Get npm package latest version from a gitlab registry - npm

Question

I'm trying to put a package in a Gitlab registry using npm and .gitlab-ci.yml.
.gitlab-ci.yml
npm-package:
stage: build
image: node:buster
before_script:
- git config --global user.name "${GITLAB_USER_NAME}"
- git config --global user.email "${GITLAB_USER_EMAIL}"
script:
- npm config set #${CI_PROJECT_ROOT_NAMESPACE}:registry=https://${CI_SERVER_HOST}/api/v4/projects/${CI_PROJECT_ID}/packages/npm/
- npm config set //${CI_SERVER_HOST}/api/v4/projects/${CI_PROJECT_ID}/packages/npm/:_authToken=${CI_JOB_TOKEN}
- NPM_PACKAGE_NAME=$(node -p "require('.package.json').name")
- NPM_PACKAGE_VERSION=$(node -p "require('./package.json').version")
- echo $(npm view "${NPM_PACKAGE_NAME}" versions)
- echo ${NPM_PACKAGE_NAME}
- echo ${NPM_PACKAGE_VERSION}
- |
if [[ $(npm view "${NPM_PACKAGE_NAME}" versions) != *"'${NPM_PACKAGE_VERSION}'"* ]]; then
npm config set //${CI_SERVER_HOST}/api/v4/projects/${CI_PROJECT_ID}/packages/npm/:_authToken=${CI_JOB_TOKEN}
npm publish
echo "Successfully published version ${NPM_PACKAGE_VERSION} of ${NPM_PACKAGE_NAME} to GitLab's NPM registry: ${CI_PROJECT_URL}/-/packages"
else
echo "Version ${NPM_PACKAGE_VERSION} of ${NPM_PACKAGE_NAME} has already been published, so no new version has been published."
fi
I tried my first time and the package was saved successfully in the repo. And now I'm trying to run it under the condition: if the version's package has changed then run an npm publish.
But the variable $(npm view "${NPM_PACKAGE_NAME}" versions) seems to be empty, and when I try to echo it I get the error:
npm ERR! code E401
npm ERR! 401 Unauthorized - GET https://gitlab.example.com/api/v4/projects/1/packages/npm/#my_scope/my_package
Any help?

Answer 1

Your CI does not have enough rights.
1- You need to generate an access token (automation type) from your npm registry via the npm UI (or via the command line).
The process with the UI:
https://docs.npmjs.com/creating-and-viewing-access-tokens
2- Assign the token to an environment variable (named NPM_TOKEN in this example) accessible to your CI
3- Then create (or update) a .npmrc file with this line at the top:
//registry.npmjs.org/:_authToken=${NPM_TOKEN}