HarperDB with Helm on EKS
This post first appeared on dev.to
This post builds on top of this where we discussed how to launch HarperDB on EKS with kubectl. Here, we would use those same manifests. But, we would go with the helm cli tool instead of kubectl for the deployment. Please check this link for the final chart we make in this post.
Get set go :fire:
First, ensure helm is installed. If you want to use AWS cloud shell for this, please click on the shell icon on the top navigation bar of the cloud console, and execute the following.
$ curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
$ chmod 700 get_helm.sh
$ sudo yum install openssl -y
$ ./get_helm.sh
Ensure the kubeconfig is updated.
$ aws eks update-kubeconfig --name k8s-cluster-01
Pl. change the cluster name above with what you have created.
Let’s just create the namespace with kubectl, rest will be created with helm.
$ kubectl create ns harperdb
namespace/harperdb created
Create a directory for the helm chart.
$ mkdir harperdb
$ cd harperdb
Create a directory for templates in the chart.
$ mkdir templates
Copy the manifests from this post and keep it in the templates directory.
$ ls templates/
deploy.yaml pvc.yaml secret.yaml svc.yaml
Create the chart file where we would just keep the name and version, we are keeping to hold just the mandatory information, though we can add more.
$ cat <<EOF > Chart.yaml
name: harperdb
version: 1.0.0
EOF
So what we created so far is our harperdb helm chart, we are staring with chart version 1.0.0.
We can use this to install the release in a separate namespace. The namespace below means the helm release namespace and not the kubernetes
namespace. And . refers to the chart directory which is the current directory.
$ helm install harperdb . -n harperdb
NAME: harperdb
LAST DEPLOYED: Fri Jan 13 09:52:08 2023
NAMESPACE: harperdb
STATUS: deployed
REVISION: 1
TEST SUITE: None
We are using the same name for both the helm and kubernetes namespaces. Note that the kubernetes namespace is mentioned in all of the manifests.
$ cat templates/deploy.yaml | grep namespace
namespace: harperdb
The helm release is deployed.
$ helm list -n harperdb
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
harperdb harperdb 1 2023-01-13 09:52:08.953758683 +0000 UTC deployed harperdb-1.0.0
This has deployed the workloads in kubernetes, which we can check with kubectl.
$ kubectl get deploy,pvc,secret,svc -n harperdb
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/harperdb 1/1 1 1 5m11s
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
persistentvolumeclaim/harperdb Bound pvc-6ef558ee-86ad-460d-8379-c34a12aaf283 5Gi RWO gp2 5m11s
NAME TYPE DATA AGE
secret/default-token-llbqm kubernetes.io/service-account-token 3 3h50m
secret/harperdb Opaque 2 5m11s
secret/sh.helm.release.v1.harperdb.v1 helm.sh/release.v1 1 5m11s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S)
AGE
service/harperdb LoadBalancer 10.100.29.79 a86501cc7a7024fff92b7212cd844e45-1677629392.us-east-1.elb.amazonaws.com 8080:31549/TCP
5m11s
Let’s test with an API call. The endpoint refers to the loadbalancer service.
$ HDB_API_ENDPOINT=a86501cc7a7024fff92b7212cd844e45-1677629392.us-east-1.elb.amazonaws.com:8080
$ curl --location --request POST ${HDB_API_ENDPOINT} --header 'Content-Type: application/json' --header 'Authorization: Basic
YWRtaW46cGFzc3dvcmQxMjM0NQ==' --data-raw '{
"operation": "create_schema",
"schema": "uat"
}'
{"message":"schema 'uat' successfully created"}
Awesome, works !!!.
Let’s now revisit the helm chart and do a couple changes. For now, we haven’t used any values file, which is commonly used with any helm chart. We need values when we would like to parameterize certain things in our manifests. For instance, let’s say we want to parameterize the service port.
$ cat <<EOF > values.yaml
servicePort: 8080
EOF
We can the change the port section in the service template to refer to the value from values file.
$ cat templates/svc.yaml | grep port
ports:
port:
Let’s call this chart version 2.0.0 and upgrade our release.
$ cat Chart.yaml | grep version
version: 2.0.0
$ helm upgrade harperdb . -n harperdb
Release "harperdb" has been upgraded. Happy Helming!
NAME: harperdb
LAST DEPLOYED: Fri Jan 13 12:35:53 2023
NAMESPACE: harperdb
STATUS: deployed
REVISION: 2
TEST SUITE: None
We can verify the service port.
$ kubectl get svc harperdb -n harperdb -o jsonpath={.spec.ports[0].port}
8080
Let’s do another change, this time we would try to refer to the release name and namespace as the name and namespace for each of the resources.
$ grep -ir .Release templates/
templates/pvc.yaml: name:
templates/pvc.yaml: namespace:
templates/svc.yaml: name:
templates/svc.yaml: namespace:
templates/deploy.yaml: name:
templates/deploy.yaml: namespace:
templates/secret.yaml: name:
templates/secret.yaml: namespace:
Note you have to modify each file, so that the grep output looks like above.
Let’s change the chart version to 3.0.0, and upgrade the release.
$ cat Chart.yaml
name: harperdb
version: 3.0.0
$ helm upgrade harperdb . -n harperdb
We can validate.
$ kubectl get deploy,pvc,secret,svc -n harperdb | awk '{print $1}'
NAME
deployment.apps/harperdb
NAME
persistentvolumeclaim/harperdb
NAME
secret/default-token-llbqm
secret/harperdb
secret/sh.helm.release.v1.harperdb.v1
NAME
service/harperdb
You could see the workload details on the EKS page. Here is a sample screenshot.
All good, so we have reached the end of this post, we saw how to install harperdb with a minimal helm chart, tested it with an API call, and tweaked the helm chart a bit to understand some fundamentals of it. Thank you for reading !!!.