ci-automation: Add URL template handling

ci-automation/ci-config.env

@@ -17,6 +17,8 @@ CONTAINER_REGISTRY="ghcr.io/flatcar-linux"
 
 GC_BUCKET="flatcar-linux"
 
+DEFAULT_HTTP_IMAGE_URL_TEMPLATE="@PROTO@://${BUILDCACHE_SERVER}/images/@ARCH@/@VERNUM@"
+
 if ! command -v pigz > /dev/null; then
   # No PIGZ on Flatcar
   PIGZ="docker run --rm -i ghcr.io/flatcar-linux/pigz --fast"
@@ -85,9 +87,9 @@ GCE_PARALLEL="${PARALLEL_TESTS:-4}"
 
 # -- Digital Ocean --
 
-# Use the "@ARCH@", "@CHANNEL@" and "@VERNUM@" placeholders. They will
+# Use the "@PROTO@" "@ARCH@", "@CHANNEL@" and "@VERNUM@" placeholders. They will
 # be replaced.
-DO_IMAGE_URL="https://${BUILDCACHE_SERVER}/images/@ARCH@/@VERNUM@/flatcar_production_digitalocean_image.bin.bz2"
+DO_IMAGE_URL="${DEFAULT_HTTP_IMAGE_URL_TEMPLATE}/flatcar_production_digitalocean_image.bin.bz2"
 DO_CONFIG_FILE='do-token.json'
 DO_REGION='sfo3'
 DO_MACHINE_SIZE='s-2vcpu-2gb'

ci-automation/ci_automation_common.sh

@@ -224,3 +224,24 @@ function docker_image_from_registry_or_buildcache() {
     docker_image_from_buildcache "${image}" "${version}"
 }
 # --
+
+# Substitutes fields in the passed template and prints the
+# result. Followed by the template, the parameters used for
+# replacement are in alphabetical order: arch, channel, proto and
+# vernum.
+function url_from_template() {
+    local template="${1}"; shift
+    local arch="${1}"; shift
+    local channel="${1}"; shift
+    local proto="${1}"; shift
+    local vernum="${1}"; shift
+    local url="${template}"
+
+    url="${url//@ARCH@/${arch}}"
+    url="${url//@CHANNEL@/${channel}}"
+    url="${url//@PROTO@/${proto}}"
+    url="${url//@VERNUM@/${vernum}}"
+
+    echo "${url}"
+}
+# --

ci-automation/vendor-testing/digitalocean.sh

@@ -38,9 +38,7 @@ if [[ "${channel}" = 'developer' ]]; then
 fi
 image_name="ci-${vernum//+/-}"
 testscript="$(basename "$0")"
-image_url="${DO_IMAGE_URL//@ARCH@/${arch}}"
-image_url="${image_url//@CHANNEL@/${channel}}"
-image_url="${image_url//@VERNUM@/${vernum}}"
+image_url="$(url_from_template "${DO_IMAGE_URL}" "${arch}" "${channel}" 'https' "${vernum}")"
 
 ore do create-image \
     --config-file="${DO_CONFIG_FILE}" \