natashawso2 / 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

Supported Annotations:

@kubernetes:Deployment{}

• Supported with ballerina services or endpoints.

Annotation Name	Description	Default value
name	Name of the deployment	<outputfilename>-deployment
labels	Labels for deployment	"app: <outputfilename>"
replicas	Number of replicas	1
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:latest
singleYAML	Generate a single yaml file for all k8s resources	false

@kubernetes:Service{}

• Supported with ballerina endpoints.

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 endpoints.

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
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
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:latest

How to run

1. Download and install JDK 8 or later
2. Get a clone or download the source from this repository (https://github.com/ballerinax/docker)
3. Run the Maven command mvn clean install from within the kubernetes directory.
4. Copy target/kubernetes-extension-0.962.0.jar file to <BALLERINA_HOME>/bre/lib directory.
5. Run ballerina build <.bal filename> to generate artifacts.

The docker artifacts will be created in a folder called target with following structure.

    └── kubernetes
    │           ├── deployment.yaml
    │           ├── ingress.yaml
    │           ├── secret.yaml
    │           ├── config_map.yaml
    │           ├── volume_claim.yaml
    │           ├── service.yaml
    │           └── docker
    │	        	  └── Dockerfile
    │  	
    └── outputfilename.balx	

Annotation Usage Sample:

import ballerina/http;
import ballerinax/kubernetes;

@kubernetes:Service{name:"hello"}
endpoint http:Listener helloEP {
    port:9090
};

@kubernetes:Deployment{
    enableLiveness:true
}
@kubernetes:Ingress{
    hostname:"abc.com"
}
@http:serviceConfig {
    basePath:"/helloWorld"
}
service<http:Service> helloWorld bind helloEP {
    sayHello (endpoint outboundEP, http:Request request) {
        http:Response response = new;
        response.setTextPayload("Hello, World from service helloWorld ! ");
        _ = outboundEP -> respond(response);
    }
}

Refer samples for more info.