feat: stable version
Co-authored-by: Dmitry Fedotov <dmitry@uint32.ru> Co-committed-by: Dmitry Fedotov <dmitry@uint32.ru>
This commit is contained in:
22
LICENSE
Normal file
22
LICENSE
Normal file
@@ -0,0 +1,22 @@
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Copyright 2025 Dmitry Fedotov
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Permission is hereby granted, free of charge, to any person
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obtaining a copy of this software and associated documentation
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files (the “Software”), to deal in the Software without
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restriction, including without limitation the rights to use,
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copy, modify, merge, publish, distribute, sublicense, and/or
|
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sell copies of the Software, and to permit persons to whom
|
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the Software is furnished to do so,
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subject to the following conditions:
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The above copyright notice and this permission notice shall
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be included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
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OR OTHER DEALINGS IN THE SOFTWARE.
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6
README.md
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6
README.md
Normal file
@@ -0,0 +1,6 @@
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# watchdog
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go get code.uint32.ru/tiny/watchdog
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This package is a dead simple monitoring systems which may be used to check availability of online resources.
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It is a work in progress, but also a working code with decent test coverage. API might change in later versions as well as more features might be added.
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17
checks.go
17
checks.go
@@ -14,12 +14,13 @@ import (
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const DefaultTimeout = time.Second * 10
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// GetHTTP creates a CheckFunc that operates as follows.
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// The check calls GET method for provided addr using http.DefaultClient.
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// The check makes a request with GET method to provided addr using http.DefaultClient.
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// If request fails within specified timeout the returned status is StatusDown.
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// The function then tries to read response body. If it fails,
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// the returned status is StatusDown.
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// If request secceeds but reponse code is not 200, the returned
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// status is StatusPartiallyAvailable and response body is contained in the
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//
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// If request succeeds but reponse code is not 200, the returned
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// status is StatusDown and response body is contained in the
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// returned error.
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//
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// GetHTTP return an error if addr can not be parsed with url.Parse.
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@@ -64,11 +65,11 @@ func GetHTTP(addr string, timeout time.Duration) (CheckFunc, error) {
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}
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// HeadHTTP creates a CheckFunc that operates as follows.
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// The check calls GET method for provided addr using http.DefaultClient.
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// The check make a request with HEAD method to provided addr using http.DefaultClient.
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// If request fails within specified timeout the returned status is StatusDown.
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//
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// If request secceeds but reponse code is not 200, the returned
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// status is StatusPartiallyAvailable.
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// If request succeeds but reponse code is not 200, the returned
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// status is StatusDown.
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//
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// HeadHTTP return an error if addr can not be parsed with url.Parse.
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// If zero timeout is provided then the DefaultTimeout (10 second) is used.
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@@ -102,16 +103,18 @@ func HeadHTTP(addr string, timeout time.Duration) (CheckFunc, error) {
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return StatusDown, fmt.Errorf("got HTTP response code %d", resp.StatusCode)
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}
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return http.StatusOK, nil
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return StatusOK, nil
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}, nil
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}
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// DialTCP creates a CheckFunc that may be used to check tcp connectivity
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// to a host.
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//
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// The check tries to net.DialTimeout to the provided addr. If it fails,
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// the returned status is StatusDown.
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//
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// No validation of addr is made.
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//
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// If zero timeout is provided then the DefaultTimeout (10 second) is used.
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func DialTCP(addr string, timeout time.Duration) (CheckFunc, error) {
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if timeout == 0 {
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127
checks_test.go
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127
checks_test.go
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@@ -0,0 +1,127 @@
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package watchdog_test
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import (
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"net"
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"net/http"
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"net/http/httptest"
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"testing"
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"time"
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"code.uint32.ru/tiny/watchdog"
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)
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func TestGetHTTPSuccess(t *testing.T) {
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srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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w.Write([]byte("OK"))
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}))
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addr := srv.URL
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fn, err := watchdog.GetHTTP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if err != nil {
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t.Fatal(err)
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}
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if status != watchdog.StatusOK {
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t.Fatalf("incorrect status %s, expected %s", status, watchdog.StatusOK)
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}
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}
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func TestGetHTTPError(t *testing.T) {
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addr := "https://127.0.0.1:42014"
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fn, err := watchdog.GetHTTP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if status != watchdog.StatusDown || err == nil {
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t.Errorf("incorrect status for unavalable host")
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}
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}
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func TestHeadHTTPSuccess(t *testing.T) {
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srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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w.WriteHeader(http.StatusOK)
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}))
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addr := srv.URL
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fn, err := watchdog.HeadHTTP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if err != nil {
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t.Fatal(err)
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}
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if status != watchdog.StatusOK {
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t.Fatalf("incorrect status %s, expected %s", status, watchdog.StatusOK)
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}
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}
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func TestHeadHTTPError(t *testing.T) {
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addr := "https://127.0.0.1:42014"
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fn, err := watchdog.HeadHTTP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if status != watchdog.StatusDown || err == nil {
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t.Errorf("incorrect status for unavalable host")
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}
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}
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func TestDialTCPSuccess(t *testing.T) {
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addr := "127.0.0.1:42013"
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lis, err := net.Listen("tcp", addr)
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if err != nil {
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t.Fatal(err)
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}
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go func() {
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conn, err := lis.Accept()
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if err != nil {
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t.Error(err)
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}
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<-t.Context().Done()
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conn.Close()
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}()
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fn, err := watchdog.DialTCP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if err != nil {
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t.Fatal(err)
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}
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if status != watchdog.StatusOK {
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t.Error("incorrect status for available addr")
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}
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}
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func TestDialTCPError(t *testing.T) {
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addr := "127.0.0.1:65535"
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// check for non-existent addr
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fn, err := watchdog.DialTCP(addr, time.Second)
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if err != nil {
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t.Fatal(err)
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}
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status, err := fn(t.Context())
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if (status != watchdog.StatusDown) || (err == nil) {
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t.Errorf("incorrect status %s, expected %s", status, watchdog.StatusDown)
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}
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}
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91
coverage.out
91
coverage.out
@@ -1,91 +0,0 @@
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mode: set
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code.uint32.ru/tiny/watchdog/checks.go:27.69,29.16 2 0
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code.uint32.ru/tiny/watchdog/checks.go:29.16,31.3 1 0
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code.uint32.ru/tiny/watchdog/checks.go:33.2,33.18 1 0
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code.uint32.ru/tiny/watchdog/checks.go:33.18,35.3 1 0
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code.uint32.ru/tiny/watchdog/checks.go:37.2,37.51 1 0
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code.uint32.ru/tiny/watchdog/checks.go:37.51,42.17 4 0
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code.uint32.ru/tiny/watchdog/checks.go:42.17,44.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:46.3,47.17 2 0
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code.uint32.ru/tiny/watchdog/checks.go:47.17,49.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:51.3,54.17 3 0
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code.uint32.ru/tiny/watchdog/checks.go:54.17,56.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:58.3,58.39 1 0
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code.uint32.ru/tiny/watchdog/checks.go:58.39,60.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:62.3,62.23 1 0
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code.uint32.ru/tiny/watchdog/checks.go:75.70,77.16 2 0
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code.uint32.ru/tiny/watchdog/checks.go:77.16,79.3 1 0
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code.uint32.ru/tiny/watchdog/checks.go:81.2,81.18 1 0
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code.uint32.ru/tiny/watchdog/checks.go:81.18,83.3 1 0
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code.uint32.ru/tiny/watchdog/checks.go:85.2,85.51 1 0
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code.uint32.ru/tiny/watchdog/checks.go:85.51,90.17 4 0
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code.uint32.ru/tiny/watchdog/checks.go:90.17,92.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:94.3,95.17 2 0
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code.uint32.ru/tiny/watchdog/checks.go:95.17,97.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:99.3,101.39 2 0
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code.uint32.ru/tiny/watchdog/checks.go:101.39,103.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:105.3,105.28 1 0
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code.uint32.ru/tiny/watchdog/checks.go:116.69,117.18 1 0
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code.uint32.ru/tiny/watchdog/checks.go:117.18,119.3 1 0
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code.uint32.ru/tiny/watchdog/checks.go:121.2,121.51 1 0
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code.uint32.ru/tiny/watchdog/checks.go:121.51,123.56 2 0
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code.uint32.ru/tiny/watchdog/checks.go:123.56,125.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:127.3,128.17 2 0
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code.uint32.ru/tiny/watchdog/checks.go:128.17,130.4 1 0
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code.uint32.ru/tiny/watchdog/checks.go:132.3,134.23 2 0
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code.uint32.ru/tiny/watchdog/entity.go:16.33,17.11 1 0
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code.uint32.ru/tiny/watchdog/entity.go:18.16,19.14 1 0
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code.uint32.ru/tiny/watchdog/entity.go:20.18,21.16 1 0
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code.uint32.ru/tiny/watchdog/entity.go:22.10,23.19 1 0
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code.uint32.ru/tiny/watchdog/watchdog.go:25.37,31.2 2 1
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code.uint32.ru/tiny/watchdog/watchdog.go:38.41,46.2 5 1
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code.uint32.ru/tiny/watchdog/watchdog.go:53.47,58.2 3 1
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code.uint32.ru/tiny/watchdog/watchdog.go:62.50,67.29 4 1
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code.uint32.ru/tiny/watchdog/watchdog.go:67.29,68.37 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:68.37,69.12 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:72.3,72.35 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:75.2,75.22 1 1
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code.uint32.ru/tiny/watchdog/watchdog.go:85.92,89.22 3 1
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code.uint32.ru/tiny/watchdog/watchdog.go:89.22,91.3 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:94.2,94.24 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:94.24,96.3 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:98.2,99.22 2 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:99.22,101.3 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:103.2,105.27 2 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:111.33,115.22 3 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:115.22,117.3 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:119.2,119.9 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:120.24,120.24 0 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:122.10,123.24 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:126.2,126.26 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:126.27,128.3 0 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:130.2,130.12 1 1
|
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code.uint32.ru/tiny/watchdog/watchdog.go:136.96,138.24 2 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:138.24,141.3 2 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:143.2,146.22 3 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:146.22,148.3 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:150.2,152.55 2 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:152.55,153.22 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:153.22,155.4 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:155.9,155.29 1 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:155.29,157.4 1 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:158.3,158.11 1 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:161.2,161.22 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:164.41,169.2 3 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:171.96,180.27 6 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:180.27,181.23 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:181.23,185.8 3 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:185.8,198.33 5 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:198.33,200.6 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:202.5,204.12 2 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:205.19,205.19 0 0
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:207.17,208.16 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:209.23,210.22 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:218.2,218.12 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:218.12,226.3 5 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:229.92,237.23 5 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:237.23,240.25 2 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:240.25,241.17 1 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:241.18,242.5 0 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:246.4,260.14 7 1
|
||||
code.uint32.ru/tiny/watchdog/watchdog.go:264.2,266.17 2 1
|
||||
@@ -24,7 +24,9 @@ func (s Status) String() string {
|
||||
}
|
||||
}
|
||||
|
||||
// CheckFunc is a function run by Watchdog.
|
||||
// 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)
|
||||
|
||||
|
||||
272
watchdog.go
272
watchdog.go
@@ -6,8 +6,6 @@ import (
|
||||
"slices"
|
||||
"sync"
|
||||
"time"
|
||||
|
||||
"golang.org/x/sync/errgroup"
|
||||
)
|
||||
|
||||
var (
|
||||
@@ -18,20 +16,37 @@ var (
|
||||
// Watchdog keeps checks to run either periodically
|
||||
// or on demand.
|
||||
type Watchdog struct {
|
||||
checks []Check
|
||||
running *running
|
||||
mu sync.Mutex
|
||||
checks []*wdCheck
|
||||
mu sync.Mutex
|
||||
|
||||
monitoring bool // is monitoring currently in progress
|
||||
|
||||
events chan CheckResult // output channel
|
||||
limiter chan struct{} // TODO: use proper limiter here
|
||||
|
||||
timeout time.Duration
|
||||
|
||||
running int
|
||||
}
|
||||
|
||||
type running struct {
|
||||
out chan CheckResult
|
||||
stop chan struct{}
|
||||
type wdCheck struct {
|
||||
check Check
|
||||
stop chan struct{}
|
||||
}
|
||||
|
||||
// New accepts checks to run.
|
||||
// New creates instance of Watchdog with
|
||||
// provided checks.
|
||||
func New(checks ...Check) *Watchdog {
|
||||
ch := make([]*wdCheck, len(checks))
|
||||
|
||||
for i := range checks {
|
||||
ch[i] = &wdCheck{
|
||||
check: checks[i],
|
||||
}
|
||||
}
|
||||
|
||||
w := &Watchdog{
|
||||
checks: checks,
|
||||
checks: ch,
|
||||
}
|
||||
|
||||
return w
|
||||
@@ -42,94 +57,129 @@ func (w *Watchdog) ListChecks() []Check {
|
||||
defer w.mu.Unlock()
|
||||
|
||||
out := make([]Check, len(w.checks))
|
||||
copy(out, w.checks)
|
||||
for i := range w.checks {
|
||||
out[i] = w.checks[i].check
|
||||
}
|
||||
|
||||
return out
|
||||
}
|
||||
|
||||
// AddChecks adds checks to the group. This DOES NOT
|
||||
// affect already runnning monitoring for group. Use Stop and
|
||||
// then Start to restart monitoring when a new check is added.
|
||||
// SetTimeout sets timeout for all checks that
|
||||
// get started with Start method. Changing this
|
||||
// value does not affect running checks.
|
||||
// Watchdog does not enforce this timeout, it
|
||||
// just passes context.WithTimemout to check functions.
|
||||
// If this method is not called the default timeout
|
||||
// of 10 seconds is used.
|
||||
func (w *Watchdog) SetTimeout(d time.Duration) {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
w.timeout = d
|
||||
}
|
||||
|
||||
// AddChecks adds checks to the group.
|
||||
// If monitoring is in progress then monitoring it started for the newly added
|
||||
// check as well.
|
||||
// Check may have duplicate Name fields but note that RemoveChecks removes checks
|
||||
// by their Name fields.
|
||||
func (w *Watchdog) AddChecks(checks ...Check) {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
w.checks = append(w.checks, checks...)
|
||||
for i := range checks {
|
||||
nc := &wdCheck{
|
||||
check: checks[i],
|
||||
}
|
||||
w.checks = append(w.checks, nc)
|
||||
|
||||
if w.monitoring {
|
||||
w.startMonitoring(nc)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// RemoveChecks removes the named checks.
|
||||
// This does not affect the already running monitoring for the group.
|
||||
func (w *Watchdog) RemoveChecks(names ...string) {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
remaining := make([]Check, 0, len(w.checks)-len(names))
|
||||
for _, e := range w.checks {
|
||||
if slices.Contains(names, e.Name) {
|
||||
remaining := make([]*wdCheck, 0, len(w.checks)-len(names))
|
||||
for _, c := range w.checks {
|
||||
if slices.Contains(names, c.check.Name) {
|
||||
if w.monitoring {
|
||||
w.stopMonitoring(c)
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
remaining = append(remaining, e)
|
||||
remaining = append(remaining, c)
|
||||
}
|
||||
|
||||
w.checks = remaining
|
||||
}
|
||||
|
||||
// Start starts monitoring.
|
||||
// Subsequent calls to start just returns the SAME channel. If you need
|
||||
// Subsequent calls to start return the SAME channel. If you need
|
||||
// to have more that one reader from the channel - fan out on your side.
|
||||
// On start Watchdog runs all provided check and pushes current status of ALL checks of
|
||||
// the group to the channel.
|
||||
// Subsequently only changes of status are pushed regardless of return error values of
|
||||
// CheckFunc provided to Watchdog.
|
||||
// Concurrency limits the number of checks that can run concurrently. 0 means no
|
||||
// On start Watchdog runs all provided check and pushes current status of checks of
|
||||
// to the channel.
|
||||
// Subsequently if check func returns different status or if it returns an error the
|
||||
// result is pushed to the channel.
|
||||
// Concurrency argument limits the number of checks that can run concurrently. 0 means no
|
||||
// limit (all checks may run concurrently).
|
||||
func (w *Watchdog) Start(ctx context.Context, concurrency int) (<-chan CheckResult, error) {
|
||||
func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
if w.running != nil {
|
||||
return w.running.out, nil
|
||||
}
|
||||
|
||||
// start new session
|
||||
if len(w.checks) == 0 {
|
||||
return nil, ErrNotConfigured
|
||||
}
|
||||
|
||||
cp := w.copyChecks()
|
||||
if concurrency == 0 {
|
||||
concurrency = len(cp)
|
||||
if w.monitoring {
|
||||
return w.events, nil
|
||||
}
|
||||
|
||||
w.runMonitoringForGroup(ctx, cp, concurrency)
|
||||
if concurrency == 0 {
|
||||
concurrency = len(w.checks)
|
||||
}
|
||||
|
||||
return w.running.out, nil
|
||||
if w.timeout == 0 {
|
||||
w.timeout = DefaultTimeout
|
||||
}
|
||||
|
||||
w.events = make(chan CheckResult, concurrency)
|
||||
w.limiter = make(chan struct{}, concurrency)
|
||||
|
||||
for i := range w.checks {
|
||||
w.startMonitoring(w.checks[i])
|
||||
}
|
||||
|
||||
w.monitoring = true
|
||||
|
||||
return w.events, nil
|
||||
}
|
||||
|
||||
// Stop stops execution of checks.
|
||||
// Subsequent calls of Stop for the same groupID
|
||||
// return ErrNotRunning.
|
||||
// Subsequent calls return ErrNotRunning.
|
||||
func (w *Watchdog) Stop() error {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
if w.running == nil {
|
||||
if !w.monitoring {
|
||||
return ErrNotRunning
|
||||
}
|
||||
|
||||
close(w.running.stop)
|
||||
|
||||
w.running = nil
|
||||
for i := range w.checks {
|
||||
w.stopMonitoring(w.checks[i])
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// RunImmediately runs configured checks for group concurrently and returns results.
|
||||
// Concurrency limits number of checks that are allowed run concurrently. Setting
|
||||
// concurrency to 0 means that all check of the group are allowed to run simultaneously.
|
||||
// RunImmediately runs configured checks concurrently and returns results.
|
||||
// Setting concurrency to 0 means that all check of the group are allowed to run simultaneously.
|
||||
// Otherwise at most concurrency checks will be allowed to run simultaneously.
|
||||
func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]CheckResult, error) {
|
||||
w.mu.Lock()
|
||||
if len(w.checks) == 0 {
|
||||
@@ -160,86 +210,94 @@ func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]Check
|
||||
|
||||
func (w *Watchdog) copyChecks() []Check {
|
||||
cp := make([]Check, len(w.checks))
|
||||
copy(cp, w.checks)
|
||||
for i := range w.checks {
|
||||
cp[i] = w.checks[i].check
|
||||
}
|
||||
|
||||
return cp
|
||||
}
|
||||
|
||||
func (w *Watchdog) runMonitoringForGroup(ctx context.Context, checks []Check, concurrency int) {
|
||||
events := make(chan CheckResult, len(checks))
|
||||
stop := make(chan struct{})
|
||||
func (w *Watchdog) startMonitoring(wdc *wdCheck) {
|
||||
wdc.stop = make(chan struct{})
|
||||
|
||||
w.running = &running{out: events, stop: stop}
|
||||
state := CheckResult{}
|
||||
ticker := time.Tick(wdc.check.Interval)
|
||||
|
||||
grp := errgroup.Group{}
|
||||
sema := make(chan struct{}, concurrency)
|
||||
c := wdc.check
|
||||
|
||||
for _, c := range checks {
|
||||
grp.Go(func() error {
|
||||
state := CheckResult{}
|
||||
ticker := time.Tick(c.Interval)
|
||||
// this method is called only with
|
||||
// w.mu locked
|
||||
w.running++
|
||||
|
||||
for {
|
||||
sema <- struct{}{}
|
||||
|
||||
status, err := c.Check(ctx)
|
||||
|
||||
<-sema
|
||||
|
||||
s := CheckResult{
|
||||
Name: c.Name,
|
||||
Status: status,
|
||||
Error: err,
|
||||
}
|
||||
|
||||
if s.Status != state.Status {
|
||||
events <- s
|
||||
}
|
||||
|
||||
state = s
|
||||
|
||||
select {
|
||||
case <-ticker:
|
||||
// continue looping
|
||||
case <-stop:
|
||||
return nil
|
||||
case <-ctx.Done():
|
||||
return ctx.Err()
|
||||
}
|
||||
}
|
||||
})
|
||||
}
|
||||
|
||||
// separate goroutine to close the output chan
|
||||
// when everyone's dead
|
||||
go func() {
|
||||
grp.Wait()
|
||||
close(events)
|
||||
defer func() {
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
|
||||
w.mu.Lock()
|
||||
defer w.mu.Unlock()
|
||||
if w.running != nil {
|
||||
w.running = nil
|
||||
w.running--
|
||||
if w.running == 0 {
|
||||
// last goroutine to exit will also
|
||||
// close the output chan
|
||||
close(w.events)
|
||||
w.monitoring = false
|
||||
}
|
||||
}()
|
||||
|
||||
for {
|
||||
w.limiter <- struct{}{}
|
||||
|
||||
ctx, cancel := context.WithTimeout(context.Background(), w.timeout)
|
||||
defer cancel()
|
||||
|
||||
status, err := c.Check(ctx)
|
||||
|
||||
<-w.limiter
|
||||
|
||||
s := CheckResult{
|
||||
Name: c.Name,
|
||||
Status: status,
|
||||
Error: err,
|
||||
}
|
||||
|
||||
if s.Status != state.Status || s.Error != nil {
|
||||
w.events <- s
|
||||
}
|
||||
|
||||
state = s
|
||||
|
||||
select {
|
||||
case <-ticker:
|
||||
// continue looping
|
||||
case <-wdc.stop:
|
||||
// stopping this specific check
|
||||
return
|
||||
}
|
||||
}
|
||||
}()
|
||||
}
|
||||
|
||||
func (w *Watchdog) stopMonitoring(wdc *wdCheck) {
|
||||
close(wdc.stop)
|
||||
}
|
||||
|
||||
func runChecksConcurrently(ctx context.Context, ch []Check, concurrency int) []CheckResult {
|
||||
statuses := make([]CheckResult, 0, len(ch))
|
||||
m := sync.Mutex{} // for append operations
|
||||
|
||||
group := errgroup.Group{}
|
||||
|
||||
sema := make(chan struct{}, concurrency) // semaphore to limit concurrency
|
||||
done := make(chan struct{}, len(ch))
|
||||
|
||||
count := len(ch)
|
||||
|
||||
for _, e := range ch {
|
||||
sema <- struct{}{} // acquire
|
||||
|
||||
group.Go(func() error {
|
||||
go func() error {
|
||||
defer func() {
|
||||
<-sema
|
||||
done <- struct{}{}
|
||||
}()
|
||||
|
||||
// relying on fact that CheckFunc obeys context
|
||||
// relying on assumption that CheckFunc obeys context
|
||||
// cancellation
|
||||
status, err := e.Check(ctx)
|
||||
|
||||
@@ -253,13 +311,17 @@ func runChecksConcurrently(ctx context.Context, ch []Check, concurrency int) []C
|
||||
defer m.Unlock()
|
||||
statuses = append(statuses, r)
|
||||
|
||||
<-sema // release
|
||||
|
||||
return nil
|
||||
})
|
||||
}()
|
||||
}
|
||||
|
||||
group.Wait()
|
||||
// wait for all to finish
|
||||
for range done {
|
||||
count--
|
||||
if count == 0 {
|
||||
close(done)
|
||||
}
|
||||
}
|
||||
|
||||
return statuses
|
||||
}
|
||||
|
||||
@@ -2,6 +2,7 @@ package watchdog_test
|
||||
|
||||
import (
|
||||
"context"
|
||||
"errors"
|
||||
"reflect"
|
||||
"testing"
|
||||
"time"
|
||||
@@ -16,8 +17,14 @@ type mockChecker struct {
|
||||
called bool
|
||||
}
|
||||
|
||||
func (m *mockChecker) Func(_ context.Context) (watchdog.Status, error) {
|
||||
func (m *mockChecker) Func(ctx context.Context) (watchdog.Status, error) {
|
||||
m.called = true
|
||||
|
||||
time.Sleep(time.Millisecond * 10)
|
||||
if err := ctx.Err(); err != nil {
|
||||
return watchdog.StatusUnknown, err
|
||||
}
|
||||
|
||||
return m.status, m.err
|
||||
}
|
||||
|
||||
@@ -106,9 +113,9 @@ func TestRunImmediately(t *testing.T) {
|
||||
|
||||
}
|
||||
|
||||
func TestStart(t *testing.T) {
|
||||
func TestStartStop(t *testing.T) {
|
||||
w := new(watchdog.Watchdog)
|
||||
if _, err := w.Start(t.Context(), 0); err == nil {
|
||||
if _, err := w.Start(0); err == nil {
|
||||
t.Error("Start doen't error on empty checks slice")
|
||||
}
|
||||
|
||||
@@ -117,12 +124,12 @@ func TestStart(t *testing.T) {
|
||||
|
||||
w.AddChecks(m1.Check(), m2.Check())
|
||||
|
||||
out, err := w.Start(t.Context(), 0)
|
||||
out, err := w.Start(0)
|
||||
if err != nil {
|
||||
t.Error("Start returns error", err)
|
||||
}
|
||||
|
||||
out2, err := w.Start(t.Context(), 0)
|
||||
out2, err := w.Start(0)
|
||||
if err != nil {
|
||||
t.Error("second call to Start returns error")
|
||||
}
|
||||
@@ -131,13 +138,12 @@ func TestStart(t *testing.T) {
|
||||
t.Error("returned channels are not equal")
|
||||
}
|
||||
|
||||
time.Sleep(time.Second)
|
||||
if err := w.Stop(); err != nil {
|
||||
t.Error("Stop returned error", err)
|
||||
}
|
||||
|
||||
count := 0
|
||||
go func() {
|
||||
time.Sleep(time.Second)
|
||||
if err := w.Stop(); err != nil {
|
||||
t.Error("Stop returned error", err)
|
||||
}
|
||||
}()
|
||||
|
||||
for res := range out {
|
||||
if res.Status != watchdog.StatusOK || res.Error != nil {
|
||||
@@ -162,22 +168,19 @@ func TestStart(t *testing.T) {
|
||||
}
|
||||
}
|
||||
|
||||
func TestWatchdogObeysContext(t *testing.T) {
|
||||
func TestSetTimeout(t *testing.T) {
|
||||
w := new(watchdog.Watchdog)
|
||||
w.SetTimeout(time.Millisecond)
|
||||
m1 := newMockChecker("mock", watchdog.StatusOK, nil)
|
||||
m2 := newMockChecker("mock2", watchdog.StatusOK, nil)
|
||||
w.AddChecks(m1.Check())
|
||||
|
||||
w.AddChecks(m1.Check(), m2.Check())
|
||||
|
||||
ctx, stop := context.WithCancel(t.Context())
|
||||
if _, err := w.Start(ctx, 2); err != nil {
|
||||
t.Error(err)
|
||||
}
|
||||
|
||||
stop()
|
||||
// wait for goroutines to finish
|
||||
out, _ := w.Start(0)
|
||||
time.Sleep(time.Second)
|
||||
if err := w.Stop(); err == nil {
|
||||
t.Error("no error calling Stop for stopped instance")
|
||||
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)
|
||||
t.Fatal("incorrect status for timed out op")
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user