I am working on a project with a couple of micro-services(spring boot multi-module project).
I have a api-gateway microservice and it has the below setting for security which uses keycloak

spring:
  application:
    name: api-gateway
  security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: http://keycloak:8080/realms/my-realm

I have dockerized (docker-compose.yml) the whole project and below are the code samples for the api-gateway and keycloak

services:
  keycloak:
    container_name: keycloak
    image: quay.io/keycloak/keycloak:21.1
    command:
      - start-dev
    env_file:
      - app/dev/keycloak.dev.env
    ports:
      - "8890:8080"
    depends_on:
      postgres:
        condition: service_healthy
    networks:
      - keycloak-network
  apigw:
    container_name: apigw
    image: ssomlk/api-gateway:latest
    ports:
      - "8081:8081"
    environment:
      - SPRING_PROFILES_ACTIVE=docker
    networks:
      - keycloak-network
networks:
  keycloak-network:
    driver: bridge

I have created a realm, a client with service user roles activated in keycloak.

When I spin up the containers (apigw and keycloak) there are no errors. I use postman to invoke an endpoint. For authorization in postman I use the grant type ‘Client Credentials’ and client id and the client secret created.

Access token url looks something like below

http://localhost:8890/realms/my-realm/protocol/openid-connect/token

I get the token and when I invoke the end point (token attached) localhost:8081/api/monks/1
I get the 401 unauthorized error

Bearer error="invalid_token", error_description="The iss claim is not valid", error_uri="https://tools.ietf.org/html/rfc6750#section-3.1"

I think the error is due to the mismatch of iss because my access token url sent via postman is different to issuer-uri

access token url -> http://localhost:8890/realms/project-sri-kalyani-yogashrama/protocol/openid-connect/token
issuer-uri -> http://keycloak:8080/realms/my-realm

I have run the implementation by just running via IDE (IntelliJ IDEA) and this works. But the problem is when I containerize them only.

Could someone help me please?