Chapter 5. Ansible content migration

As part of the migration from earlier Ansible versions to more recent versions, you need to find and download the collections that include the modules you have been using. Once you find that list of collections, you can use one of the following options to include your collections locally:

When you are migrating from non collection-based content to collection-based content, you should use the Fully Qualified Collection Names (FQCN) in playbooks and roles to avoid unexpected behavior.

Example playbook with FQCN:

- name: get some info
  amazon.aws.ec2_vpc_net_info:
    region: "{{ec2_region}}"
  register: all_the_info
  delegate_to: localhost
  run_once: true

If you are using ansible-core modules and are not calling a module from a different Collection, you should use the FQCN ansible.builtin.copy.

Example module with FQCN:

- name: copy file with owner and permissions
  ansible.builtin.copy:
  src: /srv/myfiles/foo.conf
  dest: /etc/foo.conf
  owner: foo
  group: foo
  mode: '0644'

You will target the aape1.local execution node to run this job, because the underlying hosts already has this in place.

[awx@aape1 ~]$ ls -la /mydata/
total 4
drwxr-xr-x.  2 awx  awx   41 Apr 28 09:27 .
dr-xr-xr-x. 19 root root 258 Apr 11 15:16 ..
-rw-r--r--.  1 awx  awx   33 Apr 11 12:34 file_read
-rw-r--r--.  1 awx  awx    0 Apr 28 09:27 file_write

You will use a simple playbook to launch the automation with sleep defined to allow you access, and to understand the process, as well as demonstrate reading and writing to files.

# vim:ft=ansible:

- hosts: all
  gather_facts: false
  ignore_errors: yes
  vars:
    period: 120
    myfile: /mydata/file
  tasks:
    - name: Collect only selected facts
      ansible.builtin.setup:
        filter:
          - 'ansible_distribution'
          - 'ansible_machine_id'
          - 'ansible_memtotal_mb'
          - 'ansible_memfree_mb'
    - name: "I'm feeling real sleepy..."
      ansible.builtin.wait_for:
        timeout: "{{ period }}"
      delegate_to: localhost
    - ansible.builtin.debug:
        msg: "Isolated paths mounted into execution node: {{ AWX_ISOLATIONS_PATHS }}"
    - name: "Read pre-existing file..."
      ansible.builtin.debug:
        msg: "{{ lookup('file', '{{ myfile }}_read'
    - name: "Write to a new file..."
      ansible.builtin.copy:
        dest: "{{ myfile }}_write"
        content: |
          This is the file I've just written to.

    - name: "Read written out file..."
      ansible.builtin.debug:
        msg: "{{ lookup('file', '{{ myfile }}_write') }}"

From the Ansible Automation Platform 2 navigation panel, select Settings. Then select Job settings from the Jobs option.

Paths to expose isolated jobs:

[
"/mydata:/mydata:rw"
]

The volume mount is mapped with the same name in the container and has read-write capability. This will get used when you launch the job template.

The prompt on launch should be set for extra_vars so you can adjust the sleep duration for each run, The default is 30 seconds.

Once launched, and the wait_for module is invoked for the sleep, you can go onto the execution node and look at what is running.

To verify the run has completed successfully, run this command to get an output of the job:

$ podman exec -it 'podman ps -q' /bin/bash
bash-4.4#

You are now inside the running execution environment container.

Look at the permissions, you will see that awx has become ‘root’, but this is not really root as in the superuser, as you are using rootless Podman, which maps users into a kernel namespace similar to a sandbox. Learn more about How does rootless Podman work? for shadow-utils.

bash-4.4# ls -la /mydata/
Total 4
drwxr-xr-x. 2 root root 41 Apr 28 09:27 .
dr-xr-xr-x. 1 root root 77 Apr 28 09:40 ..
-rw-r—--r–. 1 root root 33 Apr 11 12:34 file_read
-rw-r—--r–. 1 root root  0 Apr 28 09:27 file_write

According to the results, this job failed. In order to understand why, the remaining output needs to be examined.

TASK [Read pre-existing file…]******************************* 10:50:12
ok: [localhost] =>  {
    “Msg”: “This is the file I am reading in.”

TASK {Write to a new file...}********************************* 10:50:12
An exception occurred during task execution. To see the full traceback, use -vvv. The error was: PermissionError: [Errno 13] Permission denied: b'/mydata/.ansible_tmpazyqyqdrfile_write' -> b' /mydata/file_write'
Fatal: [localhost]: FAILED! => {"changed": false, :checksum": "9f576o85d584287a3516ee8b3385cc6f69bf9ce", "msg": "Unable to make b'/root/.ansible/tmp/anisible-tim-1651139412.9808054-40-91081834383738/source' into /mydata/file_write, failed final rename from b'/mydata/.ansible_tmpazyqyqdrfile_write': [Errno 13] Permission denied: b'/mydata/.ansible_tmpazyqyqdrfile_write' -> b'/mydata/file_write}
...ignoring

TASK [Read written out file...] ****************************** 10:50:13
Fatal: [localhost]: FAILED: => {"msg": "An unhandled exception occurred while running the lookup plugin 'file'. Error was a <class 'ansible.errors.AnsibleError;>, original message: could not locate file in lookup: /mydate/file_write. Vould not locate file in lookup: /mydate/file_write"}
...ignoring

The job failed, even though :rw is set, so it should have write capability. The process was able to read the existing file, but not write out. This is due to SELinux protection that requires proper labels to be placed on the volume content mounted into the container. If the label is missing, SELinux may prevent the process from running inside the container. Labels set by the OS are not changed by Podman. See the Podman documentation for more information.

This could be a common misinterpretation. We have set the default to :z, which tells Podman to relabel file objects on shared volumes.

So we can either add :z or leave it off.

Paths to expose isolated jobs:

[
   "/mydata:/mydata"
]

The playbook will now work as expected:

PLAY [all] **************************************************** 11:05:52
TASK [I'm feeling real sleepy. . .] *************************** 11:05:52
ok: [localhost]
TASK [Read pre-existing file...] ****************************** 11:05:57
ok: [localhost] =>  {
	"Msg": "This is the file I'm reading in."
}
TASK [Write to a new file…] ********************************** 11:05:57
ok: [localhost]
TASK [Read written out file…] ******************************** 11:05:58
ok: [localhost] =>  {
      “Msg”: “This is the file I’ve just written to.”

Back on the underlying execution node host, we have the newly written out contents.

Once enabled, this will inject this as volumeMounts and volumes inside the pod spec that will be used for execution. It will look like this:

apiVersion: v1
kind: Pod
Spec:
   containers:
   - image: registry.redhat.io/ansible-automation-platform-24/ee-minimal-rhel8
  args:
    - ansible runner
    - worker
    - –private-data-dir=/runner
  volumeMounts:
mountPath: /mnt2
name: volume-0
readOnly: true
mountPath: /mnt3
name: volume-1
readOnly: true
mountPath: /mnt4
name: volume-2
readOnly: true
volumes:
hostPath:
  path: /mnt2
  type: “”
name: volume-0
hostPath:
  path: /mnt3
  type: “”
name: volume-1
hostPath:
  path: /mnt4
  type: “”
name: volume-2

Storage inside the running container is using the overlay file system. Any modifications inside the running container are destroyed after the job completes, much like a tmpfs being unmounted.