How to Install SSL Certificate on Docker

Prerequisites

Before implementing SSL certificates on Docker, ensure you have:

• Docker installed and running
• Docker Compose (optional but recommended)
• SSL certificate files:
  • Certificate file (.crt)
  • Private key file (.key)
  • Certificate chain file (if applicable)

Obtaining SSL Certificate

You can obtain SSL certificates through various methods:

Docker Volume Setup

Create a secure way to store and access certificates:

1. Create a Docker volume for certificates:

   docker volume create certs

2. Create a temporary container to manage certificates:

   docker run --rm -v certs:/certs -v $(pwd):/source alpine sh -c "cp /source/*.{crt,key} /certs/"

Container Configuration

Use our configuration generator to create your Docker SSL configuration:

FROM nginx:alpine

COPY nginx.conf /etc/nginx/nginx.conf
COPY default.conf /etc/nginx/conf.d/default.conf

VOLUME /etc/nginx/certs
EXPOSE 443

CMD ["nginx", "-g", "daemon off;"]

server {
    listen 443 ssl http2;
    server_name example.com;

    ssl_certificate /etc/nginx/certs/example.com.crt;
    ssl_certificate_key /etc/nginx/certs/example.com.key;
    
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers HIGH:!aNULL:!MD5;
    
    location / {
        proxy_pass http://app:3000;
    }
}

Testing Configuration

Verify your SSL configuration:

1. Start your container:

   docker run -d --name myapp -p 443:443 -v certs:/etc/nginx/certs myapp

2. Verify SSL connection:
   • Visit https://example.com
   • Check certificate details in browser
   • Use curl to test:

     curl -k https://localhost

Troubleshooting

Best Practices

• Security:
  • Use Docker secrets for sensitive data
  • Implement proper file permissions
  • Regular security updates
• Maintenance:
  • Automate certificate renewal
  • Use health checks
  • Implement logging

Docker Compose Setup

Use Docker Compose for easier SSL configuration:

version: '3.8'

services:
  web:
    image: nginx:alpine
    ports:
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - certs:/etc/nginx/certs:ro
    depends_on:
      - app
  
  app:
    build: .
    expose:
      - "3000"

volumes:
  certs:
    external: true