c12s-kubespray/docs/calico.md
Kenichi Omichi 486b223e01
Replace kube-master with kube_control_plane (#7256)
This replaces kube-master with kube_control_plane because of [1]:

  The Kubernetes project is moving away from wording that is
  considered offensive. A new working group WG Naming was created
  to track this work, and the word "master" was declared as offensive.
  A proposal was formalized for replacing the word "master" with
  "control plane". This means it should be removed from source code,
  documentation, and user-facing configuration from Kubernetes and
  its sub-projects.

NOTE: The reason why this changes it to kube_control_plane not
      kube-control-plane is for valid group names on ansible.

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation
2021-03-23 17:26:05 -07:00

8.9 KiB

Calico

Check if the calico-node container is running

docker ps | grep calico

The calicoctl.sh is wrap script with configured access credentials for command calicoctl allows to check the status of the network workloads.

  • Check the status of Calico nodes
calicoctl.sh node status
  • Show the configured network subnet for containers
calicoctl.sh get ippool -o wide
  • Show the workloads (ip addresses of containers and their location)
calicoctl.sh get workloadEndpoint -o wide

and

calicoctl.sh get hostEndpoint -o wide

Configuration

Optional : Define datastore type

The default datastore, Kubernetes API datastore is recommended for on-premises deployments, and supports only Kubernetes workloads; etcd is the best datastore for hybrid deployments.

Allowed values are kdd (default) and etcd.

Note: using kdd and more than 50 nodes, consider using the typha daemon to provide scaling.

To re-define you need to edit the inventory and add a group variable calico_datastore

calico_datastore: kdd

Optional : Define network backend

In some cases you may want to define Calico network backend. Allowed values are bird, vxlan or none. Bird is a default value.

To re-define you need to edit the inventory and add a group variable calico_network_backend

calico_network_backend: none

Optional : Define the default pool CIDRs

By default, kube_pods_subnet is used as the IP range CIDR for the default IP Pool, and kube_pods_subnet_ipv6 for IPv6. In some cases you may want to add several pools and not have them considered by Kubernetes as external (which means that they must be within or equal to the range defined in kube_pods_subnet and kube_pods_subnet_ipv6 ), it starts with the default IP Pools of which IP range CIDRs can by defined in group_vars (k8s-cluster/k8s-net-calico.yml):

calico_pool_cidr: 10.233.64.0/20
calico_pool_cidr_ipv6: fd85:ee78:d8a6:8607::1:0000/112

Optional : BGP Peering with border routers

In some cases you may want to route the pods subnet and so NAT is not needed on the nodes. For instance if you have a cluster spread on different locations and you want your pods to talk each other no matter where they are located. The following variables need to be set: peer_with_router to enable the peering with the datacenter's border router (default value: false). you'll need to edit the inventory and add a hostvar local_as by node.

node1 ansible_ssh_host=95.54.0.12 local_as=xxxxxx

Optional : Defining BGP peers

Peers can be defined using the peers variable (see docs/calico_peer_example examples). In order to define global peers, the peers variable can be defined in group_vars with the "scope" attribute of each global peer set to "global". In order to define peers on a per node basis, the peers variable must be defined in hostvars. NB: Ansible's hash_behaviour is by default set to "replace", thus defining both global and per node peers would end up with having only per node peers. If having both global and per node peers defined was meant to happen, global peers would have to be defined in hostvars for each host (as well as per node peers)

Since calico 3.4, Calico supports advertising Kubernetes service cluster IPs over BGP, just as it advertises pod IPs. This can be enabled by setting the following variable as follow in group_vars (k8s-cluster/k8s-net-calico.yml)

calico_advertise_cluster_ips: true

Since calico 3.10, Calico supports advertising Kubernetes service ExternalIPs over BGP in addition to cluster IPs advertising. This can be enabled by setting the following variable in group_vars (k8s-cluster/k8s-net-calico.yml)

calico_advertise_service_external_ips:
- x.x.x.x/24
- y.y.y.y/32

Optional : Define global AS number

Optional parameter global_as_num defines Calico global AS number (/calico/bgp/v1/global/as_num etcd key). It defaults to "64512".

Optional : BGP Peering with route reflectors

At large scale you may want to disable full node-to-node mesh in order to optimize your BGP topology and improve calico-node containers' start times.

To do so you can deploy BGP route reflectors and peer calico-node with them as recommended here:

You need to edit your inventory and add:

  • calico-rr group with nodes in it. calico-rr can be combined with kube-node and/or kube_control_plane. calico-rr group also must be a child group of k8s-cluster group.
  • cluster_id by route reflector node/group (see details here)

Here's an example of Kubespray inventory with standalone route reflectors:

[all]
rr0 ansible_ssh_host=10.210.1.10 ip=10.210.1.10
rr1 ansible_ssh_host=10.210.1.11 ip=10.210.1.11
node2 ansible_ssh_host=10.210.1.12 ip=10.210.1.12
node3 ansible_ssh_host=10.210.1.13 ip=10.210.1.13
node4 ansible_ssh_host=10.210.1.14 ip=10.210.1.14
node5 ansible_ssh_host=10.210.1.15 ip=10.210.1.15

[kube_control_plane]
node2
node3

[etcd]
node2
node3
node4

[kube-node]
node2
node3
node4
node5

[k8s-cluster:children]
kube-node
kube_control_plane
calico-rr

[calico-rr]
rr0
rr1

[rack0]
rr0
rr1
node2
node3
node4
node5

[rack0:vars]
cluster_id="1.0.0.1"

The inventory above will deploy the following topology assuming that calico's global_as_num is set to 65400:

Image

Optional : Define default endpoint to host action

By default Calico blocks traffic from endpoints to the host itself by using an iptables DROP action. When using it in kubernetes the action has to be changed to RETURN (default in kubespray) or ACCEPT (see https://github.com/projectcalico/felix/issues/660 and https://github.com/projectcalico/calicoctl/issues/1389). Otherwise all network packets from pods (with hostNetwork=False) to services endpoints (with hostNetwork=True) within the same node are dropped.

To re-define default action please set the following variable in your inventory:

calico_endpoint_to_host_action: "ACCEPT"

Optional : Define address on which Felix will respond to health requests

Since Calico 3.2.0, HealthCheck default behavior changed from listening on all interfaces to just listening on localhost.

To re-define health host please set the following variable in your inventory:

calico_healthhost: "0.0.0.0"

Config encapsulation for cross server traffic

Calico supports two types of encapsulation: VXLAN and IP in IP. VXLAN is supported in some environments where IP in IP is not (for example, Azure).

IP in IP and VXLAN is mutualy exclusive modes.

Configure Ip in Ip mode. Possible values is Always, CrossSubnet, Never.

calico_ipip_mode: 'Always'

Configure VXLAN mode. Possible values is Always, CrossSubnet, Never.

calico_vxlan_mode: 'Never'

If you use VXLAN mode, BGP networking is not required. You can disable BGP to reduce the moving parts in your cluster by calico_network_backend: vxlan

Cloud providers configuration

Please refer to the official documentation, for example GCE configuration requires a security rule for calico ip-ip tunnels. Note, calico is always configured with calico_ipip_mode: Always if the cloud provider was defined.

Optional : Ignore kernel's RPF check setting

By default the felix agent(calico-node) will abort if the Kernel RPF setting is not 'strict'. If you want Calico to ignore the Kernel setting:

calico_node_ignorelooserpf: true

Note that in OpenStack you must allow ipip traffic in your security groups, otherwise you will experience timeouts. To do this you must add a rule which allows it, for example:

Optional : Felix configuration via extraenvs of calico node

Possible environment variable parameters for configuring Felix

calico_node_extra_envs:
    FELIX_DEVICEROUTESOURCEADDRESS: 172.17.0.1
neutron  security-group-rule-create  --protocol 4  --direction egress  k8s-a0tp4t
neutron  security-group-rule-create  --protocol 4  --direction igress  k8s-a0tp4t

Optional : Use Calico CNI host-local IPAM plugin

Calico currently supports two types of CNI IPAM plugins, host-local and calico-ipam (default).

To allow Calico to determine the subnet to use from the Kubernetes API based on the Node.podCIDR field, enable the following setting.

calico_ipam_host_local: true

Refer to Project Calico section Using host-local IPAM for further information.