[FCM-81] Sleep for 30 seconds to ensure Kafka is stable

[TimGrist]

Sleep for 60 seconds to ensure Kafka is stable

[wojtek-oledzki]

Pure Awesomeness!

[dennisconrad]

Thank you for this PR!

We are already waiting for the port to appear:

- name: Wait for Kafka port
  wait_for:
    host: "{{ sansible_kafka_listen_address }}"

What does waiting 30s before that add to this?

[wojtek-oledzki]

@dennisconrad it's for cases when Kafka does starts up, and port 9092 is available, but then due to config error Kafka dies

[dennisconrad]

That still doesn't explain why we're waiting for 30s before we're even checking for the port :-) I would understand the other way round, but not like this.

Also, is there another way to ensure Kafka is ready? Can we check a log file instead, something like...

- name: Wait until Kafka is ready
  wait_for:
    path: /var/log/kafka/startup.log
    search_regex: "^Ready\.$"

?

[wojtek-oledzki]

ok, what about

- name: Wait for Kafka port
  wait_for:
    host: "{{ sansible_kafka_listen_address }}"
    port: "{{ sansible_kafka_port }}"
    state: started
    timeout: "{{ sansible_kafka_wait_for_kafka_port }}"

- name: "Check again after {{ sansible_kafka_waitfor_delay }} seconds to ensure Kafka is stable"
  wait_for:
    delay: "{{ sansible_kafka_waitfor_delay }}"
    host: "{{ sansible_kafka_listen_address }}"
    port: "{{ sansible_kafka_port }}"
    state: started
    timeout: "{{ sansible_kafka_wait_for_kafka_port }}"

[dennisconrad]

How about...

- name: Wait for Kafka port
  wait_for:
    delay: "{{ sansible_kafka_waitfor_delay }}"
    host: "{{ sansible_kafka_listen_address }}"
    port: "{{ sansible_kafka_port }}"
    state: started
    timeout: "{{ sansible_kafka_wait_for_kafka_port }}"
  with_items: [1, 2, 3]

1. Wait 30 seconds
2. Wait for port
3. Wait 30 seconds
4. Wait for port
5. Wait 30 seconds
6. Wait for port

If either of 2, 4, 6 times out, the task fails.

[TimGrist]

  TASK [kafka : Wait for Kafka port] *********************************************
    ok: [sansible_kafka-xenial] => (item=Initial check)
    ok: [sansible_kafka-bionic] => (item=Initial check)
    ok: [sansible_kafka-xenial] => (item=Second check)
    ok: [sansible_kafka-bionic] => (item=Second check)