Merge pull request #1488 from timtoum/weave_docs

added Weave documentation

README.md

@@ -58,7 +58,7 @@ Versions of supported components
 [flanneld](https://github.com/coreos/flannel/releases) v0.8.0 <br>
 [calicoctl](https://github.com/projectcalico/calico-docker/releases) v0.23.0 <br>
 [canal](https://github.com/projectcalico/canal) (given calico/flannel versions) <br>
-[weave](http://weave.works/) v1.8.2 <br>
+[weave](http://weave.works/) v2.0.1 <br>
 [docker](https://www.docker.com/) v1.13.1 (see note)<br>
 [rkt](https://coreos.com/rkt/docs/latest/) v1.21.0 (see Note 2)<br>
 
@@ -92,7 +92,7 @@ You can choose between 4 network plugins. (default: `calico`, except Vagrant use
 
 * [**canal**](https://github.com/projectcalico/canal): a composition of calico and flannel plugins.
 
-* **weave**: Weave is a lightweight container overlay network that doesn't require an external K/V database cluster. <br>
+* [**weave**](docs/weave.md): Weave is a lightweight container overlay network that doesn't require an external K/V database cluster. <br>
 (Please refer to `weave` [troubleshooting documentation](http://docs.weave.works/weave/latest_release/troubleshooting.html)).
 
 The choice is defined with the variable `kube_network_plugin`. There is also an

docs/weave.md

+Weave
+=======
+
+Weave 2.0.1 is supported by kubespray
+
+Weave uses [**consensus**](https://www.weave.works/docs/net/latest/ipam/##consensus) mode (default mode) and [**seed**](https://www.weave.works/docs/net/latest/ipam/#seed) mode.
+
+`Consensus` mode is best to use on static size cluster and `seed` mode is best to use on dynamic size cluster
+
+Weave encryption is supported for all communication
+
+* To use Weave encryption, specify a strong password (if no password, no encrytion)
+
+```
+# In file ./inventory/group_vars/k8s-cluster.yml
+weave_password: EnterPasswordHere
+```
+
+This password is used to set an environment variable inside weave container.
+
+Weave is deployed by kubespray using a daemonSet
+
+* Check the status of Weave containers
+
+```
+# From client
+kubectl -n kube-system get pods | grep weave
+# output
+weave-net-50wd2                       2/2       Running   0          2m
+weave-net-js9rb                       2/2       Running   0          2m
+```
+There must be as many pods as nodes (here kubernetes have 2 nodes so there are 2 weave pods).
+
+* Check status of weave (connection,encryption ...) for each node
+
+```
+# On nodes
+curl http://127.0.0.1:6784/status
+# output on node1
+Version: 2.0.1 (up to date; next check at 2017/08/01 13:51:34)
+
+        Service: router
+       Protocol: weave 1..2
+           Name: fa:16:3e:b3:d6:b2(node1)
+     Encryption: enabled
+  PeerDiscovery: enabled
+        Targets: 2
+    Connections: 2 (1 established, 1 failed)
+          Peers: 2 (with 2 established connections)
+ TrustedSubnets: none
+
+        Service: ipam
+         Status: ready
+          Range: 10.233.64.0/18
+  DefaultSubnet: 10.233.64.0/18
+```
+
+* Check parameters of weave for each node
+
+```
+# On nodes
+ps -aux | grep weaver
+# output on node1 (here its use seed mode)
+root      8559  0.2  3.0 365280 62700 ?        Sl   08:25   0:00 /home/weave/weaver --name=fa:16:3e:b3:d6:b2 --port=6783 --datapath=datapath --host-root=/host --http-addr=127.0.0.1:6784 --status-addr=0.0.0.0:6782 --docker-api= --no-dns --db-prefix=/weavedb/weave-net --ipalloc-range=10.233.64.0/18 --nickname=node1 --ipalloc-init seed=fa:16:3e:b3:d6:b2,fa:16:3e:f0:50:53 --conn-limit=30 --expect-npc 192.168.208.28 192.168.208.19
+```
+
+### Consensus mode (default mode)
+
+This mode is best to use on static size cluster
+
+### Seed mode
+
+This mode is best to use on dynamic size cluster
+
+The seed mode also allows multi-clouds and hybrid on-premise/cloud clusters deployement.
+
+* Switch from consensus mode to seed mode
+
+```
+# In file ./inventory/group_vars/k8s-cluster.yml
+weave_mode_seed: true
+```
+
+These two variables are only used when `weave_mode_seed` is set to `true` (**/!\ do not manually change these values**)
+
+```
+# In file ./inventory/group_vars/k8s-cluster.yml
+weave_seed: uninitialized
+weave_peers: uninitialized
+```
+
+The first variable, `weave_seed`, contains the initial nodes of the weave network
+
+The seconde variable, `weave_peers`, saves the IPs of all nodes joined to the weave network
+
+These two variables are used to connect a new node to the weave network. The new node needs to know the firsts nodes (seed) and the list of IPs of all nodes.
+
+To reset these variables and reset the weave network set them to `uninitialized`