Myujth

When i run my docker-compose up -d command it runs all cool buuut it creates a lot of images i dont know if this should be a normal behavior but it looks like this

Status: Downloaded newer image for node:11.1.0
 ---> 4e4c445311e6
Step 2/8 : RUN mkdir /usr/src/app
 ---> Running in 3b78051548b7
Removing intermediate container 3b78051548b7
 ---> 96e53f58ca4a
Step 3/8 : WORKDIR /usr/src/app
 ---> Running in 6c09aca5e321
Removing intermediate container 6c09aca5e321
 ---> a392a2bdd279
Step 4/8 : ENV PATH /usr/src/app/node_modules/.bin:$PATH
 ---> Running in 9443cc34dc2a
Removing intermediate container 9443cc34dc2a
 ---> 6ba4c2ed0014

As you can see it makes a new image each step

Here you can see the list of the images made by the command

somethinghere_somethinghere latest 4163a2ac78cc 14 minutes ago 1.23GB
<none> <none> 2af2d216914a 14 minutes ago 1.23GB
<none> <none> 2471e3d94378 15 minutes ago 1.11GB
<none> <none> 6ba4c2ed0014 15 minutes ago 894MB
<none> <none> 71141d30cec8 15 minutes ago 894MB
<none> <none> a392a2bdd279 15 minutes ago 894MB
<none> <none> 96e53f58ca4a 15 minutes ago 894MB

Here ill show you my docker-compose and dockerfile

Dockerfile

# base image
FROM node:11.1.0

# set working directory
RUN mkdir /usr/src/app
WORKDIR /usr/src/app

# add `/usr/src/app/node_modules/.bin` to $PATH
ENV PATH /usr/src/app/node_modules/.bin:$PATH

# install and cache app dependencies
COPY package.json /usr/src/app/package.json
RUN npm install --silent
RUN npm install react-scripts@1.1.1 -g --silent

# start app
CMD ["npm", "start"]

docker-compose

version: '3.5'

services:

 somethinghere:
 container_name: somethinghere-client
 build:
 context: .
 dockerfile: Dockerfile
 volumes:
 - '.:/usr/src/app'
 - '/usr/src/app/node_modules'
 ports:
 - '3000:3000'
 environment:
 - NODE_ENV=development

That's docker's caching mechanism working, they help the system to build faster if there are minor changes in the dockerfile.

As you can see in the build output,

Step 2/8 : RUN mkdir /usr/src/app
 ---> Running in 3b78051548b7
Removing intermediate container 3b78051548b7
 ---> 96e53f58ca4a

Creates a layer with the image 96e53f58ca4a.

Normally you won't need to worry about them, just use docker images and you won't see them.

More reading here