adding health checks

src/Microsoft.Tye.Core/ApplicationFactory.cs

@@ -96,6 +96,9 @@ public static async Task<ApplicationBuilder> CreateAsync(OutputContext output, F
                         }
                         project.Replicas = configService.Replicas ?? 1;
 
+                        project.Liveness = configService.Liveness != null ? GetProbeBuilder(configService.Liveness) : null;
+                        project.Readiness = configService.Readiness != null ? GetProbeBuilder(configService.Readiness) : null;
+
                         // We don't apply more container defaults here because we might need
                         // to prompt for the registry name.
                         project.ContainerInfo = new ContainerInfo() { UseMultiphaseDockerfile = false, };
@@ -115,6 +118,9 @@ public static async Task<ApplicationBuilder> CreateAsync(OutputContext output, F
                             DockerFileContext = configService.DockerFileContext != null ? Path.Combine(source.DirectoryName, configService.DockerFileContext) : null
                         };
                         service = container;
+
+                        container.Liveness = configService.Liveness != null ? GetProbeBuilder(configService.Liveness) : null;
+                        container.Readiness = configService.Readiness != null ? GetProbeBuilder(configService.Readiness) : null;
                     }
                     else if (!string.IsNullOrEmpty(configService.Executable))
                     {
@@ -137,6 +143,9 @@ public static async Task<ApplicationBuilder> CreateAsync(OutputContext output, F
                             Replicas = configService.Replicas ?? 1
                         };
                         service = executable;
+
+                        executable.Liveness = configService.Liveness != null ? GetProbeBuilder(configService.Liveness) : null;
+                        executable.Readiness = configService.Readiness != null ? GetProbeBuilder(configService.Readiness) : null;
                     }
                     else if (!string.IsNullOrEmpty(configService.Include))
                     {
@@ -351,5 +360,23 @@ private static void AddToRootServices(ApplicationBuilder root, HashSet<string> d
                 }
             }
         }
+
+        private static ProbeBuilder GetProbeBuilder(ConfigProbe config) => new ProbeBuilder()
+        {
+            Http = config.Http != null ? GetHttpProberBuilder(config.Http) : null,
+            InitialDelay = config.InitialDelay,
+            Period = config.Period,
+            Timeout = config.Timeout,
+            SuccessThreshold = config.SuccessThreshold,
+            FailureThreshold = config.FailureThreshold
+        };
+
+        private static HttpProberBuilder GetHttpProberBuilder(ConfigHttpProber config) => new HttpProberBuilder()
+        {
+            Path = config.Path,
+            Headers = config.Headers,
+            Port = config.Port,
+            Protocol = config.Protocol
+        };
     }
 }

src/Microsoft.Tye.Core/ConfigModel/ConfigApplication.cs

@@ -135,6 +135,21 @@ public void Validate()
                             string.Join(Environment.NewLine, results.Select(r => r.ErrorMessage)));
                     }
                 }
+
+                var probes = new[] { (Name: "liveness", Probe: service.Liveness), (Name: "readiness", Probe: service.Readiness) }.Where(p => p.Probe != null).ToArray();
+                foreach (var probe in probes)
+                {
+                    if (probe.Name == "liveness" && probe.Probe.SuccessThreshold != 1)
+                    {
+                        throw new TyeYamlException(CoreStrings.FormatSuccessThresholdMustBeOne(probe.Name));
+                    }
+
+                    // right now only http is supported, so it must be set
+                    if (probe.Probe!.Http is null)
+                    {
+                        throw new TyeYamlException(CoreStrings.FormatProberRequired(probe.Name));
+                    }
+                }
             }
 
             foreach (var ingress in config.Ingress)

src/Microsoft.Tye.Core/ConfigModel/ConfigHttpProber.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Net.Http.Headers;
+
+namespace Microsoft.Tye.ConfigModel
+{
+    public class ConfigHttpProber
+    {
+        [Required] public string Path { get; set; } = default!;
+        public int? Port { get; set; }
+        public string? Protocol { get; set; }
+        public List<KeyValuePair<string, object>> Headers { get; set; } = new List<KeyValuePair<string, object>>();
+    }
+}

src/Microsoft.Tye.Core/ConfigModel/ConfigProbe.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Tye.ConfigModel
+{
+    public class ConfigProbe
+    {
+        public ConfigHttpProber? Http { get; set; }
+        public int InitialDelay { get; set; } = 0;
+        public int Period { get; set; } = 1;
+        public int Timeout { get; set; } = 1;
+        public int SuccessThreshold { get; set; } = 1;
+        public int FailureThreshold { get; set; } = 3;
+    }
+}

src/Microsoft.Tye.Core/ConfigModel/ConfigService.cs

@@ -29,5 +29,7 @@ public class ConfigService
         [YamlMember(Alias = "env")]
         public List<ConfigConfigurationSource> Configuration { get; set; } = new List<ConfigConfigurationSource>();
         public List<BuildProperty> BuildProperties { get; set; } = new List<BuildProperty>();
+        public ConfigProbe? Liveness { get; set; }
+        public ConfigProbe? Readiness { get; set; }
     }
 }

src/Microsoft.Tye.Core/ContainerServiceBuilder.cs

@@ -29,5 +29,8 @@ public ContainerServiceBuilder(string name, string image)
         public List<EnvironmentVariableBuilder> EnvironmentVariables { get; } = new List<EnvironmentVariableBuilder>();
 
         public List<VolumeBuilder> Volumes { get; } = new List<VolumeBuilder>();
+
+        public ProbeBuilder? Liveness { get; set; }
+        public ProbeBuilder? Readiness { get; set; }
     }
 }

src/Microsoft.Tye.Core/CoreStrings.resx

@@ -141,6 +141,12 @@
   <data name="MultipleBindingWithSamePort" xml:space="preserve">
     <value>Cannot have multiple {0} bindings with the same port.</value>
   </data>
+    <data name="ProberRequired" xml:space="preserve">
+        <value>A prober must be configured for the {0} probe.</value>
+    </data>
+    <data name="SuccessThresholdMustBeOne" xml:space="preserve">
+        <value>successThreshold for {0} probe must be one.</value>
+    </data>
   <data name="MustBeABoolean" xml:space="preserve">
     <value>"{value}" must be a boolean value (true/false).</value>
   </data>
@@ -150,6 +156,9 @@
   <data name="MustBePositive" xml:space="preserve">
     <value>"{value}" value cannot be negative.</value>
   </data>
+    <data name="MustBeGreaterThanZero" xml:space="preserve">
+        <value>"{value}" value must be greater than zero.</value>
+    </data>
   <data name="ProjectImageExecutableExclusive" xml:space="preserve">
     <value>Cannot have both "{0}" and "{1}" set for a service. Only one of project, image, and executable can be set for a given service.</value>
   </data>

src/Microsoft.Tye.Core/ExecutableServiceBuilder.cs

@@ -23,5 +23,8 @@ public ExecutableServiceBuilder(string name, string executable)
         public int Replicas { get; set; } = 1;
 
         public List<EnvironmentVariableBuilder> EnvironmentVariables { get; } = new List<EnvironmentVariableBuilder>();
+
+        public ProbeBuilder? Liveness { get; set; }
+        public ProbeBuilder? Readiness { get; set; }
     }
 }

src/Microsoft.Tye.Core/HttpProberBuilder.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+
+namespace Microsoft.Tye
+{
+    public class HttpProberBuilder
+    {
+        public string Path { get; set; } = default!;
+        public int? Port { get; set; }
+        public string? Protocol { get; set; }
+        public List<KeyValuePair<string, object>> Headers { get; set; } = new List<KeyValuePair<string, object>>();
+    }
+}

src/Microsoft.Tye.Core/KubernetesManifestGenerator.cs

@@ -378,6 +378,16 @@ public static KubernetesDeploymentOutput CreateDeployment(
                         }
                     }
                 }
+
+                if (project.Liveness != null)
+                {
+                    AddProbe(project, container, project.Liveness!, "livenessProbe");
+                }
+
+                if (project.Readiness != null)
+                {
+                    AddProbe(project, container, project.Readiness!, "readinessProbe");
+                }
             }
 
             foreach (var sidecar in project.Sidecars)
@@ -452,6 +462,64 @@ public static KubernetesDeploymentOutput CreateDeployment(
             return new KubernetesDeploymentOutput(project.Name, new YamlDocument(root));
         }
 
+        private static void AddProbe(ServiceBuilder service, YamlMappingNode container, ProbeBuilder builder, string name)
+        {
+            var probe = new YamlMappingNode();
+            container.Add(name, probe);
+
+            if (builder.Http != null)
+            {
+                var builderHttp = builder.Http!;
+                var httpGet = new YamlMappingNode();
+
+                probe.Add("httpGet", httpGet);
+                httpGet.Add("path", builderHttp.Path);
+
+                if (builderHttp.Protocol != null)
+                {
+                    httpGet.Add("scheme", builderHttp.Protocol!.ToUpper());
+                }
+
+                if (builderHttp.Port != null)
+                {
+                    httpGet.Add("port", builderHttp.Port!.ToString()!);
+                }
+                else
+                {
+                    // If port is not given, we pull default port
+                    var binding = service.Bindings.First(b => builderHttp.Protocol is null || b.Protocol == builderHttp.Protocol);
+                    if (binding.Port != null)
+                    {
+                        httpGet.Add("port", binding.Port.Value.ToString());
+                    }
+
+                    if (builderHttp.Protocol is null && binding.Protocol != null)
+                    {
+                        httpGet.Add("scheme", binding.Protocol.ToUpper());
+                    }
+                }
+
+                if (builderHttp.Headers.Count > 0)
+                {
+                    var headers = new YamlSequenceNode();
+                    httpGet.Add("httpHeaders", headers);
+
+                    foreach (var builderHeader in builderHttp.Headers)
+                    {
+                        var header = new YamlMappingNode();
+                        header.Add("name", builderHeader.Key);
+                        header.Add("value", builderHeader.Value.ToString()!);
+                        headers.Add(header);
+                    }
+                }
+            }
+
+            probe.Add("initialDelaySeconds", builder.InitialDelay.ToString()!);
+            probe.Add("periodSeconds", builder.Period.ToString()!);
+            probe.Add("successThreshold", builder.SuccessThreshold.ToString()!);
+            probe.Add("failureThreshold", builder.FailureThreshold.ToString()!);
+        }
+
         private static void AddEnvironmentVariablesForComputedBindings(YamlSequenceNode env, ComputedBindings bindings)
         {
             foreach (var binding in bindings.Bindings.OfType<EnvironmentVariableInputBinding>())

src/Microsoft.Tye.Core/ProbeBuilder.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Tye
+{
+    public class ProbeBuilder
+    {
+        public HttpProberBuilder? Http { get; set; }
+        public int InitialDelay { get; set; }
+        public int Period { get; set; }
+        public int Timeout { get; set; }
+        public int SuccessThreshold { get; set; }
+        public int FailureThreshold { get; set; }
+    }
+}

src/Microsoft.Tye.Core/ProjectServiceBuilder.cs

@@ -54,5 +54,8 @@ public ProjectServiceBuilder(string name, FileInfo projectFile)
         public Dictionary<string, string> BuildProperties { get; } = new Dictionary<string, string>();
 
         public List<SidecarBuilder> Sidecars { get; } = new List<SidecarBuilder>();
+
+        public ProbeBuilder? Liveness { get; set; }
+        public ProbeBuilder? Readiness { get; set; }
     }
 }