build context for docker image very large

Question

I have created a couple different directories on my host machine as I try to learn about Docker just to keep my dockerfiles organized. My Dockerfile I just ran looks like t

Answer 1

I had the same issue as FreeStyler. However I was building from a directory one up from my context. So the -f arguments were correct the context was incorrect.

project 
|
-------docker-dir 

Building from the docker-dir the following was fine

docker build -t br_base:0.1 . 

Building from the dock-dir the the build context changed. Therefore I needed to change the context in the command. Context is given by the '.' in the command above.

The the new command from the project directory should be

docker build -t br_base:0.1 ./base

Context here is given by the './base'

Answer 2

In my case that was when i execute with wrong -f arguments - without path to directory where located Dockerfile

docker build --no-cache -t nginx5 -f /home/DF/Dockerfile /home/DF/ - right

docker build --no-cache -t nginx5 -f /home/DF/Dockerfile - wrong

Answer 3

For NodeJS Application, add a .dockerignore file your root project directory and inside the .dockerignore file add the following

node_modules
dist

Answer 4

Just to summarize what you can do if your Docker image build context too large:

• make sure you don't have unused files in the context (unused files - those that still untouchable during image building);
• add unused files and/or directories to .dockerignore (as mentioned here);
• make sure you specify the right folder as an image build context (as mentioned here);
• try to use BuildKit with DOCKER_BUILDKIT=1 (as mentioned here);
• try to split your project into smaller parts to optimize content of build context;
• if you have a complex project you may want to manually collect all necessary files in separate folder before build and use it as a build context for a specific image.