Test jobs before adding them to the crontab file

functions.sh

@@ -1,3 +1,7 @@
+timestamp() {
+  date -u "+%Y-%m-%d %H:%M:%S %Z"
+}
+
 isTrue() {
     case $1 in
         "True" | "TRUE" | "true" | 1)
@@ -11,6 +15,6 @@ isTrue() {
 
 log() {
   if isTrue "$DEBUG"; then
-    echo "$(timestamp)" "$@"
+    echo "$(timestamp) |" "$@"
   fi
 }

startup.sh

@@ -2,7 +2,8 @@
 DIR=$(dirname "$0")
 . "$DIR/functions.sh"
 
-touch /root/crontab
+# Create empty crontab file
+true > /root/crontab
 
 if isTrue "$DEBUG"; then
     supercronic -debug -inotify /root/crontab &

update_cron.sh

@@ -4,16 +4,13 @@ DIR=$(dirname "$0")
 . "$DIR/functions.sh"
 
 # Temp cron file paths
+CRON_FILE_TEST="/tmp/cron_test"
 CRON_FILE_NEW="/root/crontab.new"
 CRON_FILE="/root/crontab"
 CRON_LOG_DIR=${CRON_LOG_DIR:-/var/log/cron}
 
 mkdir -p "$CRON_LOG_DIR"
 
-timestamp() {
-  date -u "+%Y-%m-%d %H:%M:%S %Z"
-}
-
 # Function to extract specific cron job labels from a container
 extract_cron_jobs() {
   _container_id=$1
@@ -34,23 +31,24 @@ extract_cron_command() {
 
 # Get the project name
 if [ -z "$COMPOSE_PROJECT_NAME" ]; then
-  echo "$(timestamp) COMPOSE_PROJECT_NAME is not set. The service cron will run tasks for all Docker containers."
+  echo "$(timestamp) | The COMPOSE_PROJECT_NAME variable isn't set. The cron service handles jobs for all docker containers (all docker-compose stacks) on the server."
   containers=$(docker ps -q)
 else
-  echo "$(timestamp) The service cron will run tasks for Docker containers defined in the COMPOSE_PROJECT_NAME: $COMPOSE_PROJECT_NAME"
+  echo "$(timestamp) | The cron service handles jobs for the docker-compose stack defined in the COMPOSE_PROJECT_NAME variable: $COMPOSE_PROJECT_NAME"
   containers=$(docker ps --filter "label=com.docker.compose.project=$COMPOSE_PROJECT_NAME" -q)
 fi
 
-echo "$(timestamp) Updating cron jobs..."
+echo "$(timestamp) | Updating cron jobs..."
 touch $CRON_FILE_NEW
 
 # Process each container
 for container in $containers; do
   cron_jobs=$(extract_cron_jobs "$container")
+  target_container=$(docker inspect -f '{{.Name}}' "$container" | cut -c2-) # Remove leading /
   if [ -z "$cron_jobs" ]; then
-    log "No cron jobs found for container: $container"
+    log "No cron jobs found for container: $target_container ($container)"
   else
-    log "Processing container: $container"
+    log "Processing container: $target_container ($container)"
 
     echo "$cron_jobs" | while IFS= read -r job; do
       decoded_job=$(decode_cron_job "$job")
@@ -64,12 +62,22 @@ for container in $containers; do
 
       # Check if both schedule and command labels are set
       if [ -n "$job_schedule" ] && [ -n "$job_command" ]; then
-        target_container=$(docker inspect -f '{{.Name}}' "$container" | cut -c2-) # Remove leading /
         cron_entry="$job_schedule docker exec $target_container sh -c '$job_command' 2>&1 | tee -a $CRON_LOG_DIR/\$(date -u +\%Y-\%m-\%d_\%H-\%M-\%S_\%Z)_$job_key.log"
-        echo "$cron_entry" >> $CRON_FILE_NEW # Write in one line to the cron file
-        log "Scheduled task for $target_container: $cron_entry"
+        # Run the supercronic test
+        echo "$cron_entry" > $CRON_FILE_TEST
+        if ! supercronic -test $CRON_FILE_TEST > /dev/null 2>&1; then
+          echo "$(timestamp) | ========================================================"
+          printf "\nERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR\n\n"
+          echo "BAD CRON JOB: '$cron_entry'"
+          supercronic -debug -test $CRON_FILE_TEST
+          printf "==================================================================================\n\n"
+          # TODO make the cron container unhealthy
+        else
+          echo "$cron_entry" >> $CRON_FILE_NEW # Write in one line to the cron file
+          log "Scheduled task for $target_container: $cron_entry"
+        fi
       else
-        echo "$(timestamp) Error: job_schedule or job_command is missing."
+        echo "$(timestamp) | Error: job_schedule or job_command is missing."
       fi
     done
   fi
@@ -78,18 +86,34 @@ done
 # Check if there are changes
 if ! diff -u "$CRON_FILE" "$CRON_FILE_NEW" > /dev/null; then
   # Print the changes in the crontab:
-  printf "\n\n%s Changes in the crontab file:\n" "$(timestamp)"
+  printf "\n%s | Changes in the crontab file:\n" "$(timestamp)"
   diff -u "$CRON_FILE" "$CRON_FILE_NEW" | tail -n +3 # Remove the first two lines containing file names
 
-  # Print the updated crontab file
-  printf "\n%s Updated crontab file:\n=========================================\n" "$(timestamp)"
-  cat "$CRON_FILE_NEW"
-  printf "=========================================\n\n"
+  if [ ! -s "$CRON_FILE_NEW" ]; then
+    printf "\n%s | NO JOBS IN CRONTAB FILE\n\n" "$(timestamp)"
+  else
+    # Print the updated crontab file
+    printf "\n%s | Updated crontab file:\n=========================================\n" "$(timestamp)"
+    cat "$CRON_FILE_NEW"
+    printf "=========================================\n\n"
+  fi
 
-  # Update the crontab file
-  cat "$CRON_FILE_NEW" > "$CRON_FILE"
+  # Update the crontab file if it looks good for supercronic (we tested it one by one line above, but to make sure)
+  if ! supercronic -test $CRON_FILE_NEW > /dev/null 2>&1; then
+    echo "$(timestamp) | ########################################################"
+    printf "\nERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR ERROR\n\n"
+    echo "SOMETHING IS WRONG IN THE CRONTAB FILE"
+    supercronic -debug -test $CRON_FILE_NEW
+    echo "ERROR: CHANGES ARE NOT APPLIED."
+    echo "CURRENT CRONTAB FILE IS:"
+    cat "$CRON_FILE"
+    printf "##################################################################################\n\n"
+    # TODO make the cron container unhealthy
+  else
+    cat "$CRON_FILE_NEW" > "$CRON_FILE"
+  fi
 else
-  echo "$(timestamp) No changes detected in crontab file."
+  echo "$(timestamp) | No changes detected in crontab file."
 fi
 
 rm "$CRON_FILE_NEW"