure containerd
Update /etc/containerd/config.toml
. Make sure containerd-shim-runsc-v1
is in
${PATH}
or in the same directory as containerd
binary.
cat <<EOF | sudo tee /etc/containerd/config.toml
version = 2
[plugins."io.containerd.runtime.v1.linux"]
shim_debug = true
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
runtime_type = "io.containerd.runc.v2"
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc]
runtime_type = "io.containerd.runsc.v1"
EOF
Consider using the version header
version = 3
if you are using containerd 2.x. See the difference at containerd version header
Install CNI plugins
Typically, you will have to install CNI plugins to complete the following steps.
For the quick start, it is sufficient to install the plugins with default settings by running the script from the containerd project:
git clone --depth=1 -b {CONTAINERD_VERSION} https://github.com/containerd/containerd.git
cd containerd && ./script/setup/install-cni
Restart containerd
sudo systemctl restart containerd
Usage
You can run containers in gVisor via ctr or crictl.
ctr
The tool ctr
communicates directly with containerd, and it is a part of each
containerd release.
Running a container
Now run your container using the runsc runtime:
sudo ctr image pull docker.io/library/hello-world:latest
sudo ctr run --runtime io.containerd.runsc.v1 -t --rm docker.io/library/hello-world:latest hello-wrold
Verify the runtime
You can verify that you are running in gVisor using the dmesg command.
$ sudo ctr image pull docker.io/library/busybox:latest
$ sudo ctr run --runtime io.containerd.run.runsc.v1 -t --rm docker.io/library/busybox:latest gvisord dmesg
[ 0.000000] Starting gVisor...
[ 0.445958] Forking spaghetti code...
[ 0.794963] Feeding the init monster...
[ 0.842573] Synthesizing system calls...
[ 0.985066] Generating random numbers by fair dice roll...
[ 1.444465] Mounting deweydecimalfs...
[ 1.546130] Waiting for children...
[ 1.689078] Searching for socket adapter...
[ 2.026282] Accelerating teletypewriter to 9600 baud...
[ 2.274752] Creating process schedule...
[ 2.498083] Reticulating splines...
[ 2.675603] Setting up VFS...
[ 2.750186] Setting up FUSE...
[ 2.789133] Ready!
crictl
Alternatively, you can use crictl which designed for CRI-compatible containers.
Install crictl
Download and install the crictl
binary:
{
wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.13.0/crictl-v1.13.0-linux-amd64.tar.gz
tar xf crictl-v1.13.0-linux-amd64.tar.gz
sudo mv crictl /usr/local/bin
}
Write the crictl
configuration file:
cat <<EOF | sudo tee /etc/crictl.yaml
runtime-endpoint: unix:///run/containerd/containerd.sock
EOF
Create the nginx sandbox in gVisor
Pull the nginx image:
sudo crictl pull nginx
Create the sandbox creation request:
cat <<EOF | tee sandbox.json
{
"metadata": {
"name": "nginx-sandbox",
"namespace": "default",
"attempt": 1,
"uid": "hdishd83djaidwnduwk28bcsb"
},
"linux": {
},
"log_directory": "/tmp"
}
EOF
Create the pod in gVisor:
SANDBOX_ID=$(sudo crictl runp --runtime runsc sandbox.json)
Run the nginx container in the sandbox
Create the nginx container creation request:
cat <<EOF | tee container.json
{
"metadata": {
"name": "nginx"
},
"image":{
"image": "nginx"
},
"log_path":"nginx.0.log",
"linux": {
}
}
EOF
Create the nginx container:
CONTAINER_ID=$(sudo crictl create ${SANDBOX_ID} container.json sandbox.json)
Start the nginx container:
sudo crictl start ${CONTAINER_ID}
Validate the container
Inspect the created pod:
sudo crictl inspectp ${SANDBOX_ID}
Inspect the nginx container:
sudo crictl inspect ${CONTAINER_ID}
Verify that nginx is running in gVisor:
sudo crictl exec ${CONTAINER_ID} dmesg | grep -i gvisor
Set up the Kubernetes RuntimeClass
Install the RuntimeClass for gVisor:
cat <<EOF | kubectl apply -f -
apiVersion: node.k8s.io/v1
kind: RuntimeClass
metadata:
name: gvisor
handler: runsc
EOF
Create a Pod with the gVisor RuntimeClass:
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
name: nginx-gvisor
spec:
runtimeClassName: gvisor
containers:
- name: nginx
image: nginx
EOF
Verify that the Pod is running:
kubectl get pod nginx-gvisor -o wide
What’s next
This setup is already done for you on GKE Sandbox. It is an easy way to get started with gVisor.
Before taking this deployment to production, review the Production guide.