Private registry works with npm but not with yarn when deploying on vercel

[agcty]

We're using yarn to build the project and have a private github npm registry to host some of our packages.
In out vercel dashboard, we've correctly set the NPM_RC variable. When deploying our next.js project with npm, the private packages get fetched and everything works as expected. However, when we do the same thing with yarn, the deployment fails with a 401 unauthorized error code when trying to access the private registry.

Locally, both yarn and npm work with the same .npmrc file.

Local npm version: 6.14.8
Local yarn version: 1.22.10

Vercel seems to deploy with yarn 1.22.4, not sure if this is an issue.

Has anyone managed to deploy a project both yarn and a private registry?

[agcty]

So after reaching out to vercel support, they showed me this issue: yarnpkg/yarn#3093

You have to make your .npmrc look exactly like this:

always-auth=true
@zerolens-com:registry=https://npm.pkg.github.com/YOUR_USERNAME/
//npm.pkg.github.com/:_authToken=YOUR_TOKEN
//npm.pkg.github.com/YOUR_USERNAME/:_authToken=YOUR_TOKEN
registry=https://registry.npmjs.org

You somehow need always-auth=true and both npm.pkg.github.com lines

[nathanielpomianowski]

Does anyone have a solution for this when using a Gitlab private registry under a self-hosted gitlab?

[amyegan]

For private GitLab resources, you could create a deploy token and use that as part of the address (source: https://stackoverflow.com/a/27015550)

[nathanielpomianowski]

I found a solution for anyone using Gitlab private registry:

always-auth=true
@<GROUP_OR_USER_NAME>:registry=https://<PRIVATE_INSTANCE_NAME>/api/v4/packages/npm/
//<PRIVATE_INSTANCE_NAME>/api/v4/projects/:_authToken=<PROJECT_ID>/packages/npm/:_authToken=<GITLAB_TOKEN>
//<PRIVATE_INSTANCE_NAME>/api/v4/packages/npm/:_authToken=<GITLAB_TOKEN>
registry=https:registry.npmjs.org

i.e.
<GROUP_OR_USER_NAME> == foo (Either a group or your individual name. Keep this lowercase)
<PRIVATE_INSTANCE_NAME> == gitlab.example.com
<PROJECT_ID> == 42
<GITLAB_TOKEN> == jlfwjl$@l2jlwjf

[allan-almeida]

For new versions of Yarn, (I am using 2.4.0), I was able to successfully deploy to Vercel by adding the following to my .yarnrc.yml file:

npmScopes:
  YOUR_SCOPE:
    npmRegistryServer: 'https://npm.pkg.github.com'
    npmAlwaysAuth: true
    npmAuthToken: ${GITHUB_PACKAGE_TOKEN}

as per https://yarnpkg.com/configuration/yarnrc#npmScopes.

I also added GITHUB_PACKAGE_TOKEN as an environment variable to my builds in Vercel.

[heygrady]

This worked for me but it's not very portable to do it this way. It was causing issues on my local environment as some of my local apps aren't running in the same context. However, I was inspired by this solution and discovered a better way for me.

https://yarnpkg.com/configuration/yarnrc/

Finally, note that most settings can also be defined through environment variables[...]. To do this, just prefix the names and write them in snake case: YARN_CACHE_FOLDER will set the cache folder.

I added a YARN_NPM_AUTH_TOKEN environment variable in my vercel project settings and that seemed to work great.