runtime-handler-quickstart.md

Runtime Handler Quickstart

This document describes how to install and run the gvisor-containerd-shim using the containerd runtime handler support. This requires containerd 1.2 or later.

Requirements

• runsc: See the gVisor documentation for information on how to install runsc.
• containerd: See the containerd website for information on how to install containerd.

Install

Install gvisor-containerd-shim

1. Download the latest release of the gvisor-containerd-shim. See the releases page

{ # Step 1(release): Install gvisor-containerd-shim
LATEST_RELEASE=$(wget -qO - https://api.github.com/repos/google/gvisor-containerd-shim/releases | grep -oP '(?<="browser_download_url": ")https://[^"]*gvisor-containerd-shim.linux-amd64' | head -1)
wget -O gvisor-containerd-shim ${LATEST_RELEASE}
chmod +x gvisor-containerd-shim
sudo mv gvisor-containerd-shim /usr/local/bin/gvisor-containerd-shim
}

2. Create the configuration for the gvisor shim in /etc/containerd/gvisor-containerd-shim.toml:

{ # Step 2: Create the gvisor-containerd-shim.toml
cat <<EOF | sudo tee /etc/containerd/gvisor-containerd-shim.toml
# This is the path to the default runc containerd-shim.
runc_shim = "/usr/local/bin/containerd-shim"
EOF
}

Configure containerd

1. Update /etc/containerd/config.toml. Be sure to update the path to gvisor-containerd-shim and runsc if necessary:

{ # Step 1: Create containerd config.toml
cat <<EOF | sudo tee /etc/containerd/config.toml
disabled_plugins = ["restart"]
[plugins.linux]
  shim = "/usr/local/bin/gvisor-containerd-shim"
  shim_debug = true
[plugins.cri.containerd.runtimes.runsc]
  runtime_type = "io.containerd.runtime.v1.linux"
  runtime_engine = "/usr/local/bin/runsc"
  runtime_root = "/run/containerd/runsc"
EOF
}

2. Restart containerd

sudo systemctl restart containerd

Usage

You can run containers in gVisor via containerd's CRI.

Install crictl

1. Download and install the crictl binary:

{ # Step 1: Download crictl
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
}

2. Write the crictl configuration file

{ # Step 2: Configure crictl
cat <<EOF | sudo tee /etc/crictl.yaml
runtime-endpoint: unix:///run/containerd/containerd.sock
EOF
}

Create the nginx Sandbox in gVisor

1. Pull the nginx image

{ # Step 1: Pull the nginx image
sudo crictl pull nginx
}

2. Create the sandbox creation request

{ # Step 2: Create sandbox.json
cat <<EOF | tee sandbox.json
{
    "metadata": {
        "name": "nginx-sandbox",
        "namespace": "default",
        "attempt": 1,
        "uid": "hdishd83djaidwnduwk28bcsb"
    },
    "linux": {
    },
    "log_directory": "/tmp"
}
EOF
}

3. Create the pod in gVisor

{ # Step 3: Create the sandbox
SANDBOX_ID=$(sudo crictl runp --runtime runsc sandbox.json)
}

Run the nginx Container in the Sandbox

1. Create the nginx container creation request

{ # Step 1: Create nginx container config
cat <<EOF | tee container.json
{
  "metadata": {
      "name": "nginx"
    },
  "image":{
      "image": "nginx"
    },
  "log_path":"nginx.0.log",
  "linux": {
  }
}
EOF
}

2. Create the nginx container

{ # Step 2: Create nginx container
CONTAINER_ID=$(sudo crictl create ${SANDBOX_ID} container.json sandbox.json)
}

3. Start the nginx container

{ # Step 3: Start nginx container
sudo crictl start ${CONTAINER_ID}
}

Validate the container

1. Inspect the created pod

{ # Step 1: Inspect the pod
sudo crictl inspectp ${SANDBOX_ID}
}

2. Inspect the nginx container

{ # Step 2: Inspect the container
sudo crictl inspect ${CONTAINER_ID}
}

3. Verify that nginx is running in gVisor

{ # Step 3: Check dmesg
sudo crictl exec ${CONTAINER_ID} dmesg | grep -i gvisor
}

Set up the Kubernetes Runtime Class

1. Install the Runtime Class for gVisor

{ # Step 1: Install a RuntimeClass
cat <<EOF | kubectl apply -f -
apiVersion: node.k8s.io/v1beta1
kind: RuntimeClass
metadata:
  name: gvisor
handler: runsc
EOF
}

2. Create a Pod with the gVisor Runtime Class

{ # Step 2: Create a pod
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: nginx-gvisor
spec:
  runtimeClassName: gvisor
  containers:
  - name: nginx
    image: nginx
EOF
}

3. Verify that the Pod is running

{ # Step 3: Get the pod
kubectl get pod nginx-gvisor -o wide
}