csharp/tests/KubernetesClient.Tests/Util/MockKubeApiServerOptions.cs

using System;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using k8s.Models;
using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Nito.AsyncEx;

namespace k8s.Tests.Util
{
    /// <summary>
    /// Flags to configure how the server will respond to requests
    /// </summary>
    [Flags]
    public enum MockKubeServerFlags
    {
        /// <summary>
        /// No flag
        /// </summary>
        None = 0,

        /// <summary>
        /// Include a response with malformed json
        /// </summary>
        BadJson = 1,

        /// <summary>
        /// Include a pod added response
        /// </summary>
        AddedPod = 2,

        /// <summary>
        /// Include a pod delete response
        /// </summary>
        DeletedPod = 4,

        /// <summary>
        /// Include a pod modified response
        /// </summary>
        ModifiedPod = 8,

        /// <summary>
        /// Include a pod error response
        /// </summary>
        ErrorPod = 16,

        /// <summary>
        /// Include a response of pod list
        /// </summary>
        ListPods = 32,

        /// <summary>
        /// Include a reponse of get pod
        /// </summary>
        GetPod = 64,

        /// <summary>
        /// Throw a 500 Http status code on any request
        /// </summary>
        Throw500 = 128,
    }

    internal class MockKubeApiServerOptions
    {
        // paste from minikube /api/v1/namespaces/default/pods
        public const string MockPodResponse =
            "{\r\n  \"kind\": \"PodList\",\r\n  \"apiVersion\": \"v1\",\r\n  \"metadata\": {\r\n    \"selfLink\": \"/api/v1/namespaces/default/pods\",\r\n    \"resourceVersion\": \"1762810\"\r\n  },\r\n  \"items\": [\r\n    {\r\n      \"metadata\": {\r\n        \"name\": \"nginx-1493591563-xb2v4\",\r\n        \"generateName\": \"nginx-1493591563-\",\r\n        \"namespace\": \"default\",\r\n        \"selfLink\": \"/api/v1/namespaces/default/pods/nginx-1493591563-xb2v4\",\r\n        \"uid\": \"ac1abb94-9c58-11e7-aaf5-00155d744505\",\r\n        \"resourceVersion\": \"1737928\",\r\n        \"creationTimestamp\": \"2017-09-18T10:03:51Z\",\r\n        \"labels\": {\r\n          \"app\": \"nginx\",\r\n          \"pod-template-hash\": \"1493591563\"\r\n        },\r\n        \"annotations\": {\r\n          \"kubernetes.io/created-by\": \"{\\\"kind\\\":\\\"SerializedReference\\\",\\\"apiVersion\\\":\\\"v1\\\",\\\"reference\\\":{\\\"kind\\\":\\\"ReplicaSet\\\",\\\"namespace\\\":\\\"default\\\",\\\"name\\\":\\\"nginx-1493591563\\\",\\\"uid\\\":\\\"ac013b63-9c58-11e7-aaf5-00155d744505\\\",\\\"apiVersion\\\":\\\"extensions\\\",\\\"resourceVersion\\\":\\\"5306\\\"}}\\n\"\r\n        },\r\n        \"ownerReferences\": [\r\n          {\r\n            \"apiVersion\": \"extensions/v1beta1\",\r\n            \"kind\": \"ReplicaSet\",\r\n            \"name\": \"nginx-1493591563\",\r\n            \"uid\": \"ac013b63-9c58-11e7-aaf5-00155d744505\",\r\n            \"controller\": true,\r\n            \"blockOwnerDeletion\": true\r\n          }\r\n        ]\r\n      },\r\n      \"spec\": {\r\n        \"volumes\": [\r\n          {\r\n            \"name\": \"default-token-3zzcj\",\r\n            \"secret\": {\r\n              \"secretName\": \"default-token-3zzcj\",\r\n              \"defaultMode\": 420\r\n            }\r\n          }\r\n        ],\r\n        \"containers\": [\r\n          {\r\n            \"name\": \"nginx\",\r\n            \"image\": \"nginx\",\r\n            \"resources\": {},\r\n            \"volumeMounts\": [\r\n              {\r\n                \"name\": \"default-token-3zzcj\",\r\n                \"readOnly\": true,\r\n                \"mountPath\": \"/var/run/secrets/kubernetes.io/serviceaccount\"\r\n              }\r\n            ],\r\n            \"terminationMessagePath\": \"/dev/termination-log\",\r\n            \"terminationMessagePolicy\": \"File\",\r\n            \"imagePullPolicy\": \"Always\"\r\n          }\r\n        ],\r\n        \"restartPolicy\": \"Always\",\r\n        \"terminationGracePeriodSeconds\": 30,\r\n        \"dnsPolicy\": \"ClusterFirst\",\r\n        \"serviceAccountName\": \"default\",\r\n        \"serviceAccount\": \"default\",\r\n        \"nodeName\": \"ubuntu\",\r\n        \"securityContext\": {},\r\n        \"schedulerName\": \"default-scheduler\"\r\n      },\r\n      \"status\": {\r\n        \"phase\": \"Running\",\r\n        \"conditions\": [\r\n          {\r\n            \"type\": \"Initialized\",\r\n            \"status\": \"True\",\r\n            \"lastProbeTime\": null,\r\n            \"lastTransitionTime\": \"2017-09-18T10:03:51Z\"\r\n          },\r\n          {\r\n            \"type\": \"Ready\",\r\n            \"status\": \"True\",\r\n            \"lastProbeTime\": null,\r\n            \"lastTransitionTime\": \"2017-10-12T07:09:21Z\"\r\n          },\r\n          {\r\n            \"type\": \"PodScheduled\",\r\n            \"status\": \"True\",\r\n            \"lastProbeTime\": null,\r\n            \"lastTransitionTime\": \"2017-09-18T10:03:51Z\"\r\n          }\r\n        ],\r\n        \"hostIP\": \"192.168.188.42\",\r\n        \"podIP\": \"172.17.0.5\",\r\n        \"startTime\": \"2017-09-18T10:03:51Z\",\r\n        \"containerStatuses\": [\r\n          {\r\n            \"name\": \"nginx\",\r\n            \"state\": {\r\n              \"running\": {\r\n                \"startedAt\": \"2017-10-12T07:09:20Z\"\r\n              }\r\n            },\r\n            \"lastState\": {\r\n              \"terminated\": {\r\n                \"exitCode\": 0,\r\n                \"reason\": \"Completed\",\r\n                \"startedAt\": \"2017-10-10T21:35:51Z\",\r\n                \"finishedAt\": \"2017-10-12T07:07:37Z\",\r\n                \"containerID\": \"docker://94df3f3965807421ad6dc76618e00b76cb15d024919c4946f3eb46a92659c62a\"\r\n              }\r\n            },\r\n            \"ready\": true,\r\n            \"restartCount\": 7,\r\n            \"image\": \"nginx:latest\",\r\n            \"imageID\": \"docker-pullable://nginx@sha256:004ac1d5e791e705f12a17c80d7bb1e8f7f01aa7dca7deee6e65a03465392072\",\r\n            \"containerID\": \"docker://fa11bdd48c9b7d3a6c4c3f9b6d7319743c3455ab8d00c57d59c083b319b88194\"\r\n          }\r\n        ],\r\n        \"qosClass\": \"BestEffort\"\r\n      }\r\n    }\r\n  ]\r\n}";

        public AsyncManualResetEvent ServerShutdown { get; private set; }

        private readonly MockKubeServerFlags _serverFlags;
        private readonly string _mockAddedEventStreamLine = BuildWatchEventStreamLine(WatchEventType.Added);
        private readonly string _mockDeletedStreamLine = BuildWatchEventStreamLine(WatchEventType.Deleted);
        private readonly string _mockModifiedStreamLine = BuildWatchEventStreamLine(WatchEventType.Modified);
        private readonly string _mockErrorStreamLine = BuildWatchEventStreamLine(WatchEventType.Error);
        private const string MockBadStreamLine = "bad json";

        public MockKubeApiServerOptions(MockKubeServerFlags? serverFlags)
        {
            _serverFlags = serverFlags ?? MockKubeServerFlags.None;
        }

        private static string BuildWatchEventStreamLine(WatchEventType eventType)
        {
            var corev1PodList = JsonConvert.DeserializeObject<V1PodList>(MockPodResponse);
            return JsonConvert.SerializeObject(
                new Watcher<V1Pod>.WatchEvent { Type = eventType, Object = corev1PodList.Items.First() },
                new StringEnumConverter());
        }

        private async Task WriteStreamLine(HttpContext httpContext, string reponseLine)
        {
            const string crlf = "\r\n";
            await httpContext.Response.WriteAsync(reponseLine.Replace(crlf, "")).ConfigureAwait(false);
            await httpContext.Response.WriteAsync(crlf).ConfigureAwait(false);
            await httpContext.Response.Body.FlushAsync().ConfigureAwait(false);
        }

        public async Task<bool> ShouldNext(HttpContext httpContext)
        {
            var isWatch = (httpContext.Request.Query.ContainsKey("watch") && httpContext.Request.Query["watch"] == "true");
            var returnStatusCode = (_serverFlags.HasFlag(MockKubeServerFlags.Throw500) ? HttpStatusCode.InternalServerError : HttpStatusCode.OK);

            httpContext.Response.StatusCode = (int)returnStatusCode;
            httpContext.Response.ContentLength = null;

            if (isWatch)
            {
                ServerShutdown = new AsyncManualResetEvent();

                foreach (Enum flag in Enum.GetValues(_serverFlags.GetType()))
                {
                    if (!_serverFlags.HasFlag(flag))
                    {
                        continue;
                    }

                    switch (flag)
                    {
                        case MockKubeServerFlags.AddedPod:
                            await WriteStreamLine(httpContext, _mockAddedEventStreamLine).ConfigureAwait(false);
                            break;
                        case MockKubeServerFlags.ErrorPod:
                            await WriteStreamLine(httpContext, _mockErrorStreamLine).ConfigureAwait(false);
                            break;
                        case MockKubeServerFlags.DeletedPod:
                            await WriteStreamLine(httpContext, _mockDeletedStreamLine).ConfigureAwait(false);
                            break;
                        case MockKubeServerFlags.ModifiedPod:
                            await WriteStreamLine(httpContext, _mockModifiedStreamLine).ConfigureAwait(false);
                            break;
                        case MockKubeServerFlags.BadJson:
                            await WriteStreamLine(httpContext, MockBadStreamLine).ConfigureAwait(false);
                            break;
                        case MockKubeServerFlags.Throw500:
                            return false;
                    }
                }

                // keep server connection open
                await ServerShutdown.WaitAsync().ConfigureAwait(false);
                return false;
            }

            foreach (Enum flag in Enum.GetValues(_serverFlags.GetType()))
            {
                if (!_serverFlags.HasFlag(flag))
                {
                    continue;
                }

                switch (flag)
                {
                    case MockKubeServerFlags.ListPods:
                        await WriteStreamLine(httpContext, MockPodResponse).ConfigureAwait(false);
                        break;
                    case MockKubeServerFlags.GetPod:
                        var corev1PodList = JsonConvert.DeserializeObject<V1PodList>(MockPodResponse);
                        await WriteStreamLine(httpContext, JsonConvert.SerializeObject(corev1PodList.Items.First())).ConfigureAwait(false);
                        break;
                    case MockKubeServerFlags.Throw500:
                        return false;
                }
            }

            return false;
        }
    }
}