c12s-kubespray/docs/calico.md
Artem Panchenko 05c8061c24 Allow connections from pods to local endpoints
By default Calico blocks traffic from endpoints
to the host itself by using an iptables DROP
action. It could lead to a situation when service
has one alive endpoint, but pods which run on
the same node can not access it. Changed the action
to RETURN.
2017-03-01 09:21:02 +02:00

4.2 KiB

Calico

Check if the calico-node container is running

docker ps | grep calico

The calicoctl command allows to check the status of the network workloads.

  • Check the status of Calico nodes
calicoctl node status

or for versions prior v1.0.0:

calicoctl status
  • Show the configured network subnet for containers
calicoctl get ippool -o wide

or for versions prior v1.0.0:

calicoctl pool show
  • Show the workloads (ip addresses of containers and their located)
calicoctl get workloadEndpoint -o wide

and

calicoctl get hostEndpoint -o wide

or for versions prior v1.0.0:

calicoctl endpoint show --detail
Optional : Define network backend

In some cases you may want to define Calico network backend. Allowed values are 'bird', 'gobgp' 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 : 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 and a hostvar local_as by node.

node1 ansible_ssh_host=95.54.0.12 local_as=xxxxxx
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. At the moment it's incompatible with kube-node due to BGP port conflict with calico-node container. So you should not have nodes in both calico-rr and kube-node groups.
  • cluster_id by route reflector node/group (see details here)

Here's an example of Kargo inventory with 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-master]
node2
node3

[etcd]
node2
node3
node4

[kube-node]
node2
node3
node4
node5

[k8s-cluster:children]
kube-node
kube-master

[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 kargo) 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) withing the same node are dropped.

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

calico_endpoint_to_host_action: "ACCEPT"

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 ipip: true if the cloud provider was defined.