Update some README files on roles.

elasticluster/share/playbooks/roles/autofs/README.md

@@ -0,0 +1,68 @@
+AutoFS
+======
+
+Install Linux' automounter [AutoFS][1], together with scripts for
+mounting of NFS (v3 and v4) and GlusterFS filesystems on the fly in
+the `/net` directory hierarchy.
+
+[1]: https://wiki.archlinux.org/index.php/Autofs
+
+
+Requirements
+------------
+
+All major Linux distributions include packages for AutoFS; this role
+should be able to run almost everywhere without special requirements.
+
+**Running this role requires `root` access.**
+
+
+Role Variables
+--------------
+
+The following variables may be set to alter the role behavior:
+
+`autofs_home_server`
+: *If defined,* then `/home` is made into an auto-mounted directory:
+  all accesses to a directory `/home/XXX` will result in an attempt to
+  mount directory `/srv/nfs/home/XXX` from the host designated by
+  `autofs_home_server`.
+
+
+Example Playbook
+----------------
+
+The following example installs AutoFS and configures it to auto-mount
+networked filesystems under the `/net` directory:
+
+```yaml
+- hosts: servers
+  roles:
+  - role: autofs
+```
+
+The following example install AutoFS like above, and additionally
+makes each `/home/XXX` directory automounted from host
+`homeserv.example.org`:
+
+```yaml
+- hosts: servers
+  roles:
+  - role: autofs
+    autofs_home_server: homeserv.example.org
+```
+
+
+License
+-------
+
+GPLv3
+
+
+Author Information and Credits
+------------------------------
+
+[Riccardo Murri](mailto:riccardo.murri@gmail.com) originally
+contributed the role to the [ElastiCluster][2] playbook collection.
+
+[2]: http://elasticluster.readthedocs.io/

elasticluster/share/playbooks/roles/docker-ce/README.md

@@ -0,0 +1,63 @@
+Docker Engine (Community Edition)
+=================================
+
+Install [Docker Engine - Community Edition][1] and allow a designated
+sets of users to connect and use the Docker daemon.
+
+[1]: https://docs.docker.com/install/
+
+
+Requirements
+------------
+
+The role is pretty much self-contained; since most of the
+configuration is actually done by Docker's setup script, the role can
+run on any host that runs a distribution supported by Docker CE --
+see: <https://docs.docker.com/install/#supported-platforms>
+
+**Running this role requires `root` access.**
+
+
+Role Variables
+--------------
+
+The following variables may be set to alter the role behavior:
+
+`docker_group_members`
+: YAML list of user names; those users will be added to the local UNIX
+  group that can connect to the Docker Engine daemon.
+
+`docker_release_channel`
+: What repository to download Docker packages from (e.g., stable,
+  nightly, etc).  Defaults to `stable`.
+
+
+Example Playbook
+----------------
+
+The following example installs Docker Engine CE and allows users
+`admin` and `openbis` to connect to it:
+
+```yaml
+- hosts: servers
+  roles:
+  - role: docker-ce
+    docker_group_members:
+    - admin
+    - openbis
+```
+
+
+License
+-------
+
+GPLv3
+
+
+Author Information and Credits
+------------------------------
+
+[Manuele Simi](manuele.simi@gmail.com) originally contributed the role
+to the [ElastiCluster][2] playbook collection.
+
+[2]: http://elasticluster.readthedocs.io/

elasticluster/share/playbooks/roles/ntpd/README.rst

@@ -35,9 +35,9 @@ The following variables may be set to alter the role behavior:
 Example Playbook
 ----------------
 
-The following example installs EasyBuild_, configures it to write all software
-into directory ``/apps``, and uses it to build the GCC-based "foss/2016b"
-toolchain::
+The following example installs NTPd_ and configures it to use
+``master001`` as a upstream time server, and the two nodes
+``worker001`` and ``worker002`` as peers::
 
   - hosts: servers
     roles:

elasticluster/share/playbooks/roles/pdsh/README.md

@@ -0,0 +1,62 @@
+PDSH
+====
+
+Install [PDSH][1], and configure it to use SSH by default, and mark
+all hosts with "genders" that correspond to the Ansible groups they're
+in.
+
+[1]: http://www.admin-magazine.com/HPC/Articles/pdsh-Parallel-Shell
+
+Note that PDSH over SSH is only useful if all hosts have been
+configured to allow passwordless SSH connections. (Which
+[ElastiCluster][2] does by default in the `common` role.)
+
+
+Requirements
+------------
+
+All major Linux distributions include packages for PDSH; this role
+should be able to run almost everywhere without special requirements.
+
+**Running this role requires `root` access.**
+
+
+Role Variables
+--------------
+
+The following variables may be set to alter the role behavior:
+
+`hosts`
+: If this variable is defined, then it should contain a YAML list of
+  host names: the `/etc/genders` file will be populated only with
+  these hosts, instead of all hosts in the Ansible inventory
+  (default).
+
+
+Example Playbook
+----------------
+
+The following example installs PDSH with the default configuration
+(use SSH, tag each host with "genders" coming from the Ansible group
+names):
+
+```yaml
+- hosts: servers
+  roles:
+  - role: autofs
+```
+
+
+License
+-------
+
+GPLv3
+
+
+Author Information and Credits
+------------------------------
+
+[Riccardo Murri](mailto:riccardo.murri@gmail.com) originally
+contributed the role to the [ElastiCluster][2] playbook collection.
+
+[2]: http://elasticluster.readthedocs.io/