Merge "Add documentation of DIB_IMAGE_CACHE variable"
This commit is contained in:
commit
6056eec1dd
38
README.rst
38
README.rst
@ -97,16 +97,20 @@ Caches and offline mode
|
||||
=======================
|
||||
|
||||
Since retrieving and transforming operating system image files, git
|
||||
repositories, Python or Ruby packages, and so on can be a significant overhead,
|
||||
we cache many of the inputs to the build process in ~/.cache/image-create/. The
|
||||
writing an element documention describes the interface within
|
||||
disk-image-builder for caching. When invoking disk-image-builder the --offline
|
||||
option will instruct disk-image-builder to not refresh cached resources.
|
||||
repositories, Python or Ruby packages, and so on can be a significant
|
||||
overhead, we cache many of the inputs to the build process. The cache
|
||||
location is read from DIB\_IMAGE\_CACHE. The *Writing an element*
|
||||
section of this document describes the interface within
|
||||
disk-image-builder for caching. When invoking disk-image-builder, the
|
||||
``--offline`` option will instruct disk-image-builder to not refresh
|
||||
cached resources.
|
||||
|
||||
Note that we don't maintain operating system package caches, instead depending
|
||||
on your local infrastructure (e.g. Squid cache, or an APT or Yum proxy) to
|
||||
facilitate caching of that layer, so you need to arrange independently for
|
||||
offline mode.
|
||||
Note that we don't maintain operating system package caches, instead
|
||||
depending on your local infrastructure (e.g. Squid cache, or an APT or
|
||||
Yum proxy) to facilitate caching of that layer, so you need to arrange
|
||||
independently for offline mode. For more information about setting up
|
||||
a squid proxy, consult the [TripleO
|
||||
documentation](http://docs.openstack.org/developer/tripleo-incubator/devtest_setup.html#f3).
|
||||
|
||||
Base images
|
||||
-----------
|
||||
@ -239,7 +243,7 @@ named after the element itself. Elements *should* have a README.md in the root
|
||||
of the element directory describing what it is for.
|
||||
|
||||
Writing an element
|
||||
-----------------
|
||||
------------------
|
||||
|
||||
Conform to the following conventions:
|
||||
|
||||
@ -267,8 +271,15 @@ Conform to the following conventions:
|
||||
and not remounted into the filesystem image - if the mount point is needed
|
||||
again, your element will need to remount it at that point.
|
||||
|
||||
Phase Subdirectories
|
||||
^^^^^^^^^^^^^^^^^^^^
|
||||
* If caching is required, elements should use a location under
|
||||
$DIB\_IMAGE\_CACHE.
|
||||
|
||||
* Elements should allow for remote data to be cached. When
|
||||
$DIB\_OFFLINE is set, this cached data should be used if
|
||||
possible. See the *Global image-build variables* section of this
|
||||
document for more information.
|
||||
|
||||
### Phase Subdirectories ###
|
||||
|
||||
Make as many of the following subdirectories as you need, depending on what
|
||||
part of the process you need to customise. The subdirectories are executed in
|
||||
@ -416,6 +427,9 @@ Global image-build variables
|
||||
diskimage-builder is building a disk image. This works only for ext
|
||||
filesystems.
|
||||
|
||||
* DIB\_IMAGE\_CACHE : path to where cached inputs to the build process
|
||||
are stored. Defaults to ~/.cache/image_create.
|
||||
|
||||
Structure of an element
|
||||
-----------------------
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user