Image Layers and Optimization
Discover how Docker images are layered and apply techniques to optimize image size and build times.
Image Layers: Building Blocks
Docker images are not a single, giant file. Instead, they are built up from a series of read-only layers. Think of these layers like stacked transparencies.
Each layer represents a change to the image, making images efficient and flexible. This layering is fundamental to how Docker works.
Dockerfile Instructions & Layers
When you write a Dockerfile, almost every instruction creates a new layer on top of the previous one. Instructions like FROM, RUN, COPY, and ADD all contribute to new layers.
Docker executes these instructions sequentially, building each new layer based on the state of the previous one.
All lessons in this course
- Understanding Dockerfiles
- Creating Custom Docker Images
- Image Layers and Optimization
- Multi-Stage Builds & Smaller Images