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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections.Immutable;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using Aspire.Hosting.Dcp.Model;
using k8s;
using k8s.Exceptions;
using k8s.Models;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Polly;
using Polly.Retry;
using YamlDotNet.Core;
namespace Aspire.Hosting.Dcp;
internal enum DcpApiOperationType
{
Create = 1,
List = 2,
Delete = 3,
Watch = 4,
GetLogSubresource = 5,
Get = 6,
Patch = 7
}
internal interface IKubernetesService
{
Task<T> GetAsync<T>(string name, string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T: CustomResource;
Task<T> CreateAsync<T>(T obj, CancellationToken cancellationToken = default)
where T : CustomResource;
Task<T> PatchAsync<T>(T obj, V1Patch patch, CancellationToken cancellationToken = default)
where T : CustomResource;
Task<List<T>> ListAsync<T>(string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T : CustomResource;
Task<T> DeleteAsync<T>(string name, string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T : CustomResource;
IAsyncEnumerable<(WatchEventType, T)> WatchAsync<T>(
string? namespaceParameter = null,
CancellationToken cancellationToken = default)
where T : CustomResource;
Task<Stream> GetLogStreamAsync<T>(
T obj,
string logStreamType,
bool? follow = true,
bool? timestamps = false,
CancellationToken cancellationToken = default) where T : CustomResource;
}
internal sealed class KubernetesService(ILogger<KubernetesService> logger, IOptions<DcpOptions> dcpOptions, Locations locations) : IKubernetesService, IDisposable
{
private static readonly TimeSpan s_initialRetryDelay = TimeSpan.FromMilliseconds(100);
private static GroupVersion GroupVersion => Model.Dcp.GroupVersion;
private readonly SemaphoreSlim _kubeconfigReadSemaphore = new(1);
private DcpKubernetesClient? _kubernetes;
private ResiliencePipeline? _resiliencePipeline;
private bool _disposed;
public TimeSpan MaxRetryDuration { get; set; } = TimeSpan.FromSeconds(20);
public Task<T> GetAsync<T>(string name, string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T : CustomResource
{
var resourceType = GetResourceFor<T>();
return ExecuteWithRetry(
DcpApiOperationType.Get,
resourceType,
async (kubernetes) =>
{
var response = string.IsNullOrEmpty(namespaceParameter)
? await kubernetes.CustomObjects.GetClusterCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
resourceType,
name,
cancellationToken: cancellationToken).ConfigureAwait(false)
: await kubernetes.CustomObjects.GetNamespacedCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
name,
cancellationToken: cancellationToken).ConfigureAwait(false);
return KubernetesJson.Deserialize<T>(response.Body.ToString());
},
cancellationToken);
}
public Task<T> CreateAsync<T>(T obj, CancellationToken cancellationToken = default)
where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
var namespaceParameter = obj.Namespace();
return ExecuteWithRetry(
DcpApiOperationType.Create,
resourceType,
async (kubernetes) =>
{
var response = string.IsNullOrEmpty(namespaceParameter)
? await kubernetes.CustomObjects.CreateClusterCustomObjectWithHttpMessagesAsync(
obj,
GroupVersion.Group,
GroupVersion.Version,
resourceType,
cancellationToken: cancellationToken).ConfigureAwait(false)
: await kubernetes.CustomObjects.CreateNamespacedCustomObjectWithHttpMessagesAsync(
obj,
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
cancellationToken: cancellationToken).ConfigureAwait(false);
return KubernetesJson.Deserialize<T>(response.Body.ToString());
},
cancellationToken);
}
public Task<T> PatchAsync<T>(T obj, V1Patch patch, CancellationToken cancellationToken = default)
where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
var namespaceParameter = obj.Namespace();
return ExecuteWithRetry(
DcpApiOperationType.Patch,
resourceType,
async (kubernetes) =>
{
var response = string.IsNullOrEmpty(namespaceParameter)
? await kubernetes.CustomObjects.PatchClusterCustomObjectWithHttpMessagesAsync(
patch,
GroupVersion.Group,
GroupVersion.Version,
resourceType,
obj.Metadata.Name,
cancellationToken: cancellationToken).ConfigureAwait(false)
: await kubernetes.CustomObjects.PatchNamespacedCustomObjectWithHttpMessagesAsync(
patch,
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
obj.Metadata.Name,
cancellationToken: cancellationToken).ConfigureAwait(false);
return KubernetesJson.Deserialize<T>(response.Body.ToString());
},
cancellationToken);
}
public Task<List<T>> ListAsync<T>(string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
return ExecuteWithRetry(
DcpApiOperationType.List,
resourceType,
async (kubernetes) =>
{
var response = string.IsNullOrEmpty(namespaceParameter)
? await kubernetes.CustomObjects.ListClusterCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
resourceType,
cancellationToken: cancellationToken).ConfigureAwait(false)
: await kubernetes.CustomObjects.ListNamespacedCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
cancellationToken: cancellationToken).ConfigureAwait(false);
return KubernetesJson.Deserialize<CustomResourceList<T>>(response.Body.ToString()).Items;
},
cancellationToken);
}
public Task<T> DeleteAsync<T>(string name, string? namespaceParameter = null, CancellationToken cancellationToken = default)
where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
return ExecuteWithRetry(
DcpApiOperationType.Delete,
resourceType,
async (kubernetes) =>
{
var response = string.IsNullOrEmpty(namespaceParameter)
? await kubernetes.CustomObjects.DeleteClusterCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
resourceType,
name,
cancellationToken: cancellationToken).ConfigureAwait(false)
: await kubernetes.CustomObjects.DeleteNamespacedCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
name,
cancellationToken: cancellationToken).ConfigureAwait(false);
return KubernetesJson.Deserialize<T>(response.Body.ToString());
},
cancellationToken);
}
public async IAsyncEnumerable<(WatchEventType, T)> WatchAsync<T>(
string? namespaceParameter = null,
[EnumeratorCancellation] CancellationToken cancellationToken = default)
where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
var result = await ExecuteWithRetry(
DcpApiOperationType.Watch,
resourceType,
(kubernetes) =>
{
var responseTask = string.IsNullOrEmpty(namespaceParameter)
? kubernetes.CustomObjects.ListClusterCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
resourceType,
watch: true,
cancellationToken: cancellationToken)
: kubernetes.CustomObjects.ListNamespacedCustomObjectWithHttpMessagesAsync(
GroupVersion.Group,
GroupVersion.Version,
namespaceParameter,
resourceType,
watch: true,
cancellationToken: cancellationToken);
return responseTask.WatchAsync<T, object>(null, cancellationToken);
},
cancellationToken).ConfigureAwait(false);
await foreach (var item in result.ConfigureAwait(false))
{
yield return item;
}
}
public Task<Stream> GetLogStreamAsync<T>(
T obj,
string logStreamType,
bool? follow = true,
bool? timestamps = false,
CancellationToken cancellationToken = default) where T : CustomResource
{
ObjectDisposedException.ThrowIf(_disposed, this);
var resourceType = GetResourceFor<T>();
ImmutableArray<(string name, string value)>? queryParams = [
(name: "follow", value: follow == true ? "true": "false"),
(name: "timestamps", value: timestamps == true ? "true" : "false"),
(name: "source", value: logStreamType)
];
return ExecuteWithRetry(
DcpApiOperationType.GetLogSubresource,
resourceType,
async (kubernetes) =>
{
var response = await kubernetes.ReadSubResourceAsStreamAsync(
GroupVersion.Group,
GroupVersion.Version,
resourceType,
obj.Metadata.Name,
Logs.SubResourceName,
obj.Metadata.Namespace(),
queryParams,
cancellationToken
).ConfigureAwait(false);
return response.Body;
},
cancellationToken
);
}
public void Dispose()
{
_disposed = true;
_kubeconfigReadSemaphore?.Dispose();
_kubernetes?.Dispose();
}
private static string GetResourceFor<T>() where T : CustomResource
{
if (!Model.Dcp.Schema.TryGet<T>(out var kindWithResource))
{
throw new InvalidOperationException($"Unknown custom resource type: {typeof(T).Name}");
}
return kindWithResource.Resource;
}
private Task<TResult> ExecuteWithRetry<TResult>(
DcpApiOperationType operationType,
string resourceType,
Func<DcpKubernetesClient, TResult> operation,
CancellationToken cancellationToken)
{
return ExecuteWithRetry<TResult>(
operationType,
resourceType,
(DcpKubernetesClient kubernetes) => Task.FromResult(operation(kubernetes)),
cancellationToken);
}
private async Task<TResult> ExecuteWithRetry<TResult>(
DcpApiOperationType operationType,
string resourceType,
Func<DcpKubernetesClient, Task<TResult>> operation,
CancellationToken cancellationToken)
{
var currentTimestamp = DateTime.UtcNow;
var delay = s_initialRetryDelay;
AspireEventSource.Instance.DcpApiCallStart(operationType, resourceType);
try
{
while (true)
{
ObjectDisposedException.ThrowIf(_disposed, this);
try
{
await EnsureKubernetesAsync(cancellationToken).ConfigureAwait(false);
return await operation(_kubernetes!).ConfigureAwait(false);
}
catch (Exception e) when (IsRetryable(e))
{
if (DateTime.UtcNow.Subtract(currentTimestamp) > MaxRetryDuration)
{
AspireEventSource.Instance.DcpApiCallTimeout(operationType, resourceType);
throw;
}
await Task.Delay(delay, cancellationToken).ConfigureAwait(false);
delay *= 2;
AspireEventSource.Instance.DcpApiCallRetry(operationType, resourceType);
}
}
}
finally
{
AspireEventSource.Instance.DcpApiCallStop(operationType, resourceType);
}
}
private static bool IsRetryable(Exception ex) => ex is HttpRequestException || ex is KubeConfigException;
private ResiliencePipeline GetReadKubeconfigResiliencePipeline()
{
if (_resiliencePipeline == null)
{
var configurationReadRetry = new RetryStrategyOptions()
{
// Handle exceptions caused by races between writing and reading the configuration file.
// If the file is loaded while it is still being written, this can result in a YamlException being thrown.
ShouldHandle = new PredicateBuilder().Handle<KubeConfigException>().Handle<YamlException>(),
BackoffType = DelayBackoffType.Constant,
MaxRetryAttempts = dcpOptions.Value.KubernetesConfigReadRetryCount,
MaxDelay = TimeSpan.FromMilliseconds(dcpOptions.Value.KubernetesConfigReadRetryIntervalMilliseconds),
OnRetry = (retry) =>
{
logger.LogDebug(
"Waiting for Kubernetes configuration file at '{DcpKubeconfigPath}' (attempt {Iteration}).",
locations.DcpKubeconfigPath,
retry.AttemptNumber
);
return ValueTask.CompletedTask;
}
};
_resiliencePipeline = new ResiliencePipelineBuilder().AddRetry(configurationReadRetry).Build();
}
return _resiliencePipeline;
}
private async Task EnsureKubernetesAsync(CancellationToken cancellationToken = default)
{
ObjectDisposedException.ThrowIf(_disposed, this);
// Return early before waiting for the semaphore if we can.
if (_kubernetes != null)
{
return;
}
await _kubeconfigReadSemaphore.WaitAsync(-1, cancellationToken).ConfigureAwait(false);
try
{
// Second chance shortcut if multiple threads got caught.
if (_kubernetes != null)
{
return;
}
// We retry reading the kubeconfig file because DCP takes a few moments to write
// it to disk. This retry pipeline will only be invoked by a single thread the
// rest will be held at the semaphore.
var readStopwatch = new Stopwatch();
readStopwatch.Start();
var pipeline = GetReadKubeconfigResiliencePipeline();
_kubernetes = await pipeline.ExecuteAsync<DcpKubernetesClient>(async (cancellationToken) =>
{
var fileInfo = new FileInfo(locations.DcpKubeconfigPath);
while (!fileInfo.Exists)
{
await Task.Delay(TimeSpan.FromMilliseconds(dcpOptions.Value.KubernetesConfigReadRetryIntervalMilliseconds), cancellationToken).ConfigureAwait(false);
fileInfo = new FileInfo(locations.DcpKubeconfigPath);
}
var config = await KubernetesClientConfiguration.BuildConfigFromConfigFileAsync(kubeconfig: fileInfo, useRelativePaths: false).ConfigureAwait(false);
readStopwatch.Stop();
logger.LogDebug(
"Successfully read Kubernetes configuration from '{DcpKubeconfigPath}' after {DurationMs} milliseconds.",
locations.DcpKubeconfigPath,
readStopwatch.ElapsedMilliseconds
);
return new DcpKubernetesClient(config);
}, cancellationToken).ConfigureAwait(false);
}
finally
{
_kubeconfigReadSemaphore.Release();
}
}
}
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