At work we have an application that is run directly on dev machines, but deployed to Docker swarms (a QA swarm and production swarm). The code and CI/CD pipelines are all in GitLab CE.

It uses several private, internal NPM packages. We refer to these packages in the package.json like so:

"@project/utils": "git@gitlab.com:project/utils.git#branch"

This gives us a few problems:

  1. When developing locally on a feature branch, you have to manually edit the package.json but not check it in, to append the feature branch to the dependency URL.
  2. Since it's a git URL, Yarn/NPM will not check and get the latest code (even if the package.json version is incremented). You have to delete the dependency from the node_modules and delete (or edit) the yarn.lock/package-lock.json file (though I believe yarn upgrade does now upgrade git packages). We do have scripts to do this but, ew.
  3. We have script in our CI/CD pipelines that have to "fix" the branches in the package.json for internal dependencies, this increases build time considerably, and makes it quite fragile. Basically:
    1. yarn install --frozen-lockfile
    2. ./fixInternalPrivatePackages.sh package.json $BRANCH #where $branch can be #qa, feature-blah, etc.
    3. yarn install #to now get any changed dependencies, sometimes modifies other unrelated deps in the lockfile
    4. yarn run build

And then it's pushed to a Docker registry.

With this setup the lockfile sometimes gets modified causing builds to fail. It's also a pain to manage on dev machines. Devs sometimes check-in their package.json with the wrong #branch and this causes other peoples builds to fail.

Possible solutions:

  1. Automate tagging internal dependencies, then adjust the package.json with these tags (could really just be the commit hash).
  2. Private package repository. This fixes getting the latest version if the latest is always pushed. I believe this should fix the fixInternalPrivatePackages hacky script situation as well.
  3. Git/NPM pre/post hooks/scripts to fix a project's own package.json (remove all branches, etc.)

But all these solutions just seem like more band-aids on a fundamental problem. Are we doing this the right way? Are there any example projects with internal dependencies like this that I could get some inspiration from?

I feel like one fundamental issue is that the internal dependencies need their own independent QA->Prod cycle so that they are already locked to a specific version before the rest of the app is moved along from QA->prod.

Another one is that while yarn and npm now have lockfiles (we don't talk about the time before lockfiles), our workflow breaks this functionality when it has to modify the package.json to switch branches, and reinstall dependencies without the --frozen-lockfile switch. We want reproducible builds and I can't guarantee that we have them.

It takes a long time to get a developer up to speed on our project because of all these configuration management issues, the actual code itself is much simpler than the DevOps knowledge required to get it running.

  • From your problem description it seems like the app and the dependencies are always developed together, so that work on a dependency requires changes to the application build process. This suggests such dependencies should not be treated as a separate package/repository – they are part of the same codebase. But later you note that dependencies have an independent lifecycle. Could you clarify your development approach, e.g. explain why a monorepo would not be appropriate? – amon Aug 16 '18 at 6:31
  • 1
    @amon, The project started as a monorepo (in TFS), but build times were atrocious (~30-45 mins). Though that mostly was a function of the slow TFS build server. We split it out to 2 APIs, 2 Apps (front ends), and 4 less often updated dependencies (translations, utils, configuration, common UI components). This more-or-less mirrors the Docker service setup (2 APIs, 2 Apps, +DB), but otherwise was a matter of personal preference at the time. – Nick Aug 16 '18 at 13:04
  • @amon ...but now that you bring it up I suppose we could migrate to a monorepo. The dependencies are tightly coupled. I need to see how well NPM/yarn/our build handles local dependencies. – Nick Aug 16 '18 at 13:07

Well, I stumbled on Lerna from a post from Hacker News and it appears to be just what we need. I will accept if it works out but it's going to be a while.

Splitting up large codebases into separate independently versioned packages is extremely useful for code sharing. However, making changes across many repositories is messy and difficult to track, and testing across repositories gets complicated really fast.

To solve these (and many other) problems, some projects will organize their codebases into multi-package repositories. Projects like Babel, React, Angular, Ember, Meteor, Jest, and many others develop all of their packages within a single repository.

Lerna is a tool that optimizes the workflow around managing multi-package repositories with git and npm.

I'm also removing the fixInternalPrivatePackages.sh CI step and just checking in the branched project's package.json as it should be. This will require manual steps if a new branch is added to a dependency but that happens less often than problems from the CI script.

UPDATE Sept 2018:

Lerna is nice but won't help our CI workflow. It's more for dev workstations. We really need a private package repository to keep published versions. QA and feature branches can use latest tags, where production can use our semver-ish tags.

I discovered Verdaccio, and I'm hoping it will resolve our dependency hell.

UPDATE Dec 2018:

The React project itself seems well organized and a good project to imitate. Using yarn workspaces seems like a good idea -- but it would take time to convert everything to a monorepo.

  • How'd it go with verdaccio? – thisgeek Feb 28 at 21:40
  • @thisgeek -- Couldn't tell ya, I switched jobs :) – Nick Feb 28 at 21:52

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