From dce3337f39ec95d8a56db5220ec8902b03162401 Mon Sep 17 00:00:00 2001
From: Julio Montes <julio.montes@intel.com>
Date: Thu, 28 Jan 2016 11:10:52 -0600
Subject: [PATCH] add functions to save instance id and detect vm's first boot

save_instance_id must be used by datasources to save instance id
is_firstboot uses instance id to detect vm's first boot
---
 src/lib.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.h |  2 ++
 2 files changed, 54 insertions(+)

diff --git a/src/lib.c b/src/lib.c
index 6ed2924..007c066 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -64,6 +64,8 @@
 #define MOD "lib: "
 #define LOOP_MAJOR_ID 7
 #define SUDOERS_PATH SYSCONFDIR "/sudoers.d/"
+#define INSTANCE_ID_FILE DATADIR_PATH "/instance-id"
+#define LAST_INSTANCE_ID_FILE DATADIR_PATH "/last-instance-id"
 
 
 void LOG(const char *fmt, ...) {
@@ -446,6 +448,56 @@ bool umount_filesystem(const gchar* mountdir, const gchar* loop_device) {
 	return true;
 }
 
+bool save_instance_id(const gchar* instance_id) {
+	GString* id = g_string_new(instance_id);
+	if (!write_file(id, INSTANCE_ID_FILE, O_CREAT|O_TRUNC|O_WRONLY, S_IRWXU)) {
+		LOG(MOD "Unable to save instance id\n");
+		g_string_free(id, true);
+		return false;
+	}
+
+	g_string_free(id, true);
+	return true;
+}
+
+bool is_firstboot(void) {
+	gchar* instance_id = NULL;
+	gchar* last_instance_id = NULL;
+	bool result = false;
+	struct stat st;
+
+	if (stat(LAST_INSTANCE_ID_FILE, &st) != 0) {
+		LOG(MOD "first boot!\n");
+		if (!copy_file(INSTANCE_ID_FILE, LAST_INSTANCE_ID_FILE)) {
+			LOG(MOD "Copy file failed\n");
+		}
+		return true;
+	}
+
+	if (!g_file_get_contents(INSTANCE_ID_FILE, &instance_id, NULL, NULL)) {
+		LOG(MOD "Unable to read file '%s'\n", INSTANCE_ID_FILE);
+		return false;
+	}
+
+	if (!g_file_get_contents(LAST_INSTANCE_ID_FILE, &last_instance_id, NULL, NULL)) {
+		LOG(MOD "Unable to read file '%s'\n", LAST_INSTANCE_ID_FILE);
+		goto fail1;
+	}
+
+	if (g_strcmp0(instance_id, last_instance_id) != 0) {
+		result = true;
+		LOG(MOD "first boot!\n");
+		if (!copy_file(INSTANCE_ID_FILE, LAST_INSTANCE_ID_FILE)) {
+			LOG(MOD "Copy file failed\n");
+		}
+	}
+
+	g_free(last_instance_id);
+fail1:
+	g_free(instance_id);
+	return result;
+}
+
 bool gnode_free(GNode* node, __unused__ gpointer data) {
 	if (node->data) {
 		g_free(node->data);
diff --git a/src/lib.h b/src/lib.h
index 51c7fdf..140658c 100644
--- a/src/lib.h
+++ b/src/lib.h
@@ -56,6 +56,8 @@ bool exec_task_async(const gchar* command_line, GChildWatchFunc async_func_watch
 void LOG(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 int make_dir(const char* pathname, mode_t mode) __warn_unused_result__;
 int chown_path(const char* pathname, const char* ownername, const char* groupname) __warn_unused_result__;
+bool save_instance_id(const gchar* instance_id) __warn_unused_result__;
+bool is_firstboot(void) __warn_unused_result__;
 bool write_file(const GString* data, const gchar* file_path, int oflags, mode_t mode) __warn_unused_result__;
 bool write_sudo_directives(const GString* data, const gchar* filename) __warn_unused_result__;
 bool write_ssh_keys(const GString* data, const gchar* username) __warn_unused_result__;