TUN-9371: Add logging format as JSON

Closes TUN-9371

logger/console.go

@@ -0,0 +1,37 @@
+package logger
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	jsoniter "github.com/json-iterator/go"
+)
+
+var json = jsoniter.ConfigCompatibleWithStandardLibrary
+
+// consoleWriter allows us the simplicity to prevent duplicate json keys in the logger events reported.
+//
+// By default zerolog constructs the json event in parts by appending each additional key after the first. It
+// doesn't have any internal state or struct of the json message representation so duplicate keys can be
+// inserted without notice and no pruning will occur before writing the log event out to the io.Writer.
+//
+// To help prevent these duplicate keys, we will decode the json log event and then immediately re-encode it
+// again as writing it to the output io.Writer. Since we encode it to a map[string]any, duplicate keys
+// are pruned. We pay the cost of decoding and encoding the log event for each time, but helps prevent
+// us from needing to worry about adding duplicate keys in the log event from different areas of code.
+type consoleWriter struct {
+	out io.Writer
+}
+
+func (c *consoleWriter) Write(p []byte) (n int, err error) {
+	var evt map[string]any
+	d := json.NewDecoder(bytes.NewReader(p))
+	d.UseNumber()
+	err = d.Decode(&evt)
+	if err != nil {
+		return n, fmt.Errorf("cannot decode event: %s", err)
+	}
+	e := json.NewEncoder(c.out)
+	return len(p), e.Encode(evt)
+}