Added occurrence for the WaitLogStrategy

This is related to the work @giorgioazzinnaro is doing here
#98 .

Now you can declare how many times a log line should appear before
having the container declared as ready.

Signed-off-by: Gianluca Arbezzano <[email protected]>

go.mod

@@ -32,3 +32,5 @@ require (
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gotest.tools v0.0.0-20181223230014-1083505acf35 // indirect
 )
+
+go 1.13

go.sum

@@ -71,6 +71,7 @@ golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73r
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd h1:nTDtHvHSdCn1m6ITfMRqtOd/9+7a3s8RBNOZ3eYZzJA=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f h1:wMNYb4v58l5UBM7MYRLPG6ZhfOqbKu7X5eyFl8ZhKvA=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

wait/log.go

@@ -18,6 +18,7 @@ type LogStrategy struct {
 	// additional properties
 	Log          string
 	PollInterval time.Duration
+	Occurrence   int
 }
 
 // NewLogStrategy constructs a HTTP strategy waiting on port 80 and status code 200
@@ -26,6 +27,7 @@ func NewLogStrategy(log string) *LogStrategy {
 		startupTimeout: defaultStartupTimeout(),
 		Log:            log,
 		PollInterval:   100 * time.Millisecond,
+		Occurrence:     1,
 	}
 
 }
@@ -46,6 +48,15 @@ func (ws *LogStrategy) WithPollInterval(pollInterval time.Duration) *LogStrategy
 	return ws
 }
 
+func (ws *LogStrategy) WithOccurence(o int) *LogStrategy {
+	// the number of occurence needs to be positive
+	if o <= 0 {
+		o = 1
+	}
+	ws.Occurrence = o
+	return ws
+}
+
 // ForLog is the default construction for the fluid interface.
 //
 // For Example:
@@ -61,6 +72,7 @@ func (ws *LogStrategy) WaitUntilReady(ctx context.Context, target StrategyTarget
 	// limit context to startupTimeout
 	ctx, cancelContext := context.WithTimeout(ctx, ws.startupTimeout)
 	defer cancelContext()
+	currentOccurence := 0
 
 LOOP:
 	for {
@@ -77,7 +89,10 @@ LOOP:
 			b, err := ioutil.ReadAll(reader)
 			logs := string(b)
 			if strings.Contains(logs, ws.Log) {
-				break LOOP
+				currentOccurence++
+				if ws.Occurrence == 0 || currentOccurence >= ws.Occurrence-1 {
+					break LOOP
+				}
 			} else {
 				time.Sleep(ws.PollInterval)
 				continue

wait/log_test.go

@@ -0,0 +1,65 @@
+package wait
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"io/ioutil"
+	"testing"
+	"time"
+
+	"github.com/docker/go-connections/nat"
+)
+
+type noopStrategyTarget struct {
+	ioReaderCloser io.ReadCloser
+}
+
+func (st noopStrategyTarget) Host(ctx context.Context) (string, error) {
+	return "", nil
+}
+
+func (st noopStrategyTarget) MappedPort(ctx context.Context, n nat.Port) (nat.Port, error) {
+	return n, nil
+}
+
+func (st noopStrategyTarget) Logs(ctx context.Context) (io.ReadCloser, error) {
+	return st.ioReaderCloser, nil
+}
+
+func TestWaitForLog(t *testing.T) {
+	target := noopStrategyTarget{
+		ioReaderCloser: ioutil.NopCloser(bytes.NewReader([]byte("dude"))),
+	}
+	wg := NewLogStrategy("dude").WithStartupTimeout(100 * time.Microsecond)
+	err := wg.WaitUntilReady(context.Background(), target)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWaitWithMaxOccurence(t *testing.T) {
+	target := noopStrategyTarget{
+		ioReaderCloser: ioutil.NopCloser(bytes.NewReader([]byte("hello\r\ndude\n\rdude"))),
+	}
+	wg := NewLogStrategy("dude").
+		WithStartupTimeout(100 * time.Microsecond).
+		WithOccurence(2)
+	err := wg.WaitUntilReady(context.Background(), target)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWaitWithMaxOccurenceButItWillNeverHappen(t *testing.T) {
+	target := noopStrategyTarget{
+		ioReaderCloser: ioutil.NopCloser(bytes.NewReader([]byte("hello\r\ndude"))),
+	}
+	wg := NewLogStrategy("blaaa").
+		WithStartupTimeout(100 * time.Microsecond).
+		WithOccurence(2)
+	err := wg.WaitUntilReady(context.Background(), target)
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}