make IPA download target fully customizable

This commit:
- Makes the IPA archive's file name fully customizable
- Makes the IPA archive's file extension fully customizable

The reason for these changes is to help users who download IPA images from
servers that don't follow the upstream naming conventions.

Signed-off-by: Adam Rozman <adam.rozman@est.tech>

get-resource.sh

@@ -26,9 +26,8 @@ IPA_BASEURI="${IPA_BASEURI:-https://tarballs.opendev.org/openstack/ironic-python
 IPA_BRANCH="$(echo "${IPA_BRANCH:-master}" | tr / -)"
 IPA_FLAVOR="${IPA_FLAVOR:-centos9}"
 
-FILENAME="ipa-${IPA_FLAVOR}-${IPA_BRANCH}"
-FILENAME_EXT=".tar.gz"
-FFILENAME="${FILENAME}${FILENAME_EXT}"
+FILENAME="${FILENAME:-ipa-${IPA_FLAVOR}-${IPA_BRANCH}.tar.gz}"
+FILENAME_NO_EXT="${FILENAME%%.*}"
 DESTNAME="ironic-python-agent"
 
 mkdir -p "${SHARED_DIR}"/html/images "${SHARED_DIR}"/tmp
@@ -39,41 +38,41 @@ TMPDIR="$(mktemp -d -p "${SHARED_DIR}"/tmp)"
 # If we have a CACHEURL and nothing has yet been downloaded
 # get header info from the cache
 
-if [ -n "${CACHEURL:-}" ] && [ ! -e "${FFILENAME}.headers" ]; then
-    curl_with_flags -g --fail -O "${CACHEURL}/${FFILENAME}.headers" || true
+if [ -n "${CACHEURL:-}" ] && [ ! -e "${FILENAME}.headers" ]; then
+    curl_with_flags -g --fail -O "${CACHEURL}/${FILENAME}.headers" || true
 fi
 
 # Download the most recent version of IPA
 if [ -r "${DESTNAME}.headers" ] ; then
     ETAG="$(awk '/ETag:/ {print $2}' "${DESTNAME}.headers" | tr -d "\r")"
     cd "${TMPDIR}"
-    curl_with_flags -g --dump-header "${FFILENAME}.headers" \
-        -O "${IPA_BASEURI}/${FFILENAME}" \
-        --header "If-None-Match: ${ETAG}" || cp "${SHARED_DIR}/html/images/${FFILENAME}.headers" .
+    curl_with_flags -g --dump-header "${FILENAME}.headers" \
+        -O "${IPA_BASEURI}/${FILENAME}" \
+        --header "If-None-Match: ${ETAG}" || cp "${SHARED_DIR}/html/images/${FILENAME}.headers" .
 
     # curl didn't download anything because we have the ETag already
     # but we don't have it in the images directory
     # Its in the cache, go get it
-    ETAG="$(awk '/ETag:/ {print $2}' "${FFILENAME}.headers" | tr -d "\"\r")"
-    if [ ! -s "${FFILENAME}" ] && [ ! -e "${SHARED_DIR}/html/images/${FILENAME}-${ETAG}/${FFILENAME}" ]; then
-        mv "${SHARED_DIR}/html/images/${FFILENAME}.headers" .
-        curl_with_flags -g -O "${CACHEURL}/${FILENAME}-${ETAG}/${FFILENAME}"
+    ETAG="$(awk '/ETag:/ {print $2}' "${FILENAME}.headers" | tr -d "\"\r")"
+    if [ ! -s "${FILENAME}" ] && [ ! -e "${SHARED_DIR}/html/images/${FILENAME_NO_EXT}-${ETAG}/${FILENAME}" ]; then
+        mv "${SHARED_DIR}/html/images/${FILENAME}.headers" .
+        curl_with_flags -g -O "${CACHEURL}/${FILENAME_NO_EXT}-${ETAG}/${FILENAME}"
     fi
 else
     cd "${TMPDIR}"
-    curl_with_flags -g --dump-header "${FFILENAME}.headers" -O "${IPA_BASEURI}/${FFILENAME}"
+    curl_with_flags -g --dump-header "${FILENAME}.headers" -O "${IPA_BASEURI}/${FILENAME}"
 fi
 
-if [ -s "${FFILENAME}" ]; then
-    tar -xaf "${FFILENAME}"
+if [ -s "${FILENAME}" ]; then
+    tar -xaf "${FILENAME}"
 
-    ETAG="$(awk '/ETag:/ {print $2}' "${FFILENAME}.headers" | tr -d "\"\r")"
+    ETAG="$(awk '/ETag:/ {print $2}' "${FILENAME}.headers" | tr -d "\"\r")"
     cd -
     chmod 755 "${TMPDIR}"
     mv "${TMPDIR}" "${FILENAME}-${ETAG}"
-    ln -sf "${FILENAME}-${ETAG}/${FFILENAME}.headers" "${DESTNAME}.headers"
-    ln -sf "${FILENAME}-${ETAG}/${FILENAME}.initramfs" "${DESTNAME}.initramfs"
-    ln -sf "${FILENAME}-${ETAG}/${FILENAME}.kernel" "${DESTNAME}.kernel"
+    ln -sf "${FILENAME}-${ETAG}/${FILENAME}.headers" "${DESTNAME}.headers"
+    ln -sf "${FILENAME}-${ETAG}/${FILENAME_NO_EXT}.initramfs" "${DESTNAME}.initramfs"
+    ln -sf "${FILENAME}-${ETAG}/${FILENAME_NO_EXT}.kernel" "${DESTNAME}.kernel"
 else
     rm -rf "${TMPDIR}"
 fi