feat: retry nvd cache on failure (#264)

* feat: retry nvd cache on failure

* fix: updated per peer review

vulnz/src/docker/scripts/mirror.sh

@@ -48,6 +48,21 @@ function remove_lockfile() {
 }
 trap remove_lockfile SIGHUP SIGINT SIGQUIT SIGABRT SIGALRM SIGTERM SIGTSTP
 
-java $JAVA_OPT -jar /usr/local/bin/vulnz cve $DELAY_ARG $DEBUG_ARG $MAX_RETRY_ARG $MAX_RECORDS_PER_PAGE_ARG $CONTINUE_ARG --cache --directory /usr/local/apache2/htdocs
+attempt=1
+max_attempts=5
+
+set +e
+while [ $attempt -le $max_attempts ]; do
+  java $JAVA_OPT -jar /usr/local/bin/vulnz cve $DELAY_ARG $DEBUG_ARG $MAX_RETRY_ARG $MAX_RECORDS_PER_PAGE_ARG $CONTINUE_ARG --cache --directory /usr/local/apache2/htdocs
+  exit_code=$?
+  # 100: one or more years of data failed to update; 101 there was an error updating the modified CVE list
+  # if either of these codes are returned, we will retry the update immediately
+  if [ $exit_code -ne 100 ] && [ $exit_code -ne 101 ]; then
+    break
+  fi
+  echo "Got exit code $exit_code, attempt $attempt of $max_attempts"
+  attempt=$((attempt + 1))
+done
+set -e
 
 rm -f $LOCKFILE