Adopt the lab central config server (config client) + set environment=testing

[alexmond]

What

Move this app's runtime configuration out of the image/chart into the lab's central
Spring Cloud Config Server — i.e. make the app a config client — and set its
active environment/profile to testing.

Why

• One place to retune every lab Boot app; no rebuild/redeploy to change a value on a
  running service (config re-pulls via POST /actuator/refresh).
• Consistent with the other lab services, which already source their config centrally.
• Marking the environment testing groups the instance correctly in the ops console and
  lets the server serve environment-specific overlays.

Done when

• spring-cloud-starter-config on the classpath; the app boots as a config client via
  spring.config.import=optional:configserver:<server>. Resolve the server's in-cluster
  address by its service name / an injected env var — don't hardcode a hostname.
• Active profile/environment is testing (e.g. SPRING_PROFILES_ACTIVE=testing) so the
  server serves <app-name>-testing and the instance reports its environment as testing.
• App config lives in the central config repo as <app-name>.yml (+ an
  <app-name>-testing.yml overlay). Secrets do NOT go in the config repo — keep them
  in the app's own k8s Secret and inject via env (same split the other services use).
• GET /actuator/env shows a configserver:<app-name>.yml property source — proves the
  client is pulling from the server.

Discovery / notes

• The config server already runs in the cluster; find its coordinates via service discovery
  or the platform team rather than pinning a host here.
• Keep spring.config.import prefixed optional: so local runs and a brief server outage
  don't block startup.

[alexmond]

Two corrections/additions to this issue — verified working on the other lab services before posting:

Correction: "environment = testing" was ambiguous (two different "environments")

The original checklist implied SPRING_PROFILES_ACTIVE=testing makes the ops console show the
instance's environment. It doesn't — those are two separate things:

• Spring profile (SPRING_PROFILES_ACTIVE=testing): only selects which config the server
  serves (the <app>-testing.yml overlay). Keep it if you want that overlay — but it has no
  effect on what the console displays as the environment.

• The environment the console shows comes from an info tag read off /actuator/info.
  You need BOTH of these:

  management:
    info:
      env:
        enabled: true          # default is FALSE since Boot 2.6 — without it, info.* is
                               # silently dropped from /actuator/info (this is the easy miss)
  info:
    tags:
      environment: ${INFO_TAGS_ENVIRONMENT:testing}

So: info.tags.environment + management.info.env.enabled: true is what surfaces the
environment in the console. management.info.env.enabled being off by default is exactly why an
info.tags.* value won't show up until you enable it.

Please expose full /actuator/info, including build info

Add the Spring Boot build-info goal so /actuator/info also carries build.version /
build.time / artifact coordinates (the console's Info tab uses these):

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <executions>
    <execution><goals><goal>build-info</goal></goals></execution>
  </executions>
</plugin>

Done when GET /actuator/info returns both a build section and tags.environment, and
info is in management.endpoints.web.exposure.include (you likely already expose health/info).