Deployment issue on Heroku : zuul + eureka + microservices - spring

Question

Thanks for taking the time to read my post.
My issue is as such. I have 2 microservices (auth-service and image-service) deployed on Heroku, as well as a server Eureka and a gateway Zuul.
In local, all of this works.
However, when deployed, the same calls give me 404 errors : for example :
zuul is deployed on port 8762 in local,
so http://localhost:8762/images/user/create works, it points to http://localhost:8200/user/create of the image-service.
Deployed, https://croquis-time-image.herokuapp.com/user/create works, but https://croquis-time-zuul.herokuapp.com/images/user/create throws a 404 error.
On eureka however, all my services are registered, so the trouble doesn't come from there. I thought perhaps zuul didn't manage to get all the services from Eureka, but I'm not sure how to check.
More information :
application.yml of zuul deployed :
server:
port: 8762
eureka:
client:
serviceUrl:
defaultZone: https://croquis-time-eureka.herokuapp.com/eureka/
instance:
hostName: croquis-time-eureka.herokuapp.com
zuul:
#Service will be mapped under the /api URI
prefix: /api
# Uncomment to disable auto-registering all services read from Eureka
# ignoredServices: '*'
routes:
image-service:
path: /images/**
serviceId: image-service
auth-service:
path: /auth/**
serviceId: auth-service
stripPrefix: false
sensitiveHeaders: Cookie,Set-Cookie
spring:
application:
name: zuul-server
security:
jwt:
uri: /auth/**
prefix: Bearer
expiration: 86400
header: Authorization
secret: *****************
The application.yml of eureka deployed
server:
port: 8761
eureka:
instance:
hostname: croquis-time-eureka.herokuapp.com
client:
registerWithEureka: false
fetchRegistry: false
serviceUrl:
defaultZone: https://croquis-time-eureka.herokuapp.com/eureka/
spring:
application:
name: eureka-server
The image service I'm trying to call :
server:
port: 8200
eureka:
client:
serviceUrl:
defaultZone: https://croquis-time-eureka.herokuapp.com/eureka/
instance:
hostName: croquis-time-eureka.herokuapp.com
spring:
application:
name: image-service
jpa:
showSql: true
hibernate:
ddlAuto: update
datasource:
url: jdbc:mysql://***********:3306/croquis-time
username: ******************
password: ****************
I have tried removing and adding the "ignored-services" from zuul to see if that was the problem, but it didn't change anything.
I'm very willing to edit my question with more information if you require more, I'm not sure where is the origin of the problem, so I'm a bit at a loss as to what to add.
Thanks !

Answer 1

you have an issue with the configuration of .yml in zuul server
Your .yml of zuul server must be:
instance:
hostName: croquis-time-zuul.herokuapp.com
And your .yml of image must be:
instance:
hostName: croquis-time-image.herokuapp.com
because instance.hostname is the host of your application acting as the eureka client. if you need more information please visit: https://blog.heroku.com/managing_your_microservices_on_heroku_with_netflix_s_eureka