feat(KONFLUX-4892): supply layer size information to pyxis

This is meant to be paired with a change in the step image:
konflux-ci/release-service-utils#284

If the layers of the image are found to be gzip compressed, then pull
them, decompress them, and include information about their decompressed
digests and sizes in the manifest provided to the pyxis script.

Signed-off-by: Ralph Bean <rbean@redhat.com>

tasks/create-pyxis-image/create-pyxis-image.yaml

@@ -156,19 +156,55 @@ spec:
                   ORAS_ARGS+=("--platform $os/$arch")
                 fi
 
+                # Save the OCI manifest locally, to pass to a script to create the pyxis entry
+                MANIFEST_FILE="/tmp/oras-manifest-fetch.json"
                 oras manifest fetch \
                   --registry-config "$AUTH_FILE" \
                   "${ORAS_ARGS[@]}" \
                   "${PULLSPEC}" \
-                      | tee /tmp/oras-manifest-fetch.json
+                      | tee "${MANIFEST_FILE}"
+
+                # Augment that manifest with further information about the layers, decompressed
+                # This requires pulling the layers to decompress and then measure them
+                while IFS= read -r BLOB_DETAIL;
+                do
+                    BLOB_TYPE=$(jq -r '.mediaType' <<< "$BLOB_DETAIL")
+                    BLOB_DIGEST=$(jq -r '.digest' <<< "$BLOB_DETAIL")
+
+                    if [[ "$BLOB_TYPE" =~ ^.*\.gzip$|^.*\+gzip$ ]]; then
+                        BLOB_FILE="/tmp/oras-blob-fetch-${BLOB_DIGEST}"
+                        BLOB_PULLSPEC="${PULLSPEC%%@*}@${BLOB_DIGEST}"
+
+                        # Save the blob
+                        oras blob fetch \
+                          --registry-config "$AUTH_FILE" \
+                          --output "${BLOB_FILE}.gz" \
+                          "${BLOB_PULLSPEC}"
+
+                        # Decompress it
+                        gunzip "${BLOB_FILE}.gz"
+
+                        # Measure it
+                        EXPANDED_DIGEST=$(sha256sum "${BLOB_FILE}" | cut -d " " -f 1)
+                        EXPANDED_SIZE=$(wc --bytes "${BLOB_FILE}" | awk '{print $1}' | tr -d '\n')
+
+                        # Append this information to the parsed_data manifest
+                        cat <<< $(jq \
+                          '.uncompressed_layers += [{"digest": "'"$EXPANDED_DIGEST"'", "size": '"$EXPANDED_SIZE"'}]' \
+                          "${MANIFEST_FILE}") > "${MANIFEST_FILE}"
+
+                        # Clean up, in case we're dealing with large images
+                        rm "/tmp/oras-blob-fetch-${BLOB_DIGEST}"
+                    fi
+                done <<< $(jq -c '.layers[]' "${MANIFEST_FILE}")
 
                 PYXIS_CERT_PATH=/tmp/crt PYXIS_KEY_PATH=/tmp/key create_container_image \
                   --pyxis-url $PYXIS_URL \
                   --certified $(params.certified) \
                   --tags "$TAGS" \
                   --is-latest $(params.isLatest) \
                   --verbose \
-                  --oras-manifest-fetch "/tmp/oras-manifest-fetch.json" \
+                  --oras-manifest-fetch "${MANIFEST_FILE}" \
                   --name "$REPOSITORY" \
                   --media-type "$MEDIA_TYPE" \
                   --digest "$DIGEST" \