Lecture: DevOps - Application

⚠️ Invoking make in a path containing white spaces will break execution and may lead to unforeseen side effects like DATA LOSS !

This repository contains the application that can be used as deployable workload for the project assignment implementation.

In order to adapt the application and integrate it into your automation and deployment processes, it's usually not required to change any existing code. Instead, you probably just want to add some pipeline code or even a container file (e.g. Dockerfile).

Getting started

For more information regarding the app, please take a look into its README.

The Makefile in this directory can be seen as the main entry point for this repository. It's meant to locally run the application and allow to mess around with the source code in order to better understand how it works and to be able to tear it apart if necessary. Additionally, it documents various invocations that may help you adapting this application as workload for the assignment.

Please note, that the Makefile is only meant to showcase steps that are usually taken to automate the deployment lifecycle of such an application and code base. It is NOT recommended to invoke make targets from the CI/CD, but rather to utilize platform-specific interfaces (e.g. .gitlab-ci.yml, Jenkinsfile, etc.), which may then invoke commands shown in the make target or in the scripts section of one of the package.json files.

Prerequisites

The following software must be installed and available in ${PATH}:

• node (NodeJS): latest v16
• npm (npm): latest v8
• mongod (MongoDB): latest v4.4

NOTE: the application in this repository has not been tested with versions newer than that

Choose for yourself how you want to install these dependencies. Perhaps you can use the package manager available on your operating system, or maybe you prefer using container images.

Commands

The following commands are available from the root directory:

make install

• installs all server and client dependencies via package manager npm

make build

1. copy server source into some empty location
2. copy dependency manifest (package*) into the same location right next to the server source
3. install server dependencies there
4. install all client dependencies next to its source
5. build client code and put it next to the server source (step 1)

make test

NOTE: requires/assumes a MongoDB service (see MONGODB_URL) to be reachable from the context where tests are being executed

• runs client & server tests in CI mode (exits regardless of the test outcome; closed tty)

make dev-test-client

NOTE: only demonstrates a use case during local development and are not meant to run in any other context (e.g. automation)

• runs client tests in a local development mode

make dev-start-db

NOTE: only demonstrates a use case during local development and are not meant to run in any other context (e.g. automation)

• starts a local MongoDB service

make dev-start-app

NOTE (1): only demonstrates a use case during local development and are not meant to run in any other context (e.g. automation) NOTE (2): it might be desired to first start a database service (e.g. make dev-start-db)

• builds client
• starts server in development mode with development configuration

make run

NOTE (1): showcases plain executable invocation with a shared parent process. Press Ctrl+C to send termination signal. NOTE (2): in reality those two services would always be invoked independently and never share a parent process!

• starts a MongoDB service as a child process with an explicit inline-configuration
• starts the application service with variables being set in a way so that they are only visible to that invocation (as an alternative to the configuration file app/server/dev.env that is used to set environment variables)
• blocks terminal and keeps it as output device until termination signal is being send.

make clean

• removes all node_modules dependencies that have been installed locally via npm
• removes other temporarily created folder in .local