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
Make it clear that regional backend services are only for internal load
balancing, and fix the default for protocol. It's not HTTP, as the API
docs claim, but is TCP instead.
This was done as its own resource as suggested in slack, since we don't have the option of making all fields Computed in google_compute_instance. There's precedent in the aws provider for this sort of thing (see ami_copy, ami_from_instance).
When I started working on this I assumed I could do it in the compute_instance resource and so I went ahead and reordered the schema to make it easier to work with in the future. Now it's not quite relevant, but I left it in as its own commit that can be looked at separately from the other changes.
Fixes#1582.
