diff --git a/docs/getting-started-guides/scratch.md b/docs/getting-started-guides/scratch.md index c59d22ba1c..f658fb4c1e 100644 --- a/docs/getting-started-guides/scratch.md +++ b/docs/getting-started-guides/scratch.md @@ -57,6 +57,7 @@ on how flags are set on various components. ### Network +#### Network Connectivity Kubernetes has a distinctive [networking model](/docs/admin/networking). Kubernetes allocates an IP address to each pod. When creating a cluster, you @@ -66,21 +67,25 @@ the node is added. A process in one pod should be able to communicate with another pod using the IP of the second pod. This connectivity can be accomplished in two ways: -- Configure network to route Pod IPs +- **Configure underlay network to route Pod IPs** - Harder to setup from scratch. - Google Compute Engine ([GCE](/docs/getting-started-guides/gce)) and [AWS](/docs/getting-started-guides/aws) guides use this approach. - - Need to make the Pod IPs routable by programming routers, switches, etc. - - Can be configured external to Kubernetes, or can implement in the "Routes" interface of a Cloud Provider module. + - Need to make the Pod IPs routable by programming routers, switches, etc. + - This can be done in a few different ways: + - Implement in the "Routes" interface of a Cloud Provider module. + - Manually configure static routing external to Kubernetes. - Generally highest performance. -- Create an Overlay network +- **Use a network plugin** - Easier to setup - - Traffic is encapsulated, so per-pod IPs are routable. + - Pod IPs are made accessible through route distribution or encapsulation. - Examples: - [Flannel](https://github.com/coreos/flannel) + - [Calico](http://https://github.com/projectcalico/calico-containers) - [Weave](http://weave.works/) - [Open vSwitch (OVS)](http://openvswitch.org/) - Does not require "Routes" portion of Cloud Provider module. - Reduced performance (exactly how much depends on your solution). + - More information on network plugins can be found [here](/docs/admin/networking#how-to-achieve-this). You need to select an address range for the Pod IPs. @@ -116,6 +121,16 @@ Also, you need to pick a static IP for master node. - Open any firewalls to allow access to the apiserver ports 80 and/or 443. - Enable ipv4 forwarding sysctl, `net.ipv4.ip_forward = 1` +#### Network Policy + +Kubernetes enables the definition of fine-grained network policy between Pods +using the [NetworkPolicy](/docs/user-guide/networkpolicy) resource. + +For clusters which choose to enable NetworkPolicy, the Calico +[policy controller addon](https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/calico-policy-controller) +can enforce the NetworkPolicy API on top of native cloud-provider networking, +Flannel, or Calico networking. + ### Cluster Naming You should pick a name for your cluster. Pick a short name for each cluster