nomad: working on allocation schema

nomad/schema.go

@@ -19,6 +19,7 @@ func stateStoreSchema() *memdb.DBSchema {
 		jobTableSchema,
 		taskGroupTableSchema,
 		taskTableSchema,
+		allocTableSchema,
 	}
 
 	// Add each of the tables
@@ -124,7 +125,7 @@ func taskGroupTableSchema() *memdb.TableSchema {
 					AllowMissing: false,
 					Indexes: []memdb.Indexer{
 						&memdb.StringFieldIndex{
-							Field:     "Job",
+							Field:     "JobName",
 							Lowercase: true,
 						},
 						&memdb.StringFieldIndex{
@@ -153,11 +154,11 @@ func taskTableSchema() *memdb.TableSchema {
 					AllowMissing: false,
 					Indexes: []memdb.Indexer{
 						&memdb.StringFieldIndex{
-							Field:     "Job",
+							Field:     "JobName",
 							Lowercase: true,
 						},
 						&memdb.StringFieldIndex{
-							Field:     "TaskGroup",
+							Field:     "TaskGroupName",
 							Lowercase: true,
 						},
 						&memdb.StringFieldIndex{
@@ -170,3 +171,55 @@ func taskTableSchema() *memdb.TableSchema {
 		},
 	}
 }
+
+// allocTableSchema returns the MemDB schema for the allocation table.
+// This table is used to store all the task allocations between task groups
+// and nodes.
+func allocTableSchema() *memdb.TableSchema {
+	return &memdb.TableSchema{
+		Name: "allocs",
+		Indexes: map[string]*memdb.IndexSchema{
+			// Primary index is a UUID
+			"id": &memdb.IndexSchema{
+				Name:         "ID",
+				AllowMissing: false,
+				Unique:       true,
+				Indexer: &memdb.UUIDFieldIndex{
+					Field: "ID",
+				},
+			},
+
+			// Job index is used to lookup allocations by job.
+			// It is a compound index on {JobName, TaskGroupName}
+			"job": &memdb.IndexSchema{
+				Name:         "job",
+				AllowMissing: false,
+				Unique:       false,
+				Indexer: &memdb.CompoundIndex{
+					AllowMissing: false,
+					Indexes: []memdb.Indexer{
+						&memdb.StringFieldIndex{
+							Field:     "JobName",
+							Lowercase: true,
+						},
+						&memdb.StringFieldIndex{
+							Field:     "TaskGroupName",
+							Lowercase: true,
+						},
+					},
+				},
+			},
+
+			// Node index is used to lookup allocations by node
+			"node": &memdb.IndexSchema{
+				Name:         "node",
+				AllowMissing: false,
+				Unique:       false,
+				Indexer: &memdb.StringFieldIndex{
+					Field:     "NodeID",
+					Lowercase: true,
+				},
+			},
+		},
+	}
+}

nomad/structs/structs.go

@@ -250,7 +250,7 @@ type Job struct {
 // in many replicas using the same configuration..
 type TaskGroup struct {
 	// Name of the parent job
-	Job string
+	JobName string
 
 	// Name of the task group
 	Name string
@@ -277,10 +277,10 @@ type TaskGroup struct {
 // Task is a single process typically that is executed as part of a task group.
 type Task struct {
 	// Name of the parent job
-	Job string
+	JobName string
 
 	// Name of the partent task group
-	TaskGroup string
+	TaskGroupName string
 
 	// Name of the task
 	Name string
@@ -314,6 +314,42 @@ type Constraint struct {
 	Weight  int    // Soft constraints can vary the weight
 }
 
+const (
+	AllocStatusPending  = "pending"
+	AllocStatusInit     = "initializing"
+	AllocStatusRunning  = "running"
+	AllocStatusComplete = "complete"
+	AllocStatusDead     = "dead"
+)
+
+// Allocation is used to allocate the placement of a task group to a node.
+type Allocation struct {
+	// ID of the allocation (UUID)
+	ID string
+
+	// NodeID is the node this is being placed on
+	NodeID string
+
+	// Job is the parent job of the task group being allocated.
+	// This is copied at allocation time to avoid issues if the job
+	// definition is updated.
+	JobName string
+	Job     *Job
+
+	// TaskGroup is the task being allocated to the node
+	// This is copied at allocation time to avoid issues if the job
+	// definition is updated.
+	TaskGroupName string
+	TaskGroup     *TaskGroup
+
+	// Resources is the set of resources allocated as part
+	// of this allocation of the task group.
+	Resources *Resources
+
+	// Status of the allocation
+	Status string
+}
+
 // msgpackHandle is a shared handle for encoding/decoding of structs
 var msgpackHandle = &codec.MsgpackHandle{}