[be] chore: Update to use yarn

.github/workflows/backend-e2e-tests.yml

@@ -20,18 +20,20 @@ jobs:
     env:
       API_URL: http://localhost:5000
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v1
 
-    - name: Use Node.js 18.x
-      uses: actions/setup-node@v3
+    - name: Use Node.js 20.x
+      uses: actions/setup-node@v4
       with:
-        node-version: 18.x
+        node-version: 20.x
 
     - name: Create .env file
-      run: echo "JWT_SECRET=${{ secrets.JWT_SECRET }}" > .env
+      run: |
+        echo "JWT_SECRET=${{ secrets.JWT_SECRET }}" > .env
+        echo "DATABASE_URL=${{ secrets.DATABASE_URL }}" >> .env
 
     - name: Start service in docker
       run: |

backend/Dockerfile

@@ -1,5 +1,5 @@
 # Use an official Node.js runtime based on Alpine Linux as the base image
-FROM node:18-alpine
+FROM node:20-alpine
 
 # Install bash
 RUN apk add --no-cache bash

backend/docker-compose.yml

@@ -7,6 +7,7 @@ services:
       POSTGRES_USER: test
       POSTGRES_PASSWORD: test
       POSTGRES_DB: test
+      DATABASE_URL: "postgresql://test:test@postgres:5432/test"
     env_file:
       - .env
     ports: