Deploying in CICD environment

[Viswayasas]

Hi, I wanted to deploy this application using a CICD pipeline as part of my project. I'm planning this as part of a DevSecOps pipeline which will focus on using security tools on different stages in CICD. While trying to deploy the image by using the dockerfile provided in the repo, it shows a postgressql error. Upon investigating I found that this project has multiple dependencies and running docker-compose up revealed that there are multiple containers running. Exploring the repo helped me see multiple dockerfiles present in the client and internal site folder.I'm confused seeing these multiple dockerfile and dependencies. Can someone provide me an idea or any sources of how to implement this ? I'm using gitlab for implementing my pipeline.

PS: I'm a noob.