diskimage-builder/elements/ramdisk
Ian Wienand 36b59c001c Standarise tracing for scripts
There is a wide variety of tracing options through the various shell
scripts.  Some use "set -eux", others explicity set xtrace and others
do nothing.  There is a "-x" option to bin/disk-image-create but it
doesn't flow down to the many scripts it calls.

This adds a global integer variable set by disk-image-create
DIB_DEBUG_TRACE.  All scripts have a stanza added to detect this and
turn on tracing.  Any other tracing methods are rolled into this.  So
the standard header is

---
if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
    set -x
fi
set -eu
set -o pipefail
---

Multiple -x options can be specified to dib-create-image, which
increases the value of DIB_DEBUG_TRACE.  If script authors feel their
script should only trace at higher levels, they should modify the
"-gt" value.  If they feel it should trace by default, they can modify
the default value also.

Changes to pachset 16 : scripts which currently trace themselves by
default have retained this behaviour with DIB_DEBUG_TRACE defaulting
to "1".  This was done by running [1] on patch set 15.  See the thread
beginning at [2]

dib-lint is also updated to look for the variable being matched.

[1] https://gist.github.com/ianw/71bbda9e6acc74ccd0fd
[2] http://lists.openstack.org/pipermail/openstack-dev/2014-November/051575.html

Change-Id: I6c5a962260741dcf6f89da9a33b96372a719b7b0
2015-02-12 10:41:32 +11:00
..
binary-deps.d Move busybox binary-dep to ramdisk element 2014-10-21 16:05:19 -05:00
init.d Refactor ramdisk element to allow alternate implementations 2014-09-26 00:13:55 -05:00
install.d Standarise tracing for scripts 2015-02-12 10:41:32 +11:00
post-install.d Standarise tracing for scripts 2015-02-12 10:41:32 +11:00
element-deps Refactor ramdisk element to allow alternate implementations 2014-09-26 00:13:55 -05:00
pkg-map Fix ramdisk pkg-map for openSUSE 2014-09-02 11:20:08 +02:00
README.rst Create docs site containing element READMEs 2015-02-10 11:45:35 -08:00

=======
ramdisk
=======
This is the ramdisk element.

Almost any user building a ramdisk will want to include this in their build,
as it triggers many of the vital functionality from the basic diskimage-builder
libraries (such as init script aggregation, busybox population, etc).

An example of when one might want to use this toolchain to build a ramdisk would
be the initial deployment of baremetal nodes in a TripleO setup. Various tools
and scripts need to be injected into a ramdisk that will fetch and apply a
machine image to local disks. That tooling/scripting customisation can be
easily applied in a repeatable and automatable way, using this element.

NOTE: ramdisks require 1GB minimum memory on the machines they are booting.

See the top-level README.md of the project, for more information about the
mechanisms available to a ramdisk element.