Add the ability to import filters

[mattrobenolt]

Fixes #85

[braindevices]

I like this one a lot. Why is is not merged?

[mattrobenolt]

I think it was just waiting on some outside confirmation. Wanna try it out? :)

[jjsp556]

I think it was just waiting on some outside confirmation. Wanna try it out? :)

I've been testing out this update, and it works as expected. I successfully tested both single and multiple filters (e.g. jinja2 -f myfilter.myfunction -f ansible.plugins.filter.core.combine test.txt).

[velle]

I hope you will merge this, since I really need this feature :)
I looked through the code, and its very simple and elegant, and its hard for me to see how anything could go wrong.
Sincerely.

[tierpod]

Is there any chance to see this PR merged into main branch? It can drastically extend jina2-cli capabilities.

I tested this patch and it works fine. For example, we have hostname and want to add ip address in rendered config file, so it can be one simple filter (filters/ip.py):

import socket

def get_ip(hostname):
    return socket.gethostbyname(hostname)

and in template it can be

{{ hostname }}: {{ hostname | get_ip }}

jinja2 -f filters.ip.get_ip test.j2 test.yaml

[sfc-gh-turbaszek]

@mattrobenolt any chances to merge this change?