fix: false positive when slack bot encounters error

- using jq to parse curl output
- replace docker image curl by alpine

Dockerfile

@@ -1,4 +1,7 @@
-FROM curlimages/curl:7.84.0
+FROM alpine:3.16
+
+RUN apk --update add --no-cache jq curl && \
+    rm -rf /var/cache/apk/*
 
 COPY entrypoint.sh /entrypoint.sh
 

entrypoint.sh

@@ -30,10 +30,16 @@ fi
 ##
 payload='{"channel": "'$1'", "text": "'$2'"}'
 echo "* Preparing payload: $payload"
-curl -X POST \
+response=`curl -X POST \
   -H "Content-type: application/json" \
   -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
   -d "$payload" \
-  https://slack.com/api/chat.postMessage
-echo "* Slack channel id '$1' has been notified with '$2'"
+  https://slack.com/api/chat.postMessage`
+is_ok=`echo $response | jq '.ok'`
+if [ $is_ok == 'true' ]
+then 
+  echo "* Slack channel id '$1' has been notified with '$2'"
+else
+  log_error "`echo $response | jq '.error'`"
+fi
 exit 0