Refactor Log Parsing

pkg/function/kube_task.go

@@ -22,8 +22,8 @@ import (
 	"k8s.io/client-go/kubernetes"
 
 	kanister "github.com/kanisterio/kanister/pkg"
-	"github.com/kanisterio/kanister/pkg/format"
 	"github.com/kanisterio/kanister/pkg/kube"
+	"github.com/kanisterio/kanister/pkg/output"
 	"github.com/kanisterio/kanister/pkg/param"
 )
 
@@ -81,24 +81,12 @@ func kubeTaskPodFunc(cli kubernetes.Interface) func(ctx context.Context, pod *v1
 		if err != nil {
 			return nil, errors.Wrapf(err, "Failed to fetch logs from the pod")
 		}
-		defer r.Close()
-		logCh := format.LogStream(pod.Name, pod.Spec.Containers[0].Name, r)
+		out, err := output.ParseLog(ctx, r)
 		// Wait for pod completion
-		err = kube.WaitForPodCompletion(ctx, cli, pod.Namespace, pod.Name)
-		if err != nil {
+		if err := kube.WaitForPodCompletion(ctx, cli, pod.Namespace, pod.Name); err != nil {
 			return nil, errors.Wrapf(err, "Failed while waiting for Pod %s to complete", pod.Name)
 		}
-		out := make(map[string]interface{})
-		for l := range logCh {
-			op, err := parseLogLineForOutput(l)
-			if err != nil {
-				return nil, errors.Wrap(err, "Failed to parse phase output")
-			}
-			if op != nil {
-				out[op.Key] = op.Value
-			}
-		}
-		return out, nil
+		return out, err
 	}
 }
 

pkg/output/log.go

@@ -0,0 +1,74 @@
+// Copyright 2019 The Kanister Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package output
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"regexp"
+	"strings"
+
+	"github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
+)
+
+const reStr = `###Phase-output###:(.*?)*$`
+
+var logRE = regexp.MustCompile(reStr)
+
+func parseLine(l string) (*Output, error) {
+	match := logRE.FindAllStringSubmatch(l, 1)
+	if len(match) == 0 {
+		return nil, nil
+	}
+	op, err := UnmarshalOutput(match[0][1])
+	if err != nil {
+		return nil, err
+	}
+	return op, nil
+}
+
+func ParseLog(ctx context.Context, r io.ReadCloser) (map[string]interface{}, error) {
+	// Call r.Close() if the context is canceled or if s.Scan() == false.
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	go func() {
+		<-ctx.Done()
+		_ = r.Close()
+	}()
+
+	// Scan log lines when ready.
+	s := bufio.NewScanner(r)
+	out := make(map[string]interface{})
+	for s.Scan() {
+		l := s.Text()
+		l = strings.TrimSpace(l)
+		if l == "" {
+			continue
+		}
+		// TODO(supriya): Add fields from ctx.
+		log.Info("Out: ", l)
+		o, err := parseLine(l)
+		if err != nil {
+			return nil, err
+		}
+		if o != nil {
+			out[o.Key] = o.Value
+		}
+	}
+	err := errors.Wrap(s.Err(), "Failed to parse output")
+	return out, err
+}