/*
Copyright 2016 The Kubernetes Authors.

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 common

import (
	"fmt"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/uuid"
	utilversion "k8s.io/kubernetes/pkg/util/version"
	"k8s.io/kubernetes/test/e2e/framework"

	. "github.com/onsi/ginkgo"
)

var (
	hostIPVersion = utilversion.MustParseSemantic("v1.8.0")
	podUIDVersion = utilversion.MustParseSemantic("v1.8.0")
)

var _ = Describe("[sig-api-machinery] Downward API", func() {
	f := framework.NewDefaultFramework("downward-api")

	/*
		    Testname: downwardapi-env-name-namespace-podip
		    Description: Ensure that downward API can provide pod's name, namespace
			and IP address as environment variables.
	*/
	framework.ConformanceIt("should provide pod name, namespace and IP address as env vars ", func() {
		podName := "downward-api-" + string(uuid.NewUUID())
		env := []v1.EnvVar{
			{
				Name: "POD_NAME",
				ValueFrom: &v1.EnvVarSource{
					FieldRef: &v1.ObjectFieldSelector{
						APIVersion: "v1",
						FieldPath:  "metadata.name",
					},
				},
			},
			{
				Name: "POD_NAMESPACE",
				ValueFrom: &v1.EnvVarSource{
					FieldRef: &v1.ObjectFieldSelector{
						APIVersion: "v1",
						FieldPath:  "metadata.namespace",
					},
				},
			},
			{
				Name: "POD_IP",
				ValueFrom: &v1.EnvVarSource{
					FieldRef: &v1.ObjectFieldSelector{
						APIVersion: "v1",
						FieldPath:  "status.podIP",
					},
				},
			},
		}

		expectations := []string{
			fmt.Sprintf("POD_NAME=%v", podName),
			fmt.Sprintf("POD_NAMESPACE=%v", f.Namespace.Name),
			"POD_IP=(?:\\d+)\\.(?:\\d+)\\.(?:\\d+)\\.(?:\\d+)",
		}

		testDownwardAPI(f, podName, env, expectations)
	})

	/*
		    Testname: downwardapi-env-host-ip
		    Description: Ensure that downward API can provide an IP address for
			host node as an environment variable.
	*/
	framework.ConformanceIt("should provide host IP as an env var ", func() {
		framework.SkipUnlessServerVersionGTE(hostIPVersion, f.ClientSet.Discovery())
		podName := "downward-api-" + string(uuid.NewUUID())
		env := []v1.EnvVar{
			{
				Name: "HOST_IP",
				ValueFrom: &v1.EnvVarSource{
					FieldRef: &v1.ObjectFieldSelector{
						APIVersion: "v1",
						FieldPath:  "status.hostIP",
					},
				},
			},
		}

		expectations := []string{
			"HOST_IP=(?:\\d+)\\.(?:\\d+)\\.(?:\\d+)\\.(?:\\d+)",
		}

		testDownwardAPI(f, podName, env, expectations)
	})

	/*
		    Testname: downwardapi-env-limits-requests
		    Description: Ensure that downward API can provide CPU/memory limit
			and CPU/memory request as environment variables.
	*/
	framework.ConformanceIt("should provide container's limits.cpu/memory and requests.cpu/memory as env vars ", func() {
		podName := "downward-api-" + string(uuid.NewUUID())
		env := []v1.EnvVar{
			{
				Name: "CPU_LIMIT",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "limits.cpu",
					},
				},
			},
			{
				Name: "MEMORY_LIMIT",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "limits.memory",
					},
				},
			},
			{
				Name: "CPU_REQUEST",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "requests.cpu",
					},
				},
			},
			{
				Name: "MEMORY_REQUEST",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "requests.memory",
					},
				},
			},
		}
		expectations := []string{
			"CPU_LIMIT=2",
			"MEMORY_LIMIT=67108864",
			"CPU_REQUEST=1",
			"MEMORY_REQUEST=33554432",
		}

		testDownwardAPI(f, podName, env, expectations)
	})

	/*
		    Testname: downwardapi-env-default-allocatable
		    Description: Ensure that downward API can provide default node
			allocatable values for CPU and memory as environment variables if CPU
			and memory limits are not specified for a container.
	*/
	framework.ConformanceIt("should provide default limits.cpu/memory from node allocatable ", func() {
		podName := "downward-api-" + string(uuid.NewUUID())
		env := []v1.EnvVar{
			{
				Name: "CPU_LIMIT",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "limits.cpu",
					},
				},
			},
			{
				Name: "MEMORY_LIMIT",
				ValueFrom: &v1.EnvVarSource{
					ResourceFieldRef: &v1.ResourceFieldSelector{
						Resource: "limits.memory",
					},
				},
			},
		}
		expectations := []string{
			"CPU_LIMIT=[1-9]",
			"MEMORY_LIMIT=[1-9]",
		}
		pod := &v1.Pod{
			ObjectMeta: metav1.ObjectMeta{
				Name:   podName,
				Labels: map[string]string{"name": podName},
			},
			Spec: v1.PodSpec{
				Containers: []v1.Container{
					{
						Name:    "dapi-container",
						Image:   busyboxImage,
						Command: []string{"sh", "-c", "env"},
						Env:     env,
					},
				},
				RestartPolicy: v1.RestartPolicyNever,
			},
		}

		testDownwardAPIUsingPod(f, pod, env, expectations)
	})

	/*
		    Testname: downwardapi-env-pod-uid
		    Description: Ensure that downward API can provide pod UID as an
			environment variable.
	*/
	framework.ConformanceIt("should provide pod UID as env vars ", func() {
		framework.SkipUnlessServerVersionGTE(podUIDVersion, f.ClientSet.Discovery())
		podName := "downward-api-" + string(uuid.NewUUID())
		env := []v1.EnvVar{
			{
				Name: "POD_UID",
				ValueFrom: &v1.EnvVarSource{
					FieldRef: &v1.ObjectFieldSelector{
						APIVersion: "v1",
						FieldPath:  "metadata.uid",
					},
				},
			},
		}

		expectations := []string{
			"POD_UID=[a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12}",
		}

		testDownwardAPI(f, podName, env, expectations)
	})
})

var _ = framework.KubeDescribe("Downward API [Serial] [Disruptive]", func() {
	f := framework.NewDefaultFramework("downward-api")

	Context("Downward API tests for local ephemeral storage", func() {
		BeforeEach(func() {
			framework.SkipUnlessLocalEphemeralStorageEnabled()
		})

		It("should provide container's limits.ephemeral-storage and requests.ephemeral-storage as env vars", func() {
			podName := "downward-api-" + string(uuid.NewUUID())
			env := []v1.EnvVar{
				{
					Name: "EPHEMERAL_STORAGE_LIMIT",
					ValueFrom: &v1.EnvVarSource{
						ResourceFieldRef: &v1.ResourceFieldSelector{
							Resource: "limits.ephemeral-storage",
						},
					},
				},
				{
					Name: "EPHEMERAL_STORAGE_REQUEST",
					ValueFrom: &v1.EnvVarSource{
						ResourceFieldRef: &v1.ResourceFieldSelector{
							Resource: "requests.ephemeral-storage",
						},
					},
				},
			}
			expectations := []string{
				fmt.Sprintf("EPHEMERAL_STORAGE_LIMIT=%d", 64*1024*1024),
				fmt.Sprintf("EPHEMERAL_STORAGE_REQUEST=%d", 32*1024*1024),
			}

			testDownwardAPIForEphemeralStorage(f, podName, env, expectations)
		})

		It("should provide default limits.ephemeral-storage from node allocatable", func() {
			podName := "downward-api-" + string(uuid.NewUUID())
			env := []v1.EnvVar{
				{
					Name: "EPHEMERAL_STORAGE_LIMIT",
					ValueFrom: &v1.EnvVarSource{
						ResourceFieldRef: &v1.ResourceFieldSelector{
							Resource: "limits.ephemeral-storage",
						},
					},
				},
			}
			expectations := []string{
				"EPHEMERAL_STORAGE_LIMIT=[1-9]",
			}
			pod := &v1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name:   podName,
					Labels: map[string]string{"name": podName},
				},
				Spec: v1.PodSpec{
					Containers: []v1.Container{
						{
							Name:    "dapi-container",
							Image:   busyboxImage,
							Command: []string{"sh", "-c", "env"},
							Env:     env,
						},
					},
					RestartPolicy: v1.RestartPolicyNever,
				},
			}

			testDownwardAPIUsingPod(f, pod, env, expectations)
		})
	})

})

func testDownwardAPI(f *framework.Framework, podName string, env []v1.EnvVar, expectations []string) {
	pod := &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Name:   podName,
			Labels: map[string]string{"name": podName},
		},
		Spec: v1.PodSpec{
			Containers: []v1.Container{
				{
					Name:    "dapi-container",
					Image:   busyboxImage,
					Command: []string{"sh", "-c", "env"},
					Resources: v1.ResourceRequirements{
						Requests: v1.ResourceList{
							v1.ResourceCPU:    resource.MustParse("250m"),
							v1.ResourceMemory: resource.MustParse("32Mi"),
						},
						Limits: v1.ResourceList{
							v1.ResourceCPU:    resource.MustParse("1250m"),
							v1.ResourceMemory: resource.MustParse("64Mi"),
						},
					},
					Env: env,
				},
			},
			RestartPolicy: v1.RestartPolicyNever,
		},
	}

	testDownwardAPIUsingPod(f, pod, env, expectations)
}

func testDownwardAPIForEphemeralStorage(f *framework.Framework, podName string, env []v1.EnvVar, expectations []string) {
	pod := &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Name:   podName,
			Labels: map[string]string{"name": podName},
		},
		Spec: v1.PodSpec{
			Containers: []v1.Container{
				{
					Name:    "dapi-container",
					Image:   busyboxImage,
					Command: []string{"sh", "-c", "env"},
					Resources: v1.ResourceRequirements{
						Requests: v1.ResourceList{
							v1.ResourceEphemeralStorage: resource.MustParse("32Mi"),
						},
						Limits: v1.ResourceList{
							v1.ResourceEphemeralStorage: resource.MustParse("64Mi"),
						},
					},
					Env: env,
				},
			},
			RestartPolicy: v1.RestartPolicyNever,
		},
	}

	testDownwardAPIUsingPod(f, pod, env, expectations)
}

func testDownwardAPIUsingPod(f *framework.Framework, pod *v1.Pod, env []v1.EnvVar, expectations []string) {
	f.TestContainerOutputRegexp("downward api env vars", pod, 0, expectations)
}