docker - jetty - idp

[Jim Fox]

I've had to wait a few days for my dev system's tomcat upgrade before I 
can finish upgrading to 4.0.  However, working from home I've also had more quiet time.
I've long wanted to learn something about Docker.  And Scott says anyone who's anyone runs the IdP with 
Jetty, so I thought I might as well learn something about Jetty too.

Turns out there's a somewhat 'official' Docker jetty image.  That made things easier.

To cut to the chase, I installed my upgraded but untested 4.0 installation as a 
jetty module. It was not much more difficult than my starting out Hello World 
module.  Basically you push the idp installation into the container, 
tell Jetty where your war file is, add some other info, and run the 
container.

The (localhost)/idp/status endpoint showed:  (this is on my MacBook)

### Operating Environment Information
operating_system: Linux
operating_system_version: 4.19.76-linuxkit
operating_system_architecture: amd64
jdk_version: 13.0.2
available_cores: 2
used_memory: 121 MB
maximum_memory: 498 MB
... and etc ...

And, the aacli endpoint resolved attributes for me from our production 
LDAP and group service.  Right out of the box!

I'm very pleased with the experiment. There are some unresolved issues: I had 
to take out my OIDC configuration (after a 2.0 upgrade).  And it wasn't 
accepting my local metadata file.  And my attempt at a real login failed due to no Kerberos. 
That last one will take some thought.

Will definitely revisit this container thing.

Jim