Installing a package may create a user but not update the fact

[link2xt]

Describe the bug

Operation server.user depends on the facts about the user to choose between using useradd and usermod. If the facts about users say that user does not exist, but in fact the user exists, pyinfra effectively does nothing.

To Reproduce

Create the following deploy.py file:

from pyinfra.operations import apt, server

apt.packages(name="Install postfix", packages=["postfix"], update=True)
server.group(name="Create group foo", group="foo", system=True)
server.user(
    name="Add user postfix to group foo", user="postfix", group="foo", system=True
)

Run pyinfra -vvvv --ssh-user root example.org deploy.py, where example.org is a freshly installed Ubuntu 22.04 VM.

Expected behavior

I expect that postfix package is installed and then pyinfra adds the user postfix to the group foo.
Instead, pyinfra does not add the user to the group, but checks that user exists and does not execute useradd.

--> Starting operation: Add user postfix to group foo 
[example.org] >>> sh -c 'grep '"'"'^postfix:'"'"' /etc/passwd || useradd -d /home/postfix -g foo -r postfix'
[example.org] postfix:x:114:120::/var/spool/postfix:/usr/sbin/nologin
[example.org] >>> sh -c 'mkdir -p /home/postfix'
[example.org] >>> sh -c 'chown postfix:foo /home/postfix'
[example.org] Success

It should instead run usermod.

The solution would be to fix apt to update the facts about the users to include the information about the user postfix added by the post-install script.

[link2xt]

My current workaround for this is creating all the groups and users at the beginning of the deploy, but this may not be possible in a structured deploy with functions calling each other.

[Fizzadar]

Another unfortunate example of operation side effects impacting each other (#805), I am working on a new approach that may resolve these once and for all 🤞!

[Fizzadar]

v3 fixes this, now that the first beta is out I’ll close this issue.