ConfigMapGenerator is a Kubernetes operator written in Go that automates the management of ConfigMaps and restarts associated Deployments. It uses a Custom Resource Definition (CRD) called ConfigMapManager to define updates for multiple ConfigMaps and automatically applies these changes to Kubernetes resources across namespaces.

Features

Supports bulk updates to multiple ConfigMaps using a single ConfigMapManager Custom Resource.
Automatically restarts Deployments that are linked to updated ConfigMaps using envFrom.
Monitors namespaces with a specific annotation (e.g., owner: blacksyrius) for targeted ConfigMap updates.
Modular design for easy maintenance and extensibility.
Built with Go and uses the Kubernetes client-go library.

Folder Structure

project/
├── cmd/
│   └── main.go               # Entry point of the application
├── controllers/
│   ├── cr_processor.go       # Handles Custom Resource processing
│   ├── configmap.go          # Manages ConfigMap updates
│   └── deployment.go         # Restarts Deployments linked to ConfigMaps
├── clients/
│   └── k8s_client.go         # Kubernetes client initialization
├── models/
│   └── configmap_manager.go  # Data models for ConfigMapManager CRD
├── utils/
│   └── logger.go             # Centralized logging utility
├── go.mod                    # Go module dependencies
└── go.sum                    # Dependency checksums

Custom Resource Definition (CRD)

The ConfigMapManager CRD defines which ConfigMaps to update and their associated key-value updates. Here is an example:

CRD Example

apiVersion: blacksyrius.ci.com/v1
kind: ConfigMapManager
metadata:
  name: my-configmap-update
  namespace: default
spec:
  configMaps:
    - name: example-config
      updates:
        - key: LOG_LEVEL
          newValue: "info"
        - key: DB_HOST
          newValue: "mysql.example.com"
    - name: another-config
      updates:
        - key: FEATURE_FLAG
          newValue: "true"
        - key: RETRY_LIMIT
          newValue: "5"

How It Works

Custom Resource Deployment:
- Users create a ConfigMapManager resource to define which ConfigMaps and keys to update.
Namespace Filtering:
- The operator processes only namespaces with the annotation owner: blacksyrius.
ConfigMap Updates:
- The operator updates the specified ConfigMaps with the provided key-value pairs.
Deployment Restarts:
- Deployments that reference the updated ConfigMaps via envFrom are automatically restarted by adding a timestamp annotation to their pod templates.

Installation

Prerequisites

Kubernetes cluster (v1.20+ recommended)
Go (v1.20 or higher)
kubectl CLI configured to access your cluster

Steps

Clone the Repository:

git clone https://github.com/miraccan00/configmapmanagers.git

cd configmapmanagers

Build the Operator:

go build -o configmapgenerator ./cmd/main.go

Deploy the CRD: Apply the ConfigMapManager CRD to your cluster:
```
kubectl apply -f deploy/crd.yaml
```
Run the Operator: Run the operator binary:
```
./configmapgenerator
```

Usage

Create a Namespace with Annotations: Ensure the namespace you want to target has the annotation owner: blacksyrius.

Example:

apiVersion: v1
kind: Namespace
metadata:
  name: example-namespace
  annotations:
    owner: blacksyrius

Apply it with:

kubectl apply -f namespace.yaml

Create a ConfigMapManager Resource: Create a ConfigMapManager YAML file defining the ConfigMaps and updates. Example:

apiVersion: blacksyrius.ci.com/v1
kind: ConfigMapManager
metadata:
  name: my-configmap-update
  namespace: example-namespace
spec:
  configMaps:
    - name: example-config
      updates:
        - key: LOG_LEVEL
          newValue: "info"
        - key: DB_HOST
          newValue: "mysql.example.com"

Apply it to your cluster:

kubectl apply -f configmapmanager.yaml

Verify the Updates:

Check the updated ConfigMap:
- kubectl get configmap example-config -n example-namespace -o yaml
Ensure the associated Deployments have restarted:
- kubectl describe deployment <deployment-name> -n example-namespace

Development

Adding Features

To add a new feature, create a new Go module under the appropriate folder (e.g., controllers, utils).

Testing

Run unit tests:

go test ./...
Simulate Custom Resource updates in a local cluster:

kubectl apply -f deploy/test-configmapmanager.yaml

Debugging

Use the logs to debug issues:

tail -f application.log

Contributing

Contributions are welcome! Please fork the repository, make changes in a separate branch, and submit a pull request.

Licence This project is licensed under the MIT License. See the LICENSE file for more details.

Contact

For support or inquiries, reach out to [email protected].

# Packages

# README

ConfigMapGenerator