Add ExtStorage related man pages

 * ganeti-extstorage-interface man page
 * gnt-storage man page
Signed-off-by: Constantinos Venetsanopoulos <cven@grnet.gr>
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

.gitignore

@@ -110,6 +110,7 @@
 /scripts/gnt-node
 /scripts/gnt-os
 /scripts/gnt-network
+/scripts/gnt-storage
 
 # htools-specific rules
 /htools/apidoc

Makefile.am

@@ -838,6 +838,7 @@ man_MANS = \
 	man/ganeti-masterd.8 \
 	man/ganeti-noded.8 \
 	man/ganeti-os-interface.7 \
+	man/ganeti-extstorage-interface.7 \
 	man/ganeti-rapi.8 \
 	man/ganeti-watcher.8 \
 	man/ganeti.7 \
@@ -850,6 +851,7 @@ man_MANS = \
 	man/gnt-job.8 \
 	man/gnt-node.8 \
 	man/gnt-os.8 \
+	man/gnt-storage.8 \
 	man/hail.1 \
 	man/hbal.1 \
 	man/hcheck.1 \

man/footer.rst

@@ -9,14 +9,15 @@ SEE ALSO
 --------
 
 Ganeti overview and specifications: **ganeti**(7) (general overview),
-**ganeti-os-interface**(7) (guest OS definitions).
+**ganeti-os-interface**(7) (guest OS definitions),
+**ganeti-extstorage-interface**(7) (external storage providers).
 
 Ganeti commands: **gnt-cluster**(8) (cluster-wide commands),
 **gnt-job**(8) (job-related commands), **gnt-node**(8) (node-related
-commands), **gnt-instance**(8) (instance commands), **gnt-os**(8)
-(guest OS commands), **gnt-group**(8) (node group commands),
-**gnt-backup**(8) (instance import/export commands), **gnt-debug**(8)
-(debug commands).
+commands), **gnt-instance**(8) (instance commands), **gnt-os**(8) (guest
+OS commands), **gnt-storage**(8) (storage commands), **gnt-group**(8)
+(node group commands), **gnt-backup**(8) (instance import/export
+commands), **gnt-debug**(8) (debug commands).
 
 Ganeti daemons: **ganeti-watcher**(8) (automatic instance restarter),
 **ganeti-cleaner**(8) (job queue cleaner), **ganeti-noded**(8) (node

man/ganeti-extstorage-interface.rst

+ganeti-extstorage-interface(7) Ganeti | Version @GANETI_VERSION@
+================================================================
+
+Name
+----
+
+ganeti-extstorage-interface - Specifications for ExtStorage providers
+
+DESCRIPTION
+-----------
+
+The method for supporting external shared storage in Ganeti is to have
+an ExtStorage provider for each external shared storage hardware type.
+The ExtStorage provider is a set of files (executable scripts and text
+files), contained inside a directory which is named after the provider.
+This directory must be present across all nodes of a nodegroup (Ganeti
+doesn't replicate it), in order for the provider to be usable by Ganeti
+for this nodegroup (valid). The external shared storage hardware should
+also be accessible by all nodes of this nodegroup too.
+
+REFERENCE
+---------
+
+There are seven required files: *create*, *attach*, *detach*, *remove*,
+*grow*, *verify* (executables) and *parameters.list* (text file).
+
+Common environment
+~~~~~~~~~~~~~~~~~~
+
+All commands will get their input via environment variables. A common
+set of variables will be exported for all commands, and some of them
+might have extra ones. Note that all counts are zero-based.
+
+Since Ganeti version 2.5, the environment will be cleaned up before
+being passed to scripts, therefore they will not inherit the environment
+in with which the ganeti node daemon was started. If you depend on any
+environment variables (non-Ganeti), then you will need to define or
+source them appropriately.
+
+VOL_NAME
+    The name of the volume. This is unique for Ganeti and it uses it
+    to refer to a specific volume inside the external storage. Its
+    format is ``UUID.ext.diskX`` where ``UUID`` is produced by Ganeti
+    and is unique inside the Ganeti context. ``X`` is the number of the
+    disk count.
+
+VOL_SIZE
+    The volume's size in mebibytes.
+
+VOL_NEW_SIZE
+    Available only to the **grow** script. It declares the new size of
+    the volume after grow (in mebibytes). To find the amount of grow,
+    the scipt should calculate the number VOL_NEW_SIZE - VOL_SIZE.
+
+EXTP_*name*
+    Each ExtStorage parameter (see below) will be exported in its own
+    variable, prefixed with ``EXTP_``, and upper-cased. For example, a
+    ``fromsnap`` parameter will be exported as ``EXTP_FROMSNAP``.
+
+EXECUTABLE SCRIPTS
+------------------
+
+
+create
+~~~~~~
+
+The **create** command is used for creating a new volume inside the
+external storage. The ``VOL_NAME`` denotes the volume's name, which
+should be unique. After creation, Ganeti will refer to this volume by
+this name for all other actions.
+
+Ganeti produces this name dynamically and ensures its uniqueness inside
+the Ganeti context. Therefore, you should make sure not to provision
+manually additional volumes inside the external storage with this type
+of name, because this will lead to conflicts and possible loss of data.
+
+The ``VOL_SIZE`` variable denotes the size of the new volume to be
+created in mebibytes.
+
+If the script ends successfully, a new volume of size ``VOL_SIZE``
+should exist inside the external storage. e.g:: a lun inside a NAS
+appliance.
+
+The script returns ``0`` on success.
+
+attach
+~~~~~~
+
+This command is used in order to make an already created volume visible
+to the physical node which will host the instance. This is done by
+mapping the already provisioned volume to a block device inside the host
+node.
+
+The ``VOL_NAME`` variable denotes the volume to be mapped.
+
+After successful attachment the script returns to its stdout a string,
+which is the full path of the block device to which the volume is
+mapped.  e.g:: /dev/dummy1
+
+When attach returns, this path should be a valid block device on the
+host node.
+
+The attach script should be idempotent if the volume is already mapped.
+If the requested volume is already mapped, then the script should just
+return to its stdout the path which is already mapped to.
+
+detach
+~~~~~~
+
+This command is used in order to unmap an already mapped volume from the
+host node. Detach undoes everything attach did. This is done by
+unmapping the requested volume from the block device it is mapped to.
+
+The ``VOL_NAME`` variable denotes the volume to be unmapped.
+
+``detach`` doesn't affect the volume itself. It just unmaps it from the
+host node. The volume continues to exist inside the external storage.
+It's just not accessible by the node anymore. This script doesn't return
+anything to its stdout.
+
+The detach script should be idempotent if the volume is already
+unmapped. If the volume is not mapped, the script doesn't perform any
+action at all.
+
+The script returns ``0`` on success.
+
+remove
+~~~~~~
+
+This command is used to remove an existing volume from the external
+storage. The volume is permanently removed from inside the external
+storage along with all its data.
+
+The ``VOL_NAME`` variable denotes the volume to be removed.
+
+The script returns ``0`` on success.
+
+grow
+~~~~
+
+This command is used to grow an existing volume of the external storage.
+
+The ``VOL_NAME`` variable denotes the volume to grow.
+
+The ``VOL_SIZE`` variable denotes the current volume's size (in
+mebibytes). The ``VOL_NEW_SIZE`` variable denotes the final size after
+the volume has been grown (in mebibytes).
+
+The amount of grow can be easily calculated by the scipt and is:
+
+grow_amount = VOL_NEW_SIZE - VOL_SIZE (in mebibytes)
+
+Ganeti ensures that: ``VOL_NEW_SIZE`` > ``VOL_SIZE``
+
+If the script returns successfully, then the volume inside the external
+storage will have a new size of ``VOL_NEW_SIZE``. This isn't immediately
+reflected to the instance's disk. See ``gnt-instance grow`` for more
+details on when the running instance becomes aware of its grown disk.
+
+The script returns ``0`` on success.
+
+verify
+~~~~~~
+
+The *verify* script is used to verify consistency of the external
+parameters (ext-params) (see below). The command should take one or more
+arguments denoting what checks should be performed, and return a proper
+exit code depending on whether the validation failed or succeeded.
+
+Currently, the script is not invoked by Ganeti, but should be present
+for future use and consistency with gnt-os-interface's verify script.
+
+The script should return ``0`` on success.
+
+TEXT FILES
+----------
+
+
+parameters.list
+~~~~~~~~~~~~~~~
+
+This file declares the parameters supported by the ExtStorage provider,
+one parameter per line, with name and description (space and/or tab
+separated). For example::
+
+    fromsnap Snapshot name to create the volume from
+    nas_ip The IP of the NAS appliance
+
+The parameters can then be used during instance add as follows::
+
+    # gnt-instance add --disk=0:fromsnap="file_name",nas_ip="1.2.3.4" ...
+
+NOTES
+-----
+
+Backwards compatibility
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The ExtStorage Interface was introduced in Ganeti 2.6.
+Ganeti 2.6 and up is compatible with the ExtStorage Interface.
+
+Common behaviour
+~~~~~~~~~~~~~~~~
+
+All the scripts should display an usage message when called with a wrong
+number of arguments or when the first argument is ``-h`` or ``--help``.
+
+.. vim: set textwidth=72 :
+.. Local Variables:
+.. mode: rst
+.. fill-column: 72
+.. End:

man/gnt-storage.rst

+gnt-storage(8) Ganeti | Version @GANETI_VERSION@
+================================================
+
+Name
+----
+
+gnt-storage - Ganeti storage administration
+
+Synopsis
+--------
+
+**gnt-storage** {command} [arguments...]
+
+DESCRIPTION
+-----------
+
+The **gnt-storage** is used for managing the available storage inside
+the Ganeti cluster. At the moment, it manages only external storage
+(ExtStorage).
+
+COMMANDS
+--------
+
+
+**diagnose**
+
+This command provides detailed information about the state of all
+ExtStorage providers available in the Ganeti cluster. The state of each
+provider is calculated per nodegroup. This means that a provider may be
+valid (meaning usable) for some nodegroups, and invalid (not usable) for
+some others. This command will help you see why an installed ExtStorage
+provider is not valid for a specific nodegroup. It could be that it is
+missing from a node, or is only partially installed. This command will
+show the details of all ExtStorage providers and the reasons they are or
+aren't valid for every nodegroup in the cluster.
+
+**info**
+
+This command will list detailed information about each ExtStorage
+provider found in the cluster, including its nodegroup validity, the
+supported parameters (if any) and their documentations, etc.
+
+For each ExtStorage provider only the valid nodegroups will be listed.
+
+If run with no arguments, it will display info for all ExtStorage
+providers found in the cluster. If given ExtStorage provider's names as
+arguments it will list info only for providers given.
+
+NOTES
+-----
+
+In the future **gnt-storage** can be extended to also handle internal
+storage (such as lvm, drbd, etc) and also provide diagnostics for them
+too.
+
+It can also be extended to handle internal and external storage pools,
+if/when this kind of abstraction is implemented to Ganeti.
+
+.. vim: set textwidth=72 :
+.. Local Variables:
+.. mode: rst
+.. fill-column: 72
+.. End: