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diff --git a/content/docs/tutorials/cni.md b/content/docs/tutorials/cni.md new file mode 100644 index 000000000..b8abc8689 --- /dev/null +++ b/content/docs/tutorials/cni.md @@ -0,0 +1,175 @@ ++++ +title = "Using CNI" +weight = 12 ++++ + +This tutorial will show you how to set up networking for a gVisor sandbox using +the [Container Networking Interface (CNI)](https://github.com/containernetworking/cni). + +## Install CNI Plugins + +First you will need to install the CNI plugins. CNI plugins are used to set up +a network namespace that `runsc` can use with the sandbox. + +Start by creating the directories for CNI plugin binaries: + +``` +sudo mkdir -p /opt/cni/bin +``` + +Download the CNI plugins: + +``` +wget https://github.com/containernetworking/plugins/releases/download/v0.8.3/cni-plugins-linux-amd64-v0.8.3.tgz +``` + +Next, unpack the plugins into the CNI binary directory: + +``` +sudo tar -xvf cni-plugins-linux-amd64-v0.8.3.tgz -C /opt/cni/bin/ +``` + +## Configure CNI Plugins + +This section will show you how to configure CNI plugins. This tutorial will use +the "bridge" and "loopback" plugins which will create the necessary bridge and +loopback devices in our network namespace. However, you should be able to use +any CNI compatible plugin to set up networking for gVisor sandboxes. + +The bridge plugin configuration specifies the IP address subnet range for IP +addresses that will be assigned to sandboxes as well as the network routing +configuration. This tutorial will assign IP addresses from the `10.22.0.0/16` +range and allow all outbound traffic, however you can modify this configuration +to suit your use case. + +Create the bridge and loopback plugin configurations: + +``` +sudo mkdir -p /etc/cni/net.d + +sudo sh -c 'cat > /etc/cni/net.d/10-bridge.conf << EOF +{ + "cniVersion": "0.4.0", + "name": "mynet", + "type": "bridge", + "bridge": "cni0", + "isGateway": true, + "ipMasq": true, + "ipam": { + "type": "host-local", + "subnet": "10.22.0.0/16", + "routes": [ + { "dst": "0.0.0.0/0" } + ] + } +} +EOF' + +sudo sh -c 'cat > /etc/cni/net.d/99-loopback.conf << EOF +{ + "cniVersion": "0.4.0", + "name": "lo", + "type": "loopback" +} +EOF' +``` + +## Create a Network Namespace + +For each gVisor sandbox you will create a network namespace and configure it +using CNI. First, create a random network namespace name and then create +the namespace. + +The network namespace path will then be `/var/run/netns/${CNI_CONTAINERID}`. + +``` +export CNI_PATH=/opt/cni/bin +export CNI_CONTAINERID=$(printf '%x%x%x%x' $RANDOM $RANDOM $RANDOM $RANDOM) +export CNI_COMMAND=ADD +export CNI_NETNS=/var/run/netns/${CNI_CONTAINERID} + +sudo ip netns add ${CNI_CONTAINERID} +``` + +Next, run the bridge and loopback plugins to apply the configuration that was +created earlier to the namespace. Each plugin outputs some JSON indicating the +results of executing hte plugin. For example, The bridge plugin's response +includes the IP address assigned to the ethernet device created in the network +namespace. Take note of the IP address for use later. + +``` +export CNI_IFNAME="eth0" +sudo -E /opt/cni/bin/bridge < /etc/cni/net.d/10-bridge.conf +export CNI_IFNAME="lo" +sudo -E /opt/cni/bin/loopback < /etc/cni/net.d/99-loopback.conf +``` + +Get the IP address assigned to our sandbox: + +``` +POD_IP=$(sudo ip netns exec ${CNI_CONTAINERID} ip -4 addr show eth0 | grep -oP '(?<=inet\s)\d+(\.\d+){3}') +``` + +## Create the OCI Bundle + +Now that our network namespace is created and configured, we can create the OCI +bundle for our container. As part of the bundle's `config.json` we will specify +that the container use the network namespace that we created. + +The container will run a simple python webserver that we will be able to +connect to via the IP address assigned to it via the bridge CNI plugin. + +Create the bundle and root filesystem directories: + +``` +sudo mkdir -p bundle +cd bundle +sudo mkdir rootfs +sudo docker export $(docker create python) | sudo tar --same-owner -pxf - -C rootfs +sudo mkdir -p rootfs/var/www/html +sudo sh -c 'echo "Hello World!" > rootfs/var/www/html/index.html' +``` + +Next create the `config.json` specifying the network namespace. +``` +sudo /usr/local/bin/runsc spec +sudo sed -i 's;"sh";"python", "-m", "http.server";' config.json +sudo sed -i "s;\"cwd\": \"/\";\"cwd\": \"/var/www/html\";" config.json +sudo sed -i "s;\"type\": \"network\";\"type\": \"network\",\n\t\t\t\t\"path\": \"/var/run/netns/${CNI_CONTAINERID}\";" config.json +``` + +## Run the Container + +Now we can run and connect to the webserver. Run the container in gVisor. Use +the same ID used for the network namespace to be consistent: + +``` +sudo runsc run -detach ${CNI_CONTAINERID} +``` + +Connect to the server via the sandbox's IP address: + +``` +curl http://${POD_IP}:8000/ +``` + +You should see the server returning `Hello World!`. + +## Cleanup + +After you are finished running the container, you can clean up the network +namespace . + +``` +sudo runsc kill ${CNI_CONTAINERID} +sudo runsc delete ${CNI_CONTAINERID} + +export CNI_COMMAND=DEL + +export CNI_IFNAME="lo" +sudo -E /opt/cni/bin/loopback < /etc/cni/net.d/99-loopback.conf +export CNI_IFNAME="eth0" +sudo -E /opt/cni/bin/bridge < /etc/cni/net.d/10-bridge.conf + +sudo ip netns delete ${CNI_CONTAINERID} +``` diff --git a/content/docs/tutorials/kubernetes.md b/content/docs/tutorials/kubernetes.md index 5a931bae3..36ab59c1c 100644 --- a/content/docs/tutorials/kubernetes.md +++ b/content/docs/tutorials/kubernetes.md @@ -1,5 +1,6 @@ +++ title = "WordPress with Kubernetes" +weight = 11 +++ ## Deploy a WordPress site using GKE Sandbox |