Kubernetes Client Lambda

What is Kubernetes Client Lambda?

Kubernetes Client Lambda (aka KCL) is a wrapper library for kubernetes/client-go. Basically it contains these following feature:

• Dynamic client & client pool
• Hide details about client-go's informer and lister.
• Hide annoying group & versions and use resources as enum.
• Lambda styled resource filtering & manipulating. (inspired by Groovy)
• It's really easy to use.

With KCL, you can operate kubernetes resources like this example:

// See doc for more info about lambda functions Grep / Map..
import kubernetes "github.com/yue9944882/kubernetes-client-lambda"

// In-Cluster example
// var kcl kubernetes.KubernetesClientLambda = kubernetes.InCluster()
kubernetes.InCluster().Type(kubernetes.ReplicaSet).InNamespace("test").
    List().
    NamePrefix("foo-").
    Map(func(rs *api_ext_v1.ReplicaSet) rs*api_ext_v1.ReplicaSet {
        // Edit in-place or clone a new one
        rs.Meta.Labels["foo-label1"] = "test" 
        return rs
    }).Update()


// Out-Of-Cluster example
kubernetes.OutOfClusterDefault().Type(kubernetes.Pod).InNamespace("devops").
    List().
    NameEqual("test-pod").Each(
        func(pod *api_v1.Pod) {
            count++
    })

As the following example is shown, Calling Mock() on Kubernetes Type Enumeration will create the expected mocking resources for you:

import kubernetes "github.com/yue9944882/kubernetes-client-lambda"

var kcl KubernetesClientLambda = kubernetes.Mock()

How to Get it?

go get github.com/yue9944882/kubernetes-client-lambda

Supported Lambda Function Type

We support following types of lambda function:

Primitive Lambda Type

Name	Parameter Type	Return Type
Function	Resource	-
Consumer	Resource
Predicate	Resource	bool
Producer	-	Resource

Kubernetes Resource Lambda Snippet

Name	Pipelinable	Description
NameEqual	yes	Filter out resources if its name mismatches
NamePrefix	yes	Filter out resources if its name doesn't have the prefix
NameRegex	yes	Filter out resources if its name doesn't match the regular expression
HasAnnotation	yes	Filter out resources if it doesn't have the annotation
HasAnnotationKey	yes	Filter out resources if it doesn't have the annotation key
HasLabel	yes	Filter out resources if it doesn't have the label
HasLabelKey	yes	Filter out resources if it doesn't have the label key

And these lambda can be consumed by following function:

Primitive Pipeline Type

Name	Pipelinable	Lambda Type	Description
Collect	yes	-	Deep copies the elements and put them into collection
Add	yes	Producer	Add the element returned by lambda into collection
Map	yes	Consumer	Add all the elements returned by lambda to a new collection
Grep	yes	Predicate	Remove the element from collection if applied lambda returned a false
First	yes	Predicate	Take only the first element when applied lambda returned a true
Iter	no	Function	Apply the lambda to every elements in the collection

Primitive methods like CreateIfNotExist, DeleteIfExist have no parameter and just consumes all elements at the end of the pipelining. Here are supported primitive kubernetes operation functions below:

Basic Operation

Operation	Param	Return1	Return2
Each	Function	lambda error	-
Any	Predicate	bool	lambda error
Every	Predicate	bool	lambda error
NotEmpty	-	bool	lambda error

Kubernetes Operation

Operation	Param	Return1	Return2
Create	-	bool(sucess)	lambda error
CreateIfNotExists	-	bool(success)	lambda error
Delete	-	bool(sucess)	lambda error
DeleteIfExists	-	bool(success)	lambda error
Update	-	bool(sucess)	lambda error
UpdateIfExists	-	bool(success)	lambda error
UpdateOrCreate	-	bool(success)	lambda error