Since ansible 2.5 there is an option update_only for yum (and since ansible 2.1 only_upgrade for apt) which installs latest version only if it was already installed on the system. So, instead of collecting a list of packages in another task, you can add the option.

- name: Update subset of packages.
  yum:
    name: "{{ item }}"
    state: latest
    update_only: yes
  with_items:
    - package1
    - package2

I am myself was searching the web and this article was found before I got to the official documentation. So I think it worse to be added here.

I don't think the yum module would help in this case. It currently has 3 states: absent, present, and latest. Since it sounds like you don't want to actually install or remove the package (at least at this point) then you would need to do this in two manual steps. The first task would check to see if the package exists, then the second task would invoke a command based on the output of the first command.

If you use "rpm -q" to check if a package exists then the output would look like this for a package that exists:

# rpm -q httpd
httpd-2.2.15-15.el6.centos.1.x86_64

and like this if the package doesn't exist:

# rpm -q httpdfoo
package httpdfoo is not installed

So your ansible tasks would look something like this:

- name: Check if foo.rpm is installed
  command: rpm -q foo.rpm
  register: rpm_check

- name: Execute script if foo.rpm is not installed
  command: somescript
  when: rpm_check.stdout.find('is not installed') != -1

The rpm command will also exit with a 0 if the package exists, or a 1 if the package isn't found, so another possibility is to use:

when: rpm_check.rc == 1

Just do a search first, and only install if it returns any results:

- hosts: host
  tasks:
    - name: Search for package
      yum:
        list: <package_name>
      register: package_list

    - name: Install package
      yum:
        name: <package_name>
        state: present
      become: yes
      when: 'package_list.results | length != 0'

replace <package_name> with the package you are interested in.

Here is an alternative with failed_when, but it's quite hacky as it relies on the message returned by yum to match:

- hosts: host
  tasks:
    - name: Install package
      yum:
        name: <package_name>
        state: present
      register: result
      become: yes
      failed_when: '(result.msg | regex_replace("No package matching .* found available, installed or updated","")) != ""'

Ansible is idempotent. You can run yum module as many times as you want. If there is nothing to install that task will end with changed=false status and packages will not be re-installed.

I suspect your issue is related to the difference in state: present vs state: latest.

It looks like the yum module with state: present checks the rpmdb to see if the pkg exists and does nothing further.

Since your manual install seems to indicate you have some addition dependencies or updates related to your package, try running with state: latest which internally will run a yum check-update and see if this pulls those files in.