add README.md for strategies

Signed-off-by: Victor Vieux <vieux@docker.com>

scheduler/filter/README.md

@@ -75,7 +75,7 @@ Now we want to run an `nginx` frontend in our cluster. However, we don't want
 
 ```
 $ docker run -d -P -e constraint:storage==disk --name frontend nginx
-f8b693db9cd6
+963841b138d8
 
 $ docker ps
 CONTAINER ID        IMAGE               COMMAND             CREATED                  STATUS              PORTS                           NODE        NAMES

scheduler/strategy/README.md

@@ -0,0 +1,56 @@
+---
+page_title: Docker Swarm strategies
+page_description: Swarm strategies
+page_keywords: docker, swarm, clustering, strategies
+---
+
+# Strategies
+
+The `Docker Swarm` scheduler comes with multiple strategies.
+
+These strategies are used to rank nodes using a scores computed by the strategy.
+
+`Docker Swarm` currently supports 2 strategies:
+* [BinPacking](#binpacking-strategy)
+* [Random](#random-strategy)
+
+You can choose the strategy you want to use with the `--strategy` flag of `swarm manage`
+
+## BinPacking strategy
+
+The BinPacking strategy will rank the nodes using their CPU and RAM availalble and will return the
+node the most packed already. This avoid fragementation, it will leave room for bigger containers
+on usunsed machines.
+
+For instance, let's says that both `node-1` and `node-2` have 2Go de RAM:
+
+```bash
+$ docker run -d -P -m 1G --name db mysql
+f8b693db9cd6
+
+$ docker ps
+CONTAINER ID        IMAGE               COMMAND             CREATED                  STATUS              PORTS                           NODE        NAMES
+f8b693db9cd6        mysql:latest        "mysqld"            Less than a second ago   running             192.168.0.42:49178->3306/tcp    node-1      db
+```
+
+In this case, `node-1` was chosen randomly, because no container were running, so `node-1` and
+`node-2` had the same score.
+
+Now we start another container, asking for 1G of RAM again.
+
+```bash
+$ docker run -d -P -m 1G --name frontend nginx
+963841b138d8
+
+$ docker ps
+CONTAINER ID        IMAGE               COMMAND             CREATED                  STATUS              PORTS                           NODE        NAMES
+963841b138d8        nginx:latest        "nginx"             Less than a second ago   running             192.168.0.42:49177->80/tcp      node-1      frontend
+f8b693db9cd6        mysql:latest        "mysqld"            Up About a minute        running             192.168.0.42:49178->3306/tcp    node-1      db
+```
+
+The container `frontend` was also started on `node-1` because it was the node the most packed
+already. This allows us to start a container requiring 2G of RAM on `node-2`.
+
+## Random strategy
+
+The Random strategy, as it's name says, chose a random node, it's used mainly for debug.