Config Server – Configuration Fetch Process

Overview

In adventuretube-microservice, application services (auth-service, member-service, gateway-service, etc.) fetch their configuration from config-server at startup. This document explains how this process works.

---

Why Config Server?

• Centralized Configuration – All service configs in one place
• Environment-Specific – Different configs for mac, pi, pi2 profiles
• Dynamic Updates – Can refresh config without restart
• Git-Backed – Configuration stored in version control

---

Config Server Architecture

┌─────────────────────┐
│    config-server     │
│     Port 9297        │
└──────────┬──────────┘
           │
           │ serves config
           ↓
┌───────────────────────────────────────┐
│  auth-service     (port 8010)   │
│  member-service   (port 8070)   │
│  gateway-service  (port 8030)   │
│  web-service      (port 8040)   │
│  geospatial-service (port 8060) │
└───────────────────────────────────────┘

---

Configuration Files Location

config-service/src/main/resources/config/
├── auth-service.yml
├── member-service.yml
├── gateway-service.yml
├── web-service.yml
└── geospatial-service.yml

Each file contains service-specific configuration including:

• Eureka client settings
• Database connections
• Service ports
• Custom application properties

---

Local Development Setup (IntelliJ)

Step 1: Start Infrastructure Services First

1. eureka-server (port 8761)
2. config-server (port 9297)

Step 2: Configure Application Service

In IntelliJ Run Configuration:

Field	Value
Name	AuthServiceApplication
Module	auth-service
Main Class	com.adventuretube.auth.AuthServiceApplication
Active profiles	mac
Environment variables	CONFIG_SERVER_URL=http://192.168.1.105:9297;ENV_TARGET=mac

Environment Variables Explained

CONFIG_SERVER_URL=http://192.168.1.105:9297

• Points to where config-server is running
• Service fetches its {service-name}.yml from here

ENV_TARGET=mac

• Tells DotenvEnvironmentPostProcessor which env file to load
• Loads env.mac for local development

---

Config Fetch Flow

Service Startup (e.g., auth-service)
         │
         ↓
Spring Cloud Config Client Bootstrap
         │
         ↓
HTTP GET: http://config-server:9297/auth-service/mac
         │
         ↓
Config Server returns auth-service.yml content
         │
         ↓
Merge with local application.yml
         │
         ↓
Resolve ${PLACEHOLDERS} from env file
         │
         ↓
Application Context Ready
         │
         ↓
Register with Eureka

---

Config Server Endpoints

Endpoint	Description
GET /{service}/{profile}	Fetch config for service and profile
GET /auth-service/mac	Auth service config for mac profile
GET /auth-service/pi2	Auth service config for pi2 profile
GET /actuator/health	Health check

Example Response

curl http://192.168.1.105:9297/auth-service/mac

Returns merged configuration from auth-service.yml

---

bootstrap.yml / application.yml

Services need to configure the config server location:

# bootstrap.yml or application.yml
spring:
  application:
    name: auth-service
  cloud:
    config:
      uri: ${CONFIG_SERVER_URL:http://localhost:9297}
      fail-fast: true

---

Startup Order Dependency

Critical: Config-server must be running before application services start!

Local (Manual)

1. eureka-server    ← Start first
2. config-server    ← Start second (registers with eureka)
3. auth-service     ← Fetches config, then registers with eureka
4. member-service   ← Fetches config, then registers with eureka
5. gateway-service  ← Fetches config, then registers with eureka

Remote (Docker Compose – Automated)

depends_on:
  config-service:
    condition: service_healthy

---

Troubleshooting

Error: “Could not resolve placeholder”

• Config server not running
• Wrong CONFIG_SERVER_URL
• Service name mismatch

Error: “Connection refused to config server”

• Start config-server first
• Check port 9297 is accessible

Error: “Config not found for profile”

• Check {service-name}.yml exists in config folder
• Verify profile name matches

Why ./mvnw spring-boot:run doesn’t work

Running from command line without environment variables fails:

./mvnw spring-boot:run -pl auth-service
# Error: Invalid URL: ${CONFIG_SERVER_URL}
# Error: No active profile set, falling back to default

Reason: Maven command doesn’t set:

• ENV_TARGET – DotenvEnvironmentPostProcessor can’t load env.mac
• CONFIG_SERVER_URL – Placeholder stays unresolved
• SPRING_PROFILES_ACTIVE – Falls back to “default” profile

Solution: Use IntelliJ Run Configuration which sets these in Environment Variables field.

Important: Local development runs application services (auth, member, web, geospatial) via IntelliJ only. Cloud services (eureka, config, gateway) are deployed via Jenkins CI/CD.

---

Related Documents

• AdventureTube Cloud Services – Initialization & Build Process

---

Date: 2026-01-25