Merge ~ffledgling/cloud-init:doc-fix into cloud-init:master

[Anhad Jai Singh]

    Change `nobootwait` to `nofail` in docs

    `nobootwait` is an ubuntu specific extension to the mount syntax that is
    not supported by other non-derivative linux operating systems.

    `nobootwait` support appears to have been dropped Ubuntu 16.04 onwards,
    based on http://manpages.ubuntu.com/manpages/xenial/man5/fstab.5.html.
    Last Ubuntu version with mention of `nobootwait` appears to be 15.10,
    based on http://manpages.ubuntu.com/manpages/wily/man5/fstab.5.html.

    All examples using `nobootwait` were updated to use the standard
    `nofail`, which gives the expected behaviour of not failing to boot in
    case a volume is missing. There are likely subtle differences in semantics
    between `nobootwait` and `nofail`, but it is the best (only?) substitute
    that gives behaviour similar to the defunct `nobootwait` option.

[Anhad Jai Singh (ffledgling)]

In addition to tests, there are tests (namely: tests/data/merge_sources/source8-1.yaml, tests/data/merge_sources/expected8.yaml) and some code (config?) files (namely: cloudinit/config/cc_mounts.py) that use nobootwait as well, but I haven't modified them because I'm not entirely clear about the scope of those changes. If those need to be changed as well, please let me know.

[Anhad Jai Singh (ffledgling)]

In addition to docs*

[Scott Moser (smoser)]

Hi, thanks for the change here.
Could we at least suggest that if your system is using upstart (Ubuntu 14.04) then 'nobootwait' is the best option for you. But if you are using systemd or sysvinit then nofail is all you have.

diff --git a/doc/examples/cloud-config-gluster.txt b/doc/examples/cloud-config-gluster.txt
index f8183e7..cb97912 100644
--- a/doc/examples/cloud-config-gluster.txt
+++ b/doc/examples/cloud-config-gluster.txt
@@ -1,6 +1,6 @@
 #cloud-config
 # vim: syntax=yaml
-# Mounts volfile exported by glusterfsd running on 
+# Mounts volfile exported by glusterfsd running on
 # "volfile-server-hostname" onto the local mount point '/mnt/data'
 #
 # In reality, replace 'volfile-server-hostname' with one of your nodes
@@ -10,7 +10,7 @@ packages:
  - glusterfs-client
 
 mounts:
- - [ 'volfile-server-hostname:6996', /mnt/data, glusterfs, "defaults,nobootwait", "0", "2" ]
+ - [ 'volfile-server-hostname:6996', /mnt/data, glusterfs, "defaults,nofail", "0", "2" ]
 
 runcmd:
  - [ modprobe, fuse ]
diff --git a/doc/examples/cloud-config-mount-points.txt b/doc/examples/cloud-config-mount-points.txt
index aa676c2..5a6c24f 100644
--- a/doc/examples/cloud-config-mount-points.txt
+++ b/doc/examples/cloud-config-mount-points.txt
@@ -23,19 +23,19 @@
 # - if an entry does not have all 6 fields, they will be filled in
 #   with values from 'mount_default_fields' below.
 #
-# Note, that you should set 'nobootwait' (see man fstab) for volumes that may
-# not be attached at instance boot (or reboot)
+# Note, that you should set 'nofail' (see man fstab) for volumes that may not
+# be attached at instance boot (or reboot).
 #
 mounts:
  - [ ephemeral0, /mnt, auto, "defaults,noexec" ]
  - [ sdc, /opt/data ]
- - [ xvdh, /opt/data, "auto", "defaults,nobootwait", "0", "0" ]
+ - [ xvdh, /opt/data, "auto", "defaults,nofail", "0", "0" ]
  - [ dd, /dev/zero ]
 
 # mount_default_fields
 # These values are used to fill in any entries in 'mounts' that are not
 # complete.  This must be an array, and must have 7 fields.
-mount_default_fields: [ None, None, "auto", "defaults,nobootwait", "0", "2" ]
+mount_default_fields: [ None, None, "auto", "defaults,nofail", "0", "2" ]
 
 
 # swap can also be set up by the 'mounts' module
diff --git a/doc/examples/cloud-config.txt b/doc/examples/cloud-config.txt
index 190029e..c5f84b1 100644
--- a/doc/examples/cloud-config.txt
+++ b/doc/examples/cloud-config.txt
@@ -46,19 +46,19 @@ packages:
 # - if an entry does not have all 6 fields, they will be filled in
 #   with values from 'mount_default_fields' below.
 #
-# Note, that you should set 'nobootwait' (see man fstab) for volumes that may
+# Note, that you should set 'nofail' (see man fstab) for volumes that may
 # not be attached at instance boot (or reboot)
 #
 mounts:
  - [ ephemeral0, /mnt, auto, "defaults,noexec" ]
  - [ sdc, /opt/data ]
- - [ xvdh, /opt/data, "auto", "defaults,nobootwait", "0", "0" ]
+ - [ xvdh, /opt/data, "auto", "defaults,nofail", "0", "0" ]
  - [ dd, /dev/zero ]
 
 # mount_default_fields
 # These values are used to fill in any entries in 'mounts' that are not
 # complete.  This must be an array, and must have 7 fields.
-mount_default_fields: [ None, None, "auto", "defaults,nobootwait", "0", "2" ]
+mount_default_fields: [ None, None, "auto", "defaults,nofail", "0", "2" ]
 
 # add each entry to ~/.ssh/authorized_keys for the configured user or the
 # first user defined in the user definition directive.