Deployment adds JobSpecModifyIndex

Deployment tracks the Job.JobModifyIndex so that PUTS against /v1/jobs
can be more easily coorelated with the created deployment.

Fixes https://github.com/hashicorp/nomad/issues/4301

api/deployments.go

@@ -125,17 +125,44 @@ func (d *Deployments) SetAllocHealth(deploymentID string, healthy, unhealthy []s
 
 // Deployment is used to serialize an deployment.
 type Deployment struct {
-	ID                string
-	Namespace         string
-	JobID             string
-	JobVersion        uint64
-	JobModifyIndex    uint64
-	JobCreateIndex    uint64
-	TaskGroups        map[string]*DeploymentState
-	Status            string
+	// ID is a generated UUID for the deployment
+	ID string
+
+	// Namespace is the namespace the deployment is created in
+	Namespace string
+
+	// JobID is the job the deployment is created for
+	JobID string
+
+	// JobVersion is the version of the job at which the deployment is tracking
+	JobVersion uint64
+
+	// JobModifyIndex is the modify index of the job at which the deployment is
+	// tracking. This is the ModifyIndex field on the job.
+	JobModifyIndex uint64
+
+	// JobSpecModifyIndex is the modify index of the job spec at which the
+	// deployment is tracking. This is the JobModifyIndex field on the job.
+	JobSpecModifyIndex uint64
+
+	// JobCreateIndex is the create index of the job which the deployment is
+	// tracking. It is needed so that if the job gets stopped and reran we can
+	// present the correct list of deployments for the job and not old ones.
+	JobCreateIndex uint64
+
+	// TaskGroups is the set of task groups effected by the deployment and their
+	// current deployment status.
+	TaskGroups map[string]*DeploymentState
+
+	// The status of the deployment
+	Status string
+
+	// StatusDescription allows a human readable description of the deployment
+	// status.
 	StatusDescription string
-	CreateIndex       uint64
-	ModifyIndex       uint64
+
+	CreateIndex uint64
+	ModifyIndex uint64
 }
 
 // DeploymentState tracks the state of a deployment for a given task group.