System requirements
Node requirements
-
AMD64 processor
- Linux kernel 3.10 or later with required dependencies.
The following distributions have the required kernel, its dependencies, and are
known to work well with Calico and Kubernetes.
- RedHat Linux 7
- CentOS 7
- CoreOS Container Linux stable
- Ubuntu 16.04
- Debian 8
-
Calico must be able to manage
cali*
interfaces on the host. When IPIP is enabled (the default), Calico also needs to be able to managetunl*
interfaces.Note: Many Linux distributions, such as most of the above, include NetworkManager. By default, NetworkManager does not allow Calico to manage interfaces. If your nodes have NetworkManager, complete the steps in Preventing NetworkManager from controlling Calico interfaces before installing Calico.
Key/value store
Calico v3.10 requires a key/value store accessible by all Calico components. On Kubernetes, you can configure Calico to access an etcdv3 cluster directly or to use the Kubernetes API datastore.
Network requirements
Ensure that your hosts and firewalls allow the necessary traffic based on your configuration.
Configuration | Host(s) | Connection type | Port/protocol |
---|---|---|---|
Calico networking (BGP) | All | Bidirectional | TCP 179 |
Calico networking with IP-in-IP enabled (default) | All | Bidirectional | IP-in-IP, often represented by its protocol number 4 |
Calico networking with VXLAN enabled | All | Bidirectional | UDP 4789 |
Calico networking with Typha enabled | Typha agent hosts | Incoming | TCP 5473 (default) |
flannel networking (VXLAN) | All | Bidirectional | UDP 4789 |
All | kube-apiserver host | Incoming | Often TCP 443 or 6443* |
etcd datastore | etcd hosts | Incoming | Officially TCP 2379 but can vary |
* The value passed to kube-apiserver using the --secure-port
flag. If you cannot locate this, check the targetPort
value returned by kubectl get svc kubernetes -o yaml
.
Privileges
Ensure that Calico has the CAP_SYS_ADMIN
privilege.
The simplest way to provide the necessary privilege is to run Calico as root or in a privileged container. When installed as a Kubernetes daemon set, Calico meets this requirement by running as a privileged container. This requires that the kubelet be allowed to run privileged containers. There are two ways this can be achieved.
- Specify
--allow-privileged
on the kubelet (deprecated). - Use a pod security policy.
Kubernetes requirements
Supported versions
We test Calico v3.10 against the following Kubernetes versions.
- 1.14
- 1.15
- 1.16
Other versions are likely to work, but we do not actively test Calico v3.10 against them.
CNI plug-in enabled
Calico is installed as a CNI plugin. The kubelet must be configured
to use CNI networking by passing the --network-plugin=cni
argument. (On
kubeadm, this is the default.)
Other network providers
Calico must be the only network provider in each cluster. We do not currently support migrating a cluster with another network provider to use Calico networking.
Supported kube-proxy modes
Calico supports the following kube-proxy modes:
iptables
(default)ipvs
Requires Kubernetes >=v1.9.3. Refer to Enabling IPVS in Kubernetes for more details.
IP pool configuration
The IP range selected for pod IP addresses cannot overlap with any other IP ranges in your network, including:
- The Kubernetes service cluster IP range
- The range from which host IPs are allocated
Application layer policy requirements
- MutatingAdmissionWebhook enabled
- Istio v1.0
Kernel dependencies
Tip: If you are using one of the recommended distributions, you will already satisfy these.
ip_set
ip_tables
(for IPv4)ip6_tables
(for IPv6)ipt_REJECT
ipt_rpfilter
ipt_set
nf_conntrack_netlink
subsystemxt_addrtype
xt_conntrack
xt_icmp
(for IPv4)xt_icmp6
(for IPv6)xt_ipvs
xt_mark
xt_multiport
xt_rpfilter
xt_set
xt_u32
ipip
(if using Calico networking)