driver can not parse tag values containing a coma

[RomanBednar]

Driver can not parse tag value with a coma:

$ oc -n openshift-cluster-csi-drivers get deployment.apps/gcp-pd-csi-driver-controller -o json | jq '.spec.template.spec.containers[0].args[-1]'
"--extra-tags=parent1/key1/value,with,coma/parent2/key2/value2"

$ oc -n openshift-cluster-csi-drivers logs pod/gcp-pd-csi-driver-controller-654845fb89-dqlrp
...
I0815 11:34:35.519878       1 main.go:125] Driver vendor version v1.1.0-rc1-1347-gc770b412-dirty
F0815 11:34:35.524193       1 main.go:166] Bad extra tags: tag "with" is invalid, correct format: 'parent_id1/key1/value1,parent_id2/key2/value2'

Escaping does not work either:

$ oc -n openshift-cluster-csi-drivers get deployment.apps/gcp-pd-csi-driver-controller -o json | jq '.spec.template.spec.containers[0].args[-1]'
"--extra-tags=parent1/key1/value\\,with\\,coma/parent2/key2/value2"

$ oc -n openshift-cluster-csi-drivers logs pod/gcp-pd-csi-driver-controller-78495f87c7-qjvj5
Defaulted container "csi-driver" out of: csi-driver, csi-provisioner, provisioner-kube-rbac-proxy, csi-attacher, attacher-kube-rbac-proxy, csi-resizer, resizer-kube-rbac-proxy, csi-snapshotter, snapshotter-kube-rbac-proxy, csi-liveness-probe
I0815 11:41:27.848600       1 main.go:111] Operating compute environment set to: production and computeEndpoint is set to: <nil>
I0815 11:41:27.848714       1 main.go:120] Sys info: NumCPU: 6 MAXPROC: 1
I0815 11:41:27.848721       1 main.go:125] Driver vendor version v1.1.0-rc1-1347-gc770b412-dirty
F0815 11:41:27.851228       1 main.go:166] Bad extra tags: tag value "value\\" for tag "parent1/key1/value\\" is invalid. Tag value can have a maximum of 63 characters and cannot be empty. Tag value must begin and end with an alphanumeric character, and must contain only uppercase, lowercase alphanumeric characters, and the following special characters `_-.@%=+:,*#&(){}[]` and spaces

According to GCP documentation comas are allowed for tag values: https://cloud.google.com/resource-manager/docs/tags/tags-creating-and-managing#adding_tag_values

OpenShift recently added support for allowing users to set custom GCP labels and tags during installation: https://github.com/openshift/enhancements/blob/master/enhancements/api-review/gcp_user_defined_labels.md#apply-user-defined-labels-to-all-gcp-resources-created-by-openshift

And the allowed values are documented to match the GCP documentation: https://docs.openshift.com/container-platform/4.16/installing/installing_gcp/installing-gcp-customizations.html#installing-gcp-cluster-creation_installing-gcp-customizations

So in OpenShift we don't prevent using comas either for tag values, and if users attempt to use them the driver will fail. Either we need to add some escaping to the driver or disallow using comas for tag values and update the documentation accordingly.

NOTE: This can can be reproduced easily by creating a tag in GCP manually and passing it to --extra-tags arg of the driver, followed by dynamic volume provisioning.

[RomanBednar]

cc @mattcary @sunnylovestiramisu