tiny/watchdog
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

simplify API

Browse Source
This commit is contained in:
Dmitry
2025-09-23 08:59:10 +03:00
parent 0f2f9144ed
commit 1d381420bf
5 changed files with 72 additions and 146 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
checks.go
View File

@@ -35,32 +35,32 @@ func GetHTTP(addr string, timeout time.Duration) (CheckFunc, error) {
timeout = DefaultTimeout
}
return func(ctx context.Context) (Status, error) {
return func(ctx context.Context) error {
ctx, cancel := context.WithTimeout(ctx, timeout)
defer cancel()
req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
if err != nil {
return StatusUnknown, fmt.Errorf("failed to create http request: %w", err)
return fmt.Errorf("failed to create http request: %w", err)
}
resp, err := http.DefaultClient.Do(req)
if err != nil {
return StatusDown, fmt.Errorf("do request failed: %w", err)
return fmt.Errorf("do request failed: %w", err)
}
defer resp.Body.Close()
body, err := io.ReadAll(resp.Body)
if err != nil {
return StatusDown, fmt.Errorf("err reading response body: %w", err)
return fmt.Errorf("err reading response body: %w", err)
}
if resp.StatusCode != http.StatusOK {
return StatusDown, fmt.Errorf("got HTTP response code %d, body: %s", resp.StatusCode, string(body))
return fmt.Errorf("got HTTP response code %d, body: %s", resp.StatusCode, string(body))
}
return StatusOK, nil
return nil
}, nil
}
@@ -83,27 +83,27 @@ func HeadHTTP(addr string, timeout time.Duration) (CheckFunc, error) {
timeout = DefaultTimeout
}
return func(ctx context.Context) (Status, error) {
return func(ctx context.Context) error {
ctx, cancel := context.WithTimeout(ctx, timeout)
defer cancel()
req, err := http.NewRequestWithContext(ctx, http.MethodHead, u.String(), nil)
if err != nil {
return StatusUnknown, fmt.Errorf("failed to create http request: %w", err)
return fmt.Errorf("failed to create http request: %w", err)
}
resp, err := http.DefaultClient.Do(req)
if err != nil {
return StatusDown, fmt.Errorf("do request failed: %w", err)
return fmt.Errorf("do request failed: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return StatusDown, fmt.Errorf("got HTTP response code %d", resp.StatusCode)
return fmt.Errorf("got HTTP response code %d", resp.StatusCode)
}
return StatusOK, nil
return nil
}, nil
}
@@ -121,7 +121,7 @@ func DialTCP(addr string, timeout time.Duration) (CheckFunc, error) {
timeout = DefaultTimeout
}
return func(ctx context.Context) (Status, error) {
return func(ctx context.Context) error {
deadline := time.Now().Add(timeout)
if t, ok := ctx.Deadline(); ok && t.Before(deadline) {
deadline = t
@@ -129,11 +129,11 @@ func DialTCP(addr string, timeout time.Duration) (CheckFunc, error) {
conn, err := net.DialTimeout("tcp", addr, time.Until(deadline))
if err != nil {
return StatusDown, fmt.Errorf("error dialing: %w", err)
return fmt.Errorf("error dialing: %w", err)
}
defer conn.Close()
return StatusOK, nil
return nil
}, nil
}

33
checks_test.go
View File

@@ -22,14 +22,10 @@ func TestGetHTTPSuccess(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
err = fn(t.Context())
if err != nil {
t.Fatal(err)
}
if status != watchdog.StatusOK {
t.Fatalf("incorrect status %s, expected %s", status, watchdog.StatusOK)
}
}
func TestGetHTTPError(t *testing.T) {
@@ -39,8 +35,8 @@ func TestGetHTTPError(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
if status != watchdog.StatusDown || err == nil {
err = fn(t.Context())
if err == nil {
t.Errorf("incorrect status for unavalable host")
}
}
@@ -57,14 +53,10 @@ func TestHeadHTTPSuccess(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
err = fn(t.Context())
if err != nil {
t.Fatal(err)
}
if status != watchdog.StatusOK {
t.Fatalf("incorrect status %s, expected %s", status, watchdog.StatusOK)
}
}
func TestHeadHTTPError(t *testing.T) {
@@ -74,8 +66,8 @@ func TestHeadHTTPError(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
if status != watchdog.StatusDown || err == nil {
err = fn(t.Context())
if err == nil {
t.Errorf("incorrect status for unavalable host")
}
}
@@ -101,15 +93,10 @@ func TestDialTCPSuccess(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
err = fn(t.Context())
if err != nil {
t.Fatal(err)
}
if status != watchdog.StatusOK {
t.Error("incorrect status for available addr")
}
}
func TestDialTCPError(t *testing.T) {
@@ -120,8 +107,8 @@ func TestDialTCPError(t *testing.T) {
t.Fatal(err)
}
status, err := fn(t.Context())
if (status != watchdog.StatusDown) || (err == nil) {
t.Errorf("incorrect status %s, expected %s", status, watchdog.StatusDown)
err = fn(t.Context())
if err == nil {
t.Errorf("incorrect status")
}
}

22
entity.go
View File

@@ -5,30 +5,11 @@ import (
"time"
)
type Status uint8
const (
StatusUnknown Status = iota
StatusOK
StatusDown
)
func (s Status) String() string {
switch s {
case StatusOK:
return "OK"
case StatusDown:
return "DOWN"
default:
return "UNKNOWN"
}
}
// CheckFunc is a function that does the actual work.
// This package provides a number of check functions but
// any function matching the signature may be provided.
// It must obey context dealine and cancellation.
type CheckFunc func(context.Context) (Status, error)
type CheckFunc func(context.Context) error
// Check represents a check that must be run by Watchdog.
type Check struct {
@@ -39,6 +20,5 @@ type Check struct {
type CheckResult struct {
Name string // identifier of check
Status Status // status as retuned by CheckFunc
Error error // error returned by CheckFunc
}

94
watchdog.go
View File

@@ -16,7 +16,7 @@ var (
// Watchdog keeps checks to run either periodically
// or on demand.
type Watchdog struct {
checks checksMap
checks map[string]*wdCheck
mu sync.Mutex
events chan CheckResult // output channel
@@ -28,47 +28,6 @@ type Watchdog struct {
running int // number of active checks monitored
}
type checksMap struct {
m map[string]*wdCheck
}
func (c *checksMap) build() {
if c.m == nil {
c.m = make(map[string]*wdCheck)
}
}
func (c *checksMap) Map() map[string]*wdCheck {
c.build()
return c.m
}
func (c *checksMap) Set(key string, v *wdCheck) {
c.build()
c.m[key] = v
}
func (c *checksMap) Lookup(key string) (*wdCheck, bool) {
c.build()
v, ok := c.m[key]
return v, ok
}
func (c *checksMap) Delete(key string) {
c.build()
delete(c.m, key)
}
func (c *checksMap) Len() int {
c.build()
return len(c.m)
}
type wdCheck struct {
check Check
stop chan struct{}
@@ -77,13 +36,16 @@ type wdCheck struct {
// New creates instance of Watchdog with
// provided checks.
func New(checks ...Check) *Watchdog {
w := Watchdog{}
w := Watchdog{
checks: make(map[string]*wdCheck),
}
for _, c := range checks {
nc := &wdCheck{
check: c,
}
w.checks.Set(c.Name, nc)
w.checks[c.Name] = nc
}
return &w
@@ -121,14 +83,18 @@ func (w *Watchdog) AddChecks(checks ...Check) {
w.mu.Lock()
defer w.mu.Unlock()
if w.checks == nil {
w.checks = make(map[string]*wdCheck)
}
for _, c := range checks {
nc := &wdCheck{
check: c,
}
old, haveOld := w.checks.Lookup(c.Name)
old, haveOld := w.checks[c.Name]
w.checks.Set(c.Name, nc)
w.checks[c.Name] = nc
if w.monitoring {
w.startMonitoring(nc)
@@ -146,7 +112,7 @@ func (w *Watchdog) RemoveChecks(names ...string) {
defer w.mu.Unlock()
for _, name := range names {
c, ok := w.checks.Lookup(name)
c, ok := w.checks[name]
if !ok {
continue
}
@@ -155,7 +121,7 @@ func (w *Watchdog) RemoveChecks(names ...string) {
w.stopMonitoring(c)
}
w.checks.Delete(name)
delete(w.checks, name)
}
}
@@ -172,7 +138,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
w.mu.Lock()
defer w.mu.Unlock()
if w.checks.Len() == 0 {
if len(w.checks) == 0 {
return nil, ErrNotConfigured
}
@@ -181,7 +147,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
}
if concurrency == 0 {
concurrency = w.checks.Len()
concurrency = len(w.checks)
}
if w.timeout == 0 {
@@ -191,7 +157,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
w.events = make(chan CheckResult, concurrency)
w.limiter = make(chan struct{}, concurrency)
for _, c := range w.checks.Map() {
for _, c := range w.checks {
w.startMonitoring(c)
}
@@ -208,7 +174,7 @@ func (w *Watchdog) Stop() error {
return ErrNotRunning
}
for _, c := range w.checks.Map() {
for _, c := range w.checks {
w.stopMonitoring(c)
}
@@ -221,13 +187,13 @@ func (w *Watchdog) Stop() error {
func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]CheckResult, error) {
w.mu.Lock()
if w.checks.Len() == 0 {
if len(w.checks) == 0 {
w.mu.Unlock()
return nil, ErrNotConfigured
}
cp := w.copyChecks()
w.mu.Unlock() // release
w.mu.Unlock()
if concurrency == 0 {
concurrency = len(cp)
@@ -248,8 +214,8 @@ func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]Check
}
func (w *Watchdog) copyChecks() []Check {
cp := make([]Check, 0, w.checks.Len())
for _, v := range w.checks.Map() {
cp := make([]Check, 0, len(w.checks))
for _, v := range w.checks {
cp = append(cp, v.check)
}
@@ -267,11 +233,7 @@ func (w *Watchdog) startMonitoring(wdc *wdCheck) {
w.running++
go func() {
state := CheckResult{
// on first run return anything
// other that OK
Status: StatusOK,
}
var curr error = nil
ticker := time.Tick(wdc.check.Interval)
@@ -281,23 +243,22 @@ func (w *Watchdog) startMonitoring(wdc *wdCheck) {
ctx, cancel := context.WithTimeout(context.Background(), w.timeout)
defer cancel()
status, err := c.Check(ctx)
err := c.Check(ctx)
<-w.limiter
r := CheckResult{
Name: c.Name,
Status: status,
Error: err,
}
// if status changed or we've got an error
// then report this
if r.Status != state.Status || r.Error != nil {
if !errors.Is(r.Error, curr) {
w.events <- r
}
state = r
curr = r.Error
select {
case <-ticker:
@@ -336,11 +297,10 @@ func runChecksConcurrently(ctx context.Context, ch []Check, concurrency int) []C
// relying on assumption that CheckFunc obeys context
// cancellation
status, err := e.Check(ctx)
err := e.Check(ctx)
r := CheckResult{
Name: e.Name,
Status: status,
Error: err,
}

29
watchdog_test.go
View File

@@ -12,20 +12,19 @@ import (
type mockChecker struct {
name string
status watchdog.Status
err error
called bool
}
func (m *mockChecker) Func(ctx context.Context) (watchdog.Status, error) {
func (m *mockChecker) Func(ctx context.Context) error {
m.called = true
time.Sleep(time.Millisecond * 10)
if err := ctx.Err(); err != nil {
return watchdog.StatusUnknown, err
return err
}
return m.status, m.err
return m.err
}
func (m *mockChecker) HasBeenCalled() bool {
@@ -40,8 +39,8 @@ func (m *mockChecker) Check() watchdog.Check {
}
}
func newMockChecker(name string, s watchdog.Status, err error) *mockChecker {
return &mockChecker{name: name, status: s, err: err}
func newMockChecker(name string, err error) *mockChecker {
return &mockChecker{name: name, err: err}
}
func TestCreateWith_new(t *testing.T) {
@@ -59,8 +58,8 @@ func TestNew(t *testing.T) {
t.Errorf("expected len = 0")
}
m1 := newMockChecker("mock", watchdog.StatusOK, nil)
m2 := newMockChecker("mock2", watchdog.StatusOK, nil)
m1 := newMockChecker("mock", nil)
m2 := newMockChecker("mock2", nil)
w = watchdog.New()
w.AddChecks(m1.Check(), m2.Check())
@@ -96,8 +95,8 @@ func TestRunImmediately(t *testing.T) {
t.Errorf("expected zero len slice for empty instance, got %d", len(out))
}
m1 := newMockChecker("mock", watchdog.StatusOK, nil)
m2 := newMockChecker("mock2", watchdog.StatusOK, nil)
m1 := newMockChecker("mock", nil)
m2 := newMockChecker("mock2", nil)
w = watchdog.New(m1.Check(), m2.Check())
out, _ = w.RunImmediately(t.Context(), 0)
@@ -119,8 +118,8 @@ func TestStartStop(t *testing.T) {
t.Error("Start doen't error on empty checks slice")
}
m1 := newMockChecker("mock", watchdog.StatusOK, nil)
m2 := newMockChecker("mock2", watchdog.StatusOK, nil)
m1 := newMockChecker("mock", nil)
m2 := newMockChecker("mock2", nil)
w.AddChecks(m1.Check(), m2.Check())
@@ -167,7 +166,7 @@ func TestStartStop(t *testing.T) {
func TestSetTimeout(t *testing.T) {
w := new(watchdog.Watchdog)
w.SetTimeout(time.Millisecond)
m1 := newMockChecker("mock", watchdog.StatusOK, nil)
m1 := newMockChecker("mock", nil)
w.AddChecks(m1.Check())
out, _ := w.Start(0)
@@ -175,8 +174,8 @@ func TestSetTimeout(t *testing.T) {
w.Stop()
res := <-out
if !(res.Status == watchdog.StatusUnknown) || !errors.Is(res.Error, context.DeadlineExceeded) {
t.Logf("got status: %s, err: %v", res.Status, res.Error)
if !errors.Is(res.Error, context.DeadlineExceeded) {
t.Logf("got err: %v", res.Error)
t.Fatal("incorrect status for timed out op")
}
}