Yum comand also list all the installed packages on your system like below. If you want to get a list of packages installed from a particular repository, rpm cannot help you. The rpm command does not provides the notion of repository.

Following command queries all installed packages on your system. Using RPM command, it is easiest way to list all installed packages on CentOS or RHEL via this command. In this article I will provide you four method to list all installed packages on CentOS or RHEL system. In different circumstances, you may simply need to know what packages has been installed on server from a specific third party repository Likewise when you are trying to relocate your old Linux server to a newly introduced fresh OS release, you have to monitor already installed packages list. Jsonquery: 'results.When you need to make another server which has the very same set up as any current server X, you have to discover what bundles or packages have been introduced on server X. You can then use a JSON Query Filter to get a single package ( tar): - debug: var=item It saves a list of dictionaries describing each package to a variable yum_packages. To get a list of installed packages, you should use: - name: yum_command Regarding your example, which does not give you results - you have repeated twice the same argument list and the task should fail (it doesn't, which looks like an Ansible quirk). No matter what you do, what method you use, the term 'idempotent' is just not applicable. When you query current state, you don't describe the desired state. 'Idempontent' means that the task will ensure the machine is in the desired state no matter how many times you run a certain task. You can't really talk about idempotence, when you are querying the current state of a machine. I can easily get it through using shell commands which is not idempotent

Yum list installed