1 files changed, 65 insertions, 0 deletions
diff --git a/deploy/adapters/ansible/roles/ha/templates/failover.j2 b/deploy/adapters/ansible/roles/ha/templates/failover.j2
new file mode 100644
index 00000000..e3877e6b
--- /dev/null
+++ b/deploy/adapters/ansible/roles/ha/templates/failover.j2
@@ -0,0 +1,65 @@
+import ConfigParser, os, socket
+import logging as LOG
+import pxssh
+import sys
+import re
+
+LOG_FILE="/var/log/mysql_failover"
+try:
+    os.remove(LOG_FILE)
+except:
+    pass
+
+LOG.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p', filename=LOG_FILE,level=LOG.DEBUG)
+ha_vip = {{ HA_VIP }}
+LOG.info("ha_vip: %s" % ha_vip)
+
+#ha_vip = "10.1.0.50"
+galera_path = '/etc/mysql/conf.d/wsrep.cnf'
+pattern = re.compile(r"gcomm://(?P<prev_ip>.*)")
+
+def ssh_get_hostname(ip):
+    try:
+        s = pxssh.pxssh()
+        s.login("%s" % ip, "root", "root")
+        s.sendline('hostname')   # run a command
+        s.prompt()             # match the prompt
+        result = s.before.strip()      # print everything before the prompt.
+        return result.split(os.linesep)[1]
+    except pxssh.ExceptionPxssh as e:
+        LOG.error("pxssh failed on login.")
+    raise
+
+def failover(mode):
+    config = ConfigParser.ConfigParser()
+    config.optionxform = str
+    config.readfp(open(galera_path))
+    wsrep_cluster_address = config.get("mysqld", "wsrep_cluster_address")
+    wsrep_cluster_address = pattern.match(wsrep_cluster_address).groupdict()["prev_ip"]
+
+    LOG.info("old wsrep_cluster_address = %s" % wsrep_cluster_address)
+
+    if mode == "master":
+        # refresh wsrep_cluster_address to null
+        LOG.info("I'm being master, set wsrep_cluster_address to null")
+        wsrep_cluster_address = ""
+
+    elif mode == "backup":
+        # refresh wsrep_cluster_address to master int ip
+        hostname = ssh_get_hostname(ha_vip)
+        wsrep_cluster_address = socket.gethostbyname(hostname)
+        LOG.info("I'm being slave, set wsrep_cluster_address to master internal ip")
+
+    LOG.info("new wsrep_cluster_address = %s" % wsrep_cluster_address)
+    wsrep_cluster_address  = "gcomm://%s" % wsrep_cluster_address
+    config.set("mysqld", "wsrep_cluster_address", wsrep_cluster_address)
+    with open(galera_path, 'wb') as fp:
+        #config.write(sys.stdout)
+        config.write(fp)
+
+    os.system("service mysql restart")
+    LOG.info("failover success!!!")
+
+if __name__ == "__main__":
+    LOG.debug("call me: %s" % sys.argv)
+    failover(sys.argv[1])