wtzhou74/discovery-server

Discovery Server

Discovery Server

The Discovery Server (Eureka from Netflix OSS) is one of the key tenets of a microservice based architecture. It facilitates the Consent2Share (C2S) microservices to dynamically discover each other and promotes the scalability of the C2S system. It provides the following:

• Registry of C2S service instances
• Provides means for C2S service instances to register, de-register and query instances with the registry
• Registry propagation to other C2S microservice (Eureka client) and Discovery Server (Eureka server cluster) instances

Build

Prerequisites

• Oracle Java JDK 8 with Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy
• Docker Engine (for building a Docker image from the project)

Commands

This is a Maven project and requires Apache Maven 3.3.3 or greater to build it. It is recommended to use the Maven Wrapper scripts provided with this project. Maven Wrapper requires an internet connection to download Maven and project dependencies for the very first build.

To build the project, navigate to the folder that contains pom.xml file using the terminal/command line.

• To build a JAR:
  • For Windows, run mvnw.cmd clean install
  • For *nix systems, run mvnw clean install
• To build a Docker Image (this will create an image with bhits/discovery-server:latest tag):
  • For Windows, run mvnw.cmd clean package docker:build
  • For *nix systems, run mvnw clean package docker:build

Run

Commands

This is a Spring Boot project and serves the API via an embedded Tomcat instance. Therefore, there is no need for a separate application server to run this service.

• Run as a JAR file: java -jar discovery-server-x.x.x-SNAPSHOT.jar <additional program arguments>
• Run as a Docker Container: docker run -d bhits/discovery-server:latest <additional program arguments>

NOTE: In order for this API to fully function as a microservice in the Consent2Share application, it is required to setup the dependency microservices and the support level infrastructure. Please refer to the Consent2Share Deployment Guide in the corresponding Consent2Share release (see Consent2Share Releases Page) for instructions to setup the Consent2Share infrastructure.

Configure

This API runs with some default configuration that is primarily targeted for development environment. However, Spring Boot supports several methods to override the default configuration to configure the API for a certain deployment environment.

Please see the default configuration for this API as a guidance and override the specific configuration per environment as needed. Also, please refer to Spring Boot Externalized Configuration documentation to see how Spring Boot applies the order to load the properties and Spring Boot Common Properties documentation to see the common properties used by Spring Boot.

The default configuration provided with this Discovery Server is setup to run as a Standalone Discovery Server. To run as a Discovery Server Cluster in High Availability mode, please refer to the Spring Cloud documentation.

Examples for Overriding a Configuration in Spring Boot

Override a Configuration Using Program Arguments While Running as a JAR:

• java -jar discovery-server-x.x.x-SNAPSHOT.jar --server.port=80

Override a Configuration Using Program Arguments While Running as a Docker Container:

• docker run -d bhits/discovery-server:latest --server.port=80

• In a docker-compose.yml, this can be provided as:

version: '2'
services:
...
  discovery-server.c2s.com:
    image: "bhits/discovery-server:latest"
    command: ["--server.port=80"]
...

NOTE: Please note that these additional arguments will be appended to the default ENTRYPOINT specified in the Dockerfile unless the ENTRYPOINT is overridden.

Enable SSL

For simplicity in development and testing environments, SSL is NOT enabled by default configuration. SSL can easily be enabled following the examples below:

Enable SSL While Running as a JAR

• java -jar discovery-server-x.x.x-SNAPSHOT.jar --spring.profiles.active=ssl --server.ssl.key-store=/path/to/ssl_keystore.keystore --server.ssl.key-store-password=strongkeystorepassword

Enable SSL While Running as a Docker Container

• docker run -d -v "/path/on/dockerhost/ssl_keystore.keystore:/path/to/ssl_keystore.keystore" bhits/discovery-server:latest --spring.profiles.active=ssl --server.ssl.key-store=/path/to/ssl_keystore.keystore --server.ssl.key-store-password=strongkeystorepassword
• In a docker-compose.yml, this can be provided as:

version: '2'
services:
...
  discovery-server.c2s.com:
    image: "bhits/discovery-server:latest"
    command: ["--spring.profiles.active=ssl","--server.ssl.key-store=/path/to/ssl_keystore.keystore", "--server.ssl.key-store-password=strongkeystorepassword"]
    volumes:
      - /path/on/dockerhost/ssl_keystore.keystore:/path/to/ssl_keystore.keystore
...

NOTE: As seen in the examples above, /path/to/ssl_keystore.keystore is made available to the container via a volume mounted from the Docker host running this container.

Override Java CA Certificates Store In Docker Environment

Java has a default CA Certificates Store that allows it to trust well-known certificate authorities. For development and testing purposes, one might want to trust additional self-signed certificates. In order to override the default Java CA Certificates Store in a Docker container, one can mount a custom cacerts file over the default one in the Docker image as follows: docker run -d -v "/path/on/dockerhost/to/custom/cacerts:/etc/ssl/certs/java/cacerts" bhits/discovery-server:latest

NOTE: The cacerts references regarding volume mapping above are files, not directories.

Contact

If you have any questions, comments, or concerns please see Consent2Share project site.

Report Issues

Please use GitHub Issues page to report issues.