Node.js app runner

Why?

To learn some docker stuff while making it easier to run node.js modules and apps inside docker.

Also to stop inflating yarn downloads, since i don't use it at all. I don't know why it's injected into official node.js docker images while something that probably will be needed, e.g., python and g++ for building some of the binary modules, is not.

Preparation

If you do not want to use pre-built images (for security reasons? just because?), you can build one from Dockerfile. Go to docker-nodejs-app directory and run:

make

It will download and use latest stable Alpine Linux and build latest "current" Node.js version. You can use specific version of Node.js by passing it through environmental variable. For example:

NODE_VERSION=15.6.0 make

To use different Alpine Linux version, you can specify two variables:

ALPINE_URL=http://dl-cdn.alpinelinux.org/alpine/v3.13/releases/x86_64 ALPINE_VERSION=3.13.0 make

It will take a while to finish, because it needs to build node.js from sources. After that, all commands will reuse this pre-build image, and you can find it and remove it later with regular docker and podman commands.

Usage (docker)

Next try single-run "session". Go to your node.js application directory and run:

docker run --rm -v $(pwd):/app -it ahwayakchih/nodeapp

It will remove the container as soon as you finish (exit the shell).

To keep a "session" for multiple runs, use following command:

docker run --name my-node-app -v $(pwd):/app -it ahwayakchih/nodeapp

And then, to continue last "session" (and keep docker running):

docker start my-node-app && docker exec -it ahwayakchih/nodeapp /bin/sh -l

Or, to stop container after exiting:

docker start my-node-app && docker attach my-node-app

To remove session, run following command:

docker stop my-node-app && docker rm my-node-app --volumes

Usage (podman)

Since podman supports docker's commands, most of the examples above should work. To keep current user's and group's id when running podman, use additional --userns=keep-id parameter:

podman run --rm -v $(pwd):/app --userns=keep-id -it ahwayakchih/nodeapp

That will make sure that, for example, node_modules directory created by npm install command will be owned by the user who started podman container.

If image was built locally with docker, you can quickly import it to podman without a need for rebuild:

podman pull docker-daemon:ahwayakchih/nodeapp:latest

App/module testing

Simple, one-time test run can be done with:

docker run --rm -v $(pwd):/app -it ahwayakchih/nodeapp /bin/sh -l -c "npm install && npm test"

That will install modules into local node_modules directory. Each next run will simply check if modules are installed and continue. After work is done, or just to "clear cached modules", simply remove local node_modules directory.

App/module running

If application (or module) provides additional "commands" in the form of scripts included in package.json, you can easly run them too. It's similar to Testing, only instead of npm test use npm run COMMAND. For example, if there is a benchmarks command:

docker run --rm -v $(pwd):/app -it ahwayakchih/nodeapp /bin/sh -l -c "npm install && npm run benchmarks"

Simplify

Instead of having to remember long command lines, you can simplify everything by adding following aliases to your ~/.profile (or counterpart on your system of choice):

alias _nodeapp='mkdir -p ./node_modules && docker run --rm -v $(pwd):/app -it ahwayakchih/nodeapp'
alias nodeapp-sh='_nodeapp /bin/sh -l'
alias nodeapp-run='_nodeapp npm run'
alias nodeapp-test='_nodeapp /bin/sh -l -c "npm install && npm test"'
alias nodeapp-benchmark='_nodeapp /bin/sh -l -c "npm install && npm run benchmarks"'