Today containers have become the de-factor across the industries owning cloud platforms. You must be wondering what makes it so popular. It offers many benefits like isolating one application environment from others and replicating APIs in other containers’ machines. To do such, Kubernetes comes as the excellent handful factor – a container management system that auto-scale containers across multiple servers residing in one cluster and makes developers work easy in making replicas of cluster applications along with Kubernetes instances in other VMs or different nodes.
To manage those Kubernetes packages, many developers use Helm, also known as package management for Kubernetes. It simplifies deployment procedures of complex applications in the Kubernetes due to its rich ecosystem that uses several production-ready packages known as Helm Charts. Helm also allows deploying packed applications as a collection of versioned and configured Kubernetes resources.
Now consider deploying a database storing information about several deployments, containers, mission-critical company data, and services using Kubernetes, then it will proceed in multiple stages. On the other hand, Helm allows deploying the database using a single command with single value-sets. Helm contains a set of declarative and idempotent commands, making it the best tool choice for continuous delivery.
You also need some knowledge about Helm Best Practices to get the best results from this tool and achieve ease in Kubernetes-based application management.
So, let’s understand the nine best practices or considerations for Helm.
Make the Most out of the Helm:
The best benefit of Helm is that it lets developers access community expertise to solve their difficulties and clear all doubts. Helm contains a broad community of developers that gathers work modules shared by them through chart repositories.
And Helm itself shares stable chart releases for your local setup using a command: $ Helm repo-add stable https://charts.helm.sh/stable. After this, you can also search for charts according to your requirements using a command: $ helm search hub chart_name. Here, in the place of chart_name, you can add the name of a chart you’re looking for. This command will show you various charts, making you think about how vast the Helm Chart Ecosystem is.
Managing Dependencies Using Sub-charts:
Most Kubernetes-based applications are well developed. Comprise various interdependencies between objects, and their Helm charts also contain different resource templates and dependencies. Let’s assume your API depends on a database entity and a queue of messages, where both are standalone applications, such as PostgreSQL and RabbitMQ. In this case, developers may need to create separate charts for such standalone applications and link them to the parent charts. Here those separated charts can also be called sub-charts.
To create and configure sub-charts, you need to consider the three essential elements, which are:
- Proper chart folder structure
- Chart. yaml
While creating a sub-chart, it is necessary to follow a proper chart structure throughout the development, which is shown below:
Chart.yaml resided in the parent chart should have some dependencies and conditions:
Using this element, developers can override sub-charts values in its parent chart following below mentioned file:
The motive behind creating sub-charts is to establish an abstraction layer between parent and associated applications. They also ensure that developers can quickly deploy, troubleshoot, and update Kubernetes-based applications alongside their unique values and lifecycles.
Use Labels for Ease in Resource Finding:
In each Kubernetes internal operation, its operators widely use Labels, which are essential to Kubernetes. Plus, Kubernetes’ every resource offers labels for different functions, like grouping, load balancing, scheduling, or resource allocation. For any process, resources play a vital role, and it is also essential to know the origin of resources, and that’s where labels come to help create quick Helm releases to find resources. Labels can be defined by using helpers.tpl method as shown below:
Then you have to add the “include” function with labels in the resource file, enabling you to list resources and label selectors.
Document Helm Charts:
Documentation helps maintain Helm charts, add comments to the resource files, and ease development. Now, let’s have a look at the following three essential options to use for the chart documentation:
Comments are usually used to provide helpful information in the YAML files, such as Templates and Values.
It provides instructions to use the particular chart. You can also check the text of the README file using the command: helm show readme [Chart_Name].
It provides information about how to deploy the application release. Its content can also be templated with values and functions, which look the same as resource templates.
Helm charts contain several resources, which are further deployed to the cluster. It makes it essential to verify whether the values of charts created in the group are correct or not. Plus, application validation is also necessary. Helm provides a test function, which can be run on some containers of the cluster. For instance, Helm can also help run resource templates as the test cases: “Helm.sh/hook”: test-success.
Ensure the Security of Confidential Data:
Users’ essential data, for example, passwords, are usually stored in the Kubernetes as secrets. However, Kubernetes provides security to its stored data as they are part of the Helm templates and values. Helm’s help-secret plugin offers intensive secrecy management and protection of confidential data. It leverages the secret encryption method to Mozilla SOPS, which supports popular clouds, such as AWS and GCP’s Key Management Services, Azure Key Vault, and PGP (Pretty Good Privacy).
Make Charts Reusable Through Template Functions:
Helm supports 60+ template functions by defining them into the Go template language and Sprig template library. These functions are used to simplify Helm operations. For example, in the chart, if any value does not specify the environment function, then it will be set to default by the temp function. Another important template function is “required,”. Which lets developers configure the value according to the template rendering requirement and must be specified by some name.
The overall benefits of the template functions during Helm charts creation are:
- Enhanced templating
- Reduced amount of code duplication
- Validate the application value before deploying it to Kubernetes.
Make Changes in the Deployment with ConfigMap or Secret Changes:
Typically, most containers consist of ConfigMaps or secrets, which do not change more often with changes in container images and Kubernetes deployments. However, some notations can cause changes in the ConfigMaps, calculate a new sha256|sum along with its changes, and create an entirely new version of ConfigMaps. This output of the following annotations enforces Helm to change the container deployments using a new ConfigMap.
Debugging Helm Charts:
Usually, Helm template files contain various functions and value sources required for designing Kubernetes resources. However, you must decide which parts will be deployed to the cluster. Therefore, they must learn about debugging templates and verifying Helm charts. So, let’s have a glance at the most used debugging commands:
This command is used by the linter tool to test the formation of helm charts.
helm install – dry – run – debug:
This command checks all templates and represents the resulting resource manifests. It lets developers check the resources before deploying them and verifies their values and the working of the template functions.
help get manifest:
It retrieves and manifests cluster resources, and if the release is not working correctly, this command helps identify the currently running process(es) in the cluster.
Helm gets values:
It helps to find cluster release values, and if developers have any doubt regarding matters, it is an asset to figure out the right one and should be in every developer’s toolset.
Finally, we can say that all considerations will ease up developers’ processes. Like creating, operating, and updating ready-to-be-released distributed applications. While talking about development processes, all Helm charts will become easy to manage and protect. As Helm is the suitable choice for continuous delivery, it will reduce your workloads at specific rates and ultimately save time and resources.
If you need professional assistance in managing your Kubernetes deployments, you can contact CloudStakes Technology Pvt. Ltd., a leading cloud computing services & solutions company in India. Or book a cloud consultation appointment with our cloud experts.