From 7f2b30d33c5898d31f9b6623657d93d272b8ea7a Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Wed, 7 Sep 2016 11:22:38 +0100
Subject: [PATCH 1/1] Add a small preload library to flush files on close

---
 cookbooks/planet/files/default/flush/Makefile |  2 ++
 cookbooks/planet/files/default/flush/flush.c  | 16 ++++++++++++++
 cookbooks/planet/recipes/replication.rb       | 22 +++++++++++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 cookbooks/planet/files/default/flush/Makefile
 create mode 100644 cookbooks/planet/files/default/flush/flush.c

diff --git a/cookbooks/planet/files/default/flush/Makefile b/cookbooks/planet/files/default/flush/Makefile
new file mode 100644
index 000000000..b42035e7b
--- /dev/null
+++ b/cookbooks/planet/files/default/flush/Makefile
@@ -0,0 +1,2 @@
+flush.so: flush.c
+	cc -O2 -fPIC -D_GNU_SOURCE -shared -o flush.so flush.c -ldl
diff --git a/cookbooks/planet/files/default/flush/flush.c b/cookbooks/planet/files/default/flush/flush.c
new file mode 100644
index 000000000..c80e86af2
--- /dev/null
+++ b/cookbooks/planet/files/default/flush/flush.c
@@ -0,0 +1,16 @@
+#include <dlfcn.h>
+#include <unistd.h>
+
+static int (*real_close)(int fd);
+
+static void __attribute__((constructor)) initialise(void)
+{
+  real_close = dlsym(RTLD_NEXT, "close");
+}
+
+int close(int fd)
+{
+  fdatasync(fd);
+
+  return real_close(fd);
+}
diff --git a/cookbooks/planet/recipes/replication.rb b/cookbooks/planet/recipes/replication.rb
index d9ff9b67c..25fe9671d 100644
--- a/cookbooks/planet/recipes/replication.rb
+++ b/cookbooks/planet/recipes/replication.rb
@@ -30,6 +30,28 @@ package "ruby-libxml"
 package "libpq-dev"
 gem_package "pg"
 
+package "make"
+package "gcc"
+
+remote_directory "/opt/flush" do
+  source "flush"
+  owner "root"
+  group "root"
+  mode 0o755
+  files_owner "root"
+  files_group "root"
+  files_mode 0o755
+end
+
+execute "/opt/flush/Makefile" do
+  action :nothing
+  command "make"
+  cwd "/opt/flush"
+  user "root"
+  group "root"
+  subscribes :run, "remote_directory[/opt/flush]"
+end
+
 remote_directory "/usr/local/bin" do
   source "replication-bin"
   owner "root"
-- 
2.43.2