output debug message in a better format.

src/docker_hub_rate.sh

@@ -49,15 +49,25 @@ _docker_hub_rate_read_rate() {
 docker_hub_rate() {
   local IMAGE="${1:-ratelimitpreview/test}"
   local USER_AND_PASS="${2}"
-  if ! log INFO "" 1>/dev/null 2>/dev/null; then
-    # Assume the error is due to log function is not available.
+  if ! type log 1>/dev/null 2>&1; then
     log() {
       echo "${*}" >&2
     }
   fi
+  if ! type log_lines 1>/dev/null 2>&1; then
+    # Usage: echo "${LOGS}" | log_lines LEVLE
+    log_lines() {
+      local LEVEL="${1}";
+      while read -r LINE; do
+        [ -z "${LINE}" ] && continue;
+        log "${LEVEL}" "${LINE}";
+      done
+    }
+  fi
   local RESPONSE=
   if ! RESPONSE=$(_docker_hub_rate_token "${IMAGE}" "${USER_AND_PASS}"); then
-    log DEBUG "_docker_hub_rate_token error: RESPONSE=${RESPONSE}"
+    log DEBUG "_docker_hub_rate_token error: RESPONSE="
+    echo "${RESPONSE}" | log_lines DEBUG
     echo "[GET TOKEN RESPONSE ERROR]"
     return 1
   fi
@@ -73,7 +83,8 @@ docker_hub_rate() {
       echo "0"
       return 0
     fi
-    log DEBUG "_docker_hub_rate_read_rate error: RESPONSE=${RESPONSE}"
+    log DEBUG "_docker_hub_rate_read_rate error: RESPONSE="
+    echo "${RESPONSE}" | log_lines DEBUG
     echo "[GET RATE RESPONSE ERROR]"
     return 1
   fi