add vpcaccess role

[awsible] / roles / vpcaccess / files / routeUpdater.py

diff --git a/roles/vpcaccess/files/routeUpdater.py b/roles/vpcaccess/files/routeUpdater.py
new file mode 100644 (file)
index 0000000..8901179
--- /dev/null
+++ b/roles/vpcaccess/files/routeUpdater.py
@@ -0,0 +1,64 @@
+#!/usr/bin/python
+
+import boto.utils
+import boto.ec2
+import boto.vpc
+import sys
+
+dry_run = False
+
+# AWS access/secret keys
+aws_access      = None
+aws_secret      = None
+
+# Get all of the instance info e.g. curl 169.254.169.254/latest/meta-data/
+try:
+    instance_info = boto.utils.get_instance_metadata()
+except:
+    print "Could not get EC2 instance ID!"
+    sys.exit(1)
+
+instance_id = instance_info['instance-id']
+region_name = instance_info['placement']['availability-zone'][:-1]
+vpc_id      = instance_info['network']['interfaces']['macs'][instance_info['mac']]['vpc-id']
+
+vpc_conn = boto.vpc.connect_to_region(region_name, aws_access_key_id=aws_access, aws_secret_access_key=aws_secret)
+ec2_conn = boto.ec2.connect_to_region(region_name, aws_access_key_id=aws_access, aws_secret_access_key=aws_secret)
+
+# Turn off Source/Destination checking if it's on
+source_dest_check = ec2_conn.get_instance_attribute(instance_id, 'sourceDestCheck')['sourceDestCheck']
+print "Source/Dest check: %s" % (source_dest_check,)
+
+if source_dest_check:
+    print "Instance must have source/dest checking disabled to NAT properly!"
+    try:
+        ec2_conn.modify_instance_attribute(instance_id, 'sourceDestCheck', False, dry_run=dry_run)
+    except Exception, e:
+        print "Could not modify source/dest check: %s" % (e,)
+        sys.exit(1)
+
+# Get the managed route tables for my VPC
+rt = vpc_conn.get_all_route_tables(filters={'vpc_id':vpc_id,'tag:managed':'yes'})
+
+# Just in case there's more than one
+for table in rt:
+    # See if there's a default route (0.0.0.0/0)
+    gw_route = next((route for route in table.routes if route.destination_cidr_block == '0.0.0.0/0'), None)
+    if not gw_route:
+        print "Could not find default gw route in routing table!"
+    else:
+        print "Found a gateway route: %s, %s, %s" % (table.id, gw_route.destination_cidr_block, instance_id)
+        try:
+            # If there is delete it, because I'm taking it over
+            vpc_conn.delete_route(table.id, '0.0.0.0/0', dry_run=dry_run)
+        except Exception, e:
+            print "Could not delete gw route! %s" % (e,)
+            sys.exit(1)
+    try:
+        # Make me the default route, I'm the router now!
+        vpc_conn.create_route(table.id, '0.0.0.0/0', instance_id=instance_id, dry_run=dry_run)
+    except Exception, e:
+        print "Could not replace gw route! %s" % (e,)
+        sys.exit(1)
+
+