Improve fonts generation: enable CircleCI to build Docker image and fonts

[ylemkimon]

This PR is part of #12.

I think it's best to have another branch for Dockerfile and CircleCI configs to build the image. I've pushed the branch to https://github.com/KaTeX/katex-fonts/tree/docker:

katex-fonts/.circleci/config.yml

Lines 1 to 19 in 8d0cfd8

	version: 2
	jobs:
	build:
	machine: true
	steps:
	- checkout
	- run:
	name: Login to Docker
	command: docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD
	- run:
	name: Build Docker image
	command: docker build -t $DOCKER_USERNAME/katex-fonts:$(openssl sha1 Dockerfile | tail -c 9) .
	- run:
	name: Push Docker image
	command: docker push $DOCKER_USERNAME/katex-fonts

Example CircleCI builds: docker branch, PR branch

• Enable CircleCI on the repo
• Set Docker username and password as DOCKER_USERNAME and DOCKER_PASSWORD, respectively, in the environment variables

[kevinbarabash]

Does this docker image live on docker hub? Why do we need environment variables for the user name?

[ylemkimon]

@kevinbarabash Yes. Using environment variables is for easier maintenance.

[kevinbarabash]

Why bother storing artifacts if we're using this repo as a submodule?

[kevinbarabash]

I guess if we moved font creation into the main repo, we could avoid checking the built fonts in and instead grab the most recent artifact so that people don't have to build fonts themselves when doing KaTeX development.

[ylemkimon]

@kevinbarabash It's like screenshots. CircleCI doesn't commit files and they have to be manually committed.

[kevinbarabash]

@ylemkimon I've granted circleci access to the KaTeX organization and set up https://circleci.com/setup-project/gh/KaTeX/katex-fonts.

[kevinbarabash]

LGTM

[kevinbarabash]

I forgot about the second item on the checklist before merging this. 😞

I also should've asked more questions about how the docker image in https://github.com/KaTeX/katex-fonts/tree/docker gets built and how $DOCKER_USERNAME and $DOCKER_PASSWORD get set.

[kevinbarabash]

I totally messed that up https://circleci.com/gh/KaTeX/katex-fonts/2.

[kevinbarabash]

I temporarily fixed it https://circleci.com/gh/KaTeX/katex-fonts/3.

[ylemkimon]

@kevinbarabash I've put my account to environment variables temporarily.

[kevinbarabash]

I see, there's a way to set environment variables in the project settings part on circleci.

[ylemkimon]

@kevinbarabash But to test PRs, it seems we should hard-code the DOCKER_USERNAME, anyway.