Manuri/kubernetes

Ballerina Kubernetes Extension

Annotation based kubernetes extension implementation for ballerina.

Features:

• Kubernetes deployment support.
• Kubernetes service support.
• Kubernetes liveness probe support
• Kubernetes ingress support.
• Kubernetes horizontal pod autoscaler support.
• Docker image generation.
• Docker push support with remote docker registry.
• Kubernetes secret support.
• Kubernetes config map support.
• Kubernetes persistent volume claim support.
• Kubernetes resource quotas.
• Istio gateways.
• Istio virtual services.

Refer samples for more info.

Supported Annotations:

@kubernetes:Deployment{}

• Supported with ballerina services or listeners.

Annotation Name	Description	Default value
name	Name of the deployment	<outputfilename>-deployment
namespace	Namespace of the deployment	null
labels	Labels for deployment	"app: <outputfilename>"
annotations	Annotations for deployment	{}
podAnnotations	Pod annotations	{}
replicas	Number of replicas	1
dependsOn	Listeners this deployment Depends on	null
enableLiveness	Enable or disable liveness probe	false
initialDelaySeconds	Initial delay in seconds before performing the first probe	10s
periodSeconds	Liveness probe interval	5s
livenessPort	Port which the Liveness probe check	<ServicePort>
imagePullPolicy	Docker image pull policy	IfNotPresent
image	Docker image with tag	:latest
env	List of environment variables	null
buildImage	Building docker image	true
copyFiles	Copy external files for Docker image	null
dockerHost	Docker host IP and docker PORT.(e.g "tcp://192.168.99.100:2376")	null
dockerCertPath	Docker cert path	null
push	Push docker image to registry. This can only be true if image build is true.	false
username	Username for the docker registry	null
password	Password for the docker registry	null
baseImage	Base image to create the docker image	ballerina/ballerina-runtime:latest
imagePullSecrets	Image pull secrets value	null
singleYAML	Generate a single yaml file for all k8s resources	true

@kubernetes:Service{}

• Supported with ballerina listeners.

Annotation Name	Description	Default value
name	Name of the Service	<ballerina service name>-service
labels	Labels for service	"app: <outputfilename>"
serviceType	Service type of the service	ClusterIP
port	Service port	Port of the ballerina service

@kubernetes:Ingress{}

• Supported with ballerina listeners.

Annotation Name	Description	Default value
name	Name of the Ingress	<ballerina service name>-ingress
labels	Labels for service	"app: <outputfilename>"
hostname	Host name of the ingress	<ballerina service name>.com
annotations	Map of additional annotations	null
path	Resource path.	/
targetPath	This will use for URL rewrite.	null
ingressClass	Ingress class	nginx
enableTLS	Enable ingress TLS	false

@kubernetes:HPA{}

• Supported with ballerina services.

Annotation Name	Description	Default value
name	Name of the Horizontal Pod Autoscaler	<ballerina service name>-hpa
labels	Labels for service	"app: <outputfilename>"
minReplicas	Minimum number of replicas	No of replicas in deployment
maxReplicas	Maximum number of replicas	minReplicas+1
cpuPrecentage	CPU percentage to start scaling	50

@kubernetes:Secret{}

• Supported with ballerina service.

Annotation Name	Description	Default value
name	Name secret mount	<service_name>-secret
mountPath	Path to mount on container	null
readOnly	Is mount read only	true
data	Paths to data files	null

@kubernetes:ConfigMap{}

• Supported with ballerina services.

Annotation Name	Description	Default value
name	Name config map mount	<service_name>-config-map
mountPath	Path to mount on container	null
readOnly	Is mount read only	true
ballerinaConf	Ballerina conf file location	null
data	Paths to data files	null

@kubernetes:PersistentVolumeClaim{}

• Supported with ballerina services.

Annotation Name	Description	Default value
name	Name secret mount	null
annotations	Metadata Annotations map	null
mountPath	Path to mount on container	null
readOnly	Is mount read only	false
accessMode	Access mode	ReadWriteOnce
volumeClaimSize	Size of the volume claim	null

@kubernetes:Job{}

• Supported with ballerina main function.

Annotation Name	Description	Default value
name	Name of the job	<output file name>-job
namespace	Namespace for the Job	default
labels	Labels for job	"app: <outputfilename>"
restartPolicy	Restart policy	Never
backoffLimit	Backoff limit	3
activeDeadlineSeconds	Active deadline seconds	20
schedule	Schedule for cron jobs	none
imagePullPolicy	Docker image pull policy	IfNotPresent
image	Docker image with tag	<output file name>:latest
env	List of environment variables	null
buildImage	Building docker image	true
dockerHost	Docker host IP and docker PORT.(e.g "tcp://192.168.99.100:2376")	null
dockerCertPath	Docker cert path	null
push	Push docker image to registry. This can only be true if image build is true.	false
username	Username for the docker registry	null
password	Password for the docker registry	null
baseImage	Base image to create the docker image	ballerina/ballerina-runtime:latest

@kubernetes:ResourceQuota{}

• Support with ballerina services, listeners and functions.

Annotation Name	Description	Default value
name	Name of the resource quota	<output file name>_resource_quota
labels	Labels for resource quota	"app: <outputfilename>"
hard	Hard rules	{}
scopes	scopes to which the resource quota will be applied to	[]

How to build

1. Download and install JDK 8 or later
2. Install Docker
3. Get a clone or download the source from this repository (https://github.com/ballerinax/kubernetes)
4. Run the Maven command mvn clean install from within the kubernetes directory.

Annotation Usage Sample:

import ballerina/http;
import ballerinax/kubernetes;

@kubernetes:Ingress{
    hostname:"abc.com"
}
@kubernetes:Service{name:"hello"}
listener http:Listener helloEP = new(9090);

@kubernetes:Deployment{
    enableLiveness:true
}
@http:ServiceConfig {
    basePath:"/helloWorld"
}
service helloWorld on helloEP {
    resource functino sayHello (http:Caller outboundEP, http:Request request) {
        http:Response response = new;
        response.setTextPayload("Hello, World from service helloWorld ! ");
        _ = outboundEP -> respond(response);
    }
}

The kubernetes artifacts will be created in following structure.

kubernetes
├── deployment.yaml
├── ingress.yaml
├── secret.yaml
├── config_map.yaml
├── volume_claim.yaml
├── svc.yaml
└── docker
 └── Dockerfile