Update example containers to fix security vulnerabilities

[roberthbailey]

While working on #1126 and verifying that the new images were successfully uploaded, I noticed that many of our images have vulnerabilities that are identified by Google's automated image analysis.

Most of the vulnerabilites are probably just because we are using older dependencies in the base image layers (e.g. linux distro with outdated glibc) and should be easy to fix by going through the Dockerfiles and updating them to pick up patches.

[aLekSer]

Have enabled containers security analysis, now I am able to see them. Useful links to enable this feature:
https://cloud.google.com/container-registry/docs/enabling-disabling-container-analysis
https://cloud.google.com/container-registry/docs/get-image-vulnerabilities
Main 4 images agones-controller, agones-sdk, agones-ping and agones-allocator does not have any security vulnerabilities.
However build image has, most of them should be fixed by using buster Debian release instead of stretch.

[markmandel]

Just looking through the examples - with the exclusion of the Unity sample (which requires a Unity licence to update, which requires so work to get 😄 ) everything else looks relatively up to date.

I'm figuring we close this, and if need be open a specific ticket to update the Unity example ?

[roberthbailey]

I'm figuring we close this, and if need be open a specific ticket to update the Unity example?

sounds good to me.

[markmandel]

Looks like we marked this stale in July 😄 - going close it, since there is no objections.