LocalOps Variables

When deploying your application using LocalOps, certain Helm values are automatically passed to your application. These values can be utilized within your application to configure settings dynamically based on the deployment environment. This guide will explain how developers can consume these LocalOps passed Helm values within their applications.

Helm Values passed by LocalOps

LocalOps passes the following Helm values to your application:

localops:
  app_release: 1.0.0
  region: us-east-1
  vpc_id: vpc-0b9d9ae510445316b
  public_subnets:
    - id: subnet-01371395ceb9c9675
    - id: subnet-0e04a7a31b7ecdfcc
    - id: subnet-037a70bac21c5f9e3
  private_subnets:
    - id: subnet-06bc4ffd44a1900e4
    - id: subnet-003d4beba19dfe16e
    - id: subnet-01a64fef6965ba41e

These values provide essential information about the environment in which your application is deployed, such as the AWS region, VPC ID, and subnet IDs.

Accessing LocalOps Helm Values in Your Application

To access these Helm values in your application, you need to include them in your application's configuration files or environment variables. Here's how you can do this,

Using Environment Variables

You can set up your Kubernetes Deployment manifest to export these Helm values as environment variables. Here's an example,

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-application
spec:
  replicas: 1
  selector:
    matchLabels:
      app: my-application
  template:
    metadata:
      labels:
        app: my-application
    spec:
      containers:
        - name: my-container
          image: my-image:1.0.1
          env:
            - name: APP_RELEASE
              value: '{{ .Values.localops.app_release }}'
            - name: AWS_REGION
              value: '{{ .Values.localops.region }}'
            - name: VPC_ID
              value: '{{ .Values.localops.vpc_id }}'
            - name: PUBLIC_SUBNETS
              value: { { .Values.localops.public_subnets | toJson | quote } }
            - name: PRIVATE_SUBNETS
              value: { { .Values.localops.private_subnets | toJson | quote } }

In this example, the Helm values are injected as environment variables, which can then be accessed by your application code.

Accessing Helm Values in Application Code

Depending on your programming language, you can access these environment variables in your application code. For example, in a Node.js application, you can access the environment variables as follows,

const appRelease = process.env.APP_RELEASE;
const awsRegion = process.env.AWS_REGION;
const vpcId = process.env.VPC_ID;
const publicSubnets = JSON.parse(process.env.PUBLIC_SUBNETS);
const privateSubnets = JSON.parse(process.env.PRIVATE_SUBNETS);

console.log('App Release:', appRelease);
console.log('AWS Region:', awsRegion);
console.log('VPC ID:', vpcId);
console.log('Public Subnets:\n', JSON.stringify(publicSubnets, null, 2));
console.log('Private Subnets:\n', JSON.stringify(privateSubnets, null, 2));

Result:

LocalOps Version: 1.0.0
AWS Region: us-east-1
VPC ID: vpc-0b9d9ae510445316b
Public Subnets:
[
  {
    "id": "subnet-01371395ceb9c9675"
  },
  {
    "id": "subnet-0e04a7a31b7ecdfcc"
  },
  {
    "id": "subnet-037a70bac21c5f9e3"
  }
]
Private Subnets:
[
  {
    "id": "subnet-06bc4ffd44a1900e4"
  },
  {
    "id": "subnet-003d4beba19dfe16e"
  },
  {
    "id": "subnet-01a64fef6965ba41e"
  }
]

Utilizing LocalOps Helm Values in Your Helm Chart

You can seamlessly integrate LocalOps Helm values directly into your Helm chart configurations. For instance, when creating S3 buckets within your Helm chart, you can specify the S3 bucket region using the localops.region Helm value provided by LocalOps. This ensures that your S3 buckets are correctly configured based on the App Environment region.

Here's a quick example of how to use the localops.region value in your Helm chart,

apiVersion: s3.aws.upbound.io/v1beta1
kind: Bucket
metadata:
  name: { { .Values.s3.bucket_name } }
spec:
  forProvider:
    region: { { .Values.localops.region } } # This is a LocalOps passed Helm Value
    forceDestory: true
  providerConfigRef:
    name: default

For detailed instructions on provisioning an S3 bucket, refer to the Provisioning an S3 Bucket article.

Conclusion

In this article, you have learned about the Helm values provided by LocalOps and how to effectively use them within your Helm chart and application. 👌🏽