Optimize Docker images for efficient, secure deployments. Learn best practices for streamlined CI/CD and scalable containerized applications.

Java Code Geeks is a community-driven platform that provides Java developers with tutorials, articles, and code snippets covering various aspects of Java programming. With a focus on practical examples and real-world solutions, Java Code Geeks helps developers enhance their Java skills, explore new frameworks and libraries, and stay updated on the latest trends in Java development. Developers can learn about best practices, design patterns, and optimization techniques to build robust and efficient Java applications.

Java Code Geeks

Learn how to optimize your Docker deployments through best practices such as choosing the right base image, minimizing layers, using .dockerignore, optimizing Dockerfile instructions, updating dependencies wisely, implementing security best practices, reducing image size, using Docker Compose for multi-container applications, automating image builds with CI/CD, and monitoring and optimizing runtime performance.

Optimize Your Deployments: Docker Image Best Practices

9. Use Docker Compose for Multi-Container Applications

11. Monitor and Optimize Runtime Performance

<blockquote>
<ol start="8">
<li>Optimize Image Size</li>
</ol>
<pre><code class="language-dockerfile"># Remove unnecessary dependencies
RUN apk del .build-deps
 
# Clean up package cache
RUN rm -rf /var/cache/apk/*
</code></pre>
</blockquote>
The example that you provided is not a good one, cleaning package manager cache files with separate <code>RUN</code> command is not decreasing image size in any way.
You need to be aware of image architecture - stack of layers applied one on another, mostly holding changes in filesystem done in particular layer.
Even if you delete some files in separate layer, they will be visible and - most importantly - stored in previous layer that created it.
Of course those files will not be visible in final image, but - as they were added in one of the layers - will be part of whole image source and will have impact on image size.
If you want to do this kind on cleanup - it needs to be done in single layer so that those cache files are not part of ANY layer.

In the section “Minimize layers” you used this example:
<pre><code>FROM node:14 as build
WORKDIR /app
COPY . .
RUN npm install
RUN npm run build
</code></pre>
And to minimize the layers you could put the RUN commands together, like that:
<pre><code>RUN npm install &amp;&amp; npm run build
</code></pre>
Doing it, you would transform two layers in one.