diskimage-builder/diskimage_builder/elements/centos-minimal/README.rst

==============
centos-minimal
==============
Create a minimal image based on CentOS 7.

Use of this element will require 'yum' and 'yum-utils' to be installed on
Ubuntu and Debian. Nothing additional is needed on Fedora or CentOS.

By default, ``DIB_YUM_MINIMAL_CREATE_INTERFACES`` is set to enable the
creation of ``/etc/sysconfig/network-scripts/ifcfg-eth[0|1]`` scripts to
enable DHCP on the ``eth0`` & ``eth1`` interfaces.  If you do not have
these interfaces, or if you are using something else to setup the
network such as cloud-init, glean or network-manager, you would want
to set this to ``0``.
Create docs site containing element READMEs We currently do not have the ability to create a docs site which outlines all the elements. Change-Id: I77ccf61e0c4b1509b3e7ce9b8f15ea5ccfd50d9b 2015-02-07 10:30:02 +00:00			`==============`
			`centos-minimal`
			`==============`
Add minimal ubuntu and centos base elements There are times when a much more stripped down base image is desired over the distro cloud images. For instance, Infra would like some base images that do not have cloud-init or really much of anything else. This is easy to accomplish with debootstrap and rinse. Change-Id: I44ff22457165afb048fdaea469210ae47d83dd3f 2014-11-22 23:46:33 +00:00			`Create a minimal image based on CentOS 7.`

Port centos-minimal to yum-minimal Now that we have a generic yum-minimal element, just use it in centos instead of rinse. Adding base as an element-provides of yum-minimal because this element conflicts with the base element. Co-Authored-By: Gregory Haynes <greg@greghaynes.net> Change-Id: I15275d821781171c118f21aa0c0bca55f65a65b3 2015-03-22 17:45:07 +00:00			`Use of this element will require 'yum' and 'yum-utils' to be installed on`
			`Ubuntu and Debian. Nothing additional is needed on Fedora or CentOS.`
Add minimal ubuntu and centos base elements There are times when a much more stripped down base image is desired over the distro cloud images. For instance, Infra would like some base images that do not have cloud-init or really much of anything else. This is easy to accomplish with debootstrap and rinse. Change-Id: I44ff22457165afb048fdaea469210ae47d83dd3f 2014-11-22 23:46:33 +00:00
Remove yum chroot caching Every run we are doing a full tar.gz of the chroot environment that never gets used. It's not suitable for CI since we use fresh images each time there. The cache in general isn't really isn't a very safe thing to have around, because there's no invalidation procedure and no real way to make one -- we've no guarantee that a new chroot build even moments after a previous one wouldn't bring in or different packages, etc (of course this is unlikely, but the longer you go between builds the worse the problem becomes. Also, tons of packages get installed after this not from any cache, so potential speed-up is rather marginal. Debian turned this off with I58fc485aacacaa17243bf9ce760ed91256d1f182. However, given the reasons above and it's complete lack of testing, I don't see this as useful. If we really want this type of thing, I think we should come up with a way to use a persistent external yum/dnf cache that yum/dnf keeps in sync with it's usual invalidation rules. Change-Id: I66789c35db75c41bc45ea1ad2e26f87456de4e4d 2016-12-09 03:41:24 +00:00			By default, ``DIB_YUM_MINIMAL_CREATE_INTERFACES`` is set to enable the
			creation of ``/etc/sysconfig/network-scripts/ifcfg-eth[0\|1]`` scripts to
			enable DHCP on the ``eth0`` & ``eth1`` interfaces. If you do not have
yum-minimal: do not configure eth0 & eth1 for DHCP automatically Add an environment variable to control the creation of eth0/1 interface enablement scripts. With a tool such as glean, the presence of these scripts will indicate the interface is configured and configuration-drive settings will not be applied. This means in a non-dhcp situation like on Rackspace, network is broken. On Fedora, where later systemd provides "predictable network interface names" [1] eth0 & eth1 ironically aren't predictable so this just confuses things. You really need cloud-init or glean or something to bring up your interfaces in a sane fashion. This maintains the status-quo on centos-minimal, but disables creation for fedora-minimal. [1] http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/ Change-Id: I3f1ffeb6de3b1f952292a144efab9554f7f99a5f 2015-12-14 04:26:11 +00:00			`these interfaces, or if you are using something else to setup the`
			`network such as cloud-init, glean or network-manager, you would want`
Remove yum chroot caching Every run we are doing a full tar.gz of the chroot environment that never gets used. It's not suitable for CI since we use fresh images each time there. The cache in general isn't really isn't a very safe thing to have around, because there's no invalidation procedure and no real way to make one -- we've no guarantee that a new chroot build even moments after a previous one wouldn't bring in or different packages, etc (of course this is unlikely, but the longer you go between builds the worse the problem becomes. Also, tons of packages get installed after this not from any cache, so potential speed-up is rather marginal. Debian turned this off with I58fc485aacacaa17243bf9ce760ed91256d1f182. However, given the reasons above and it's complete lack of testing, I don't see this as useful. If we really want this type of thing, I think we should come up with a way to use a persistent external yum/dnf cache that yum/dnf keeps in sync with it's usual invalidation rules. Change-Id: I66789c35db75c41bc45ea1ad2e26f87456de4e4d 2016-12-09 03:41:24 +00:00			to set this to ``0``.