We had a bad type coercion in the code to update container cluster
resource labels. This fixes the coercion.
We didn't notice this because there was no test exercising the update
code path. I've added the test, which reproduced the panic before this
PR was applied and passes successfully now that the coercion is fixed.
Images now have a licenses field, which lets users specify licenses to
use on an image. But official images already have licenses on them, adn
so Terraform is reading those as a diff. To preserve backwards
compatiblity and avoid a breaking change that would require all
`google_compute_image` users to update their configs, I've set the field
to computed. This means that if no licenses are set in the config, there
can be licenses in the config without prompting a diff. Obviously, this
isn't ideal, as it means you can't ever remove all the licenses from an
image, but I think the benefits here outweigh the drawbacks.
In testing an upcoming `google_compute_region_disk` resource, I had to make these changes. Checking them in separately so that when the magician runs, these changes will already be a part of TF.
Currently, the rolling-update API expects a PUT (regionInstanceGroupManager.update())
instead of a PATCH (regionInstanceGroupManager.patch()) call, so immediate rolling updates
(as specified with `update_strategy = "ROLLING_UPDATE"``) are never triggered:
```
[DEBUG]: ---[ REQUEST ]---------------------------------------
[DEBUG]: POST /compute/beta/projects/mycompany-myapp-staging/regions/europe-west3/instanceGroupManagers/myapp-server/setInstanceTemplate?alt=json HTTP/1.1
....
[DEBUG]: ---[ RESPONSE ]--------------------------------------
...
[DEBUG]: "warnings": [
[DEBUG]: {
[DEBUG]: "code": "FIELD_VALUE_OVERRIDEN",
[DEBUG]: "message": "Update policy type was set to OPPORTUNISTIC. Please use regionInstanceGroupManager.update() to preserve the policy."
[DEBUG]: }
```
refs:
https://cloud.google.com/compute/docs/reference/rest/beta/instanceGroupManagers/patchhttps://cloud.google.com/compute/docs/reference/rest/beta/instanceGroupManagers/updateFix#1506