Bahmni Lite Helm Charts

1 What is Helm-chart?
2 Why Bahmni prefer using helm-charts ?
3 Bahmni: Helm Charts
4 Pipeline Visualisation
5 References
6 Video Recording about Bahmni Helm-charts

What is Helm-chart?

Helm is the package manager for Kubernetes.
Helm uses a packaging format called charts. A chart is a collection of files that describe a related set of Kubernetes resources. A single chart might be used to deploy something simple, like a memcached pod, or something complex, like a full web app stack with HTTP servers, databases, caches, and so on.

https://helm.sh/

Why Bahmni prefer using helm-charts ?

Bahmni preferred using helm-charts over other tools due to the following reasons:

  🔘 Reduces the complexity of deploying microservices
  🔘 Simplifies deployment scripts and files (all defined in YAML)
  🔘 Improves the productivity of the deployments and rollback
  🔘 Provides a way of versioning the Kubernetes resources as a single unit.

Bahmni: Helm Charts

Bahmni is using Helm-charts for its Kubernetes Packaging Structure . All the deployments in the Lite env happened using helm-charts deployment. We have implemented helm-umbrella-charts for better management of resources.

Below is the K8s packaging Structure we follow in Bahmni:

 Helm with Umbrella Charts
      Directory Structure for Applications:
        --- bahmni    (openmrs-module-bahmniapps repo)
          - package
              - docker
                  - Dockerfile
                  - ....
              - helm
                  -- Chart.yaml        --> holds the chart definition
                  -- values.yaml       --> default values, secret ref
                  - templates
                      -- deployment
                      -- service
                      -- secrets
      
        --- openmrs    (openmrs-module-bahmni-distro repo)
            - package
                - docker
                    - Dockerfile
                    - ...
                - helm
                    -- Chart.yaml      --> holds the chart definition
                    -- values.yaml      --> default values, secret ref
                    - templates
                        -- deployment
                        -- service
                        -- secrets

=================================================================================
=================================================================================

--- helm-charts   (https://github.com/Bahmni/helm-charts/tree/gh-pages)
      -- openmrs    (Application folder)
         - openmrs-<release_tag>.tgz      ---> Relase of <Application>
      -- clinic-config
         - clinic-config-<Release_tag>.tgz


--- Umbrella charts   (https://github.com/Bahmni/helm-umbrella-chart)
      -- Chart.yaml      --> Contains the dependencies defined helm-charts
         - clinic
           - dev.yaml
           - qa.yaml
           - demo.yaml
           - prod.yaml

All the Deployments are automated using Github actions. Refer the repository links attached with helm-charts & Umbrella-charts.

For any application in Bahmni we have followed the above directory structure.
- Lets refer to Bahmni-lab repo as an example
- Docker folder contains Dockerfile & other related files needed for docker-compose setup
- Helm folder contains the helm templates like, values.yaml, chart.yaml & related Kubernetes components definition like deployments , services , secrets etc.

Helm-charts: This is used to store the deployed helm-charts tagged build under gh-pages
Umbrella-charts: This is used to define the dependent charts to be deployed in the environment along with the individual env values defined in dev.yaml , qa.yaml , demo.yaml .

Pipeline Visualisation

Below is the pictorial representation of deployment pipeline.

References

https://www.containiq.com/post/helm-charts

https://www.digitalocean.com/community/tutorials/an-introduction-to-helm-the-package-manager-for-kubernetes

https://github.com/helm/examples

Video Recording about Bahmni Helm-charts

https://thoughtworks.zoom.us/rec/share/y_mdW5zvdapFmpZ1ymkLEOHEob9vu7u-GjelszpmEsEuDG_AIj5U2LPB98-Rm_HS.RjrPR9cd58KNKdJ0
Passcode: VB?WSC#3

NOTE: Please contact Infra squad (Slack: #bahmni-infra) if you are facing any issues related to helm-charts & Deployments