Affinity struct, API and parsing

api/compose_test.go

@@ -31,6 +31,7 @@ func TestCompose(t *testing.T) {
 	// Compose a task group
 	grp := NewTaskGroup("grp1", 2).
 		Constrain(NewConstraint("kernel.name", "=", "linux")).
+		AddAffinity(NewAffinity("${node.class}", "=", "large", 50)).
 		SetMeta("foo", "bar").
 		AddTask(task)
 
@@ -72,6 +73,14 @@ func TestCompose(t *testing.T) {
 						Operand: "=",
 					},
 				},
+				Affinities: []*Affinity{
+					{
+						LTarget: "${node.class}",
+						RTarget: "large",
+						Operand: "=",
+						Weight:  50,
+					},
+				},
 				Tasks: []*Task{
 					{
 						Name:   "task1",

api/jobs.go

@@ -610,6 +610,7 @@ type Job struct {
 	AllAtOnce         *bool `mapstructure:"all_at_once"`
 	Datacenters       []string
 	Constraints       []*Constraint
+	Affinities        []*Affinity
 	TaskGroups        []*TaskGroup
 	Update            *UpdateStrategy
 	Periodic          *PeriodicConfig
@@ -836,6 +837,12 @@ func (j *Job) Constrain(c *Constraint) *Job {
 	return j
 }
 
+// AddAffinity is used to add an affinity to a job.
+func (j *Job) AddAffinity(a *Affinity) *Job {
+	j.Affinities = append(j.Affinities, a)
+	return j
+}
+
 // AddTaskGroup adds a task group to an existing job.
 func (j *Job) AddTaskGroup(grp *TaskGroup) *Job {
 	j.TaskGroups = append(j.TaskGroups, grp)

api/jobs_test.go

@@ -1332,6 +1332,42 @@ func TestJobs_Constrain(t *testing.T) {
 	}
 }
 
+func TestJobs_AddAffinity(t *testing.T) {
+	t.Parallel()
+	job := &Job{Affinities: nil}
+
+	// Create and add an affinity
+	out := job.AddAffinity(NewAffinity("kernel.version", "=", "4.6", 100))
+	if n := len(job.Affinities); n != 1 {
+		t.Fatalf("expected 1 affinity, got: %d", n)
+	}
+
+	// Check that the job was returned
+	if job != out {
+		t.Fatalf("expect: %#v, got: %#v", job, out)
+	}
+
+	// Adding another affinity preserves the original
+	job.AddAffinity(NewAffinity("${node.datacenter}", "=", "dc2", 50))
+	expect := []*Affinity{
+		{
+			LTarget: "kernel.version",
+			RTarget: "4.6",
+			Operand: "=",
+			Weight:  100,
+		},
+		{
+			LTarget: "${node.datacenter}",
+			RTarget: "dc2",
+			Operand: "=",
+			Weight:  50,
+		},
+	}
+	if !reflect.DeepEqual(job.Affinities, expect) {
+		t.Fatalf("expect: %#v, got: %#v", expect, job.Affinities)
+	}
+}
+
 func TestJobs_Sort(t *testing.T) {
 	t.Parallel()
 	jobs := []*JobListStub{

api/tasks.go

@@ -148,6 +148,23 @@ func (r *ReschedulePolicy) Canonicalize(jobType string) {
 	}
 }
 
+// Affinity is used to serialize task group affinities
+type Affinity struct {
+	LTarget string  // Left-hand target
+	RTarget string  // Right-hand target
+	Operand string  // Constraint operand (<=, <, =, !=, >, >=), set_contains_all, set_contains_any
+	Weight  float64 // Weight applied to nodes that match the affinity. Can be negative
+}
+
+func NewAffinity(LTarget string, Operand string, RTarget string, Weight float64) *Affinity {
+	return &Affinity{
+		LTarget: LTarget,
+		RTarget: RTarget,
+		Operand: Operand,
+		Weight:  Weight,
+	}
+}
+
 func NewDefaultReschedulePolicy(jobType string) *ReschedulePolicy {
 	var dp *ReschedulePolicy
 	switch jobType {
@@ -413,6 +430,7 @@ type TaskGroup struct {
 	Name             *string
 	Count            *int
 	Constraints      []*Constraint
+	Affinities       []*Affinity
 	Tasks            []*Task
 	RestartPolicy    *RestartPolicy
 	ReschedulePolicy *ReschedulePolicy
@@ -543,6 +561,12 @@ func (g *TaskGroup) AddTask(t *Task) *TaskGroup {
 	return g
 }
 
+// AddAffinity is used to add a new affinity to a task group.
+func (g *TaskGroup) AddAffinity(a *Affinity) *TaskGroup {
+	g.Affinities = append(g.Affinities, a)
+	return g
+}
+
 // RequireDisk adds a ephemeral disk to the task group
 func (g *TaskGroup) RequireDisk(disk *EphemeralDisk) *TaskGroup {
 	g.EphemeralDisk = disk
@@ -583,6 +607,7 @@ type Task struct {
 	User            string
 	Config          map[string]interface{}
 	Constraints     []*Constraint
+	Affinities      []*Affinity
 	Env             map[string]string
 	Services        []*Service
 	Resources       *Resources
@@ -771,6 +796,12 @@ func (t *Task) Constrain(c *Constraint) *Task {
 	return t
 }
 
+// AddAffinity adds a new affinity to a single task.
+func (t *Task) AddAffinity(a *Affinity) *Task {
+	t.Affinities = append(t.Affinities, a)
+	return t
+}
+
 // SetLogConfig sets a log config to a task
 func (t *Task) SetLogConfig(l *LogConfig) *Task {
 	t.LogConfig = l

api/tasks_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/hashicorp/nomad/helper"
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestTaskGroup_NewTaskGroup(t *testing.T) {
@@ -56,6 +57,42 @@ func TestTaskGroup_Constrain(t *testing.T) {
 	}
 }
 
+func TestTaskGroup_AddAffinity(t *testing.T) {
+	t.Parallel()
+	grp := NewTaskGroup("grp1", 1)
+
+	// Add an affinity to the group
+	out := grp.AddAffinity(NewAffinity("kernel.version", "=", "4.6", 100))
+	if n := len(grp.Affinities); n != 1 {
+		t.Fatalf("expected 1 affinity, got: %d", n)
+	}
+
+	// Check that the group was returned
+	if out != grp {
+		t.Fatalf("expected: %#v, got: %#v", grp, out)
+	}
+
+	// Add a second affinity
+	grp.AddAffinity(NewAffinity("${node.affinity}", "=", "dc2", 50))
+	expect := []*Affinity{
+		{
+			LTarget: "kernel.version",
+			RTarget: "4.6",
+			Operand: "=",
+			Weight:  100,
+		},
+		{
+			LTarget: "${node.affinity}",
+			RTarget: "dc2",
+			Operand: "=",
+			Weight:  50,
+		},
+	}
+	if !reflect.DeepEqual(grp.Affinities, expect) {
+		t.Fatalf("expect: %#v, got: %#v", expect, grp.Constraints)
+	}
+}
+
 func TestTaskGroup_SetMeta(t *testing.T) {
 	t.Parallel()
 	grp := NewTaskGroup("grp1", 1)
@@ -232,6 +269,41 @@ func TestTask_Constrain(t *testing.T) {
 	}
 }
 
+func TestTask_AddAffinity(t *testing.T) {
+	t.Parallel()
+	task := NewTask("task1", "exec")
+
+	// Add an affinity to the task
+	out := task.AddAffinity(NewAffinity("kernel.version", "=", "4.6", 100))
+	require := require.New(t)
+	require.Len(out, 1)
+
+	// Check that the task was returned
+	if out != task {
+		t.Fatalf("expected: %#v, got: %#v", task, out)
+	}
+
+	// Add a second affinity
+	task.AddAffinity(NewAffinity("${node.datacenter}", "=", "dc2", 50))
+	expect := []*Affinity{
+		{
+			LTarget: "kernel.version",
+			RTarget: "4.6",
+			Operand: "=",
+			Weight:  100,
+		},
+		{
+			LTarget: "${node.datacenter}",
+			RTarget: "dc2",
+			Operand: "=",
+			Weight:  50,
+		},
+	}
+	if !reflect.DeepEqual(task.Affinities, expect) {
+		t.Fatalf("expect: %#v, got: %#v", expect, task.Affinities)
+	}
+}
+
 func TestTask_Artifact(t *testing.T) {
 	t.Parallel()
 	a := TaskArtifact{

command/agent/job_endpoint.go

@@ -616,6 +616,13 @@ func ApiJobToStructJob(job *api.Job) *structs.Job {
 		}
 	}
 
+	if l := len(job.Affinities); l != 0 {
+		j.Affinities = make([]*structs.Affinity, l)
+		for i, a := range job.Affinities {
+			j.Affinities[i] = ApiAffinityToStructs(a)
+		}
+	}
+
 	// COMPAT: Remove in 0.7.0. Update has been pushed into the task groups
 	if job.Update != nil {
 		j.Update = structs.UpdateStrategy{}
@@ -675,6 +682,13 @@ func ApiTgToStructsTG(taskGroup *api.TaskGroup, tg *structs.TaskGroup) {
 		}
 	}
 
+	if l := len(taskGroup.Affinities); l != 0 {
+		tg.Affinities = make([]*structs.Affinity, l)
+		for k, affinity := range taskGroup.Affinities {
+			tg.Affinities[k] = ApiAffinityToStructs(affinity)
+		}
+	}
+
 	tg.RestartPolicy = &structs.RestartPolicy{
 		Attempts: *taskGroup.RestartPolicy.Attempts,
 		Interval: *taskGroup.RestartPolicy.Interval,
@@ -754,6 +768,13 @@ func ApiTaskToStructsTask(apiTask *api.Task, structsTask *structs.Task) {
 		}
 	}
 
+	if l := len(apiTask.Affinities); l != 0 {
+		structsTask.Affinities = make([]*structs.Affinity, l)
+		for i, a := range apiTask.Affinities {
+			structsTask.Affinities[i] = ApiAffinityToStructs(a)
+		}
+	}
+
 	if l := len(apiTask.Services); l != 0 {
 		structsTask.Services = make([]*structs.Service, l)
 		for i, service := range apiTask.Services {
@@ -892,3 +913,12 @@ func ApiConstraintToStructs(c1 *api.Constraint, c2 *structs.Constraint) {
 	c2.RTarget = c1.RTarget
 	c2.Operand = c1.Operand
 }
+
+func ApiAffinityToStructs(a1 *api.Affinity) *structs.Affinity {
+	return &structs.Affinity{
+		LTarget: a1.LTarget,
+		Operand: a1.Operand,
+		RTarget: a1.RTarget,
+		Weight:  a1.Weight,
+	}
+}

command/agent/job_endpoint_test.go

@@ -1211,6 +1211,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 				Operand: "c",
 			},
 		},
+		Affinities: []*api.Affinity{
+			{
+				LTarget: "a",
+				RTarget: "b",
+				Operand: "c",
+				Weight:  50,
+			},
+		},
 		Update: &api.UpdateStrategy{
 			Stagger:          helper.TimeToPtr(1 * time.Second),
 			MaxParallel:      helper.IntToPtr(5),
@@ -1248,6 +1256,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 						Operand: "z",
 					},
 				},
+				Affinities: []*api.Affinity{
+					{
+						LTarget: "x",
+						RTarget: "y",
+						Operand: "z",
+						Weight:  100,
+					},
+				},
 				RestartPolicy: &api.RestartPolicy{
 					Interval: helper.TimeToPtr(1 * time.Second),
 					Attempts: helper.IntToPtr(5),
@@ -1303,6 +1319,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 								Operand: "z",
 							},
 						},
+						Affinities: []*api.Affinity{
+							{
+								LTarget: "a",
+								RTarget: "b",
+								Operand: "c",
+								Weight:  50,
+							},
+						},
 
 						Services: []*api.Service{
 							{
@@ -1443,6 +1467,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 				Operand: "c",
 			},
 		},
+		Affinities: []*structs.Affinity{
+			{
+				LTarget: "a",
+				RTarget: "b",
+				Operand: "c",
+				Weight:  50,
+			},
+		},
 		Update: structs.UpdateStrategy{
 			Stagger:     1 * time.Second,
 			MaxParallel: 5,
@@ -1474,6 +1506,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 						Operand: "z",
 					},
 				},
+				Affinities: []*structs.Affinity{
+					{
+						LTarget: "x",
+						RTarget: "y",
+						Operand: "z",
+						Weight:  100,
+					},
+				},
 				RestartPolicy: &structs.RestartPolicy{
 					Interval: 1 * time.Second,
 					Attempts: 5,
@@ -1528,6 +1568,14 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 								Operand: "z",
 							},
 						},
+						Affinities: []*structs.Affinity{
+							{
+								LTarget: "a",
+								RTarget: "b",
+								Operand: "c",
+								Weight:  50,
+							},
+						},
 						Env: map[string]string{
 							"hello": "world",
 						},