使用 Google Cloud API 和 Python - 使用库创建计划 Sanpshots

Question

I'm probably very confused with the API concepts but I'm not understanding how to use REST Google API with Python.

On the API documentation , it said to use HTTP Requests or client libs (in case of Python, libcloud or Google API Python Client Library. I saw examples for some functionalities that work well like, create VMs or attaching disks.

Although, I could not find an example pure REST request, like, if I want to create a scheduled snapshot.

So I have two questions:

1. How to use libs to authenticate and call a function that the lib doesn't have a built-in method (like schedule snapshots)?

According to documentation, should be a request like this:

https://compute.googleapis.com/compute/v1/projects/{PROJECT_ID}/regions/{REGION_ID}/resourcePolicies

    {
        "name": "name",
        "snapshotSchedulePolicy": {
        "schedule": {
            "dailySchedule": {
            "startTime": "12:00",
            "daysInCycle": "1"
            }
        },
        "retentionPolicy": {
            "maxRetentionDays": "5"
        },
        "snapshotProperties": {
            "guestFlush": "False",
            "labels": {
            "env": "dev",
            "media": "images"
            },
            "storageLocations": ["US"]
        }
    }

2. Can I use the API, inside a Cloud Functions, without worrying to get a Token?

Someone can help me understand this better?

Thanks in advance

Answer 1

This can be confusing but it's reasonably well documented on Google Cloud and I encourage you to have a read around on there for more details.

For the specific API method you describe:

https://cloud.google.com/compute/docs/reference/rest/beta/resourcePolicies/insert

This page includes the ability to invoke the API method yourself (see right hand side of the page). This uses the most-excellent Google APIs Explorer which you may also access directly:

https://developers.google.com/apis-explorer

and, drilling down into Compute Engine beta:

https://cloud.google.com/compute/docs/reference/rest/beta/#rest-resource:-beta.resourcepolicies

Another useful (trick) is to issue (any) gcloud command with the flag --log-http . This will then include the HTTP method request|response details that underlie the command and this can help you better understand what's going on. In your case:

gcloud beta compute resource-policies ... --log-http

There are 2 types of Google-provided library. The older API client libraries and the newer Cloud. See:

https://cloud.google.com/apis/docs/client-libraries-explained

API client libraries are machine-generated and you should be able to access all API methods for all libraries for all Google's supported languages with these.

Cloud client libraries are hand-crafted (mainly) and these often lag the underlying APIs.

Compute Engine does not have Cloud client libraries (for any language; go figure.), So. you should be able to invoke the beta resourcepolicies using the Python API client library.

That said, you may always hand-craft REST calls yourself in your preferred language but this is discouraged because it requires you to manage auth etc. yourself and this can be challenging .

Yes, you could make (any) REST call from Cloud Functions but you will always need to auth the call if the backing service requires authentication.