k3s-client 0.2.0

Swarmchestrate k3s client

k3s-client

A lightweight Python client for managing microservices on Kubernetes k3s clusters. Provides a clean API layer for deploying applications, managing secrets and ConfigMaps, generating Kubernetes manifests from TOSCA definitions, and performing node-aware scheduling operations.

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Features

• Registry Secret Management — Create and rotate Docker registry secrets for private image pulls
• ConfigMap Management — Create ConfigMaps from literals or files
• Microservice Lifecycle — Scale, update images, migrate nodes, and delete microservices
• Manifest Generation — Generate Kubernetes manifests from TOSCA definitions
• Node-Aware Scheduling — Migrate microservices across nodes using label-based selectors
• Pod Management — List and launch pods with node affinity support
• Kubectl Wrapper — Declarative apply and delete via kubectl

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Prerequisites

• Python 3.12 or higher
• A running k3s server with a valid kubeconfig (default: /etc/rancher/k3s/k3s.yaml)
• kubectl installed

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Installation

git clone https://github.com/Swarmchestrate/k3s-client.git
cd k3s-client
make install

This will install all dependencies and the Puccini TOSCA parser required for manifest generation.

Methods

ApplicationManager

Method	Parameters	Description
create_registry_secret	name, registry, username, password, namespace=None, replace=True	Create a Docker registry pull secret
create_configmap	name, namespace=None, from_literal=None, from_file=None	Create a ConfigMap from literals or files
delete_configmap	name, namespace=None	Delete a ConfigMap by name
create_registry_secret	name, registry, username, password, namespace=None, replace=True	Create a Docker registry pull secret
apply_manifest	manifest_file, namespace=None	Apply a Kubernetes manifest via kubectl
delete_manifest	manifest_file	Delete resources defined in a manifest
create_microservice	deployment_name, image, container_name='app', replicas=1, namespace=None, labels=None, env=None, ports=None, node_selector=None, service_type='ClusterIP'	Create a new deployment and optional service
scale_microservice	deployment_name, replicas, namespace=None	Scale a deployment
update_microservice_image	deployment_name, container_name, new_image, namespace=None	Update a container image in-place
migrate_microservice_node	deployment_name, node_selector, namespace=None	Migrate a deployment to a different node
delete_microservice	app_label, namespace=None	Delete all resources for a given app label
get_pod_node_mapping	namespace=None, label_selector=None	Return a mapping of pod names to node names

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PodManager

Method	Parameters	Description
list_pods	namespace=None, label_selector=None	List pods, optionally filtered by label
launch_pod	name, image, pod_labels=None, node_labels=None, node_name=None, namespace=None, container_port=None	Launch a pod for internal testing with optional node affinity

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get_kubernetes_manifest

Function	Parameters	Description
get_kubernetes_manifest	tosca_yaml, image_pull_secret=None	Generate Kubernetes manifests from a TOSCA definition

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Kubectl

Method	Parameters	Description
apply	manifest_path=None, configmap_name=None, namespace=None, from_literal=None, from_file=None	Apply resources declaratively
delete	manifest_path	Delete resources from a manifest

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Examples

The examples/ directory contains complete runnable scripts:

File	Description
registry_secret_example.py	Managing Docker registry secrets
configmap_example.py	Creating ConfigMaps from literals and files
manifest_generator_example.py	Generating Kubernetes manifests from TOSCA definitions
manifest_apply_example.py	Applying a generated manifest to the cluster
manifest_delete_example.py	Deleting resources defined in a manifest
deploy_microservice_example.py	Create a new deployment and optional service
scale_microservice_example.py	Scale a deployment by replica count
update_microservice_image_example.py	Update a deployment container image
migrate_microservice_node_example.py	Migrate a deployment to specific nodes
delete_microservice_example.py	Delete a microservice deployment and service
pod_node_mapping_example.py	Show pod-to-node mapping for a namespace

Run any example:

python examples/scale_microservice_example.py

By default, examples use the k3s kubeconfig at /etc/rancher/k3s/k3s.yaml. You can also override this path in the script or via environment configuration when needed.

Set the environment variable like this:

export KUBECONFIG=/etc/rancher/k3s/k3s.yaml

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Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/my-feature)
3. Make your changes and add tests where applicable
4. Run the test suite (pytest)
5. Open a pull request

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License

Licensed under the Apache License 2.0.

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Contact

For questions or feedback, reach out to [e-mail]