No package matching 'python3-pip' is available - fails on dtr

[samsysdig]

It's strange that it succeeds on all the nodes except dtr1. Ran it a few times same issue.

I logged into dtr manually and had to apt-get update first then apt-get install python3-pip. Then all ran perfectly.

Running apt-get install python3-pip before updating gave the following error:

ubuntu@dtr1:~$ sudo apt-get install python3-pip
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package python3-pip is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'python3-pip' has no installation candidate

I saw this fix here:
leesoh/ansible-role-pipenv#2

I believe the issue is in here:
demokit/roles/docker_py/tasks/main.yml
and need to add update_cache to "Install packages" to fix