Add pre-requisites instructions to server setup (#1217)

contributions/ServerSetup.md

@@ -1,30 +1,39 @@
 ## Running Server Codebase
-- We use the Spring framework in Java for all backend development.
-- We use `maven` as our build tool.
-- We use pf4j as a library for plugins.
-- We use MongoDB for our database.
-- We use IntelliJ as our primary IDE for backend development
+
+The server codebase is written in Java and is powered by Spring + WebFlux. This document explains how you can setup a development environment to make changes and test your changes.
+
+## Pre-requisites
+
+- Java --- OpenJDK 11.
+- Maven --- version 3+ (preferably 3.6).
+- A MongoDB database --- A simple way to get this up is explained [further down in this document](#setting-up-a-local-mongodb).
+- A Redis instance --- A simple way to get this up is explained [further down in this document](#setting-up-a-local-redis).
+- An IDE --- We use IntelliJ IDEA as our primary IDE for backend development.
+
+## Steps for Setup
 
 1. After cloning the repository, change your directory to `app/server`
 
 2. Run the command  
-```bash
-  mvn clean compile
+
+```sh
+mvn clean compile
 ```  
   
 This generates a bunch of classes required by IntelliJ for compiling the rest of the source code. Without this step, your IDE may complain about missing classes and will be unable to compile the code.
 
 3. Create a copy of the `envs/dev.env.example` 
 
-    ```shell script
-    cp envs/dev.env.example .env
-    ```
+```sh
+cp envs/dev.env.example .env
+```
 
 This command creates a `.env` file in the `app/server` folder. All run scripts pick up environment configuration from this file.
 
 4. Modify the property values in the file `.env` to point to your local running instance of MongoDB and Redis.
 
 5. In order to create the final JAR for the Appsmith server, run the command:
+
 ```
 ./build.sh
 ```
@@ -36,8 +45,33 @@ This command will create a `dist` folder which contains the final packaged jar a
 ```
 ./scripts/start-dev-server.sh
 ```
+
 By default, the server will start on port 8080.
 
 7. When the server starts, it automatically runs migrations on MongoDB and will populate it with some initial required data.
 
-8. You can check the status of the server by hitting the endpoint: [http://localhost:8080](http://localhost:8080) on your browser. By default you should see an blank page.
+8. You can check the status of the server by hitting the endpoint: [http://localhost:8080](http://localhost:8080) on your browser. By default you should see a blank page.
+
+## Setting up a local MongoDB
+
+The following command can bring up a MongoDB docker instance locally.
+
+```sh
+docker run -p 127.0.0.1:27017:27017 --name appsmith-mongodb -e MONGO_INITDB_DATABASE=appsmith -v /path/to/store/data:/data/db mongo
+```
+
+Please change the `/path/to/store/data` to a valid path on your system. This is where MongoDB will persist it's data across runs of this container.
+
+Note that this command doesn't set any username or password on the database so we make it accessible only from localhost using the `127.0.0.1:` part in the port mapping argument. Please refer to the documentation of this image to learn [how to set a username and password](https://hub.docker.com/_/mongo).
+
+When using this command, the value of `APPSMITH_MONGODB_URI` should be set to `mongodb://localhost:27017/appsmith` (which is what's provided in the example env file).
+
+## Setting up a local Redis
+
+The following command can bring up a Redis docker instance locally.
+
+```sh
+docker run -p 127.0.0.1:6379:6379 --name appsmith-redis redis
+```
+
+When using this command, the value of `APPSMITH_REDIS_URI` should be set to `redis://localhost:6379`.