Repository: kubernetes/klog (go)

Issue:
klogr: Don't print level=n in a log line
/kind bug

**What steps did you take and what happened:**
When printing logs I see a lot of `level="0"` or `level="1"` etc. 

There is no reason to print this information and only adds to the difficulty of reading lines. If anything the level could be similar to the `I` or `E` that starts an `Info` or `Error` Log, but it does not need a whole field.

**Anything else you would like to add:**

The change is a matter of removing the `lvlStr` in this function:

https://github.com/kubernetes/klog/blob/master/klogr/klogr.go#L143-L148

edit: "no reason" is too strong. There may be a use case for leaving this in, but I can't think of it beyond some other system parsing logs and wanting to only see specific log lines. Or perhaps logging -vMAX and then filtering on your logging backend.

Pull request description:
Remove "level" from klogr Info
Signed-off-by: Vince Prignano <vincepri@vmware.com>

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**What this PR does / why we need it**:
This PR reduces `klogr` verbosity by removing the `"level"=N` key present in every Info line. Usually users set this value before starting a program, or the application decides a sensible default which is printed using CLI help.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #61

**Special notes for your reviewer**:

_Please confirm that if this PR changes any image versions, then that's the sole change this PR makes._

**Release note**:
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1. Enter your extended release note in the below block. If the PR requires additional action from users switching to the new release, include the string "action required".
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```release-note
Removed "level" key and value from klogr Info output.
```

Patch:
diff --git a/klogr/klogr.go b/klogr/klogr.go
index f63557d..e145950 100644
--- a/klogr/klogr.go
+++ b/klogr/klogr.go
@@ -140,12 +140,11 @@ func pretty(value interface{}) string {
 
 func (l klogger) Info(msg string, kvList ...interface{}) {
 	if l.Enabled() {
-		lvlStr := flatten("level", l.level)
 		msgStr := flatten("msg", msg)
 		trimmed := trimDuplicates(l.values, kvList)
 		fixedStr := flatten(trimmed[0]...)
 		userStr := flatten(trimmed[1]...)
-		klog.InfoDepth(framesToCaller(), l.prefix, " ", lvlStr, " ", msgStr, " ", fixedStr, " ", userStr)
+		klog.InfoDepth(framesToCaller(), l.prefix, " ", msgStr, " ", fixedStr, " ", userStr)
 	}
 }
 


Test patch:
diff --git a/klogr/klogr_test.go b/klogr/klogr_test.go
index 7b84fa7..baa9045 100644
--- a/klogr/klogr_test.go
+++ b/klogr/klogr_test.go
@@ -28,54 +28,48 @@ func TestInfo(t *testing.T) {
 			klogr:         New().V(0),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue"
+			expectedOutput: ` "msg"="test"  "akey"="avalue"
 `,
 		},
 		"should not print duplicate keys with the same value": {
 			klogr:         New().V(0),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey", "avalue"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue"
+			expectedOutput: ` "msg"="test"  "akey"="avalue"
 `,
 		},
 		"should only print the last duplicate key when the values are passed to Info": {
 			klogr:         New().V(0),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey", "avalue2"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue2"
+			expectedOutput: ` "msg"="test"  "akey"="avalue2"
 `,
 		},
 		"should only print the duplicate key that is passed to Info if one was passed to the logger": {
 			klogr:         New().WithValues("akey", "avalue"),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue"
+			expectedOutput: ` "msg"="test"  "akey"="avalue"
 `,
 		},
 		"should only print the key passed to Info when one is already set on the logger": {
 			klogr:         New().WithValues("akey", "avalue"),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue2"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue2"
-`,
-		},
-		"should print different log level if set": {
-			klogr: New().V(4),
-			text:  "test",
-			expectedOutput: ` "level"=4 "msg"="test"  
+			expectedOutput: ` "msg"="test"  "akey"="avalue2"
 `,
 		},
 		"should correctly handle odd-numbers of KVs": {
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey2"},
-			expectedOutput: ` "level"=0 "msg"="test"  "akey"="avalue" "akey2"=null
+			expectedOutput: ` "msg"="test"  "akey"="avalue" "akey2"=null
 `,
 		},
 		"should correctly handle odd-numbers of KVs in both log values and Info args": {
 			klogr:         New().WithValues("basekey1", "basevar1", "basekey2"),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey2"},
-			expectedOutput: ` "level"=0 "msg"="test" "basekey1"="basevar1" "basekey2"=null "akey"="avalue" "akey2"=null
+			expectedOutput: ` "msg"="test" "basekey1"="basevar1" "basekey2"=null "akey"="avalue" "akey2"=null
 `,
 		},
 	}