Kubernetes in Production Best Practices by Aly Saleh & Murat Karslioglu

Author:Aly Saleh & Murat Karslioglu [Aly Saleh]
Language: eng
Format: epub
ISBN: 9781800202450
Publisher: Packt Publishing
Published: 2021-03-12T00:00:00+00:00

I encourage you to use the preceding CoreDNS plugins, and also check the plugins directory, which could have other interesting and useful plugins that solve specific problems or provide options for your applications, here: https://coredns.io/manual/plugins/.

Configuring ExternalDNS

While CoreDNS serves as the internal DNS server for Kubernetes clusters, ExternalDNS is a Kubernetes add-on that is used to manage your cluster external DNS providers, including Route 53, AzureDNS, and Google Cloud DNS.

It makes Kubernetes deployments and services discoverable through public DNS services, such as Route 53. It queries the Kubernetes API to retrieve a list of services and ingresses, and then it communicates with the public DNS and registers these records.

ExternalDNS allows you to control DNS records (via cloud DNS services such as AWS Route 53 or Google Cloud DNS) dynamically via Kubernetes services and ingresses.

ExternalDNS does not come pre-installed with the cluster, so you need to deploy it and specify its configuration, which includes its Docker image, the number of replicas to run, DNS record syncing and interval updates, the cloud provider type (that is, AWS, Azure, and so on), and the hosted zone ID (in the case of AWS Route 53).

Important note

You can find the complete source code at https://github.com/PacktPublishing/Kubernetes-in-Production-Best-Practices/blob/master/Chapter05/ansible/templates/external-dns/external-dns.yaml.

Now, let's create the Ansible template and configuration for ExternalDNS:

Define the configuration variables and add them to the group_vars directory in this path: ansible/group_vars/all/external-dns.yaml. The basic configuration contains the image and its tag, which are useful for keeping track of the ExternalDNS version that is deployed to your cluster, and for controlling its upgrades. Also, you specify the values for other configuration variables, including log_level, provider, aws_zone_type, interval, route53_zone_type, and external_dns_replicas:

log_level: error

provider: aws

aws_zone_type: private

interval: 1m

route53_zone_id: Z09817802WZ9HZYSUI2RE

external_dns_replicas: 2

external_dns:

image: "registry.opensource.zalan.do/teapot/external-dns"

tag: "v0.5.9"

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.