From c9783fac610652a848a89de478a74d1924ab50d0 Mon Sep 17 00:00:00 2001
From: Raul Cabello Martin <raulcabm@gmail.com>
Date: Wed, 26 May 2021 23:33:03 +0200
Subject: [PATCH] =?UTF-8?q?feat(log):=20Support=20of=20kubectl.kubernetes.?=
 =?UTF-8?q?io/default-logs-container=20an=E2=80=A6=20(#1133)?=
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* feat(log): Support of kubectl.kubernetes.io/default-logs-container annotation

Closes #1057

* feat(log): Support of kubectl.kubernetes.io/default-logs-container annotation

refactored to return ok bool with the container

Closes #1057

* feat(log): Support of kubectl.kubernetes.io/default-logs-container annotation

refactored getDefaultLogContainer
log if container was not found
---
 internal/dao/pod.go      | 26 ++++++++++++++++++++++--
 internal/dao/pod_test.go | 44 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 internal/dao/pod_test.go

diff --git a/internal/dao/pod.go b/internal/dao/pod.go
index 1de4ed59..b1942e05 100644
--- a/internal/dao/pod.go
+++ b/internal/dao/pod.go
@@ -32,8 +32,9 @@ var (
 )
 
 const (
-	logRetryCount = 20
-	logRetryWait  = 1 * time.Second
+	logRetryCount                 = 20
+	logRetryWait                  = 1 * time.Second
+	defaultLogContainerAnnotation = "kubectl.kubernetes.io/default-logs-container"
 )
 
 // Pod represents a pod resource.
@@ -195,6 +196,13 @@ func (p *Pod) TailLogs(ctx context.Context, c LogChan, opts LogOptions) error {
 		opts.SingleContainer = true
 		return tailLogs(ctx, p, c, opts)
 	}
+
+	if defaultContainer, ok := getDefaultLogContainer(po); ok {
+		opts.SingleContainer = true
+		opts.Container = defaultContainer
+		return tailLogs(ctx, p, c, opts)
+	}
+
 	if len(po.Spec.InitContainers)+len(po.Spec.Containers) == 1 {
 		opts.SingleContainer = true
 	}
@@ -491,3 +499,17 @@ func (p *Pod) isControlled(path string) (string, bool, error) {
 	}
 	return "", false, nil
 }
+
+func getDefaultLogContainer(po v1.Pod) (string, bool) {
+	defaultContainer, ok := po.GetAnnotations()[defaultLogContainerAnnotation]
+	if ok {
+		for _, container := range po.Spec.Containers {
+			if container.Name == defaultContainer {
+				return defaultContainer, true
+			}
+		}
+		log.Warn().Msg(defaultContainer + " container  not found. " + defaultLogContainerAnnotation + " annotation will be ignored")
+	}
+
+	return "", false
+}
diff --git a/internal/dao/pod_test.go b/internal/dao/pod_test.go
new file mode 100644
index 00000000..a340dbfd
--- /dev/null
+++ b/internal/dao/pod_test.go
@@ -0,0 +1,44 @@
+package dao
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestGetDefaultLogContainer(t *testing.T) {
+	type args struct {
+		imageSpecs ImageSpecs
+	}
+	uu := map[string]struct {
+		po            v1.Pod
+		wantContainer string
+		wantOk        bool
+	}{
+		"no_annotation": {
+			po:            v1.Pod{},
+			wantContainer: "",
+			wantOk:        false,
+		},
+		"container_not_present": {
+			po:            v1.Pod{ObjectMeta: metav1.ObjectMeta{Annotations: map[string]string{"kubectl.kubernetes.io/default-logs-container": "container1"}}},
+			wantContainer: "",
+			wantOk:        false,
+		},
+		"container_found": {
+			po:            v1.Pod{ObjectMeta: metav1.ObjectMeta{Annotations: map[string]string{"kubectl.kubernetes.io/default-logs-container": "container1"}}, Spec: v1.PodSpec{Containers: []v1.Container{{Name: "container1"}}}},
+			wantContainer: "container1",
+			wantOk:        true,
+		},
+	}
+	for k := range uu {
+		u := uu[k]
+		t.Run(k, func(t *testing.T) {
+			container, ok := getDefaultLogContainer(u.po)
+			assert.Equal(t, u.wantContainer, container)
+			assert.Equal(t, u.wantOk, ok)
+		})
+	}
+}