Jason Lo's questions

I am working on packing an application using charmcarft tool. The application, named Concourse CI is running in a docker-composed way. After reading quite a few documents online, I guess I can use the subordinate charm-docker to complete my job. I have followed the hello-operator tutorial to come out with a template for my principal charm. But I still have hard time to bring things together. There are 2 main questions:

1. To charcraft build my docker-compose application, what need to be verified in meta.yaml, config.yaml, and charm.py? I need an example but I can hardly got one.

2. How to connect principal charm with subordinate charm when deploying the application using juju?

When installing davfs2 on Ubuntu bionic, I have got the following errors:

Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: davfs2 : Depends: libneon27 but it is not going to be installed

E: Unable to correct problems, you have held broken packages.

Then I have to install previous version of libneon27 first to make it right.

sudo apt install libneon27=0.30.2-2build1