Yarn is not installed

[GoldFlsh]

We are using a self-hosted runner and using this action to setup-node and install yarn.

I know on github-hosted runners, yarn is already pre-installed but it would be good if yarn was installed by this action for those of us using self-hosted.

Running setup-node with the following workflow and it works

 with:
    node-version: 12.13.0
    always-auth: true
    registry-url: https://registry.npmjs.org

/usr/bin/tar xz --warning=no-unknown-keyword -C /actions-runner/_work/_temp/febce1c0-314e-4a14-9a65-5bde8a990b71 -f /actions-runner/_work/_temp/d4bf33ab-571e-458e-9495-bd6c5b994814
/actions-runner/_work/_tool/node/12.13.0/x64/bin/node --version
v12.13.0
/actions-runner/_work/_tool/node/12.13.0/x64/bin/npm --version
6.12.0

Note that node and npm are installed.

A later step in the workflow then attempts to run yarn:

Run yarn install --ignore-scripts --frozen-lockfile
/actions-runner/_work/_temp/58e53b82-f9ae-4c68-9cec-75f75831208b.sh: line 1: yarn: command not found
##[error]Process completed with exit code 127.

This of course works on github hosted runners just fine, but since I just migrated to an EC2 instance that doesn't have yarn installed, I am now having issues.

[GoldFlsh]

Workaround is to install yarn yourself using npm (after running this action)

- name: Install Yarn
   run: npm install -g yarn

and later can uninstall it -

- name: Uninstall Yarn
   if: always()
   run: npm uninstall -g yarn

While this works, I find it rather hacky. It would be good for this action to not need to rely on github's instances to have yarn package installed.

EDIT:
I wanted to add the documentation acts as if yarn is a given, since it has sections on usage with yarn
Publish to npmjs and GPR with yarn:. Perhaps some clarification in that section that if you're on self-hosted runners you will need to install yarn yourself via npm install -g yarn and uninstall it at the end of your job with npm uninstall -g yarn

[pperzyna]

GitHub Runners creates a file called .path in the same directory where you have config.sh. It contains the content of $PATH variable, which is further used during the execution of your workflows.

You have to add a directory with the yarn binary. In my case:

/home/github/.yarn/bin`

[vicke4]

@pperzyna thanks! I spent 30mins guessing why it was not working even after updating the path. Seems run.sh has to be restarted.

[konsalex]

npm install -g yarn

Hey @GoldFlsh , why should we uninstall yarn at the end of a job?

[GoldFlsh]

@konsalex Since self-hosted runners are shared and are not a clean instance per job execution, like a github hosted runner would be, the job should do its best to clean itself up after a run so that each future workflow run is running on what amounts to a fresh instance.

If you install software during the run, such as yarn, redis, or terraform without uninstalling it, could potentially cause conflicts with other jobs running as the state of the instance moves further away from the original state.

Say then you try to upgrade versions of something in your workflow but since the old version is still installed from a previous run it may use that and create a difficult to debug situation.

As others have mentioned you can pre-install any software on a self-hosted runner so the workflow itself does not have to be responsible for installing anything, which would side-step this altogether.

Up to you, of course, how you best want to manage that 😃

https://docs.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners#differences-between-github-hosted-and-self-hosted-runners

[davide-bertola-deltatre]

Note that if you use with: cache: yarn this action will fail if you don't have yarn pre-installed... But since you need node to install yarn.. you can't get out of this without running this action twice or using other actions.

[chriskilding]

To +1 on Davide's comment, the lack of yarn install support is a significant obstacle to those of us on self-hosted runners.

The only way to break the chicken-or-egg with: cache: yarn problem, and make caching work on self-hosted runners, is to preinstall yarn on the runner base image (like GitHub does for its own runners). This is not good because then yarn is being managed both by setup-node, and out-of-band by the preinstall step.

[mila411]

Hi everyone. I faced the same problem and this may sound really stupid, but I solved it this way:
(Thanks for the tip, @davide-bertola-deltatre)

jobs:
  node-ci:
    runs-on: self-hosted
    steps:
      - uses: actions/checkout@v2

      - name: Setup Nodejs and npm
        uses: actions/setup-node@v2
        with:
          node-version: "14"

      - name: Setup yarn
        run: npm install -g yarn

      - name: Setup Nodejs with yarn caching
        uses: actions/setup-node@v2
        with:
          node-version: "14"
          cache: yarn

      - name: Install dependencies
        run: yarn

NOTE: This way, if you run the yarn uninstall in the step, the Post process will not be able to find yarn and the job will fail.

Actions log shows that the cache was successful, but I am not sure if it is really cached in this case.

Cache Size: ~118 MB (124177777 B)
Cache saved successfully
Cache saved with the key: foo-bar-baz

When I connected to the runner instance that ran the job and ran the yarn command, I got not found, so everything seems to be working. However, this is not an essential solution and I also hope that yarn will be installed with it.

[jasonk]

FYI: There isn't a chicken-and-egg problem, you don't need Node to install yarn:

curl -fsSL -o ~/bin/yarn \
  https://github.com/yarnpkg/yarn/releases/download/v1.22.17/yarn-1.22.17.js
chmod +x ~/bin/yarn

[mila411]

I think the point of contention here is that we need to return the runner back clean. It's easy enough to install the binaries, but given the hassle of making sure they're purged every time, I'd prefer to see them included under Node's control