yarn with private npm registries and authentication
We recently switched over a project from npm to yarn. Our existing project npm configuration (i.e. npmrc) specified private registries with authentication. I assumed that yarn would use existing npm configurations. However, after following this yarn issue thread, you must have a project yarnrc with the custom registries specified. Once the registries are defined, the existing npm configurations are used for authentication.
For example, the project folder already had the following .npmrc:
registry=https://npm.joegornick.com
@foo:registry=https://npm.foo.com
_auth={token}
//npm.foo.com/:_authToken={token}
I then added the following .yarnrc to the project:
registry "https://npm.joegornick.com"
"@foo:registry" "https://npm.foo.com"