scripts/install-release-image: Extract the RHCOS AMI from the release…

… image

A temporary workaround while [1] is in flight.

[1]: openshift#1286

scripts/install-release-image.sh

@@ -5,14 +5,15 @@
 #
 # Usage:
 #
-#   install-release-image.sh [ARG...]
+#   AWS_DEFAULT_REGION=us-east-1 install-release-image.sh [ARG...]
 #
 # Requires:
 #
-# * oc, to extract the installer image
+# * oc, to extract the installer and machine-os-content images
 # * podman, to run the installer image
 # * realpath, which is not in POSIX as a shell command [1], but is in
 #   GNU coreutils [2].  The backing C function is in POSIX [3].
+# * jq, for processing the machine-os-content metadata
 # * A pull secret in ~/.docker/config.json for both oc and podman.
 #
 # Optional:
@@ -32,6 +33,10 @@
 # * AWS_CONFIG_FILE [4]
 #   This defaults to ~/.aws/config, and, if set to an existing file,
 #   it is mounted into the installer container at ~/.aws/config
+# * AWS_DEFAULT_REGION
+#   Where you want to launch the cluster.  We won't need this once
+#   #1286 lands, but until then we need it to look up the apropriate
+#   AMI.  Sorry libvirt and OpenStack folks :p.
 # * AWS_SHARED_CREDENTIALS_FILE [4]
 #   If set, this is mounted into the installer container at
 #   ~/.aws/credentials
@@ -84,8 +89,32 @@ then
 	set -- --volume "${AWS_SHARED_CREDENTIALS_FILE}:/home/.aws/credentials:z" "${@}" || die 'failed to insert AWS_SHARED_CREDENTIALS_FILE into podman arguments'
 fi
 
+# Begin workaround while we wait for https://github.com/openshift/installer/pull/1286
+OS_IMAGE="$(oc adm release info --image-for=machine-os-content "${RELEASE}")" || die 'failed to resolve machine-os-content image'
+OS_ANNOTATIONS="$(oc image info --output=json "${OS_IMAGE}")" || die 'failed to extract machine-os-content metadata'
+OS_BUILD="$(echo "${OS_ANNOTATIONS}" | jq -r .config.config.Labels.version)" || die 'failed to extract RHCOS build'
+OS_BASE_URL="${OS_BASE_URL:-https://releases-rhcos.svc.ci.openshift.org/storage/releases}"
+OS_CHANNEL="${OS_CHANNEL:=maipo}"
+
+# assume we're using AWS
+REGION="${REGION:-${AWS_DEFAULT_REGION}}"
+
+if test -z "${REGION}"
+then
+	die "REGION unset\n"
+fi
+
+AMIS="$(curl -s "${OS_BASE_URL}/${OS_CHANNEL}/${OS_BUILD}/meta.json" | jq -r ".amis")" || die "failed to pull metadata for ${OS_BUILD}"
+AMI="$(echo "${AMIS}" | jq -r ".[] | select(.name == \"${REGION}\").hvm")" || die 'failed to extract RHCOS AMI ID'
+if test -z "${AMI}"
+then
+	die "no AMI for %s.  Available regions:\n%s\n" "${REGION}" "$(echo "${AMIS}" | jq -r '.[].name')"
+fi
+# End of #1286 workaround
+
 exec podman run --rm -it \
 	--user "$(id -u):$(id -g)" \
 	--env OPENSHIFT_INSTALL_RELEASE_IMAGE_OVERRIDE="${RELEASE}" \
+	--env OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE="${AMI}" \
 	--volume "${ASSETS}:/output:z" \
 	"${@}"