Why is the pushed image so big?

Docker Hub
1

I’m going through the getting-started tutorial. When I
docker push myusername/getting-started
I see 200+ MM is sent, and then the hub shows
COMPRESSED SIZE
137.73 MB

The “app” folder on my desktop is only 4.5 MB. Why is the pushed image so much larger?

2

Hi

can you provide which tutorial you’re following?
also if you’re using a dockerfile provide that?

because, lets say that you’re using an apache og php image, thats the first 150mb there, and then you add your data to it afterwards

3

Tutorial started here
https://docs.docker.com/get-started/

Here’s where the created image gets pushed to hub
https://docs.docker.com/get-started/04_sharing_app/

4

Ah okay

FROM node:12-alpine
RUN apk add --no-cache python2 g++ make
WORKDIR /app
COPY . .
RUN yarn install --production
CMD ["node", "src/index.js"]

each line in this, creates a layer of a docker image, so its starts by downloading node:12-alpine, which is 50mb
then it downloads python and a compiler (no idea how much that is, lets just say +50mb), now totals: 100mb
then it copies the local app folder to the app folder in the container, thats +4.5mb (now: 104,5mb)
then it installs the dependencies of your project (yarn install), lets say that +30mb, now totals 134,5mb

so its because it all adds up. :slight_smile: