DDCLient

---

DDClient is a Dynamic DNS (DDNS) tool to check what your external IP address is and then update your DNS service with your new IP when it changes. It supports many services, including Google and Cloudflare.

Product: DDCLient
Install Type: Manifest Files
Container Image: LinuxServer.io

Installation Details

Before beginning your installation, I'd recommend reading through the DDClient Documentation to get an idea of what is needed for your particular installation and how to create your configuration file.

Because this is a "headless" service (with no direct user interaction) we will not be defining any services or ingresses. However I will share some scripts to help manage your configuration at the end.

Now let's create the files we'll need to configure DDClient in Kubernetes

00-utility-namespace.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: utility
  labels:
    name: utility

01-config.yaml

The configuration is mostly stored in the ddclient.conf file and there is not much to define here. This file could be eliminated all together and the settings configured with the deployment. I tend to define things separately to maintain consistency in my configurations

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: ddclient-configs
  namespace: utility
data:
  TZ: "America/New York"

02-storage.yaml

This container does store config files on the file system I defined a 10 MB config volume using Longhorn for this volume.

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  namespace: utility
  name: ddclient-data
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn
  resources:
    requests:
      storage: 10Mi

03-deploy.yaml

The Deployment brings together the configuration and storage with the container image:

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ddclient
  namespace: utility
  labels:
    app: ddclient
    app.kubernetes.io/name: ddclient
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: ddclient
  template:
    metadata:
      labels:
        app: ddclient
        app.kubernetes.io/name: ddclient
    spec:
      volumes:
        - name: ddclient-data
          persistentVolumeClaim:
            claimName: ddclient-data
      containers:
        - name: ddclient
          image: lscr.io/linuxserver/ddclient:latest
          imagePullPolicy: Always
          volumeMounts:
          - name: ddclient-data
            mountPath: /config
          envFrom:
            - configMapRef:
                name: ddclient-configs

build-ddclient.sh

Now that we have prepared our manifests we need to deploy them to the cluster with kubectl. I create shell scripts for all my deployments so I can quickly redeploy if I make any adjustments. The below script does assume you have configured kubectl properly already.

#!/bin/bash

kubectl apply -f 00-utility-namespace.yaml \
              -f 01-config.yaml \
              -f 02-storage.yaml \
              -f 03-deploy.yaml

We can deploy the manifests for DDClient to the Kubernetes cluster by executing the following:

chmod 755 build-ddclient.sh
./build-ddclient.sh

Configuring DDClient

You'll want to consult the DDClient Documentation for specific information about your setup, but I've included an example of a configuration that I use successfully with Cloudflare.

ddclient.conf

daemon=300              # check every 300 seconds
syslog=yes              # log update msgs to syslog
pid=/run/ddclient/ddclient.pid      # record PID in file.
ssl=yes                 # use ssl-support.  Works with
use=web # get IP with website below
web='https://cloudflare.com/cdn-cgi/trace'

##
## CloudFlare (www.cloudflare.com)
##
protocol=cloudflare,        \
zone=your.domain,            \
ttl=1,                      \
login='YourCloudFlareUserName',     \
password='YourAPITokenFromCloudflare'             \
subdomain1.your.zone,subdomain2.your.zone,subdomain3.your.zone

Administering DDClient Configs

DDClient is setup to automatically pick up changes to the ddclient.conf file. This means that you can adjust your ddclient.conf file and put it in the pod and the service will automatically apply it. Because of this, I keep my ddclient.conf file with my manifest files and store it in a git repository for easy version control. I also wrote this quick script that will place the new ddclient.conf file into your pod after you make any changes to it.

update-ddclient.sh

#!/bin/bash

CONTAINER=$(kubectl get pods -n utility|grep ddclient|awk '{print $1}')
echo "Updating the ddclient.conf file on $CONTAINER"

kubectl cp ddclient.conf $CONTAINER:config/ddclient.conf -n utility
kubectl exec -it -n utility $CONTAINER -- bash -c "chown abc:abc /config/ddclient.conf"

After creating the file, be sure to remember to make it executable

chmod 755 ddclient-config.sh

Now, after you make any changes to your ddclient.conf file you can update your pod with these changes easily by executing:

./ddclient-update.sh

This will copy your ddclient.conf file (located in the same directory) to your ddclient pod and then update the permissions of the file to the runtime user of the pod. From there the DDCLient pod will automatically pick up the config changes and apply them.