1 files changed, 61 insertions, 0 deletions
diff --git a/internal/log/log.go b/internal/log/log.go
new file mode 100644
index 0000000..071a816
--- /dev/null
+++ b/internal/log/log.go
@@ -0,0 +1,61 @@
+// Copyright 2018 ThousandEyes Inc.
+//
+// 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 log
+
+import (
+	"io"
+
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
+)
+
+// Logger struct holds a log.Logger plus functions required for logging
+// with different levels. They functions are syntactic sugar to avoid
+// having to import "github.com/go-kit/kit/log/level" in every package that
+// has to cast a log.
+type Logger struct {
+	Raw   log.Logger
+	Info  func(...interface{}) error
+	Debug func(...interface{}) error
+	Error func(...interface{}) error
+}
+
+const callerLevel int = 6
+
+// MakeLogger receives a io.Writer and return a Logger struct.
+func MakeLogger(w io.Writer) Logger {
+	raw := log.NewLogfmtLogger(log.NewSyncWriter(w))
+	raw = log.With(raw, "ts", log.DefaultTimestampUTC, "caller", log.Caller(callerLevel))
+	filtered := level.NewFilter(raw, level.AllowInfo())
+
+	return Logger{
+		Raw:   raw,
+		Info:  level.Info(filtered).Log,
+		Debug: level.Debug(filtered).Log,
+		Error: level.Error(filtered).Log,
+	}
+}
+
+// AllowDebug receives a Logger and enables the debug logging level.
+func AllowDebug(l Logger) Logger {
+	filtered := level.NewFilter(l.Raw, level.AllowDebug())
+
+	return Logger{
+		Raw:   l.Raw,
+		Info:  level.Info(filtered).Log,
+		Debug: level.Debug(filtered).Log,
+		Error: level.Error(filtered).Log,
+	}
+}