Configuration¶

ConfigMap Options¶

In the ConfigMap there are several options that can be configured according to your preferences:

• debug - Sets to run Cilium in full debug mode, which enables verbose logging and configures BPF programs to emit more visibility events into the output of cilium monitor.
• enable-ipv4 - Enable IPv4 addressing support
• enable-ipv6 - Enable IPv6 addressing support
• clean-cilium-bpf-state - Removes all BPF state from the filesystem on startup. Endpoints will be restored with the same IP addresses, but ongoing connections may be briefly disrupted and loadbalancing decisions will be lost, so active connections via the loadbalancer will break. All BPF state will be reconstructed from their original sources (for example, from kubernetes or the kvstore). This may be used to mitigate serious issues regarding BPF maps. This option should be turned off again after restarting the daemon.
• clean-cilium-state - Removes all Cilium state, including unrecoverable information such as all endpoint state, as well as recoverable state such as BPF state pinned to the filesystem, CNI configuration files, library code, links, routes, and other information. This operation is irreversible. Existing endpoints currently managed by Cilium may continue to operate as before, but Cilium will no longer manage them and they may stop working without warning. After using this operation, endpoints must be deleted and reconnected to allow the new instance of Cilium to manage them.
• monitor-aggregation - This option enables coalescing of tracing events in cilium monitor to only include periodic updates from active flows, or any packets that involve an L4 connection state change. Valid options are none, low, medium, maximum.
• preallocate-bpf-maps - Pre-allocation of map entries allows per-packet latency to be reduced, at the expense of up-front memory allocation for the entries in the maps. Set to true to optimize for latency. If this value is modified, then during the next Cilium startup connectivity may be temporarily disrupted for endpoints with active connections.

Any changes that you perform in the Cilium ConfigMap and in cilium-etcd-secrets Secret will require you to restart any existing Cilium pods in order for them to pick the latest configuration.

The following ConfigMap is an example where the etcd cluster is running in 2 nodes, node-1 and node-2 with TLS, and client to server authentication enabled.

apiVersion: v1
kind: ConfigMap
metadata:
  name: cilium-config
  namespace: kube-system
data:
    endpoints:
    - https://node-1:31079
    - https://node-2:31079
    #
    # In case you want to use TLS in etcd, uncomment the 'ca-file' line
    # and create a kubernetes secret by following the tutorial in
    # https://cilium.link/etcd-config
    ca-file: '/var/lib/etcd-secrets/etcd-client-ca.crt'
    #
    # In case you want client to server authentication, uncomment the following
    # lines and create a kubernetes secret by following the tutorial in
    # https://cilium.link/etcd-config
    key-file: '/var/lib/etcd-secrets/etcd-client.key'
    cert-file: '/var/lib/etcd-secrets/etcd-client.crt'

  # If you want to run cilium in debug mode change this value to true
  debug: "false"
  enable-ipv4: "true"
  # If you want to clean cilium state; change this value to true
  clean-cilium-state: "false"

Manually installing CNI¶

This step is typically already included in all Kubernetes distributions or Kubernetes installers but can be performed manually:

sudo mkdir -p /opt/cni
wget https://storage.googleapis.com/kubernetes-release/network-plugins/cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz
sudo tar -xvf cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz -C /opt/cni
rm cni-0799f5732f2a11b329d9e3d51b9c8f2e3759f2ff.tar.gz

Adjusting CNI configuration¶

The CNI configuration file is automatically written and maintained by the scripts cni-install.sh and cni-uninstall.sh which are running as postStart and preStop hooks of the Cilium pod.

If you want to provide your own custom CNI configuration file, set the CILIUM_CUSTOM_CNI_CONF environment variable to avoid overwriting the configuration file by adding the following to the env: section of the cilium DaemonSet:

- name: CILIUM_CUSTOM_CNI_CONF
  value: "true"

The CNI installation can be configured with environment variables. These environment variables can be specified in the DaemonSet file like this:

env:
  - name: "CNI_CONF_NAME"
    value: "05-cilium.conf"

The following variables are supported:

If you want to further adjust the CNI configuration you may do so by creating the CNI configuration /etc/cni/net.d/05-cilium.conf manually:

sudo mkdir -p /etc/cni/net.d
sudo sh -c 'echo "{
    "name": "cilium",
    "type": "cilium-cni"
}
" > /etc/cni/net.d/05-cilium.conf'

Cilium will use any existing /etc/cni/net.d/05-cilium.conf file if it already exists on a worker node and only creates it if it does not exist yet.

kubectl get crd ciliumnetworkpolicies.cilium.io -o json | grep -A 12 openAPIV3Schema
    "openAPIV3Schema": {
        "oneOf": [
            {
                "required": [
                    "spec"
                ]
            },
            {
                "required": [
                    "specs"
                ]
            }
        ],

cat <<EOF > ./bad-cnp.yaml
apiVersion: "cilium.io/v2"
kind: CiliumNetworkPolicy
description: "Policy to test multiple rules in a single file"
metadata:
  name: my-new-cilium-object
spec:
  endpointSelector:
    matchLabels:
      app: details
      track: stable
      version: v1
  ingress:
  - fromEndpoints:
    - matchLabels:
        app: reviews
        track: stable
        version: v1
    toPorts:
    - ports:
      - port: '65536'
        protocol: TCP
      rules:
        http:
        - method: GET
          path: "/health"
EOF

kubectl create -f ./bad-cnp.yaml
...
spec.ingress.toPorts.ports.port in body should match '^(6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[0-9]{1,4})$'

cat <<EOF | sudo tee /etc/systemd/system/sys-fs-bpf.mount
[Unit]
Description=Cilium BPF mounts
Documentation=http://docs.cilium.io/
DefaultDependencies=no
Before=local-fs.target umount.target
After=swap.target

[Mount]
What=bpffs
Where=/sys/fs/bpf
Type=bpf

[Install]
WantedBy=multi-user.target
EOF

CRIO¶

If you want to use CRIO, use the following YAML instead:

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.15/cilium-crio.yaml

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.14/cilium-crio.yaml

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.13/cilium-crio.yaml

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.12/cilium-crio.yaml

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.11/cilium-crio.yaml

kubectl create -f https://raw.githubusercontent.com/cilium/cilium/HEAD/examples/kubernetes/1.10/cilium-crio.yaml

Since CRI-O does not automatically detect that a new CNI plugin has been installed, you will need to restart the CRI-O daemon for it to pick up the Cilium CNI configuration.

First make sure cilium is running:

kubectl get pods -n kube-system -o wide
NAME               READY     STATUS    RESTARTS   AGE       IP          NODE
cilium-mqtdz       1/1       Running   0          3m       10.0.2.15   minikube

After that you can restart CRI-O:

minikube ssh -- sudo systemctl restart crio

Finally, you need to restart the Cilium pod so it can re-mount /var/run/crio/crio.sock which was recreated by CRI-O

kubectl delete -n kube-system pod -l k8s-app=cilium

Disable container runtime¶

If you want to run the Cilium agent on a node that will not host any application containers, then that node may not have a container runtime installed at all. You may still want to run the Cilium agent on the node to ensure that local processes on that node can reach application containers on other nodes. The default behavior of Cilium on startup when no container runtime has been found is to abort startup. To avoid this abort, you can run the cilium-agent with the following option.

--container-runtime=none