Template: Deploy a Kubernetes Cluster on Azure¶
A highly-available Kubernetes cluster requires at least five virtual machines (three for the master and two for your app’s containers). Therefore we don’t recommend using Kubernetes to run a BigchainDB node if that’s the only thing the Kubernetes cluster will be running. Instead, see our Simple Deployment Template. If your organization already has a big Kubernetes cluster running many containers, and your organization has people who know Kubernetes, then this Kubernetes deployment template might be helpful.
A BigchainDB node can be run inside a Kubernetes cluster. This page describes one way to deploy a Kubernetes cluster on Azure.
Step 1: Get a Pay-As-You-Go Azure Subscription¶
Microsoft Azure has a Free Trial subscription (at the time of writing), but it’s too limited to run an advanced BigchainDB node. Sign up for a Pay-As-You-Go Azure subscription via the Azure website.
You may find that you have to sign up for a Free Trial subscription first. That’s okay: you can have many subscriptions.
Step 2: Create an SSH Key Pair¶
You’ll want an SSH key pair so you’ll be able to SSH to the virtual machines that you’ll deploy in the next step. (If you already have an SSH key pair, you could reuse it, but it’s probably a good idea to make a new SSH key pair for your Kubernetes VMs and nothing else.)
Step 3: Deploy an Azure Container Service (ACS)¶
It’s possible to deploy an Azure Container Service (ACS) from the Azure Portal (i.e. online in your web browser) but it’s actually easier to do it using the Azure Command-Line Interface (CLI).
Microsoft has instructions to install the Azure CLI 2.0 on most common operating systems. Do that.
If you already have the Azure CLI installed, you may want to update it.
az component update isn’t supported if you installed the CLI using some of Microsoft’s provided installation instructions. See the Microsoft docs for update instructions.
Next, login to your account using:
$ az login
It will tell you to open a web page and to copy a code to that page.
If the login is a success, you will see some information
about all your subscriptions, including the one that is currently
"state": "Enabled"). If the wrong one is enabled,
you can switch to the right one using:
$ az account set --subscription <subscription name or ID>
Next, you will have to pick the Azure data center location where you’d like to deploy your cluster. You can get a list of all available locations using:
$ az account list-locations
Next, create an Azure “resource group” to contain all the resources (virtual machines, subnets, etc.) associated with your soon-to-be-deployed cluster. You can name it whatever you like but avoid fancy characters because they may confuse some software.
$ az group create --name <resource group name> --location <location name>
Example location names are
Finally, you can deploy an ACS using something like:
$ az acs create --name <a made-up cluster name> \ --resource-group <name of resource group created earlier> \ --master-count 3 \ --agent-count 3 \ --admin-username ubuntu \ --agent-vm-size Standard_L4s \ --dns-prefix <make up a name> \ --ssh-key-value ~/.ssh/<name>.pub \ --orchestrator-type kubernetes \ --debug --output json
The Azure documentation
has a list of all
az acs create options.
You might prefer a smaller agent VM size, for example.
You can also get a list of the options using:
$ az acs create --help
It takes a few minutes for all the resources to deploy. You can watch the progress in the Azure Portal: go to Resource groups (with the blue cube icon) and click on the one you created to see all the resources in it.
Trouble with the Service Principal? Then Read This!¶
az acs create command fails with an error message including the text,
“The Service Principal in ServicePrincipalProfile could not be validated”,
then we found you can prevent that by creating a Service Principal ahead of time
az acs create to use that one. (It’s supposed to create one,
but sometimes that fails, I guess.)
Create a new resource group, even if you created one before. They’re free anyway:
$ az login $ az group create --name <new resource group name> \ --location <Azure region like westeurope>
id in the output. It looks like
It can be copied into the next command.
Create a Service Principal using:
$ az ad sp create-for-rbac --role="Contributor" \ --scopes=<id value copied from above, including the double quotes on the ends>
Put those in a new
az acs create command like above, with two new options added:
$ az acs create ... \ --service-principal <appId> \ --client-secret <password>
Optional: SSH to Your New Kubernetes Cluster Nodes¶
You can SSH to one of the just-deployed Kubernetes “master” nodes (virtual machines) using:
$ ssh -i ~/.ssh/<name> ubuntu@<master-ip-address-or-fqdn>
where you can get the IP address or FQDN of a master node from the Azure Portal. For example:
$ ssh -i ~/.ssh/mykey123 firstname.lastname@example.org
All the master nodes are accessible behind the same public IP address and FQDN. You connect to one of the masters randomly based on the load balancing policy.
The “agent” nodes shouldn’t get public IP addresses or externally accessible FQDNs, so you can’t SSH to them directly, but you can first SSH to the master and then SSH to an agent from there using their hostname. To do that, you could copy your SSH key pair to the master (a bad idea), or use SSH agent forwarding (better). To do the latter, do the following on the machine you used to SSH to the master:
$ echo -e "Host <FQDN of the cluster from Azure Portal>\n ForwardAgent yes" >> ~/.ssh/config
To verify that SSH agent forwarding works properly, SSH to the one of the master nodes and do:
$ echo "$SSH_AUTH_SOCK"
If you get an empty response, then SSH agent forwarding hasn’t been set up correctly. If you get a non-empty response, then SSH agent forwarding should work fine and you can SSH to one of the agent nodes (from a master) using:
$ ssh ubuntu@k8s-agent-4AC80E97-0
k8s-agent-4AC80E97-0 is the name
of a Kubernetes agent node in your Kubernetes cluster.
You will have to replace it by the name
of an agent node in your cluster.
Optional: Delete the Kubernetes Cluster¶
$ az acs delete \ --name <ACS cluster name> \ --resource-group <name of resource group containing the cluster>