How to specify local registry in yarn?

Question

I have a local nexus server, I'd like yarn to look through it before going online, basically prefer-offline

yarn install \   --prefer-offline \   --cache-folder C:\folder\yarn-cache \   --preferred-cache-folder C:\folder\yarn-cache \   --non-interactive \   --no-lockfile \   --registry http://server/repository/npm-group 

Yarn fails to find a dependency offline then fails to go online. I don't know if that can be fixed.

Answer 1

• Create an npm (hosted) repository to use as your private registry. I believe you have already done this.
• Create an npm (proxy) repository pointing to your external repository of choice (https://registry.yarnpkg.com or https://registry.npmjs.org/).
• Create an npm (group) with your private registry on first position and the proxy registry on second position.
• Point yarn to your group repository: yarn config set registry http://nexus.local/repository/npm-group/. If required by your Nexus configuration, authenticate yarn: yarn login.

Also be wary of yarn using any npm config you might have over it's own: https://github.com/yarnpkg/yarn/issues/4862

Update for Yarn v2+:

Yarn v2+ uses a different configuration key for updating the NPM registry, called npmRegistryServer (see their Migration page for details):

yarn config set npmRegistryServer http://nexus.local/repository/npm-group/ 

Answer 2

You can set a different registry in yarn by using the following command:

yarn config set registry <url-to-your-registry> 

Verify that it has been set by typing the following command:

yarn config get registry 

For a one-off change in registry you can use the variable YARN_REGISTRY like this:

YARN_REGISTRY="<url-to-your-registry>" yarn config get registry 

or

YARN_REGISTRY="<url-to-your-registry>" yarn publish