OCM Description Service

Overview

The ocm-description-service is a service designed to offload workloads on various orchestrators such as OCM, Nuvla, and others. This service provides a set of RESTful endpoints to execute jobs pulled from Job Manager, perform health checks, and synchronize resources efficiently.

Table of Contents

• 1. Job Types and Subtypes
• 2. Locking and Ownership Mechanism
• 3. Remediation Actions
• 4. Deployment Management
• 5. Resource Status Tracking
• 6. Docker Installation
• 7. Kind Installation
• 8. Usage
• 8. Contributing
• 10. Legal

1. Job Types and Subtypes

In the ICOS continuum, various job types and subtypes are used to manage deployment and remediation tasks effectively. Below is a brief explanation of each job type and its associated subtypes:

• CreateDeployment: initiates the deployment of an application.
• DeleteDeployment: removes an application.
• UpdateDeployment: updates a certain deployment.
  • Subtypes:
    • ScaleIn
    • ScaleOut
    • ScaleUp
    • ScaleDown
    • SecurityRemediation

2. Locking and Ownership Mechanism

Whenever an OCM Descriptor Service instance picks up a job, it sends a request to the Job Manager to "Lock" the job from being executed by other Descriptor Service instances. Additionally, "Ownership" is set to ensure that, in the context of a multicluster deployment with multiple hubs, a certain job is locked and owned by an OCM Hub. This mechanism ensures job consistency and prevents race conditions across the deployment clusters.

3. Remediation Actions

When the Policy Manager detects an incompliance, it sends a request to the Job Manager to create an UpdateDeployment job. This job is then processed by the Description Service. Currently, we support five different job subtypes to handle remediation actions:

• ScaleIn: Adds a replica to a deployment to handle increased load or improve redundancy.
• ScaleOut: Removes a replica from a deployment to reduce resource usage when demand decreases.
• ScaleUp: Increases a deployment's resources by adding 100 MB of memory and 100 CPU units.
• ScaleDown: Decreases a deployment's resources by removing 100 MB of memory and 100 CPU units.
• SecurityRemediation: Applies a security update to ensure the deployment adheres to the latest security standards. (TODO: Detailed implementation pending)

4. Deployment Management

In the ICOS continuum, the deployment and undeployment of applications are managed through two primary job types: CreateDeployment and DeleteDeployment:

• CreateDeployment: this job type will create a ManifestWork in a target ManagedCluster that is specified in the specs of the job.
• DeleteDeployment: this job type will remove a ManifestWork in a target ManagedCluster that is specified in the specs of the job.

5. Resource Status Tracking

The OCM Descriptor Service relies on a sidecar container responsible for scheduling. The sidecar container ensures that resource statuses are regularly updated and synchronized.

6. Docker Installation

To install and run the ocm-description-service, follow these steps:

1. Clone the repository:

   git clone https://production.eng.it/gitlab/icos/meta-kernel/ocm-description-service.git

2. Navigate to the project directory:

   cd ocm-description-service

3. Build the Docker image:

   docker build -t ocm-description-service .

4. Set up the environment variable for the job manager URL.

   export JOBMANAGER_URL=http://localhost:8082

5. Run the Docker container:

   docker run -e JOBMANAGER_URL=$JOBMANAGER_URL -p 8083:8083 ocm-description-service

7. Kind Installation

Please, refer to the helm suite in ICOS Agent Repository

8. Usage

After running the service, you can use tools like curl, Postman, Swagger or any other API client to interact with the endpoints. Beware that you will need a Keycloak Token to perform requests to this service.

Example Request

curl --location 'http://localhost:8083/deploy-manager/execute' \
--header 'Authorization: Bearer (Token)'

9. Contributing

In order to contribute to this repository, feel free to open a pull request and assign @x_alvolkovor x_magallar as a reviewer.

10. Legal

The OCM Deployment Manager is released under the Apache 2.0 license. Copyright © 2022-2024 Eviden. All rights reserved.

🇪🇺 This work has received funding from the European Union's HORIZON research and innovation programme under grant agreement No. 101070177.