Unlocking Docker’s Hidden Powers: 5 Features You Need to Know

I am an expert at using Docker.

Unfortunately, I wasted hours because I was using the wrong commands.

Save yourself time and effort by using these 5 hidden Docker features guaranteed to streamline your development process:

Docker Secrets

Manage sensitive data like passwords and API keys securely. Instead of hardcoding them in your Dockerfiles or source code, use Docker secrets to keep this data secure and out of your codebase.

# Create a secret
echo "mysecretpassword" | docker secret create db_password -

# Use the secret in a service
docker service create --secret db_password myapp        

Docker Swarm

Leverage the power of Docker Swarm for container orchestration. It allows you to manage containers across multiple host machines seamlessly, providing high availability and scalability for your applications.

# Initialize the swarm on the manager node
docker swarm init

# Join the worker node to the swarm
docker swarm join --token <worker-token> <manager-ip>

# Deploy a service
docker service create --replicas 3 myapp        

Service Discovery

Utilize Docker's service discovery mechanism to automatically detect services on the network. This feature simplifies the process of connecting containers and services, especially in a microservices architecture.

# Python example
import requests

response = requests.get("https://myapp-service:8080")
print(response.text)        

Health Checks

Implement health checks in your Docker containers to ensure they are running as expected. Docker can automatically restart containers that fail their health checks, maintaining the reliability of your services.

FROM nginx

HEALTHCHECK --interval=30s --timeout=3s \
    CMD curl -f https://localhost/ || exit 1        

Multi-stage Builds

Use multi-stage builds to optimize your Docker images. This feature allows you to compile/build your application in a temporary image and then copy only the necessary artifacts to the final image, reducing the size and improving security.

# Build stage
FROM golang:1.16 AS builder
WORKDIR /app
COPY . .
RUN go build -o myapp

# Final stage
FROM alpine
WORKDIR /app
COPY --from=builder /app/myapp .
CMD ["./myapp"]        

These features have been game-changers for me, and I'm confident they will be for you too. Have you tried any of these? What's your experience been like? Share your thoughts in the comments!

Source:

(1) The Complete Guide to Docker Secrets - Earthly Blog. https://earthly.dev/blog/docker-secrets/.

(2) Introduction to Docker Secrets | Baeldung on Ops. https://www.baeldung.com/ops/docker-secrets.

(3) how can I create a hidden docker container? - Stack Overflow. https://stackoverflow.com/questions/52414146/how-can-i-create-a-hidden-docker-container.

(4) Features of Docker - GeeksforGeeks. https://www.geeksforgeeks.org/features-of-docker/.