Webhook is a user-defined callback which gets triggered by any events in code like receiving a message from a user in SUSI bot is an event. Few bots need webhook URI for callback like in SUSI Viber bot we need to define a webhook URI in the code to receive callbacks and make our Viber bot work. In this blog, we will learn how can we get an SSL activated webhook while deploying our bot to Google container using Kubernetes. We will generate SSL certificate using kube lego service that is included in kubernetes and you will define that in yaml files below. We can also generate SSL certificate using third party services like CloudFlare but by using it we will be dependant on CloudFlare so we will use kube lego.
We will start off by registering a domain first on which we will activate SSL certificate and use that domain as a webhook. Go to freenom and register your account. After logging in, register a free domain of any name and check out that order. Next, you have to set IP for DNS of this domain. To do so we will reserve an IP address in our Google cloud project with this command:
gcloud compute addresses create IPname --region us-central1
You will get a created message. To see your IP go to VPC Network -> External IP addresses. Add this IP to DNS zone of your domain and save it for later use in yaml files that we will use for deployment. Now we will deploy our bot using yaml files but before deployment, we will create a cluster
gcloud container clusters create clusterName
After creating cluster add these yaml files to your bot repository and add your IP address that you have saved above to the yamls/nginx/service.yaml file for “loadBalancerIP” parameter. Replace domain name in yamls/application/ingress-notls.yaml and yamls/application/ingress-tls.yaml with your domain name that you have registered already. Add your email ID to yamls/lego/configmap.yaml for “lego.email” parameter. Replace “image” and “env” parameters in yamls/application/deployment.yaml with your docker image and your environment variables that you are using in your code. After changing yaml files we will use this deploy script to create a deployment. Change paths for yaml files in script according to your yaml files path.
In gcloud shell run the following command to deploy an application using given configurations.
bash ./path-to-deploy-script/deploy.sh create all
This will create the deployment as we have defined in the script. The Kubernetes master creates the load balancer and related Compute Engine forwarding rules, target pools, and firewall rules to make the service fully accessible from outside of Google Cloud Platform. Wait for a few minutes for all the containers to be created and the SSL Certificates to be generated and loaded.
You have successfully created a secure webhook. Test it by opening the domain that you have registered at the start.
Enabling SSL using CloudFlare: https://jonnyjordan.com/blog/how-to-setup-cloudflare-flexible-ssl-for-wordpress/