open-nomad/client/allocrunner/health_hook_test.go
Mahmood Ali 07a30580ac health: fail health if any task is pending
Fixes a bug where an allocation is considered healthy if some of the
tasks are being restarted and as such, their checks aren't tracked by
consul agent client.

Here, we fix the immediate case by ensuring that an alloc is healthy
only if tasks are running and the registered checks at the time are
healthy.

Previously, health tracker tracked task "health" independently from
checks and leads to problems when a task restarts.  Consider the
following series of events:

1. all tasks start running -> `tracker.tasksHealthy` is true
2. one task has unhealthy checks and get restarted
3. remaining checks are healthy -> `tracker.checksHealthy` is true
4. propagate health status now that `tracker.tasksHealthy` and
`tracker.checksHealthy`.

This change ensures that we accurately use the latest status of tasks
and checks regardless of their status changes.

Also, ensures that we only consider check health after tasks are
considered healthy, otherwise we risk trusting incomplete checks.

This approach accomodates task dependencies well.  Service jobs can have
prestart short-lived tasks that will terminate before main process runs.
These dead tasks that complete successfully will not negate health
status.
2020-03-22 11:13:41 -04:00

418 lines
11 KiB
Go

package allocrunner
import (
"sync"
"testing"
"time"
consulapi "github.com/hashicorp/consul/api"
"github.com/hashicorp/nomad/client/allocrunner/interfaces"
"github.com/hashicorp/nomad/client/consul"
cstructs "github.com/hashicorp/nomad/client/structs"
agentconsul "github.com/hashicorp/nomad/command/agent/consul"
"github.com/hashicorp/nomad/helper/testlog"
"github.com/hashicorp/nomad/helper/uuid"
"github.com/hashicorp/nomad/nomad/mock"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
// statically assert health hook implements the expected interfaces
var _ interfaces.RunnerPrerunHook = (*allocHealthWatcherHook)(nil)
var _ interfaces.RunnerUpdateHook = (*allocHealthWatcherHook)(nil)
var _ interfaces.RunnerPostrunHook = (*allocHealthWatcherHook)(nil)
var _ interfaces.ShutdownHook = (*allocHealthWatcherHook)(nil)
// allocHealth is emitted to a chan whenever SetHealth is called
type allocHealth struct {
healthy bool
taskEvents map[string]*structs.TaskEvent
}
// mockHealthSetter implements healthSetter that stores health internally
type mockHealthSetter struct {
setCalls int
clearCalls int
healthy *bool
isDeploy *bool
taskEvents map[string]*structs.TaskEvent
mu sync.Mutex
healthCh chan allocHealth
}
// newMockHealthSetter returns a mock HealthSetter that emits all SetHealth
// calls on a buffered chan. Callers who do need need notifications of health
// changes may just create the struct directly.
func newMockHealthSetter() *mockHealthSetter {
return &mockHealthSetter{
healthCh: make(chan allocHealth, 1),
}
}
func (m *mockHealthSetter) SetHealth(healthy, isDeploy bool, taskEvents map[string]*structs.TaskEvent) {
m.mu.Lock()
defer m.mu.Unlock()
m.setCalls++
m.healthy = &healthy
m.isDeploy = &isDeploy
m.taskEvents = taskEvents
if m.healthCh != nil {
m.healthCh <- allocHealth{healthy, taskEvents}
}
}
func (m *mockHealthSetter) ClearHealth() {
m.mu.Lock()
defer m.mu.Unlock()
m.clearCalls++
m.healthy = nil
m.isDeploy = nil
m.taskEvents = nil
}
func (m *mockHealthSetter) HasHealth() bool {
m.mu.Lock()
defer m.mu.Unlock()
return m.healthy != nil
}
// TestHealthHook_PrerunPostrun asserts a health hook does not error if it is
// run and postrunned.
func TestHealthHook_PrerunPostrun(t *testing.T) {
t.Parallel()
require := require.New(t)
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
consul := consul.NewMockConsulServiceClient(t, logger)
hs := &mockHealthSetter{}
h := newAllocHealthWatcherHook(logger, mock.Alloc(), hs, b.Listen(), consul)
// Assert we implemented the right interfaces
prerunh, ok := h.(interfaces.RunnerPrerunHook)
require.True(ok)
_, ok = h.(interfaces.RunnerUpdateHook)
require.True(ok)
postrunh, ok := h.(interfaces.RunnerPostrunHook)
require.True(ok)
// Prerun
require.NoError(prerunh.Prerun())
// Assert isDeploy is false (other tests peek at isDeploy to determine
// if an Update applied)
ahw := h.(*allocHealthWatcherHook)
ahw.hookLock.Lock()
assert.False(t, ahw.isDeploy)
ahw.hookLock.Unlock()
// Postrun
require.NoError(postrunh.Postrun())
}
// TestHealthHook_PrerunUpdatePostrun asserts Updates may be applied concurrently.
func TestHealthHook_PrerunUpdatePostrun(t *testing.T) {
t.Parallel()
require := require.New(t)
alloc := mock.Alloc()
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
consul := consul.NewMockConsulServiceClient(t, logger)
hs := &mockHealthSetter{}
h := newAllocHealthWatcherHook(logger, alloc.Copy(), hs, b.Listen(), consul).(*allocHealthWatcherHook)
// Prerun
require.NoError(h.Prerun())
// Update multiple times in a goroutine to mimic Client behavior
// (Updates are concurrent with alloc runner but are applied serially).
errs := make(chan error, 2)
go func() {
defer close(errs)
for i := 0; i < cap(errs); i++ {
alloc.AllocModifyIndex++
errs <- h.Update(&interfaces.RunnerUpdateRequest{Alloc: alloc.Copy()})
}
}()
for err := range errs {
assert.NoError(t, err)
}
// Postrun
require.NoError(h.Postrun())
}
// TestHealthHook_UpdatePrerunPostrun asserts that a hook may have Update
// called before Prerun.
func TestHealthHook_UpdatePrerunPostrun(t *testing.T) {
t.Parallel()
require := require.New(t)
alloc := mock.Alloc()
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
consul := consul.NewMockConsulServiceClient(t, logger)
hs := &mockHealthSetter{}
h := newAllocHealthWatcherHook(logger, alloc.Copy(), hs, b.Listen(), consul).(*allocHealthWatcherHook)
// Set a DeploymentID to cause ClearHealth to be called
alloc.DeploymentID = uuid.Generate()
// Update in a goroutine to mimic Client behavior (Updates are
// concurrent with alloc runner).
errs := make(chan error, 1)
go func(alloc *structs.Allocation) {
errs <- h.Update(&interfaces.RunnerUpdateRequest{Alloc: alloc})
close(errs)
}(alloc.Copy())
for err := range errs {
assert.NoError(t, err)
}
// Prerun should be a noop
require.NoError(h.Prerun())
// Assert that the Update took affect by isDeploy being true
h.hookLock.Lock()
assert.True(t, h.isDeploy)
h.hookLock.Unlock()
// Postrun
require.NoError(h.Postrun())
}
// TestHealthHook_Postrun asserts that a hook may have only Postrun called.
func TestHealthHook_Postrun(t *testing.T) {
t.Parallel()
require := require.New(t)
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
consul := consul.NewMockConsulServiceClient(t, logger)
hs := &mockHealthSetter{}
h := newAllocHealthWatcherHook(logger, mock.Alloc(), hs, b.Listen(), consul).(*allocHealthWatcherHook)
// Postrun
require.NoError(h.Postrun())
}
// TestHealthHook_SetHealth_healthy asserts SetHealth is called when health status is
// set. Uses task state and health checks.
func TestHealthHook_SetHealth_healthy(t *testing.T) {
t.Parallel()
require := require.New(t)
alloc := mock.Alloc()
alloc.Job.TaskGroups[0].Migrate.MinHealthyTime = 1 // let's speed things up
task := alloc.Job.TaskGroups[0].Tasks[0]
// Synthesize running alloc and tasks
alloc.ClientStatus = structs.AllocClientStatusRunning
alloc.TaskStates = map[string]*structs.TaskState{
task.Name: {
State: structs.TaskStateRunning,
StartedAt: time.Now(),
},
}
// Make Consul response
check := &consulapi.AgentCheck{
Name: task.Services[0].Checks[0].Name,
Status: consulapi.HealthPassing,
}
taskRegs := map[string]*agentconsul.ServiceRegistrations{
task.Name: {
Services: map[string]*agentconsul.ServiceRegistration{
task.Services[0].Name: {
Service: &consulapi.AgentService{
ID: "foo",
Service: task.Services[0].Name,
},
Checks: []*consulapi.AgentCheck{check},
},
},
},
}
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
// Don't reply on the first call
called := false
consul := consul.NewMockConsulServiceClient(t, logger)
consul.AllocRegistrationsFn = func(string) (*agentconsul.AllocRegistration, error) {
if !called {
called = true
return nil, nil
}
reg := &agentconsul.AllocRegistration{
Tasks: taskRegs,
}
return reg, nil
}
hs := newMockHealthSetter()
h := newAllocHealthWatcherHook(logger, alloc.Copy(), hs, b.Listen(), consul).(*allocHealthWatcherHook)
// Prerun
require.NoError(h.Prerun())
// Wait for health to be set (healthy)
select {
case <-time.After(5 * time.Second):
t.Fatalf("timeout waiting for health to be set")
case health := <-hs.healthCh:
require.True(health.healthy)
// Healthy allocs shouldn't emit task events
ev := health.taskEvents[task.Name]
require.Nilf(ev, "%#v", health.taskEvents)
}
// Postrun
require.NoError(h.Postrun())
}
// TestHealthHook_SetHealth_unhealthy asserts SetHealth notices unhealthy allocs
func TestHealthHook_SetHealth_unhealthy(t *testing.T) {
t.Parallel()
require := require.New(t)
alloc := mock.Alloc()
alloc.Job.TaskGroups[0].Migrate.MinHealthyTime = 1 // let's speed things up
task := alloc.Job.TaskGroups[0].Tasks[0]
newCheck := task.Services[0].Checks[0].Copy()
newCheck.Name = "failing-check"
task.Services[0].Checks = append(task.Services[0].Checks, newCheck)
// Synthesize running alloc and tasks
alloc.ClientStatus = structs.AllocClientStatusRunning
alloc.TaskStates = map[string]*structs.TaskState{
task.Name: {
State: structs.TaskStateRunning,
StartedAt: time.Now(),
},
}
// Make Consul response
checkHealthy := &consulapi.AgentCheck{
Name: task.Services[0].Checks[0].Name,
Status: consulapi.HealthPassing,
}
checksUnhealthy := &consulapi.AgentCheck{
Name: task.Services[0].Checks[1].Name,
Status: consulapi.HealthCritical,
}
taskRegs := map[string]*agentconsul.ServiceRegistrations{
task.Name: {
Services: map[string]*agentconsul.ServiceRegistration{
task.Services[0].Name: {
Service: &consulapi.AgentService{
ID: "foo",
Service: task.Services[0].Name,
},
Checks: []*consulapi.AgentCheck{checkHealthy, checksUnhealthy},
},
},
},
}
logger := testlog.HCLogger(t)
b := cstructs.NewAllocBroadcaster(logger)
defer b.Close()
// Don't reply on the first call
called := false
consul := consul.NewMockConsulServiceClient(t, logger)
consul.AllocRegistrationsFn = func(string) (*agentconsul.AllocRegistration, error) {
if !called {
called = true
return nil, nil
}
reg := &agentconsul.AllocRegistration{
Tasks: taskRegs,
}
return reg, nil
}
hs := newMockHealthSetter()
h := newAllocHealthWatcherHook(logger, alloc.Copy(), hs, b.Listen(), consul).(*allocHealthWatcherHook)
// Prerun
require.NoError(h.Prerun())
// Wait to ensure we don't get a healthy status
select {
case <-time.After(2 * time.Second):
// great no healthy status
case health := <-hs.healthCh:
require.Fail("expected no health event", "got %v", health)
}
// Postrun
require.NoError(h.Postrun())
}
// TestHealthHook_SystemNoop asserts that system jobs return the noop tracker.
func TestHealthHook_SystemNoop(t *testing.T) {
t.Parallel()
h := newAllocHealthWatcherHook(testlog.HCLogger(t), mock.SystemAlloc(), nil, nil, nil)
// Assert that it's the noop impl
_, ok := h.(noopAllocHealthWatcherHook)
require.True(t, ok)
// Assert the noop impl does not implement any hooks
_, ok = h.(interfaces.RunnerPrerunHook)
require.False(t, ok)
_, ok = h.(interfaces.RunnerUpdateHook)
require.False(t, ok)
_, ok = h.(interfaces.RunnerPostrunHook)
require.False(t, ok)
_, ok = h.(interfaces.ShutdownHook)
require.False(t, ok)
}
// TestHealthHook_BatchNoop asserts that batch jobs return the noop tracker.
func TestHealthHook_BatchNoop(t *testing.T) {
t.Parallel()
h := newAllocHealthWatcherHook(testlog.HCLogger(t), mock.BatchAlloc(), nil, nil, nil)
// Assert that it's the noop impl
_, ok := h.(noopAllocHealthWatcherHook)
require.True(t, ok)
}