Chris Bergeron chrisbergeron

AWS CLI command to update CNAME

When you have a set of application servers running in EC2 in an active/passive configuration, the easiest way to failover is to simply update the DNS to point to the second server as soon as it's available to serve requests. If you are using Route 53 to manage your DNS configuration, with the AWS CLI you can make this change in a single command.

Initial Setup

Install the AWS CLI
Login with an account that has an IAM Policy that gives it access to the Route53 Service
Get the HostedZoneID for the domain you want to update from the AWS console here: https://console.aws.amazon.com/route53/home#hosted-zones:

The CLI expects the change to be submitted via a JSON-formatted configuration file. I've inclu

SSH CA use-case with Vault

In this scenario we are going to set up Vault to sign SSH keys using an internal CA. We will configure the SSH secrets engine and create a CA within Vault. We will then configure an SSH server to trust the CA key we just created. Finally we will attempt to SSH using a private key, and a public key signed by Vault SSH CA.

Prerequisites

This guide assumes you have already provisioned a Vault server, SSH host using OpenSSH server, and a SSH client machine.
The client system must be able to reach the Vault server and the OpenSSH server.
We will refer to these systems respectively as:
VAULT_SERVER

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