Grabbing all *el7* packages from Ansible Package facts

We are doing an In-Place Upgrade from RHEL 7 to RHEL 8 in my organization and we've come to find out that not all RHEL 7 packages are removed after an OS Upgrade. I've been asked to report on all RHEL 7 packages leftover on the device. To start I've looked into Ansible Package facts which has a variable that looks something like:

'ansible_facts.packages:{
zlib: [
    {
        "arch": "x86_64",
        "epoch": null,
        "release": "11.el7",
        "source": "rpm",
        "version": "1.2.7"
    },
    {
        "arch": "x86_64",
        "epoch": null,
        "release": "10.el7",
        "source": "rpm",
        "version": "1.2.6"
    },
    {
        "arch": "x86_64",
        "epoch": null,
        "release": "10.el8",
        "source": "rpm",
        "version": "1.2.7"
    }
]
}
    

This occurs for a handful of packages, what I would like to do is to run a json_query against the entire dictionary of package_facts and determine what "el7" packages live on the host. That can tell me what I want to remove. Are there any suggestions on the json_query to run in order to find all packages that have an 'el7' in the release key?

Here's what I've tried so far:

vars:
  example_query1: "[?contains(release, 'el7')]"
  example_query2: "[?release == '*el7*']"
tasks:
  new_package_list: "{{ ansible_facts.packages | json_query(example_query) | list }}"

A quick (and dirty) variant with Ansible and Jinja2 filter techniques is as follows:

- name: Grab all packages with el7 releases
  set_fact:
    el7_packages: "{{ el7_packages | default({}) | combine(new_item | items2dict) }}"
  with_dict: "{{ ansible_facts.packages }}"
  loop_control:
    label: "{{ item.key }}"
  vars:
    el7_releases: "{{ item.value | map(attribute='release') | select('search', 'el7') }}"
    new_item:
      - key: "{{ item.key }}"
        value: "{{ el7_releases }}"
  when: el7_releases | list | length

- name: Print found el7 packages
  debug:
    var: el7_packages

1. you iterate over each entry of the dict
   with_dict: "{{ ansible_facts.packages }}"

2. you reduce the list of dicts to the release value and then filter the list by el7
el7_releases: "{{ item.value | map(attribute='release') | select('search', 'el7') }}"

3. only if a release with el7 exists, the package with its el7 releases is saved in the target dict el7_packages

   • Condition to ensure the list is not empty (means el7 release exists)
     when: el7_releases | list | length
   • Add new_item to target dict
     set_fact with el7_packages: "{{ el7_packages | default({}) | combine(new_item | items2dict) }}"

4. the result is a dict, the keys are the package names, the values are lists of release strings containing el7

Notes:

• loop_control with label is only for cosmetics in the terminal
• the new entry (new_item) is prepared as an array and converted into a dict via items2dict before combining

Result:

TASK [Grab all packages with el7 releases] *********************
ok: [localhost] => (item=zlib)
ok: [localhost] => (item=other_pkg)
skipping: [localhost] => (item=an_other_tool)

TASK [Print found el7 packages] ********************************
ok: [localhost] => {
    "el7_packages": {
        "other_pkg": [
            "11.el7"
        ],
        "zlib": [
            "11.el7",
            "10.el7"
        ]
    }
}

---

Edit:

To get the whole dict as a result, instead of just the release string, only a minimal change of the variable assignment for el7_releases is required:

el7_releases: "{{ item.value | selectattr('release', 'search', 'el7') }}"

Code:

- name: Grab all packages with el7 releases
  set_fact:
    el7_packages: "{{ el7_packages | default({}) | combine(new_item | items2dict) }}"
  with_dict: "{{ ansible_facts.packages }}"
  loop_control:
    label: "{{ item.key }}"
  vars:
    el7_releases: "{{ item.value | selectattr('release', 'search', 'el7') }}"
    new_item:
      - key: "{{ item.key }}"
        value: "{{ el7_releases }}"
  when: el7_releases | list | length

- name: Print found el7 packages
  debug:
    var: el7_packages

Reslut:

TASK [Grab all packages with el7 releases] ****************************
ok: [localhost] => (item=zlib)
ok: [localhost] => (item=other_pkg)
skipping: [localhost] => (item=an_other_tool)

TASK [Print found el7 packages] ***************************************
ok: [localhost] => {
    "el7_packages": {
        "other_pkg": [
            {
                "arch": "x86_64",
                "epoch": null,
                "release": "11.el7",
                "source": "rpm",
                "version": "1.2.7"
            }
        ],
        "zlib": [
            {
                "arch": "x86_64",
                "epoch": null,
                "release": "11.el7",
                "source": "rpm",
                "version": "1.2.7"
            },
            {
                "arch": "x86_64",
                "epoch": null,
                "release": "10.el7",
                "source": "rpm",
                "version": "1.2.6"
            }
        ]
    }
}

---

example input data:

packages:
  zlib:
    - arch: "x86_64"
      epoch: null
      release: "11.el7"
      source: "rpm"
      version: "1.2.7"

    - arch: "x86_64"
      epoch: null
      release: "10.el7"
      source: "rpm"
      version: "1.2.6"

    - arch: "x86_64"
      epoch: null
      release: "10.el8"
      source: "rpm"
      version: "1.2.7"

  other_pkg:
    - arch: "x86_64"
      epoch: null
      release: "11.el7"
      source: "rpm"
      version: "1.2.7"

    - arch: "x86_64"
      epoch: null
      release: "10.el8"
      source: "rpm"
      version: "1.2.7"

  an_other_tool:
    - arch: "x86_64"
      epoch: null
      release: "10.el8"
      source: "rpm"
      version: "1.2.7"