Add RHEL 7 image element

This is being added as a separate element because RHEL 7 is too
different from either RHEL 6 or Fedora to share all of the
configuration they do.  It uses the redhat-common element for
pieces that are duplicated.

Some current limitations of the element:
-RHEL 7 is currently still in beta, so final image locations are
 not available.  This currently defaults to the RHEL 6.5 image,
 but that will need to be overridden using the DIB_* env vars.
-There are additional tripleo-image-elements changes that will be
 needed to be able to use this for building tripleo images.
-Open vSwitch packages are not currently available in the official
 RHEL 7 repos.
-RHEL does not support qemu without kvm acceleration, so at this
 time it cannot be used as a compute node for virtualized testing.

Change-Id: I705fd475303576525a27ce6801c673b5721792c9

elements/rhel7/README.md

@@ -0,0 +1,8 @@
+Use RHEL 7 cloud images as the baseline for built disk images.
+
+Note: As of this writing, RHEL 7 is still in beta, so final download
+locations are not available.  This element defaults to using the RHEL 6.5
+image, but that will need to be overridden using the appropriate DIB_*
+environment variables to point at a RHEL 7 image.
+
+For further details see the redhat-common README.

elements/rhel7/element-deps

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+cache-url
+dib-run-parts
+redhat-common
+rpm-distro
+source-repositories
+yum

elements/rhel7/pre-install.d/05-yum-repos

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+#!/bin/bash
+
+cat << EOF > /etc/yum.repos.d/rhel7.repo
+[rhel7]
+name=RHEL7
+failovermethod=priority
+baseurl=http://ftp.redhat.com/redhat/rhel/beta/7/x86_64/os/
+enabled=1
+metadata_expire=7d
+gpgcheck=0
+EOF
+
+cat << EOF > /etc/yum.repos.d/epel.repo
+[epel]
+name=epel
+failovermethod=priority
+baseurl=http://download-i2.fedoraproject.org/pub/epel/beta/7/x86_64/
+enabled=1
+metadata_expire=7d
+gpgcheck=0
+EOF

elements/rhel7/root.d/10-rhel-cloud-image

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+#!/bin/bash
+
+set -eu
+
+[ -n "$ARCH" ]
+[ -n "$TARGET_ROOT" ]
+
+if [ 'amd64' = "$ARCH" ] ; then
+  ARCH="x86_64"
+fi
+
+DIB_LOCAL_IMAGE=${DIB_LOCAL_IMAGE:-""}
+
+if [ -n "$DIB_LOCAL_IMAGE" ]; then
+    IMAGE_LOCATION=$DIB_LOCAL_IMAGE
+    # No need to copy a local image into the cache directory, so just specify
+    # the cached path as the original path.
+    CACHED_IMAGE=$IMAGE_LOCATION
+    BASE_IMAGE_FILE=`basename $DIB_LOCAL_IMAGE`
+    BASE_IMAGE_TAR=$BASE_IMAGE_FILE.tgz
+else
+    DIB_RELEASE=${DIB_RELEASE:-latest}
+    DIB_CLOUD_IMAGES=${DIB_CLOUD_IMAGES:-http://rhn.redhat.com}
+    BASE_IMAGE_FILE=${BASE_IMAGE_FILE:-rhel-guest-image-6-6.5-20131115.0-1.qcow2}
+    BASE_IMAGE_TAR=$DIB_RELEASE-rhel-server-$ARCH-latest.tgz
+    IMAGE_LOCATION=$DIB_CLOUD_IMAGES/$BASE_IMAGE_FILE
+    CACHED_IMAGE=$DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
+
+fi
+
+$TMP_HOOKS_PATH/bin/extract-image $BASE_IMAGE_FILE $BASE_IMAGE_TAR $IMAGE_LOCATION $CACHED_IMAGE

elements/rhel7/source-repository-rhel7

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+lsb-release file /opt/stack/lsb-release/lsb_release https://bzr.linuxfoundation.org/loggerhead/lsb/devel/si/download/head:/lsb_release-20060624065236-gakl5b7e37gwk5mg-12/lsb_release