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Update networking doc wrt --configure-cbr0

pull/6/head
Tim Hockin 2015-07-06 12:48:59 -07:00
parent 6c88401889
commit 9fe0d74473
1 changed files with 6 additions and 14 deletions
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docs/networking.md
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@ -96,24 +96,16 @@ outbound internet access. A linux bridge (called `cbr0`) is configured to exist
on that subnet, and is passed to docker's `--bridge` flag.
We start Docker with:
```
DOCKER_OPTS="--bridge cbr0 --iptables=false --ip-masq=false"
DOCKER_OPTS="--bridge=cbr0 --iptables=false --ip-masq=false"
```
We set up this bridge on each node with SaltStack, in
[container_bridge.py](../cluster/saltbase/salt/_states/container_bridge.py).
This bridge is created by Kubelet (controlled by the `--configure-cbr0=true`
flag) according to the `Node`'s `spec.podCIDR`.
```
cbr0:
container_bridge.ensure:
- cidr: {{ grains['cbr-cidr'] }}
- mtu: 1460
```
Docker will now allocate `Pod` IPs from the `cbr-cidr` block. Containers
can reach each other and `Nodes` over the `cbr0` bridge. Those IPs are all
routable within the GCE project network.
Docker will now allocate IPs from the `cbr-cidr` block. Containers can reach
each other and `Nodes` over the `cbr0` bridge. Those IPs are all routable
within the GCE project network.
GCE itself does not know anything about these IPs, though, so it will not NAT
them for outbound internet traffic. To achieve that we use an iptables rule to