From 1adfe3f1d06b6957c0d4d2b47eb7a1decdf286c5 Mon Sep 17 00:00:00 2001
From: Camilo Schoeningh <camilo.schoeningh@lhsystems.com>
Date: Sun, 27 Feb 2022 18:33:27 +0100
Subject: [PATCH 1/3] [HTTP] Send back response_code and header

To use the web server in applications like k8s, we should return the
response code. This can be used inside the readiness and livenessprobe.
---
 http_server.rb | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/http_server.rb b/http_server.rb
index 7a11960..203c793 100644
--- a/http_server.rb
+++ b/http_server.rb
@@ -10,6 +10,9 @@
 
   puts "#{method} #{path} #{version}"
 
+  headers = "HTTP/1.1 200 OK\r\nDate: #{Time.now}\r\nContent-Type: text/html; charset=iso-8859-1\r\n\r\n"
+  client.puts headers
+
   if path == "/healthcheck"
     client.write("OK")
   else

From 11e08fe76945284e288a464533fb0fffa19bf4e9 Mon Sep 17 00:00:00 2001
From: Camilo Schoeningh <camilo.schoeningh@lhsystems.com>
Date: Sun, 27 Feb 2022 19:05:32 +0100
Subject: [PATCH 2/3] [ADHOC] Use puts instead of write, to append new line

---
 http_server.rb | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/http_server.rb b/http_server.rb
index 203c793..c0293a5 100644
--- a/http_server.rb
+++ b/http_server.rb
@@ -7,17 +7,17 @@
   request = client.readpartial(2048)
   
   method, path, version = request.lines[0].split
-
   puts "#{method} #{path} #{version}"
 
-  headers = "HTTP/1.1 200 OK\r\nDate: #{Time.now}\r\nContent-Type: text/html; charset=iso-8859-1\r\n\r\n"
-  client.puts headers
-
-  if path == "/healthcheck"
-    client.write("OK")
+  if path == "/healthcheck" 
+    response = "OK"
   else
-    client.write("Well, hello there!")
+    response = "Well, hello there!"
   end
 
+  headers = "HTTP/1.1 200 OK\r\nDate: #{Time.now}\r\nContent-Length: #{response.bytesize}\r\nContent-Type: text/html; charset=iso-8859-1\r\n\r\n"
+  client.puts headers
+  client.puts response
+
   client.close
 }

From 6c84c3b20ceb4a8126063beae0e3f3527aaebcd0 Mon Sep 17 00:00:00 2001
From: Camilo Schoeningh <camilo.schoeningh@lhsystems.com>
Date: Sun, 27 Feb 2022 20:42:03 +0100
Subject: [PATCH 3/3] [STDOUT] Make sure all output is flushed to stdout
 immediately

Ruby is buffering output until the output buffer is full.
To change the behavior we set sync=true

https://ruby-doc.org/core-2.3.1/IO.html#method-i-sync
---
 http_server.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/http_server.rb b/http_server.rb
index c0293a5..d975658 100644
--- a/http_server.rb
+++ b/http_server.rb
@@ -1,13 +1,14 @@
 require 'socket'
 
 server  = TCPServer.new('0.0.0.0', 80)
+$stdout.sync = true
 
 loop {
   client  = server.accept
   request = client.readpartial(2048)
   
   method, path, version = request.lines[0].split
-  puts "#{method} #{path} #{version}"
+  STDOUT.puts "#{method} #{path} #{version}"
 
   if path == "/healthcheck" 
     response = "OK"