# pf9-hostagent Failing With Error "No module named 'apt\_pkg'"

## Problem

The host is disconnected from Management Plane and `pf9-hostagent` service is failing and `hostagent-daemon.log` shows error `No module named 'apt_pkg'`

{% tabs %}
{% tab title="hostagent-daemon.log" %}

```javascript
customlogger.py INFO - from pf9app.pf9_app_db import Pf9AppDb as AppDb, Pf9AgentDb
customlogger.py INFO -   File "/opt/pf9/hostagent/lib/python3.9/site-packages/pf9app/pf9_app_db.py", line 21, in <module>

customlogger.py INFO - import apt
customlogger.py INFO -   File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>

customlogger.py INFO - import apt_pkg
customlogger.py INFO - ModuleNotFoundError
customlogger.py INFO - :
customlogger.py INFO - No module named 'apt_pkg'
```

{% endtab %}
{% endtabs %}

## Environment

* pf9-hostagent
* Python3

## Cause

When a newer python version is installed the link will update to point to the newest python version, which leads to the error of `apt_pkg` module not being found.

## Resolution

* Make sure package `python3-apt` is installed on the host.
* Fix the python symblink:

{% tabs %}
{% tab title="command" %}

```javascript
# cd /usr/lib/python3/dist-packages
# ln -s apt_pkg.cpython-35m-x86_64-linux-gnu.so apt_pkg.so
# ln -s apt_inst.cpython-35m-x86_64-linux-gnu.so  apt_inst.so
```

{% endtab %}
{% endtabs %}

* Restart `pf9-hostagent` service:

{% tabs %}
{% tab title="command" %}

```javascript
# systemctl restart pf9-hostagent
```

{% endtab %}
{% endtabs %}