Golang Web App

Overview

This is a Golang web application that uses:

• PostgreSQL for persistent storage
• Redis for session management
• AWS S3 for media storage
• CloudFront (optional) for CDN-backed media delivery
• golang-migrate for database migrations

The application can be run locally using Docker Compose and deployed to production as a single Go executable, with migrations executed separately.

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Running the App Locally

Prerequisites

• Go 1.20+
• Docker & Docker Compose
• AWS CLI
• Make

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Local Setup Instructions

1. Generate an application secret key

openssl rand -hex 32

e7ca0377e91a43a5b0a2b30978339e11cbcb1dd4578da7a00fad89bf085acd3b

Set it as an environment variable:

APP_SECRET=<generated_secret>

2. Configure AWS S3 and CloudFront (optional)

• Create an S3 bucket for storing profile images.
• (Optional) Set up a CloudFront distribution with read access to the bucket.
• Ensure you have an IAM user with s3:PutObject permission.

Set the environment variables:

AWS_REGION=<aws_region>
AWS_S3_BUCKET=<s3_bucket_name>
MEDIA_BASE_URL=<https://cloudfront_or_s3_base_url>

MEDIA_BASE_URL must include https://.

3. Install and configure AWS CLI

aws configure

Verify credentials:

aws sts get-caller-identity

A successful response includes UserId, Account, Arn.

4. Start all services

docker compose up

5. Run database migrations

make migrate-up

This step does the following

• Apply the migrations.
• Remove the container of the migrate service since it is no longer needed.

6. Verify the application

Visit in a browser:

• http://127.0.0.1:8000/register
• http://127.0.0.1:8000/login

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Deployment to Production

One-Time Infrastructure Setup

1. PostgreSQL

Provision a database and set:

DATABASE_URL=postgres://user:password@host:port/dbname?sslmode=disable

2. Redis

Provision Redis and set:

REDIS_ADDR=<host:port>
REDIS_PASSWORD=<password>
REDIS_DB=<db_number>
SESSION_TTL_HOURS=<hours>

3. AWS S3 & CloudFront

• Create an S3 bucket for media storage.
• (Optional) Configure CloudFront distribution for read access.
• Ensure IAM user has s3:PutObject permission.
• Configure AWS CLI on production:

aws configure

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Deployment Steps

1. Transfer migration files to the server

scp -r migrations user@server:/opt/myapp/

2. Run database migrations

migrate -path /opt/myapp/migrations -database "$DATABASE_URL" up

3. Set AWS-related environment variables

AWS_REGION=<production_region>
AWS_S3_BUCKET=<production_bucket>
MEDIA_BASE_URL=<https://cloudfront_or_s3_base_url>

4. Build the Go executable

go build -o myapp ./cmd/web

5. Transfer the binary to the server

scp myapp user@server:/opt/myapp/

6. Run the application

./myapp

7. Verify deployment

Check all API endpoints and web routes to ensure they work.

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Notes & Best Practices

• Migrations are not run automatically; run them before starting the app.
• Media URLs are stored as absolute HTTPS URLs.
• AWS credentials are resolved via the standard AWS chain (~/.aws/credentials, IAM roles).
• The app binary is stateless and safe for horizontal scaling.

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