From 9c820cf8558d60e5348fed8cef09f67c188fe81f Mon Sep 17 00:00:00 2001
From: Simone Basso <bassosimone@gmail.com>
Date: Wed, 24 Mar 2021 11:39:45 +0100
Subject: [PATCH] fix(ooniprobe): send batch output to stdout (#261)

Rationale explained in detail in a documentation comment.

Reference issue: https://github.com/ooni/probe/issues/1384.
---
 cmd/ooniprobe/internal/log/handlers/batch/batch.go | 13 +++++++++++--
 cmd/ooniprobe/internal/log/handlers/cli/cli.go     |  2 +-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/cmd/ooniprobe/internal/log/handlers/batch/batch.go b/cmd/ooniprobe/internal/log/handlers/batch/batch.go
index 2b11371..2d06a4f 100644
--- a/cmd/ooniprobe/internal/log/handlers/batch/batch.go
+++ b/cmd/ooniprobe/internal/log/handlers/batch/batch.go
@@ -9,8 +9,17 @@ import (
 	"github.com/apex/log"
 )
 
-// Default handler outputting to stderr.
-var Default = New(os.Stderr)
+// Default handler outputting to stdout. We want to emit the batch
+// output on the standard output, for two reasons:
+//
+// 1. because third party libraries MAY log on the stderr and
+// their logs are most likely not JSON;
+//
+// 2. because this enables piping to `jq` or other tools in
+// a much more natural way than when emitting on stderr.
+//
+// See https://github.com/ooni/probe/issues/1384.
+var Default = New(os.Stdout)
 
 // Handler implementation.
 type Handler struct {
diff --git a/cmd/ooniprobe/internal/log/handlers/cli/cli.go b/cmd/ooniprobe/internal/log/handlers/cli/cli.go
index bd34346..575c922 100644
--- a/cmd/ooniprobe/internal/log/handlers/cli/cli.go
+++ b/cmd/ooniprobe/internal/log/handlers/cli/cli.go
@@ -14,7 +14,7 @@ import (
 	"github.com/ooni/probe-cli/v3/cmd/ooniprobe/internal/utils"
 )
 
-// Default handler outputting to stderr.
+// Default handler outputting to stdout.
 var Default = New(os.Stdout)
 
 // start time.