Helm Values Synchronization Script

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Managing Helm chart configurations across different environments requires propagating image updates and new environment variables between values files. Manual synchronization is error-prone and time-consuming.

The update-values.js script synchronizes Docker images and environment variables between Helm values files while preserving existing configurations and comments.

The Script

update-values.js - Cross-Environment Values Sync

  • Function: Synchronizes images and environment variables between any two values files

  • Compatibility: Handles both Alpha Application and Workflow Studio YAML structures automatically

  • Preservation: Maintains existing comments, formatting, and non-matching configurations

Key Features

Structure Detection

Detects whether files use the traditional image.repository/image.tag format (Workflow Studio) or the newer container.image format (Alpha Application) by examining directory names and content structure.

Service Matching

  • Direct name matching between services

  • Fuzzy matching for similar service names (e.g., alpha-backend matches backend-service)

  • Handles common prefix/suffix variations

Image Updates

  • Full image replacement: Updates both repository and tag

  • Tag-only updates: Preserves existing repository, updates only the tag using --only-tag flag

  • Maintains proper YAML structure for each format

Environment Variable Sync

  • Identifies new environment variables in source file that don’t exist in target

  • Adds missing variables with empty values and TODO comments

  • Preserves existing environment variables in target file

How to Use

Prerequisites

  • Node.js 16+

Basic Usage

Sync complete images and environment variables:


./scripts/update-values.js alpha-application/values-uat.yaml alpha-application/values-prod.yaml

Update only tags (preserve repositories):


./scripts/update-values.js alpha-application/values-uat.yaml alpha-application/values-prod.yaml --only-tag

Example Output


Reading from file: alpha-application/values-uat.yaml

Reading to file: alpha-application/values-prod.yaml

From structure: alpha-application

To structure: alpha-application

Found 3 matching services:

alpha-backend -> alpha-backend

frontend-ui -> frontend-ui

notification-service -> notification-service

Updated image for alpha-backend: myregistry.azurecr.io/alpha-backend:v2.1.0

Updated image for frontend-ui: myregistry.azurecr.io/frontend-ui:v1.8.2

Added new env var to notification-service: SMTP_HOST with inline comment (original: smtp.company.com)

=== Update Summary ===

Updated 3 services with new images

Added 3 new environment variables with TODO comments

Output written to: alpha-application/values-dev.yaml

Use Cases

Dev to Prod Sync

Propagate Dev image versions to Prod environments while preserving prod-specific configurations.

Environment Variable Management

When new environment variables are added to Dev configurations, identify and add them to other environments with placeholder values and TODO comments.

Tag-Only Updates

Update only image tags when repositories remain the same but versions change.

Technical Details

YAML Structure Handling

Workflow Studio Format:


service-name:

image:

repository: myregistry.azurecr.io/service

tag: v1.0.0

env:

- name: DATABASE_URL

value: "postgres://..."

Alpha Application Format:


service-name:

container:

image: "myregistry.azurecr.io/service:v1.0.0"

secret:

environment:

DATABASE_URL: "postgres://..."

Environment Variable Comments

New environment variables are added with TODO comments:


NEW_CONFIG_VAR: "" # TODO: example value - (original-value-from-source)

Integration

CI/CD Pipeline Integration


- name: Sync UAT Images to Prod

run: |

./scripts/update-values.js values-uat.yaml values-prod.yaml --only-tag

git add values-prod.yaml

git commit -m "sync: update prod environment with uat image tags"

Release Management

Use tag-only updates during release cycles to maintain repository consistency while updating versions across environments.

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