Spring Boot microservice deployment in Docker

Question

I need to develop a Spring Boot microservice and need to deploy in Docker. Now I developed a sample microservice. When I am learning Docker and container deployment I found many documentations for installing Docker and building images and running the application as container packaging. Here I have some doubts in deployment procedure:

• If I need to deploy 4 Spring Boot microservice in Docker, do I need to create separate image for all? Or can I use the same Docker file in all my Spring Boot microservices?

• I am using PostgreSQL database. So can I include that connection into Docker image file? Or I need to manage separately?

Answer 1

• If you have four different Spring Boot applications, I suggest creating four different Dockerfiles, and building four different images from those files. Basically put one Dockerfile in each Spring application folder.
• You can build PostgreSQL credentials (hostname, username & password) into the application by writing it in the code. This is easiest.

If you use AWS and ECS (Elastic Container Service) or EC2 to run your Docker containers you could store the credentials in the EC2 Parameter Store, and have your application fetch them at startup, however this takes a bit more AWS knowledge and you have to use the AWS SDK to fetch the credentials from the application. Here is a StackOverflow question about exactly this: Accessing AWS parameter store values with custom KMS key Ask Question

Answer 2

1. There can be one single image for your all micro-services but its not a good design and not suggested. Always try to decoupled the things one from another. In your case, create separate images(separate Dockerfile) for each micro-service.
2. Again same thing for your second question, create a separate image(one Dockerfile) for your database as well. And for the credentials, you can follow the Jonatan's suggestion.