How Do I Create and Manage Helm Charts?

Helm charts are a useful way to manage applications on Kubernetes. They give us a simple way to package our apps. With Helm charts, we can define, install, and upgrade even complex Kubernetes apps easily. Using Helm charts helps us make the deployment process smoother. It also helps us keep things consistent across different environments.

In this article, we will talk about how to create and manage Helm charts well. We will look at these topics:

  • How Can I Create and Manage Helm Charts?
  • What Are Helm Charts and Why Are They Important?
  • How Do I Set Up Helm on My Local Machine?
  • How Can I Create a New Helm Chart from Scratch?
  • What Is the Structure of a Helm Chart?
  • How Do I Customize Values in Helm Charts?
  • How Can I Install and Upgrade Helm Charts?
  • What Are Real-Life Use Cases for Helm Charts?
  • How Do I Manage Helm Chart Repositories?
  • Frequently Asked Questions

By the end of this article, we will understand Helm charts better. We will also know how to use them for our Kubernetes deployments. For more insights, we can check the article on what is Helm and how does it help with Kubernetes deployments.

What Are Helm Charts and Why Are They Important?

Helm Charts are a way to manage packages for Kubernetes applications. They help us to deploy, manage, and configure applications on Kubernetes clusters. They give us a clear method to define and handle Kubernetes resources.

Importance of Helm Charts:

  1. Simplified Deployment: With Helm Charts, we can deploy complex applications using just one command. It helps us manage many Kubernetes resources easily.

  2. Version Control: Helm lets us keep track of different versions of charts. If something goes wrong, we can go back to an earlier version. This is very important for keeping things stable in production.

  3. Reusable Templates: Charts use templates to manage configurations. This means we do not have to repeat ourselves. It makes it easier to keep things updated and maintained.

  4. Configuration Management: Helm helps us manage configurations apart from the application code. This makes it simple to change deployments for different environments like development, staging, or production.

  5. Dependency Management: Helm Charts can show connections to other charts. This way, we can bundle complex applications together and deploy them in a careful way.

  6. Community Support: There are many ready-made charts in the Helm Hub. This helps developers find and use solutions instead of starting from the beginning.

  7. Easier Rollbacks: If a deployment does not work, Helm gives us commands to go back to a previous version quickly. This helps to reduce downtime.

Helm Charts are very important for managing Kubernetes well. They help teams to make their deployment processes easier. This also helps keep our applications available and reliable. For more information on Helm and its benefits in Kubernetes, check out this guide on Helm.

How Do I Set Up Helm on My Local Machine?

To set up Helm on our local machine, we can follow these steps:

  1. Install Helm: We can install Helm using package managers. For macOS, we use Homebrew. For Windows, we use Chocolatey. Or we can also download it from the Helm releases page.

    For macOS with Homebrew, we type:

    brew install helm

    For Windows with Chocolatey, we type:

    choco install kubernetes-helm

    For Linux, we can use:

    snap install helm --classic

  2. Initialize Helm: Helm v3 does not need Tiller. We can configure Helm directly with our Kubernetes cluster.

    helm repo add stable https://charts.helm.sh/stable

  3. Verify Installation: We should check the Helm version to make sure it is installed right.

    helm version

  4. Configure Kubernetes Context: We need to make sure that our kubectl points to the right Kubernetes cluster.

    kubectl config use-context <your-context-name>

  5. Update Helm Repositories: It is good to update our Helm repositories. This way we can get the latest charts.

    helm repo update

After we finish these steps, Helm will be ready to manage our Kubernetes applications. For more details on using Helm, we can read about what Helm is and how it helps with Kubernetes deployments.

How Can We Create a New Helm Chart from Scratch?

To create a new Helm chart from scratch, we can follow these steps:

  1. Install Helm: First, we need to make sure Helm is installed on our local machine. We can check this by running:

    helm version

  2. Create a New Chart: We use the helm create command to start a new chart. We should change mychart to the name we want:

    helm create mychart

  3. Chart Structure: This command makes a folder called mychart. Inside, we find this structure:

    mychart/
├── Chart.yaml       # Info about the chart
├── values.yaml      # Default settings
├── charts/          # Folder for other charts we depend on
├── templates/       # Folder for Kubernetes resource templates
│   ├── deployment.yaml
│   ├── service.yaml
│   └── _helpers.tpl
└── .helmignore      # Patterns to ignore when we package the chart

  4. Edit Chart.yaml: Next, we update the info in Chart.yaml:

    apiVersion: v2
name: mychart
description: A Helm chart for Kubernetes
version: 0.1.0
appVersion: "1.0"

  5. Customize values.yaml: We need to change values.yaml to set default settings:

    replicaCount: 1

image:
  repository: myimage
  pullPolicy: IfNotPresent
  tag: "latest"

service:
  type: ClusterIP
  port: 80

  6. Modify Templates: We customize the templates in the templates folder. For example, we can change deployment.yaml to set up the deployment:

    apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Release.Name }}-deployment
  labels:
    app: {{ .Release.Name }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Release.Name }}
  template:
    metadata:
      labels:
        app: {{ .Release.Name }}
    spec:
      containers:
        - name: {{ .Release.Name }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
          ports:
            - containerPort: 80

  7. Package the Chart: To package our Helm chart for sharing, we run:

    helm package mychart

  8. Install the Chart: Finally, we can install our new chart on our Kubernetes cluster:

    helm install myrelease mychart

These steps give us a simple way to create and manage our own Helm chart from scratch. This helps us deploy applications easily on our Kubernetes cluster. For more about Helm and why it is important in Kubernetes deployments, check out what is Helm and how does it help with Kubernetes deployments.

What Is the Structure of a Helm Chart?

A Helm chart is made up of several important parts. These parts help define how the chart works. The main elements of a Helm chart include:

  1. Chart.yaml: This file holds information about the chart. It includes the name, version, and description. A sample Chart.yaml looks like this:

    apiVersion: v2
name: my-chart
version: 0.1.0
description: A Helm chart for Kubernetes

  2. values.yaml: This file has the default settings for the chart. Users can change these settings when they install the chart. An example of a values.yaml file could be:

    replicaCount: 1
image:
  repository: my-image
  tag: latest
service:
  type: ClusterIP
  port: 80

  3. templates/: This folder has Kubernetes manifest templates. These templates turn into valid Kubernetes resources. Here is a simple deployment template (deployment.yaml):

    apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ .Release.Name }}-deployment
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Release.Name }}
  template:
    metadata:
      labels:
        app: {{ .Release.Name }}
    spec:
      containers:
        - name: {{ .Release.Name }}
          image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
          ports:
            - containerPort: 80

  4. charts/: This folder can hold other charts that the current chart needs. These are called sub-charts.

  5. **templates/_helpers.tpl**: This file helps to define template functions that can be used in other templates.

  6. LICENSE: This is the license file for the chart.

  7. README.md: This markdown file gives information about the chart. It includes how to use it.

Each of these parts is important. They help define how the Helm chart works and how we can set it up and use it in a Kubernetes environment. If we want to learn more about Helm and its features, we can read more about what Helm is and how it helps with Kubernetes deployments.

How Do We Customize Values in Helm Charts?

Customizing values in Helm charts is important for setting up applications to meet our needs. Helm uses a values.yaml file to show default values. We can change these values when we install or upgrade.

Overriding Values

We can customize values by using the --set flag with the helm install or helm upgrade commands. For example:

helm install my-release my-chart --set image.tag=1.0 --set service.type=LoadBalancer

This command changes the image tag to 1.0 and the service type to LoadBalancer.

Using a Custom Values File

Instead of using the --set option, we can make a custom YAML file (like my-values.yaml) and use the -f flag:

# my-values.yaml
image:
  repository: myrepo/myapp
  tag: 1.0
service:
  type: LoadBalancer

Then we can install or upgrade our release like this:

helm install my-release my-chart -f my-values.yaml

Accessing Customized Values in Templates

In our Helm templates, we can get these values from the Values object. For example:

apiVersion: v1
kind: Service
metadata:
  name: {{ .Release.Name }}
spec:
  type: {{ .Values.service.type }}
  ports:
    - port: 80
      targetPort: 8080
  selector:
    app: {{ .Release.Name }}

Default Values in values.yaml

We can define default values in the values.yaml file in our chart. This helps users to see what options they can customize.

# values.yaml
image:
  repository: nginx
  tag: stable
service:
  type: ClusterIP

Tips for Customization

  • Use --set-string if we want to make sure the value is a string.
  • Use --set-file to get the value from a file.
  • We can set nested values using dot notation, like --set service.annotations."example.com/annotation"=value.

For more information about Helm and its deployment features, we can check this article on Helm.

How Can We Install and Upgrade Helm Charts?

To install and upgrade Helm charts, we use the Helm CLI. Here are the steps for both things.

Installing a Helm Chart

  1. Add a Chart Repository (this is optional if the chart is in a default repo):

    helm repo add <repository-name> <repository-url>
helm repo update

  2. Install the Chart:

    helm install <release-name> <chart> [--namespace <namespace>] [--values <values-file>] [--set key=value]
    • <release-name>: This is a unique name for the release.
    • <chart>: This is the name of the chart or the path to the chart directory.
    • --namespace: We can specify the Kubernetes namespace (the default is default).
    • --values: Here, we specify a YAML file with custom values for the chart.
    • --set: We can change values directly from the command line.

    Example:

    helm install my-release stable/mysql --namespace database --values my-values.yaml

Upgrading a Helm Chart

  1. Upgrade the Release:

    helm upgrade <release-name> <chart> [--namespace <namespace>] [--values <values-file>] [--set key=value]
    • <release-name>: This is the name of the release we want to upgrade.
    • <chart>: This is the new chart version or the path to the updated chart.
    • Other options are similar to the install command.

    Example:

    helm upgrade my-release stable/mysql --namespace database --values updated-values.yaml

Rollback to Previous Release

If we need, we can rollback to a previous release using:

helm rollback <release-name> [revision]
  • [revision]: This is optional. If we do not specify it, it rolls back to the last revision.

By using these commands, we can manage the installation and upgrade of Helm charts in our Kubernetes environment. For more details on Helm and what it can do, check out what is Helm and how it helps with Kubernetes deployments.

What Are Real-Life Use Cases for Helm Charts?

Helm charts help us deploy and manage applications on Kubernetes. Here are some easy examples of how we can use Helm charts in real life:

  1. Microservices Deployment: We can use Helm charts to deploy microservices. In microservices, many services need to be packed and managed separately. Each microservice can have its own Helm chart. This helps us keep track of versions and makes updates easier.

  2. Continuous Integration/Continuous Deployment (CI/CD): We can add Helm into CI/CD pipelines. It helps to automate the deployment of applications. With Helm, we can write the deployment settings as code. This is very important for making sure builds are the same every time.

  3. Multi-Environment Management: Helm charts help us manage deployments in different environments. We can work in development, staging, or production. By changing the values.yaml file, we can easily set configurations for each environment. We do not need to change the main chart.

  4. Application Versioning: Helm helps us version applications. This makes it easy to upgrade or go back to older versions if needed. We can install certain chart versions. This way, if an upgrade does not work, we can go back.

    helm install my-app ./my-app-chart --version 1.0.0
helm rollback my-app 1

  5. Dependency Management: Helm helps us manage dependencies between apps or services. We can list dependencies in our Helm chart. These will be installed automatically when we deploy the main chart.

    dependencies:
  - name: redis
    version: 6.0.0
    repository: https://charts.bitnami.com/bitnami

  6. Configuration Management: Helm charts give us a standard way to handle configurations for Kubernetes apps. We can use templates. This helps us set different configurations based on the environment and what users input when they install.

  7. Custom Resource Definitions (CRDs): We can use Helm to deploy apps that need CRDs. CRDs are important to extend what Kubernetes can do. Helm charts can include CRDs when we install.

  8. Ecosystem Integration: Many apps in the Kubernetes ecosystem come as Helm charts. This includes databases like MySQL and PostgreSQL, monitoring tools like Prometheus, and ingress controllers like NGINX. This makes installation easier and helps us follow best practices.

For more insights on how Helm makes application deployment easier, visit What is Helm and How Does it Help with Kubernetes Deployments?.

How Do We Manage Helm Chart Repositories?

Managing Helm chart repositories is important for us to organize and share our Helm charts well. Helm repositories are groups of packaged charts. We use them to install apps in our Kubernetes cluster. Here is how we can manage them:

Adding a Helm Chart Repository

To add a new Helm chart repository, we use this command:

helm repo add <repository-name> <repository-url>

For example:

helm repo add stable https://charts.helm.sh/stable

Updating Helm Repositories

To update our local cache of Helm chart repositories, we run:

helm repo update

This command gets the latest charts from the repositories we set up.

Listing Helm Repositories

To see all the Helm repositories we have added, we use:

helm repo list

Removing a Helm Chart Repository

If we want to remove a Helm repository, we can use this command:

helm repo remove <repository-name>

For example:

helm repo remove stable

Searching for Charts in Repositories

To search for specific charts in our repositories, we use:

helm search repo <keyword>

For example:

helm search repo nginx

Installing Charts from a Repository

We can install a chart directly from a repository with this command:

helm install <release-name> <repository-name>/<chart-name>

For example:

helm install my-nginx stable/nginx

Managing Chart Versions

If we want to choose a version when we install a chart, we use:

helm install <release-name> <repository-name>/<chart-name> --version <chart-version>

Using Private Helm Repositories

For private repositories, we might need to give authentication. We can use basic auth by adding the credentials to the URL:

helm repo add <repository-name> https://username:password@<repository-url>

Conclusion

By managing our Helm chart repositories well, we can make our Kubernetes deployments easier and keep better control over our apps. For more info on Helm and what it can do, we can check this article on Helm.

Frequently Asked Questions

What is a Helm Chart?

We can say that a Helm chart is a package format for deploying apps on Kubernetes. It has all the settings needed to run an app or service. This includes Kubernetes resources like Deployments, Services, and ConfigMaps. Helm charts make it easier to deploy by allowing us to manage Kubernetes apps as one unit. This way, we can deploy, upgrade, and maintain our apps more simply.

How do I install Helm on my local machine?

To install Helm on our local machine, we first need to download the Helm binary from the official Helm GitHub releases page. After we download it, we extract the binary and move it to a folder in our PATH. Then, we run helm version in our terminal to check if it is installed. We can also check our guide on how to set up Helm on my local machine for more details.

How can I customize values in Helm charts?

We can customize values in Helm charts using a values.yaml file or by passing parameters directly when we install or upgrade. We can make our own values.yaml to change the default chart values. Also, we can use the --set flag to specify single values. This gives us the freedom to change the deployment to fit our needs without changing the chart itself.

What are the best practices for managing Helm chart repositories?

To manage Helm chart repositories well, we should update them often and use versioning to keep track of changes. It is a good idea to use a private repository for our custom charts to improve security and control. We can also use tools like helm repo add to manage external repositories and helm search to find charts easily. For more details, we can look at our guide on managing Helm chart repositories.

What are common use cases for Helm charts in Kubernetes?

We use Helm charts often for deploying complex apps, managing microservices, and automating the setup of development and production environments in Kubernetes. They help teams make deployments standard, support continuous integration and delivery (CI/CD) pipelines, and make application upgrades and rollbacks easier. We can learn more about real-life use cases for Helm charts to see how they can help our projects.