Debugging

Why Ansible include_tasks Variables Are Not Defined in the Parent Play You define a variable inside an include_tasks file. The task runs successfully. Then the very next task in your parent play fails with variable is undefined. What just happened? This is one of the most confusing Ansible behaviors, and it bites people repeatedly because it looks like a bug. It’s not — it’s a scoping decision — but understanding why it works this way helps you fix it fast. ...

Why Ansible register Variable Is Undefined in the Next Task You registered a variable in one task, and the next task fails with "msg": "The task includes an option with an undefined variable". The variable is right there — you can see it in the task above. What’s going on? This is one of the most common Ansible debugging rabbit holes. There are four distinct causes, and they look identical until you know what to look for. ...

You authenticate to CyberArk’s PVWA API, get a session token back with HTTP 200, then immediately call GET /PasswordVault/api/Accounts and get a 401 Unauthorized. The token looks valid. You confirmed it’s being passed in the request. The account has the right permissions. Here’s why it’s happening and how to fix it. The Problem: Wrong Authorization Header Format CyberArk’s PVWA API (v9.x and earlier) does not use the standard Bearer token format. Sending: ...

You set a variable with set_fact. You call include_role. Inside the role, the variable is undefined. You check the task order — it’s definitely set first. You add debug statements. The variable exists in the play but not inside the role. This is one of the most confusing variable scoping issues in Ansible. Here’s what’s happening and how to fix it. The Problem 1 2 3 4 5 6 7 8 9 - name: Set environment ansible.builtin.set_fact: MY_REGION: "us-east" - name: Run the role ansible.builtin.include_role: name: my_role vars: some_param: "value" Inside my_role/tasks/main.yml: ...

You set a variable with set_fact inside a role. It works perfectly. Then you run the same role again — either in a loop, or later in the same playbook — and it behaves differently. The variable has a value from the previous run that you didn’t expect. This is one of Ansible’s most common gotchas. Here’s exactly why it happens and how to fix it. Why set_fact Persists In Ansible, set_fact sets a variable at the host level for the duration of the play. It is not scoped to the role or task file that created it. Once set, it stays set until: ...

You run docker run myimage or docker compose up and the container vanishes instantly. docker ps shows nothing. docker ps -a shows the container with status Exited (0) or Exited (1) seconds ago. Here’s how to figure out what’s happening and fix it. Step 1: Check the logs first Before anything else: 1 docker logs <container_id_or_name> If the container is already gone, use the container ID from docker ps -a: ...

You’re building a frontend that calls your API, and suddenly: A h o c a n c s e t s b h s e e e t n r o e b q f l u e o e t c s c k t h e e d d a t b r y e ' s h C o t O u t R r p S c : e / p . / o l l o i c c a y l : h o N s o t : ' 8 A 0 c 0 c 0 e / s a s p - i C / o d n a t t r a o ' l - f A r l o l m o w o - r O i r g i i g n i n ' ' h t h t e p a : d / e / r l o i c s a l p h r o e s s t e : n 3 t 0 0 0 ' Your API works fine in Postman. It works with curl. But your browser refuses to load the data. What’s going on? ...

You added a cron job. It works when you run it manually. But cron just… doesn’t run it. No errors, no output, nothing. This is one of the most frustrating debugging experiences in Linux. Here’s a systematic checklist to find out what’s actually wrong. 1. Check If Cron Is Running First, make sure the cron daemon is actually running: 1 2 3 4 5 6 7 # systemd systems systemctl status cron # or systemctl status crond # Older init systems service cron status If it’s not running, start it: ...

Your pod is stuck in CrashLoopBackOff. Kubernetes keeps restarting it, each time waiting longer before trying again. Here’s how to diagnose and fix it. What CrashLoopBackOff Actually Means CrashLoopBackOff isn’t the error itself — it’s Kubernetes telling you “this container keeps crashing, so I’m backing off on restarts.” The actual problem is that your container exits with a non-zero exit code. Kubernetes notices, restarts it, it crashes again, and the backoff timer increases: 10s, 20s, 40s, up to 5 minutes. ...

You added a cron job. You’re sure the syntax is right. But nothing happens. No output, no errors, just silence. Here’s how to figure out what’s wrong. Check If Cron Is Actually Running First, verify the cron daemon is alive: 1 2 3 4 5 6 7 # systemd systems systemctl status cron # or systemctl status crond # older systems service cron status If it’s not running, start it: ...