Create nightly Google Cloud VM by Snapshot

Question

I created a Google Cloud Compute Engine and have it backuped (snapshot) nightly. I have a second VM in the same project, which is a clone of the first one. Is it possible to updated the second VM instance every time with the new just created snapshot of the first? So i have a failback server which is at worst 24h old?

Answer 1

You will most like have to create a new instance from the snapshot, validate the new instance is healthy and delete your second VM instance. The gcloud sdk has a flag for that -

gcloud compute instances create with --source-snapshot=SNAPSHOT flag.

I am not sure about your case, but it seems the newly release GCP machine images might be a good alternative to consider. It provides features not available in disk snapshot such as multiple disk backup, instance cloning and replication. You can create an instance from a machine image with all the instance properties, configuration, data intact.

Answer 2

If anyone faces the same problem, i wrote a Cloud Function and scheduled it every day. The steps are:

1. Get latest Snapshot
2. Delete old VM
3. Create new VM
4. Put the newly created VM IP to Cloudflare LoadBalancer

This is the Code for it:

    const Compute = require("@google-cloud/compute");
    const axios = require("axios");

    const compute = new Compute({
      projectId: "myProjectID",
      keyFilename: "./gcloud_key.json"
    });

    exports.updateFailOverVM = async (pubSubEvent, context) => {
      try {
        const snapshots = await compute.getSnapshots({
          orderBy: "creationTimestamp desc"
        });
        const snapshot = snapshots[0][0];
        console.log(`Going to use Snapshot: ${snapshot.name}`);
        const sourceSnapshot = `https://www.googleapis.com/compute/v1/projects/myProjectID/global/snapshots/${snapshot.name}`;

        const zone = compute.zone("MySelectedZone");
        const vm = zone.vm("MyVMName");

        // Delete old FailOver
        console.log("start deleting old VM");
        const [deleteOperation] = await vm.delete();

        deleteOperation.on("complete", async function(metadata) {
          console.log("finished deleting old VM");

          // Create new VM
          console.log("start creating new VM");
          const [newVM, createOperation] = await vm.create({
            http: false,
            https: true,
            machineType: "n1-standard-1",
            disks: [
              {
                initializeParams: {
                  sourceSnapshot
                },
                sizeGb: 50,
                type:
                  "projects/MyProjectID/zones/mySelectedZone/diskTypes/pd-standard",
                boot: true
              }
            ]
          });
          createOperation.on("complete", async function(metadata) {
            const [newVMMeta] = await vm.getMetadata();
            const newIP = newVMMeta.networkInterfaces[0].accessConfigs[0].natIP;
            console.log("finished creating new VM");

            // Route Cloudflare to new IP
            console.log("Put new IP to Cloudflare");
            await axios({
              method: "patch",
              url:
                "https://api.cloudflare.com/client/v4/user/load_balancers/pools/MyPoolID",
              data: {
                origins: [
                  {
                    name: "MyPoolName",
                    address: newIP,
                    enabled: true,
                    weight: 1
                  }
                ]
              },
              headers: {
                "X-Auth-Email": "MyCloudflareEmail",
                "X-Auth-Key": "MyCloudflareAuthKey"
              }
            });
            console.log("Finished putting IP to Cloudflare");
          });
        });
      } catch (err) {
        console.error(err);
      }
    };