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Greg Althaus 2017-01-17 13:15:48 -06:00
parent 6905edbeb6
commit 0022a2b29e
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docs/ha-mode.md
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@ -33,15 +33,20 @@ proxy. Kargo includes support for an nginx-based proxy that resides on each
non-master Kubernetes node. This is referred to as localhost loadbalancing. It
is less efficient than a dedicated load balancer because it creates extra
health checks on the Kubernetes apiserver, but is more practical for scenarios
where an external LB or virtual IP management is inconvenient.
where an external LB or virtual IP management is inconvenient. This option is
configured by the variable `loadbalancer_apiserver_localhost`. You may also
define the port the local internal loadbalancer users by changing,
`nginx_kube_apiserver_port`. This defaults to the value of `kube_apiserver_port`.
It is also import to note that Kargo will only configure kubelet and kube-proxy
on non-master nodes to use the local internal loadbalancer.
This option is configured by the variable `loadbalancer_apiserver_localhost`.
you will need to configure your own loadbalancer to achieve HA. Note that
deploying a loadbalancer is up to a user and is not covered by ansible roles
in Kargo. By default, it only configures a non-HA endpoint, which points to
the `access_ip` or IP address of the first server node in the `kube-master`
group. It can also configure clients to use endpoints for a given loadbalancer
type. The following diagram shows how traffic to the apiserver is directed.
If you choose to NOT use the local internal loadbalancer, you will need to configure
your own loadbalancer to achieve HA. Note that deploying a loadbalancer is up to
a user and is not covered by ansible roles in Kargo. By default, it only configures
a non-HA endpoint, which points to the `access_ip` or IP address of the first server
node in the `kube-master` group. It can also configure clients to use endpoints
for a given loadbalancer type. The following diagram shows how traffic to the
apiserver is directed.
![Image](figures/loadbalancer_localhost.png?raw=true)
@ -90,7 +95,7 @@ Access endpoints are evaluated automagically, as the following:
| Endpoint type | kube-master | non-master |
|------------------------------|---------------|---------------------|
| Local LB | http://lc:p | https://lc:sp |
| Local LB | http://lc:p | https://lc:nsp |
| External LB, no internal | https://lb:lp | https://lb:lp |
| No ext/int LB (default) | http://lc:p | https://m[0].aip:sp |
@ -99,7 +104,9 @@ Where:
* `lb` - LB FQDN, `apiserver_loadbalancer_domain_name`;
* `lc` - localhost;
* `p` - insecure port, `kube_apiserver_insecure_port`
* `nsp` - nginx secure port, `nginx_kube_apiserver_port`;
* `sp` - secure port, `kube_apiserver_port`;
* `lp` - LB port, `loadbalancer_apiserver.port`, defers to the secure port;
* `ip` - the node IP, defers to the ansible IP;
* `aip` - `access_ip`, defers to the ip.