Mapping properties with hyphen to environment variables

[edeandrea]

How do I map properties containing a hyphen into an environment variable? I've read through the MicroProfile Config environment variable mapping rules and can't seem to figure out how to map a property containing a hyphen correctly to an environment variable.

I have an application that uses the MicroProfile REST client and am trying to create a docker compose file for that. The docker compose needs to override the URL property via an environment variable.

The property in question is quarkus.rest-client.hero-client.url.

I've tried QUARKUS_REST-CLIENT_HERO-CLIENT_URL, QUARKUS_RESTCLIENT_HEROCLIENT_URL, and QUARKUS_REST_CLIENT_HERO_CLIENT_URL and none of those work.

The only thing I've been able to get to work is this

environment:
  QUARKUS_DATASOURCE_REACTIVE_URL: postgresql://fights-db:5432/fights_database
  KAFKA_BOOTSTRAP_SERVERS: PLAINTEXT://fights-kafka:9092
  quarkus.rest-client.hero-client.url: http://rest-heroes-java11:8083

[maxandersen]

I think your solution is right as that works for #1 rule about exact match in the microprofile docs.

using the - to _ rule works one way but is lossy the other. I don't think there is another way here.

@radcortez any suggestions ?

[edeandrea]

Is having a . in an environment variable portable though across OS'es?

[radcortez]

Yes, the issue with the - (or other chars) in env variables is that they cannot be fully represented. We have a few tricks, like for instance quotes can be represented with a double underscore.

In this situation, we don't know where to map QUARKUS_REST_CLIENT_HERO_CLIENT_URL (there are multiple candidates):

• quarkus.rest-client.hero-client.url
• quarkus.rest.client.hero.client.url
• quarkus.rest.client.hero-client.url
• quarkus.rest-client.hero.client.url

So we added another trick (if I remember correctly), which is if you add the dotted version of the property (quarkus.rest-client.hero-client.url) in application.properties or any other source for that matter, then we "guess" that QUARKUS_REST_CLIENT_HERO_CLIENT_URL must map into quarkus.rest-client.hero-client.url because you want to override it.

[radcortez]

Thanks. I'll be off till next week, but I'll try to have a look asap.

[edeandrea]

Don't work while on PTO. It can wait until next week. Its working the way I have it (using the lower-case & . notation).

[radcortez]

Hi @edeandrea,

I've tried to reproduce the problem, but I was not able to do it. It seems to work for me. This is what I did:

• Run the REST Fights app

  • Start the infra: docker compose -f docker-compose.infra.yml up -d
  • Start the app: docker compose -f docker-compose.app-jvm11.yml up
  • Call endpoint: curl http://localhost:8082/api/fights/randomfighter
  • Get fallbacks: {"hero":{"name":"Fallback hero","level":1,"picture":"https://dummyimage.com/280x380/1e8fff/ffffff&text=Fallback+Hero","powers":"Fallback hero powers"},"villain":{"name":"Fallback villain","level":45,"picture":"https://dummyimage.com/280x380/b22222/ffffff&text=Fallback+Villain","powers":"Fallback villain powers"}}

• Start REST Heroes app

  • Start the infra: docker compose -f docker-compose.infra.yml up -d (had to change the file to map to a different external database port to not conflict with the REST Fight app)
  • Start the app: docker compose -f docker-compose.app-jvm11.yml up

• Back to REST Fights app

  • Call endpoint: `curl http://localhost:8082/api/fights/randomfighter
  • Get a propert hero: {"hero":{"name":"Genesis","level":8,"picture":"https://www.superherodb.com/pictures2/portraits/10/050/1055.jpg","powers":"Energy Absorption, Energy Constructs, Illusions, Intelligence, Intuitive aptitude, Power Suit, Projection, Psionic Powers, Telepathy, Weapon-based Powers, Weapons Master"},"villain":{"name":"Fallback villain","level":45,"picture":"https://dummyimage.com/280x380/b22222/ffffff&text=Fallback+Villain","powers":"Fallback villain powers"}

• Change to the ENV variable format

  • QUARKUS_REST_CLIENT_HERO_CLIENT_URL: http://rest-heroes-java11:8083
  • Call endpoint: `curl http://localhost:8082/api/fights/randomfighter
  • Get hero still works: {"hero":{"name":"Elastigirl","level":7,"picture":"https://www.superherodb.com/pictures2/portraits/10/050/870.jpg","powers":"Agility, Durability, Elasticity, Invulnerability, Shapeshifting, Size Changing, Super Strength"},"villain":{"name":"Fallback villain","level":45,"picture":"https://dummyimage.com/280x380/b22222/ffffff&text=Fallback+Villain","powers":"Fallback villain powers"}}

• Change the ENV variable to something else

  • QUARKUS_REST_CLIENT_HERO_CLIENT_URL: http://localhost:8080
  • Call endpoint: `curl http://localhost:8082/api/fights/randomfighter
  • Get fallbacks: {"hero":{"name":"Fallback hero","level":1,"picture":"https://dummyimage.com/280x380/1e8fff/ffffff&text=Fallback+Hero","powers":"Fallback hero powers"},"villain":{"name":"Fallback villain","level":45,"picture":"https://dummyimage.com/280x380/b22222/ffffff&text=Fallback+Villain","powers":"Fallback villain powers"}}

So, for me it seems to be working because after I've changed the env var to QUARKUS_REST_CLIENT_HERO_CLIENT_URL I still got a proper hero, and once I've changed it to an url that does not have a service running, I got the fallbacks.

Are you able to confirm this behaviour?

[edeandrea]

Thank you for taking a look. I must have been doing something dumb as now I cannot reproduce it either.

DId anything change between Quarkus 2.5.1 & 2.5.2 (I upgraded all of this to 2.5.2 yesterday morning)?

FYI - in the future if you'd like to use this demo, you don't need to change ports of databases. If you want to start fights & all downstream services you can just run

docker-compose \
  -f rest-fights/infrastructure/docker-compose.infra.yml \
  -f rest-fights/infrastructure/docker-compose.infra.downstream.yml \
  -f rest-fights/infrastructure/docker-compose.app-jvm11.yml \
  -f rest-villains/infrastructure/docker-compose.app-jvm11.yml \
  -f rest-heroes/infrastructure/docker-compose.app-jvm11.yml \
  up --remove-orphans

In the future I'll most likely put some automation in place to create a single docker-compose.yaml for this.

[radcortez]

DId anything change between Quarkus 2.5.1 & 2.5.2 (I upgraded all of this to 2.5.2 yesterday morning)?

Not that I'm aware. Should we revert and try with 2.5.1? :)