Geo Location Routing

This recipe lets you define a DNS configuration to two different Gerrit sites, deployed in AWS, so that the traffic routed to a specific site based on the location of the users.

It is based on the Route53's GeoLocation routing strategy (docs can be found here)

How to run it

Prerequisites

This recipe assumes that you do have a multi-site Gerrit deployment in two regions. You can refer to the relevant documentation to understand how to setup Gerrit in a multi-site deployment.

Configuration

  • GEO_LOCATION_ROUTING_STACK_NAME: Required. The name of the cloudformation stack

  • created by this recipe.

  • HOSTED_ZONE_NAME: Required. The name of the DNS zone name that will host the geo-location entries.

  • HOSTED_ZONE_ID: Required. The Id of the route53 zone that will host the geo-location entries. You can find this value by navigating to the relevant zone via the Route53 control panel. Alternatively you can inspect it by issuing

aws route53 list-hosted-zones

  • GLOBAL_SUBDOMAIN_NAME: Required. The subdomain for the record that will perform the geo-location-based routing. This will be used together with the HOSTED_ZONE_NAME to define a fqdn. Specifying global.gerrit-demo for example will generate an entry global.gerrit-demo.yourcompany.com

  • SITE_A_CONTINENT_CODE: Required. Traffic coming from this continent will be routed to the SITE_A_ALIAS_TARGET. Allowed values are: (‘AF’, ‘AN’, ‘AS’, ‘EU’, ‘OC’, ‘NA’, ‘SA’). For more details on this please check the AWS documentation

  • SITE_A_ALIAS_TARGET: Required. Gerrit site to route traffic to, when it originates from SITE_A_CONTINENT_CODE

  • SITE_B_CONTINENT_CODE: Required. Traffic coming from this continent will be routed to the SITE_A_ALIAS_TARGET. Allowed values are: (‘AF’, ‘AN’, ‘AS’, ‘EU’, ‘OC’, ‘NA’, ‘SA’). For more details on this please check the AWS documentation

  • SITE_B_ALIAS_TARGET: Required. Gerrit site to route traffic to, when it originates from SITE_B_CONTINENT_CODE

  • DEFAULT_ALIAS_TARGET: Required. Gerrit site to route traffic to when it doesn't originate from SITE_A_CONTINENT_CODE nor SITE_A_CONTINENT_CODE

Healthcheck

In addition to the DNS records, two healthchecks will also be created: one to monitor SITE_A_ALIAS_TARGET and one to monitor SITE_B_ALIAS_TARGET respectively.

The healthcheck polls the healthcheck endpoint exposed by the gerrit target, over HTTPS, as such:

https://SITE_A_ALIAS_TARGET/config/server/healthcheck~status

Should one of the two healthcheck become unhealthy, the traffic will be routed to the healthy one.

Deploy

make [AWS_REGION=a-valid-aws-region] [AWS_PREFIX=some-cluster-prefix] create-all

The optional AWS_REGION and AWS_REFIX allow you to define where it will be deployed and what it will be named.

It might take several minutes to build the stack. You can monitor the creations of the stacks in CloudFormation

Cleaning up

make [AWS_REGION=a-valid-aws-region] [AWS_PREFIX=some-cluster-prefix] delete-all

The optional AWS_REGION and AWS_REFIX allow you to specify exactly which stack you target for deletion.

Limitations

  • Only support two sites at the moment.
  • Only support mapping of one location to one target. All other traffic will be routed to the default target.
  • Only continents can be used for routing, countries and states are not supported
  • The healthcheck request interval is hardcoded to be every “30 secs” and the failure threshold is set to “3”