Configuring the Calico CNI plugins

The Calico CNI plugin is configured through the standard CNI configuration mechanism

A minimal configuration file that uses Calico for networking and IPAM looks like this

{
    "name": "any_name",
    "type": "calico",
    "ipam": {
        "type": "calico-ipam"
    }
}

Additional configuration can be added as detailed below.

Generic

Datastore type

The following option allows configuration of the Calico datastore type.

• datastore_type (default: etcdv2)

The Calico CNI plugin supports the following datastore types:

• etcdv2 (default)
• kubernetes (experimental)

Etcd location

The following options are valid when datastore_type is etcdv2.

Configure access to your etcd cluster using the following options

• etcd_endpoints (no default. Format is comma separated list of etcd servers e.g. http://1.2.3.4:2379,http://5.6.7.8:2379)
• etcd_key_file (no default. Format is an absolute path to a file)
• etcd_cert_file (no default. Format is an absolute path to a file)
• etcd_ca_cert_file (no default. Format is an absolute path to a file)

The following deprecated options are also supported

• etcd_authority (default is 127.0.0.1:2379)
  • If etcd_authority is set at the same time as etcd_endpoints then etcd_endpoints is used.
• etcd_scheme (default is http)

Logging

• Logging is always to stderr
• Logging level can be controlled by setting "log_level" in the netconf. Allowed levels are
  • WARNING - the default.
  • INFO - Enables some additional logging from the CNI plugin.
  • DEBUG - Enables lots of debug logging from both the CNI plugin and the underlying libcalico library.

{
    "name": "any_name",
    "type": "calico",
    "log_level": "DEBUG",
    "ipam": {
        "type": "calico-ipam"
    }
}

IPAM

When using Calico IPAM, the following flags determine what IP addresses should be assigned. NOTE: These flags are strings and not boolean values.

• assign_ipv4 (default "true")
• assign_ipv6 (default "false")

A specific IP address can be chosen by using CNI_ARGS and setting IP to the desired value.

Kubernetes specific

When using the Calico CNI plugin with Kubernetes, the plugin must be able to access the Kubernetes API server in order to find the labels assigned to the Kubernetes pods. The recommended way to configure access is through a kubeconfig file specified in the kubernetes section of the network config. e.g.

{
    "name": "any_name",
    "type": "calico",
    "kubernetes": {
        "kubeconfig": "/path/to/kubeconfig"
    },
    "ipam": {
        "type": "calico-ipam"
    }
}

As a convenience, the API location location can also be configured directly, e.g.

{
    "name": "any_name",
    "type": "calico",
    "kubernetes": {
        "k8s_api_root": "http://127.0.0.1:8080"
    },
    "ipam": {
        "type": "calico-ipam"
    }
}

Enabling Kubernetes Policy

If you wish to use the Kubernetes NetworkPolicy API then you must set a policy type in the network config. There is a single supported policy type, k8s which uses the Kubernetes NetworkPolicy API in conjunction with the calico/kube-policy-controller.

{
    "name": "any_name",
    "type": "calico",
    "policy": {
      "type": "k8s",
      "k8s_api_root": "http://127.0.0.1:8080"
    },
    "ipam": {
        "type": "calico-ipam"
    }
}

When using type: k8s, the Calico CNI plugin requires read-only Kubernetes API access to the Pods resource in all namespaces.

Previous versions of the plugin (v1.3.1 and earlier) supported an alternative type called k8s-annotations This uses annotations on pods to specify network policy but is no longer supported.

Deprecated ways of specifying Kubernetes API access details

From the examples above, you can see that the k8s_api_root can appear in either the kubernetes or policy configuration blocks.

• k8s_api_root (default http://127.0.0.1:8080)

In addition, the following methods are supported in the policy section of the CNI network config only. None of them have default values.

• k8s_auth_token
• k8s_client_certificate
• k8s_client_key
• k8s_certificate_authority

IPAM

When using the CNI host-local IPAM plugin, a special value usePodCidr is allowed for the subnet field. This tells the plugin to determine the subnet to use from the Kubernetes API based on the Node.podCIDR field.

• node_name
  • The node name to use when looking up the usePodCidr value (defaults to current hostname)

{
    "name": "any_name",
    "type": "calico",
    "kubernetes": {
        "kubeconfig": "/path/to/kubeconfig",
        "node_name": "node-name-in-k8s"
    },
    "ipam": {
        "type": "host-local",
        "subnet": "usePodCidr"
    }
}

When making use of the usePodCidr option, the Calico CNI plugin requires read-only Kubernetes API access to the Nodes resource.