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##### SUMMARY
If you don't have an ssh client installed in container image or on your system, ansible just throws following error -  `The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'` error. 

```
TASK [Gathering Facts] *********************************************************
[WARNING]: Unhandled error in Python interpreter discovery for host <hostname1>: [Errno 2] No such file or directory: b'ssh': b'ssh'

[WARNING]: Unhandled error in Python interpreter discovery for host <hostname2>: [Errno 2] No such file or directory: b'ssh': b'ssh'

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname1>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname2>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.6
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
Run playbook on the system where ssh client is not installed & playbook is expecting to use ssh keys for remote hosts.


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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
If possible adding an error message indicating `ssh client is not installed on the system`

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Error message mentioned in the summary 
The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
```

Thank you!!
For example, when using sudo operations you must first disable 'requiretty' in the sudoers file for the target hosts,
              which is why this feature is disabled by default.
          env:
            - name: ANSIBLE_PIPELINING
            - name: ANSIBLE_SSH_PIPELINING
          ini:
            - section: defaults
              key: pipelining
            - section: ssh_connection
              key: pipelining
          type: boolean
          vars:
            - name: ansible_pipelining
            - name: ansible_ssh_pipelining
      private_key_file:
          description:
              - Path to private key file to use for authentication
          ini:
            - section: defaults
              key: private_key_file
          env:
            - name: ANSIBLE_PRIVATE_KEY_FILE
          vars:
            - name: ansible_private_key_file
            - name: ansible_ssh_private_key_file
      control_path:
        description:
          - This is the location to save ssh's ControlPath sockets, it uses ssh's variable substitution.
          - Since 2.3, if null, ansible will generate a unique hash. Use `%(directory)s` to indicate where to use the control dir path setting.
        env: