Merge pull request #1419 from infosiftr/less-EXPOSE

Drop/adjust a few explicit EXPOSE references (mostly implied, not really adding value)

docker/content.md

@@ -26,7 +26,7 @@ $ docker run --privileged --name some-docker -d %%IMAGE%%:stable-dind
 
 **Note:** `--privileged` is required for Docker-in-Docker to function properly, but it should be used with care as it provides full access to the host environment, as explained [in the relevant section of the Docker documentation](https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities).
 
-This image includes `EXPOSE 2375` (the Docker port), so standard container linking will make it automatically available to the linked containers (as the following examples illustrate).
+By default, the `dind` variants of this image add `--host=tcp://0.0.0.0:2375` (on top of the explicit default of `--host=unix:///var/run/docker.sock`) in order to allow external containers to access `dockerd` appropriately (as the following examples illustrate).
 
 ## Connect to it from a second container
 

postgres/content.md

@@ -16,7 +16,7 @@ PostgreSQL implements the majority of the SQL:2011 standard, is ACID-compliant a
 $ docker run --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d %%IMAGE%%
 ```
 
-This image includes `EXPOSE 5432` (the postgres port), so standard container linking will make it automatically available to the linked containers. The default `postgres` user and database are created in the entrypoint with `initdb`.
+The default `postgres` user and database are created in the entrypoint with `initdb`.
 
 > The postgres database is a default database meant for use by users, utilities and third party applications.
 >

redis/content.md

@@ -14,8 +14,6 @@ Redis is an open-source, networked, in-memory, key-value data store with optiona
 $ docker run --name some-redis -d %%IMAGE%%
 ```
 
-This image includes `EXPOSE 6379` (the redis port), so standard container linking will make it automatically available to the linked containers (as the following examples illustrate).
-
 ## start with persistent storage
 
 ```console