From 04631800f29af06d44f214f14e6174f32e7f5abd Mon Sep 17 00:00:00 2001
From: Christopher Winslett <chris@compose.io>
Date: Mon, 16 Mar 2015 15:46:09 -0700
Subject: [PATCH] add a haproxy router for a single connection point

---
 README.md         |  8 ++++++++
 haproxy.cfg       | 21 +++++++++++++++++++++
 haproxy_status.sh | 16 ++++++++++++++++
 3 files changed, 45 insertions(+)
 create mode 100644 haproxy.cfg
 create mode 100755 haproxy_status.sh

diff --git a/README.md b/README.md
index 95edeb83..697ac050 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,14 @@ From there, you will see a high-availability cluster start up. Test
 different settings in the YAML files to see how behavior changes.  Kill
 some of the different components to see how the system behaves.
 
+To get a haproxy load balancing between these two hosts, run:
+
+```
+> haproxy -f haproxy.cfg
+> sh haproxy_status.sh 127.0.0.1 5432 15432
+> sh haproxy_status.sh 127.0.0.1 5433 15433
+```
+
 # Requirements on a Mac
 
 Run the following on a Mac to install requirements:
diff --git a/haproxy.cfg b/haproxy.cfg
new file mode 100644
index 00000000..2f794acd
--- /dev/null
+++ b/haproxy.cfg
@@ -0,0 +1,21 @@
+global
+	maxconn 100
+
+defaults
+	log	global
+	mode	tcp
+	retries 2
+	timeout client 30m
+	timeout connect 4s
+	timeout server 30m
+	timeout check 5s
+
+frontend ft_postgresql
+	bind *:5000
+	default_backend bk_db
+
+backend bk_db
+	option httpchk GET
+
+  server postgresql_127.0.0.1_5432 127.0.0.1:5432 maxconn 100 check port 15432
+  server postgresql_127.0.0.1_5433 127.0.0.1:5433 maxconn 100 check port 15433
diff --git a/haproxy_status.sh b/haproxy_status.sh
new file mode 100755
index 00000000..570af9d6
--- /dev/null
+++ b/haproxy_status.sh
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+while true
+do {
+        response=$(echo "SELECT pg_is_in_recovery();" | psql -t postgres --port $2 --host $1 2> /dev/null)
+
+        if [ "${response}" == " f" ]
+        then
+                echo "HTTP/1.1 200 OK"
+                echo "X-XLOG-POSITION: $(echo "SELECT pg_current_xlog_location();" | psql -t postgres 2> /dev/null | tr -d ' ' | head -n 1)"
+        else
+                echo "HTTP/1.1 503 Service unavailable"
+                echo "X-XLOG-POSITION: $(echo "SELECT pg_last_xlog_replay_location();" | psql -t postgres 2> /dev/null | tr -d ' ' | head -n 1)"
+        fi
+
+} | nc -l $3; done