cmd/coordinator: start of logging

For now, just log the process's start time and alive/heartbeat time.

Updates golang/go#12669

Change-Id: I4dd28f7ba761b5487f86a4cdb0f721b2aeb4fa57
Reviewed-on: https://go-review.googlesource.com/22701
Reviewed-by: Andrew Gerrand <adg@golang.org>

cmd/coordinator/buildongce/create.go

@@ -29,6 +29,7 @@ import (
 	compute "google.golang.org/api/compute/v1"
 	dm "google.golang.org/api/deploymentmanager/v2"
 	"google.golang.org/api/googleapi"
+	"google.golang.org/cloud/datastore"
 )
 
 var (
@@ -241,6 +242,7 @@ func createCoordinator() error {
 					compute.DevstorageFullControlScope,
 					compute.ComputeScope,
 					compute.CloudPlatformScope,
+					datastore.ScopeDatastore,
 				},
 			},
 		},

cmd/coordinator/coordinator.go

@@ -55,7 +55,10 @@ import (
 
 const subrepoPrefix = "golang.org/x/"
 
-var processStartTime = time.Now()
+var (
+	processStartTime = time.Now()
+	processID        = "P" + randHex(9)
+)
 
 var Version string // set by linker -X
 
@@ -268,6 +271,9 @@ func main() {
 		kubeErr = err
 		log.Printf("Kube support disabled due to eror initializing Kubernetes: %v", err)
 	}
+
+	go updateInstanceRecord()
+
 	switch *mode {
 	case "dev", "prod":
 		log.Printf("Running in %s mode", *mode)

cmd/coordinator/gce.go

@@ -33,6 +33,7 @@ import (
 	"google.golang.org/api/googleapi"
 	"google.golang.org/cloud"
 	"google.golang.org/cloud/compute/metadata"
+	"google.golang.org/cloud/datastore"
 	"google.golang.org/cloud/storage"
 )
 
@@ -53,6 +54,7 @@ func gceAPIGate() {
 var (
 	buildEnv *buildenv.Environment
 
+	dsClient       *datastore.Client
 	computeService *compute.Service
 	tokenSource    oauth2.TokenSource
 	serviceCtx     context.Context
@@ -122,6 +124,12 @@ func initGCE() error {
 		}
 	}
 
+	dsClient, err = datastore.NewClient(context.Background(), buildEnv.ProjectName)
+	if err != nil {
+		// TODO(bradfitz): make fatal later, once working.
+		log.Printf("Error creating datastore client: %v", err)
+	}
+
 	computeService, _ = compute.New(httpClient)
 	errTryDeps = checkTryBuildDeps()
 	if errTryDeps != nil {

cmd/coordinator/log.go

@@ -0,0 +1,46 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"log"
+	"time"
+
+	"google.golang.org/cloud/datastore"
+
+	"golang.org/x/net/context"
+)
+
+// Process is a datastore record about the lifetime of a coordinator process.
+//
+// Example GQL query:
+// SELECT * From Process where LastHeartbeat > datetime("2016-01-01T00:00:00Z")
+type Process struct {
+	ID            string
+	Start         time.Time
+	LastHeartbeat time.Time
+
+	// TODO: version, who deployed, CoreOS version, Docker version,
+	// GCE instance type?
+}
+
+func updateInstanceRecord() {
+	if dsClient == nil {
+		return
+	}
+	ctx := context.Background()
+	for {
+		key := datastore.NewKey(ctx, "Process", processID, 0, nil)
+		_, err := dsClient.Put(ctx, key, &Process{
+			ID:            processID,
+			Start:         processStartTime,
+			LastHeartbeat: time.Now(),
+		})
+		if err != nil {
+			log.Printf("datastore Process Put: %v", err)
+		}
+		time.Sleep(30 * time.Second)
+	}
+}