Add information about how to configure GCS for runners cache via values.yaml
GCS configuration for runners cache is described in the [runners.cache.gcs] section, and values.yaml file has an example section about GCS:
## If you want to use gcs based distributing caching:
## First of all you need to uncomment General settings and GCS settings sections.
##
## Access using credentials file:
## Create a secret 'google-application-credentials' containing your application credentials file.
## ref: https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-runners-cache-gcs-section
## You could configure
## $ kubectl create secret generic google-application-credentials \
## --from-file=gcs-applicaton-credentials-file=./path-to-your-google-application-credentials-file.json
## ref: https://kubernetes.io/docs/concepts/configuration/secret/
##
## Access using access-id and private-key:
## Create a secret 'gcsaccess' containing 'gcs-access-id' & 'gcs-private-key'.
## ref: https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-runners-cache-gcs-section
## You could configure
## $ kubectl create secret generic gcsaccess \
## --from-literal=gcs-access-id="YourAccessID" \
## --from-literal=gcs-private-key="YourPrivateKey"
## ref: https://kubernetes.io/docs/concepts/configuration/secret/
cache: {}
## General settings
# cacheType: s3
# cachePath: "gitlab_runner"
# cacheShared: true
## S3 settings
# s3ServerAddress: s3.amazonaws.com
# s3BucketName:
# s3BucketLocation:
# s3CacheInsecure: false
# secretName: s3access
## GCS settings
# gcsBucketName:
## Use this line for access using access-id and private-key
# secretName: gcsaccess
## Use this line for access using google-application-credentials file
# secretName: google-application-credentials
However, this section is not clear and hard to find on the spot. We should add the steps about configuring GCS runners cache to https://docs.gitlab.com/runner/configuration/advanced-configuration.html, I suppose the table in the [runners.cache] section could be updated with the additional row values.yaml
.