Custom circleci 2 image for testing

With Per-project tags and branches

Process

Decide a docker tag based on project name and date (typically):

${PROJECT}-${DATE} e.g. bws-2019-08-25

build locally to ensure it works...

docker build .             

Get image onto docker hub -- push option 1

push the local build to docker hub

docker build . -t red56/capybara-webkit-deps:bws-2019-08-25
docker push red56/capybara-webkit-deps:bws-2019-08-25

Get image onto docker hub -- push option 2

push to github and let docker hub autobuild

git checkout -b bws-2019-08-25
git commit (etc)
git push -u origin head             

And test with circleci

when built, change ref in circeci/config.yml ensure it works and then

Fossilize

• if push option 1, then just commit changes to the project branch and push

• if push option 2, then git PR to project branch, merge, and delete old branch

• In commit message / PR message, ensure intent of the changes is recorded. something like "pin nodejs to 10.15.3"

• tag git with docker tag (it's just easier to have them both linked this way).

• keep using the git == docker tag in circleci, it helps for traceability (don't switch to branch-named docker tag, despite its existance)

• master? Can optionally force-update master with the latest changes. Master is only a nicety for github. project branches are what's being used.

Another branch on same day?

yes sometimes - if so add on a reason or letter to the date.

Docker reminders

remember earlier things are the base layers -- keep those to be the least chainging