Generating synthetic logs for GCP Cloud Logging

synthetic.go

package main

/*
$ gcloud compute instances create vm1 --shielded-secure-boot  --scopes=cloud-platform  --zone=us-central1-a   --shielded-vtpm --shielded-integrity-monitoring
NAME  ZONE           MACHINE_TYPE   PREEMPTIBLE  INTERNAL_IP   EXTERNAL_IP     STATUS
vm1   us-central1-a  n1-standard-1               10.128.0.104  35.224.160.133  RUNNING



$ gcloud compute instances describe vm1 --format="value(id)"
8208965068975117794
*/


import (
	"flag"
	"fmt"

	"cloud.google.com/go/logging"
	"golang.org/x/net/context"
	"google.golang.org/genproto/googleapis/api/monitoredres"
)

const ()

type PcrValue struct {
	HashAlgo string `json:"hashAlgo,omitempty"`
	PcrNum   string `json:"pcrNum,omitempty"`
	Value    string `json:"value,omitempty"`
}
type EarlyBootAttestationReportEvent struct {
	ActualMeasurements     []PcrValue `json:"actualMeasurements,omitempty"`
	PolicyEvaluationPassed bool       `json:"policyEvaluationPassed,omitempty"`
}

// type.googleapis.com/cloud_integrity.IntegrityEvent is not exported to github so have to make parts
// of the struct by hand
type IntegrityEvent struct {
	Type                 string                          `json:"@type,omitempty"`
	BootCounter          uint64                          `json:"bootCounter,omitempty"`
	EarlyBootReportEvent EarlyBootAttestationReportEvent `json:"earlyBootReportEvent,omitempty"`
}

var (
	projectID = flag.String("projectID", "mineral-minutia-820", "projectID")
)

func main() {

	flag.Parse()

	if *projectID == "" {
		fmt.Println("projectID must be set")
		return
	}
	ctx := context.Background()

	client, err := logging.NewClient(ctx, *projectID)
	if err != nil {
		fmt.Printf("%v", err)
		return
	}

	defer client.Close()

	logName := "compute.googleapis.com%2Fshielded_vm_integrity"

	logger := client.Logger(logName)
	jsonPayload := &IntegrityEvent{
		Type: "type.googleapis.com/cloud_integrity.IntegrityEvent",
		EarlyBootReportEvent: EarlyBootAttestationReportEvent{
			ActualMeasurements: []PcrValue{
				{
					HashAlgo: "SHA1",
					PcrNum:   "PCR_1",
					Value:    "foooooo",
				},
			},
			PolicyEvaluationPassed: true,
		},

		BootCounter: 10,
	}

	m := make(map[string]string)

	m["project_id"] = "mineral-minutia-820"
	m["instance_id"] = "8208965068975117794"
	m["zone"] = "us-central1-a"

	logger.Log(logging.Entry{
		Resource: &monitoredres.MonitoredResource{
			Type:   "gce_instance",
			Labels: m,
		},
		Payload: jsonPayload,
	})

	if err := client.Close(); err != nil {
		fmt.Printf("Failed to close client: %v", err)
		return
	}

	fmt.Printf("Logged:\n")

}

Actual logs

Synthetic logs