Install and setup containerd on Ubuntu

setup_containerd.sh

#! /bin/bash

TMPROOT=$(mktemp -d)
cd /$TMPROOT

SUDO=''
if (( $EUID != 0 )); then
    SUDO='sudo'
fi

echo "INSTALLING CONTAINERD"
echo ""

CONTAINERD_VERSION="1.7.7"

wget https://github.com/containerd/containerd/releases/download/v$CONTAINERD_VERSION/containerd-$CONTAINERD_VERSION-linux-amd64.tar.gz
wget https://github.com/containerd/containerd/releases/download/v$CONTAINERD_VERSION/containerd-$CONTAINERD_VERSION-linux-amd64.tar.gz.sha256sum

CONTAINERD_CHECKSUM=$(containerd-$CONTAINERD_VERSION-linux-amd64.tar.gz)
GIVEN_SHA256=$(cat containerd-$CONTAINERD_VERSION-linux-amd64.tar.gz.sha256sum)

if [[ $CONTAINERD_CHECKSUM -ne $GIVEN_SHA256 ]]; then
    echo "Failed: Verify containerd checksum"
    exit 1
fi

sudo tar Cxzvf /usr/local containerd-$CONTAINERD_VERSION-linux-amd64.tar.gz

echo ""
echo "DONE"

echo ""
echo "SETTING UP CONTAINERD SERVICE"
echo ""

sudo mkdir -p /usr/local/lib/systemd/system/

sudo curl -o /usr/local/lib/systemd/system/containerd.service https://raw.githubusercontent.com/containerd/containerd/main/containerd.service

sudo systemctl daemon-reload
sudo systemctl enable --now containerd

echo ""
echo "INSTALLING RUNC"
echo ""

RUNC_VERSION="1.1.9"

wget https://github.com/opencontainers/runc/releases/download/v$RUNC_VERSION/runc.amd64

sudo install -m 755 runc.amd64 /usr/local/sbin/runc

echo ""
echo "DONE"

echo ""
echo "INSTALLING CNI Plugins"
echo ""

CRI_VERSION="1.3.0"

wget https://github.com/containernetworking/plugins/releases/download/v$CRI_VERSION/cni-plugins-linux-amd64-v$CRI_VERSION.tgz

wget https://github.com/containernetworking/plugins/releases/download/v$CRI_VERSION/cni-plugins-linux-amd64-v$CRI_VERSION.tgz.sha256

CNI_CHECKSUM=$(cni-plugins-linux-amd64-v$CRI_VERSION.tgz)

GIVEN_CNI_SHA256=$(cat cni-plugins-linux-amd64-v$CRI_VERSION.tgz.sha256)

if [[ $CNI_CHECKSUM -ne $GIVEN_CNI_SHA256 ]]; then
    echo "Failed: Verify CNI Plugins checksum"
    exit 1
fi

sudo mkdir -p /opt/cni/bin

sudo tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v$CRI_VERSION.tgz

echo ""
echo "DONE"

echo ""
echo "Confering CONTAINERD"
echo ""

sudo mkdir -p /etc/containerd
sudo containerd config default | sudo tee /etc/containerd/config.toml

sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/g' /etc/containerd/config.toml

echo ""
echo "DONE"

CNI_CONFIG_DIR=${DESTDIR}/etc/cni/net.d
$SUDO mkdir -p $CNI_CONFIG_DIR

$SUDO cat << EOF | $SUDO tee $CNI_CONFIG_DIR/10-containerd-net.conflist
{
  "cniVersion": "1.0.0",
  "name": "containerd-net",
  "plugins": [
    {
      "type": "bridge",
      "bridge": "cni0",
      "isGateway": true,
      "ipMasq": true,
      "promiscMode": true,
      "ipam": {
        "type": "host-local",
        "ranges": [
          [{
            "subnet": "10.88.0.0/16"
          }],
          [{
            "subnet": "2001:4860:4860::/64"
          }]
        ],
        "routes": [
          { "dst": "0.0.0.0/0" },
          { "dst": "::/0" }
        ]
      }
    },
    {
      "type": "portmap",
      "capabilities": {"portMappings": true}
    }
  ]
}
EOF

sudo systemctl restart containerd

cd

rm -rf $TMPROOT

if still con't able to read /etc/cni/net.d then just give read permission to this dir
like

sudo chmod 777 /etc/cni/net.d