What runs
The four containers on the VM, and what each one is reachable from. Click to enlarge.
Ports and trust zones
Four zones, and which one a service is in is the whole of its network exposure.
Canvas is an operator tool, not a public page. It is not on the load balancer. You reach
it directly, from the address you nominated, in the same trust ring as SSH and the log
viewer. It then talks to the platform over the public surface like any other client.
Two of those are worth reading carefully.
4104 and 5001 are published on the VM
rather than bound to loopback, so what keeps them private is the cloud firewallβs
default-deny, not the way the container is configured. That is a real control and it is
enforced in your cloud account, but it is one layer rather than two. Binding them to the
Docker network is tracked work.
The gate is in the application, not in the proxy. That matters when a review asks what
happens if the load balancer is misconfigured: the answer is that requests still fail
authentication, because nothing about the proxy is load bearing.
Your code and the platform stay separate
The platform runs on the VM as Docker images, pulled from the registry by tag. You never fork it, and it never writes to your folders.
Nothing you author rides inside an image. An image carries code and only code, which is why
a platform upgrade cannot disturb your content and a content change cannot require a
deployment.

