cmd-buildextend-metal: create generate_runvm_osbuild_config(); cache results

Let's refactor the generation of the runvm-osbuild config into
a function and cache the results since we don't need to compute
these values every time we run OSBuild.

Author: dustymabe

src/cmd-buildextend-metal

@@ -154,44 +154,52 @@ getconfig_def() {
     jq -re .\""$k"\"//\""${default}"\" < "${config}"
 }
 
-# Grab a few values from ${image_json}
-deploy_via_container=$(getconfig_def "deploy-via-container" "" "${image_json}")
-extra_kargs="$(python3 -c 'import sys, json; args = json.load(sys.stdin)["extra-kargs"]; print(" ".join(args))' < "${image_json}")"
-
-# OStree container ociarchive file path
-ostree_container="${builddir}/$(meta_key images.ostree.path)"
-# If no container_imgref was set let's just set it to some professional
-# looking default. The name of the ociarchive file should suffice.
-container_imgref_default="ostree-image-signed:oci-archive:/$(basename "${ostree_container}")"
-container_imgref=$(getconfig_def "container_imgref" "${container_imgref_default}" "${image_json}")
-
-echo "Estimating disk size..."
-# The additional 35% here is obviously a hack, but we can't easily completely fill the filesystem,
-# and doing so has apparently negative performance implications.
-ostree_size_json="$(/usr/lib/coreos-assembler/estimate-commit-disk-size --repo "$ostree_repo" "$commit" --add-percent 35)"
-rootfs_size_mb="$(jq '."estimate-mb".final' <<< "${ostree_size_json}")"
-# The minimum size of a disk image we'll need will be the rootfs_size
-# estimate plus the size of the non-root partitions. We'll use this
-# size for the metal images, but for the IaaS/virt image we'll use
-# the size set in the configs since some of them have minimum sizes that
-# the platforms require and we want a "default" disk size that has some
-# free space.
-nonroot_partition_sizes=513
-# On s390x there is one more build - Secure Execution case, which has
-# different image layout. We add the sizes of the se and verity
-# partitions so that they don't "eat into" the 35% buffer (though note
-# this is all blown away on first boot anyway). For 's390x.mpp.yaml'
-# simplicity all s390x images have same size (of secex image).
-if [[ $basearch == "s390x" ]]; then
-    nonroot_partition_sizes=$((nonroot_partition_sizes + 200 + 128 + 256 + 1))
-fi
-metal_image_size_mb="$(( rootfs_size_mb + nonroot_partition_sizes ))"
-cloud_image_size_mb="$(jq -r ".size*1024" < "${image_json}")"
-echo "Disk sizes: metal: ${metal_image_size_mb}M (estimated), cloud: ${cloud_image_size_mb}M"
+# Here we generate the input JSON we pass to runvm_osbuild for all of our image builds
+generate_runvm_osbuild_config() {
+    runvm_osbuild_config_json="${workdir}/tmp/runvm-osbuild-config-${build}.json"
+    echo "${runvm_osbuild_config_json}" # Let the caller know where the config will be
+    if [ -f "${runvm_osbuild_config_json}" ]; then
+       return # only need to generate this once per build
+    fi
+    rm -f ${workdir}/tmp/runvm-osbuild-config-*.json # clean up any previous configs
+
+    # Grab a few values from $image_json
+    deploy_via_container=$(getconfig_def "deploy-via-container" "" "${image_json}")
+    extra_kargs="$(python3 -c 'import sys, json; args = json.load(sys.stdin)["extra-kargs"]; print(" ".join(args))' < "${image_json}")"
+
+    # OStree container ociarchive file path
+    ostree_container="${builddir}/$(meta_key images.ostree.path)"
+    # If no container_imgref was set let's just set it to some professional
+    # looking default. The name of the ociarchive file should suffice.
+    container_imgref_default="ostree-image-signed:oci-archive:/$(basename "${ostree_container}")"
+    container_imgref=$(getconfig_def "container_imgref" "${container_imgref_default}" "${image_json}")
 
-# Generate the JSON describing the disk we want to build
-runvm_osbuild_config_json="${tmp_builddir}/runvm-osbuild-config.json"
-yaml2json /dev/stdin "${runvm_osbuild_config_json}" <<EOF
+    echo "Estimating disk size..." &>2
+    # The additional 35% here is obviously a hack, but we can't easily completely fill the filesystem,
+    # and doing so has apparently negative performance implications.
+    ostree_size_json="$(/usr/lib/coreos-assembler/estimate-commit-disk-size --repo "$ostree_repo" "$commit" --add-percent 35)"
+    rootfs_size_mb="$(jq '."estimate-mb".final' <<< "${ostree_size_json}")"
+    # The minimum size of a disk image we'll need will be the rootfs_size
+    # estimate plus the size of the non-root partitions. We'll use this
+    # size for the metal images, but for the IaaS/virt image we'll use
+    # the size set in the configs since some of them have minimum sizes that
+    # the platforms require and we want a "default" disk size that has some
+    # free space.
+    nonroot_partition_sizes=513
+    # On s390x there is one more build - Secure Execution case, which has
+    # different image layout. We add the sizes of the se and verity
+    # partitions so that they don't "eat into" the 35% buffer (though note
+    # this is all blown away on first boot anyway). For 's390x.mpp.yaml'
+    # simplicity all s390x images have same size (of secex image).
+    if [[ $basearch == "s390x" ]]; then
+        nonroot_partition_sizes=$((nonroot_partition_sizes + 200 + 128 + 256 + 1))
+    fi
+    metal_image_size_mb="$(( rootfs_size_mb + nonroot_partition_sizes ))"
+    cloud_image_size_mb="$(jq -r ".size*1024" < "${image_json}")"
+    echo "Disk sizes: metal: ${metal_image_size_mb}M (estimated), cloud: ${cloud_image_size_mb}M" &>2
+
+    # Generate the JSON describing the disk we want to build
+    yaml2json /dev/stdin "${runvm_osbuild_config_json}" <<EOF
 container-imgref: "${container_imgref}"
 deploy-via-container: "${deploy_via_container}"
 osname: "${name}"
@@ -205,6 +213,7 @@ cloud-image-size: "${cloud_image_size_mb}"
 # not the last partition on the disk so we need to explicitly size it
 rootfs-size: "${rootfs_size_mb}"
 EOF
+}
 
 # In the jenkins pipelines we build the qemu image first and that operation
 # will do a lot of the same work required for later artifacts (metal, metal4k, etc)
@@ -213,6 +222,7 @@ EOF
 # so for those we'll set `snapshot=on` so that each will get their own disk image.
 # This is OK because we don't checkpoint (cache) any of those stages.
 [ "${image_type}" == "qemu" ] && snapshot="off" || snapshot="on"
+runvm_osbuild_config_json="$(generate_runvm_osbuild_config)"
 runvm_with_cache_snapshot "$snapshot" -- /usr/lib/coreos-assembler/runvm-osbuild                    \
             --config "${runvm_osbuild_config_json}"                                                 \
             --mpp "/usr/lib/coreos-assembler/osbuild-manifests/coreos.osbuild.${basearch}.mpp.yaml" \