ansible 脚本“SHELL”与在 ubuntu 机器 20.04 EC2 上直接运行 Shell 命令的细微差别？

Question

I come with a Vagrant script that pulls down an bionic 18 which then runs an ansible playbook which generates two EC2s ubuntu 20.04 which successfully run though every "task:" I assign. I am able to run everything I want in a largely automated download and execution for a publisher subscriber method. Here is the issue: I can run my.sh and.py scripts manually and the systems works, but when I use the ansible methods I must be doing something wrong much like these solutions point to:

• Shell command works on direct hosts but fail on Ansible
• ansible run command on remote host in background
• https://superuser.com/questions/870871/run-a-remote-script-application-in-detached-mode-in-ansible

What I want to do is simply correct the issue with this, and run it in the background.

- name: Start Zookeeper
  shell: sudo /usr/local/kafka-server/bin/zookeeper-server-start.sh  /usr/local/kafka-server/config/zookeeper.properties </dev/null >/dev/null 2>&1 &
- name: Sleep for 30 seconds and continue with play
  wait_for:
    timeout: 15
- name: Start Kafka broker
  shell: sudo /usr/local/kafka-server/bin/kafka-server-start.sh  /home/ubuntu/usr/local/kafka-server/config/server.properties </dev/null >/dev/null 2>&1 &

I have tried it with just a single "&" at the end as well as passing in explicit calls to my user account "ubuntu" . I've used the "become: yes" . I really don't want to use a daemon especially since others seem to have used this successfully before.

I do want to note that a glaring sign to you that I can't seem to think through is that it hangs when I don't include the &, but if I do include the & it just outright fails, which made me think it was running, but the script won't proceed because these are listener processes.

#     - name: Start Zookeeper
#       become: yes
#       script: /usr/local/kafka-server/bin/zookeeper-server-start.sh
#       args: 
#         chdir: /usr/local/kafka-server/config/zookeeper.properties

This failed, and I'd rather not create another script to copy over the directories and localize it if there is a simple solution to the first block of code.

Multiple ways to skin this cat, but I'd rather just have my mistake on the shell ansible command fixed, and I don't see it.

Answer 1

As explained in the answers written in your third link:

https://superuser.com/questions/870871/run-a-remote-script-application-in-detached-mode-in-ansible

This happens because the script process is a child process from the shell spawned by ansible. To keep the process running after ansible has finished you would need to disown this child process.

The proper way to do this is configuring the software (zookeeper in your case) as a service. There are plenty of examples for this such as:

https://askubuntu.com/questions/979498/how-to-start-a-zookeeper-daemon-after-booting-under-specific-user-in-ubuntu-serv

Once you have configured it as a service, you can start it or stop it using ansible service module.