https://github.com/theskyinflames/dockerlightningtalk
A lightning talk about how to reduce Docker images
https://github.com/theskyinflames/dockerlightningtalk
docker docker-image-size docker-images docker-images-downsize multi-stage multi-stage-build multi-stage-docker
Last synced: about 2 months ago
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A lightning talk about how to reduce Docker images
- Host: GitHub
- URL: https://github.com/theskyinflames/dockerlightningtalk
- Owner: theskyinflames
- Created: 2020-05-08T17:47:38.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-05-20T11:28:35.000Z (over 5 years ago)
- Last Synced: 2025-03-22T05:33:02.637Z (7 months ago)
- Topics: docker, docker-image-size, docker-images, docker-images-downsize, multi-stage, multi-stage-build, multi-stage-docker
- Language: HTML
- Homepage:
- Size: 866 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Minimizing Docker images lightning talk
A lightning talk about how to reduce Docker images.
The goal is to explain how can we decrease the size of our Docker images and why it's important.
## Start the presentation:
This presentation uses the [present tool](https://godoc.org/golang.org/x/tools/present) from Go. You must install it and do:
```sh
dockerLightningTalk git:(master) ✗ present
2020/05/17 21:43:07 Open your web browser and visit http://127.0.0.1:3999
```
## Approach
I've taken a minimal service in golang as a example to be dockerized:
```go
import (
"fmt"
"net/http"
)
func main() {
http.HandleFunc("/", HelloServer)
fmt.Println("server started on :8080")
http.ListenAndServe(":8080", nil)
}
func HelloServer(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello world!\n"))
}
```
From here, I dockerlize the above serivice in a four different ways. With each iteration, I get an smaller Docker image. All images does the same, dockerizing the above service. But all Dockerfiles are different:
* First Dockerfile uses a Debian Linux as base image.
* Second Dockerfile uses an Alpine Linux as base image.
* Third Dockerfile uses multi stage building. This dereases dramatically the size of the docker image-
* Fourth Dockerfile combines multi stage building and *scratch* image usage.
This is the result:
```sh
docker images|grep hello-|sort -k1nr
hello-1-debian latest a57e328870c3 27 minutes ago 818MB
hello-2-alpine latest 91b9333cc751 27 minutes ago 378MB
hello-3-multi-stage latest 151363ae52cd 27 minutes ago 13.1MB
hello-4-ms-scratch latest d1ea8ed7079f 26 minutes ago 7.41MB
```
As you can see, we pass from a **818 Mb** docker image to a **7.41 Mb** one. The two images are equivalent and does the same, dockerizing the service.
## Check it out for yourself
1. Compile the Dockerfiles
```sh
make build-all
```
2. List Docker images and compare its sizes
```sh
make list-imgages
```