Developing Advanced Automation with Red Hat Ansible Automation Platform
Run a playbook that includes a task that is delegated to another host.
Outcomes
Delegate a task to run on another host.
As the student user on the workstation machine, use the lab command to prepare your system for this exercise.
[student@workstation ~]$ lab start update-delegation
Procedure 8.1. Instructions
Clone the
https://git.lab.example.com/student/update-delegation.gitGit repository to the/home/student/git-reposdirectory and then create a branch for this exercise.From a terminal, create the
/home/student/git-reposdirectory if it does not already exist, and then change into it.[student@workstation ~]$
mkdir -p ~/git-repos/[student@workstation ~]$cd ~/git-repos/Clone the
https://git.lab.example.com/student/update-delegation.gitrepository and then change into the cloned repository:[student@workstation git-repos]$
git clone \>https://git.lab.example.com/student/update-delegation.gitCloning into 'update-delegation'... ...output omitted... [student@workstation git-repos]$cd update-delegationCreate the
exercisebranch.[student@workstation update-delegation]$
git checkout -b exerciseSwitched to a new branch 'exercise'
Review the contents of the
inventory.ymlinventory file. Verify that theweb_servershost group contains servers A to F.web_servers: hosts:server[a:f].lab.example.com:Add a task to the
query_times.ymlplaybook that perform the following actions:Query the time on each server in the
web_servershost group.Store the results in the
/tmp/times.txtfile on theworkstationmachine.
Add a task that adds two lines of text for each server to the
/tmp/times.txtfile on theworkstationmachine. The first line in that file contains the name of a web server. The second line contains the time on the managed host. For both lines, the task uses the facts gathered from theweb_servershost group. If the file does not exist, it is created.Ensure that each line of text appends to the end of the
/tmp/times.txtfile on theworkstationmachine by delegating this task for each managed host toworkstation.The task should consist of the following content:
- name: Save server times to workstation ansible.builtin.lineinfile: path: /tmp/times.txt state: present mode: '0644' create: true insertafter: EOF line: | {{ ansible_facts['fqdn'] }} {{ '%c' | strftime(ansible_facts['date_time']['epoch']) }} delegate_to: workstationNote
You can use the
strftimefilter to display time in a particular format by passing a format to the filter. Consult thedate(1)man page for available formats.
Run the playbook by using the
ansible-navigator runcommand to test the delegation of tasks:[student@workstation update-delegation]$
ansible-navigator run \>-m stdout query_times.ymlPLAY [Query server times and store them locally] **************************... TASK [Gathering Facts] ****************************************************... ok: [servera.lab.example.com] ...output omitted... ok: [serverf.lab.example.com] TASK [Save server times to workstation] ***********************************... changed: [servera.lab.example.com -> workstation] ...output omitted... changed: [serverf.lab.example.com -> workstation] PLAY RECAP ****************************************************************... servera.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ... serverb.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ... serverc.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ... serverd.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ... servere.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ... serverf.lab.example.com : ok=2 changed=1 unreachable=0 failed=0 ...Verify that the playbook has gathered the times correctly and that Ansible stored the information in the
/tmp/times.txtfile on theworkstationmachine.[student@workstation update-delegation]$
cat /tmp/times.txtserverb.lab.example.com Thu Dec 1 14:49:24 2022 servera.lab.example.com Thu Dec 1 14:49:24 2022 serverd.lab.example.com Thu Dec 1 14:49:24 2022 serverc.lab.example.com Thu Dec 1 14:49:24 2022 servere.lab.example.com Thu Dec 1 14:49:24 2022 serverf.lab.example.com Thu Dec 1 14:49:25 2022The order of hosts in your file might differ. There might be multiple entries for each host if you run the playbook multiple times.
