kubetest.go

/*
Copyright 2017 Frederic Branczyk All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package kubetest

import (
	"testing"
	"time"

	"k8s.io/apimachinery/pkg/util/rand"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/clientcmd"
)

type Suite struct {
	KubeClient kubernetes.Interface
}

func NewSuiteFromKubeconfig(path string) (*Suite, error) {
	config, err := clientcmd.BuildConfigFromFlags("", path)
	if err != nil {
		return nil, err
	}

	client, err := kubernetes.NewForConfig(config)
	if err != nil {
		return nil, err
	}

	return &Suite{KubeClient: client}, nil
}

type TestSuite func(t *testing.T)

type Scenario struct {
	KubeClient kubernetes.Interface

	Name        string
	Description string

	Given Setup
	When  Condition
	Then  Check
}

type ScenarioContext struct {
	Namespace string
	Finalizer []Finalizer
}

func (ctx *ScenarioContext) AddFinalizer(f Finalizer) {
	ctx.Finalizer = append(ctx.Finalizer, f)
}

type RunOpts func(ctx *ScenarioContext) *ScenarioContext

func RandomNamespace(client kubernetes.Interface) RunOpts {
	return func(ctx *ScenarioContext) *ScenarioContext {
		ctx.Namespace = rand.String(8)

		ctx.AddFinalizer(func() error {
			return DeleteNamespace(client, ctx.Namespace)
		})

		if err := CreateNamespace(client, ctx.Namespace); err != nil {
			panic(err)
		}

		return ctx
	}
}

func Timeout(d time.Duration) RunOpts {
	return func(ctx *ScenarioContext) *ScenarioContext {
		// TODO
		return ctx
	}
}

func (s Scenario) Run(t *testing.T, opts ...RunOpts) bool {
	ctx := &ScenarioContext{
		Namespace: "default",
	}

	for _, o := range opts {
		o(ctx)
	}

	defer func(ctx *ScenarioContext) {
		for _, f := range ctx.Finalizer {
			if err := f(); err != nil {
				panic(err)
			}
		}
	}(ctx)

	return t.Run(s.Name, func(t *testing.T) {
		if s.Given != nil {
			if err := s.Given(ctx); err != nil {
				t.Fatalf("failed to create given setup: %v", err)
			}
		}

		if s.When != nil {
			if err := s.When(ctx); err != nil {
				t.Errorf("failed to evaluate state: %v", err)
			}
		}

		if s.Given != nil {
			if err := s.Then(ctx); err != nil {
				t.Errorf("checks failed: %v", err)
			}
		}
	})
}

type Setup func(ctx *ScenarioContext) error

func Setups(ss ...Setup) Setup {
	return func(ctx *ScenarioContext) error {
		for _, s := range ss {
			if err := s(ctx); err != nil {
				return err
			}
		}
		return nil
	}
}

type Condition func(ctx *ScenarioContext) error

func Conditions(cs ...Condition) Condition {
	return func(ctx *ScenarioContext) error {
		for _, c := range cs {
			if err := c(ctx); err != nil {
				return err
			}
		}
		return nil
	}
}

type Check func(ctx *ScenarioContext) error

func Checks(cs ...Check) Check {
	return func(ctx *ScenarioContext) error {
		for _, c := range cs {
			if err := c(ctx); err != nil {
				return err
			}
		}
		return nil
	}
}

type Finalizer func() error