Manually failover DNS

Power outages, natural disasters, or fiber lines being cut in construction projects are just a few things that can cause outages. One of the most common Disaster Recovery (DR) methods is to have a secondary site where you can update the Domain Name System (DNS) record and be back online.

Infrastructure as a Service (IaaS) DNS failover

Popular IaaS providers such as Azure, AWS, or GCP provide a CLI to make it easy update your DNS record to point to another site with just a couple of commands.

The following example uses the Azure CLI to update the DNS record for www.octopussamples.com

Create the runbook

1. To create a runbook, navigate to Project ➜ Operations ➜ Runbooks ➜ Add Runbook.
2. Give the runbook a name and click SAVE.
3. Click DEFINE YOUR RUNBOOK PROCESS, then click ADD STEP.
4. Add a new Run an Azure Script step.
5. Choose Inline source code (with optional package references)
6. Enter the following PowerShell code, we recommend using variables instead of hard-coding entries.

$resourceGroup = $OctopusParameters["OctoFX.Azure.Resource.Group"]
$zoneName = $OctopusParameters["OctoFX.DNS.Name"]
$ipAddressDR = $OctopusParameters["OctoFX.DR.IP.Address"]
$ipAddressProd = $OctopusParameters["OctoFX.Production.IP.Address"]

az network dns record-set a add-record --resource-group $resourceGroup --zone-name $zoneName --record-set-name www --ipv4-address $ipAddressProd
az network dns record-set a remove-record --resource-group $resourceGroup --zone-name $zoneName --record-set-name www --ipv4-address $ipAddressDR

This script within a runbook lets your switch your DNS entry with the click of a button, so no matter when disaster strikes, it is easy to recover.

Samples

We have a Target - Windows Space on our Samples instance of Octopus. You can sign in as Guest to take a look at this example and more runbooks in the OctoFX project.

Help us continuously improve

Please let us know if you have any feedback about this page.

Send feedback

Page updated on Sunday, January 1, 2023