Unable to generate different spring-cloud-gateway routes based on active Spring profile - spring-boot

Question

I'm trying to define different routes in Spring Cloud Gateway using Spring profiles. Everything I've read about how Spring manages profiles using yaml sems to indicate it should work, but for the life of me it just ... doesn't seem to. (My other Spring apps use properties, so I'm unused to the yaml config -- it's possible I'm missing something.)
Effectively what I'm trying to do is to have a "prod" profile which contains the URIs for my production servers, and a "dev" profile which contains the localhost equivalents.
I have two profiles, dev and prod. My application.yml file looks like this
spring:
profiles:
default: prod
management:
endpoint:
health:
enabled: true
endpoints:
web:
exposure:
include: hystrix.stream, gateway
---
spring
profiles: prod
cloud:
gateway:
routes:
- id: test_route
uri: http://foo.mycompany.com
predicates:
- Path=/status
- Method=GET
---
spring
profiles: dev
cloud:
gateway:
routes:
- id: test_route
uri: http://localhost:8080
predicates:
- Path=/status
- Method=GET
My understanding is as follows:
the spring.profiles.default property tells Spring that, if no profile is specified, to use the prod profile
Spring will treat the --- as a "file separator" and re-evaluate each set of properties and overwrite previous values if the spring.profiles parameter evaluates true
Given this understanding, I would expect Spring to parse the "default" properties first, learning that the default activated profile should be prod. Then it will parse the prod properties. Since "prod" is an active profile (the only active profile, being the default), it should parse and apply the prod routes. Then it would parse the dev routes, but recognize that dev is not an active profile, and not overwrite those values. This is my understanding from reading the documentation on how to change config based on the environment.
However, when I load this, and I hit the actuator endpoint -- /actuator/gateway/routes -- I get back [] where I would expect to see the prod routes. I do see in my logs that the prod profile is activated, but it seems like not having the properties in the "default" section at top causes them to not be applied when the parser reads them out of the profile section.
The other thing I tried was putting the "dev" properties as the defaults, and then attempting to use the "prod" profile properties to overwrite the URIs. A similar issue happened there -- I hit the actuator endpoint and got back routes, but they were just the dev ones from the default.
How can I leverage Spring profiles to configure different Spring Cloud Config routes in my application.yml ?
Versions:
spring-cloud-gateway 2.0.1.BUILD-SNAPSHOT (to get a workaround for this bug, probably not relevant)
spring-cloud-starter-gateway
spring-boot 2.0.3.RELEASE
spring-boot-starter-webflux
spring-boot-starter-actuator
(I can't use Spring Cloud Config for political reasons. My company's chief architect has a severe case of Not Invented Here Syndrome.)

Answer 1

You cannot use spring.profiles.default in the property file. It will be too late for setting such value.
So you can set it using program argument (or System property). E.g.
java -jar --spring.profiles.default=dev your-app.jar
Or you can do it in the code by hardcoding the default profile:
#SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication application = new SpringApplication(DemoApplication.class);
ConfigurableEnvironment environment = new StandardEnvironment();
environment.setDefaultProfiles("dev");
application.setEnvironment(environment);
application.run(args);
}
}
Some related information you can find here by reading all comments:
https://github.com/spring-projects/spring-boot/issues/1219