feat: implement healthcheck support

plugins/app-json/appjson.go

@@ -65,6 +65,42 @@ type Formation struct {
 	// MaxParallel is the maximum number of processes to start in parallel
 	MaxParallel *int `json:"max_parallel"`
 }
+type Healthcheck struct {
+	Attempts     int32           `json:"attempts,omitempty"`
+	Command      []string        `json:"command,omitempty"`
+	Content      string          `json:"content,omitempty"`
+	HTTPHeaders  []HTTPHeader    `json:"httpHeaders,omitempty"`
+	InitialDelay int32           `json:"initialDelay,omitempty"`
+	Listening    bool            `json:"listening,omitempty"`
+	Name         string          `json:"name,omitempty"`
+	Path         string          `json:"path,omitempty"`
+	Port         int             `json:"port,omitempty"`
+	Scheme       string          `json:"scheme,omitempty"`
+	Timeout      int32           `json:"timeout,omitempty"`
+	Type         HealthcheckType `json:"type,omitempty"`
+	Uptime       int32           `json:"uptime,omitempty"`
+	Wait         int32           `json:"wait,omitempty"`
+	Warn         bool            `json:"warn,omitempty"`
+	OnFailure    *OnFailure      `json:"onFailure,omitempty"`
+}
+
+type HealthcheckType string
+
+const (
+	HealthcheckType_Liveness  HealthcheckType = "liveness"
+	HealthcheckType_Readiness HealthcheckType = "readiness"
+	HealthcheckType_Startup   HealthcheckType = "startup"
+)
+
+type HTTPHeader struct {
+	Name  string `json:"name,omitempty"`
+	Value string `json:"value,omitempty"`
+}
+
+type OnFailure struct {
+	Command []string `json:"command,omitempty"`
+	Url     string   `json:"url,omitempty"`
+}
 
 // Healthcheck is a struct that represents a single healthcheck from an app.json file
 type Healthcheck struct {

plugins/scheduler-k3s/template.go

@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	appjson "github.com/dokku/dokku/plugins/app-json"
 	"github.com/dokku/dokku/plugins/common"
 	traefikv1alpha1 "github.com/traefik/traefik/v2/pkg/provider/kubernetes/crd/traefikio/v1alpha1"
 	orderedmap "github.com/wk8/go-ordered-map/v2"
@@ -45,6 +46,7 @@ type Deployment struct {
 	Image            string
 	ImagePullSecrets string
 	ImageSourceType  string
+	Healthchecks     []appjson.Healthcheck
 	Namespace        string
 	PrimaryPort      int32
 	PortMaps         []PortMap
@@ -402,6 +404,89 @@ func templateKubernetesDeployment(input Deployment) (appsv1.Deployment, error) {
 		deployment.Spec.Template.Spec.Containers[0].Args = input.Command
 	}
 
+	if len(input.Healthchecks) > 0 {
+		livenessChecks := []corev1.Probe{}
+		readinessChecks := []corev1.Probe{}
+		startupChecks := []corev1.Probe{}
+		uptimeSeconds := []int32{}
+		for _, healthcheck := range input.Healthchecks {
+			probe := corev1.Probe{
+				ProbeHandler:        corev1.ProbeHandler{},
+				InitialDelaySeconds: healthcheck.InitialDelay,
+				PeriodSeconds:       healthcheck.Wait,
+				TimeoutSeconds:      healthcheck.Timeout,
+				FailureThreshold:    healthcheck.Attempts,
+				SuccessThreshold:    int32(1),
+			}
+			if len(healthcheck.Command) > 0 {
+				probe.ProbeHandler.Exec = &corev1.ExecAction{
+					Command: healthcheck.Command,
+				}
+			} else if healthcheck.Listening {
+				probe.ProbeHandler.TCPSocket = &corev1.TCPSocketAction{
+					Port: intstr.FromInt32(input.PrimaryPort),
+				}
+				for _, header := range healthcheck.HTTPHeaders {
+					if header.Name == "Host" {
+						probe.ProbeHandler.TCPSocket.Host = header.Value
+					}
+				}
+			} else if healthcheck.Path != "" {
+				probe.ProbeHandler.HTTPGet = &corev1.HTTPGetAction{
+					Path:        healthcheck.Path,
+					Port:        intstr.FromInt32(input.PrimaryPort),
+					HTTPHeaders: []corev1.HTTPHeader{},
+				}
+
+				if healthcheck.Scheme != "" {
+					probe.ProbeHandler.HTTPGet.Scheme = corev1.URIScheme(strings.ToUpper(healthcheck.Scheme))
+				}
+
+				for _, header := range healthcheck.HTTPHeaders {
+					probe.ProbeHandler.HTTPGet.HTTPHeaders = append(probe.ProbeHandler.HTTPGet.HTTPHeaders, corev1.HTTPHeader{
+						Name:  header.Name,
+						Value: header.Value,
+					})
+				}
+			} else if healthcheck.Uptime > 0 {
+				uptimeSeconds = append(uptimeSeconds, healthcheck.Uptime)
+			}
+
+			if healthcheck.Type == appjson.HealthcheckType_Liveness {
+				livenessChecks = append(livenessChecks, probe)
+			} else if healthcheck.Type == appjson.HealthcheckType_Readiness {
+				readinessChecks = append(readinessChecks, probe)
+			} else if healthcheck.Type == appjson.HealthcheckType_Startup {
+				startupChecks = append(startupChecks, probe)
+			}
+		}
+		if len(livenessChecks) > 1 {
+			common.LogWarn("Multiple liveness checks are not supported, only the first one will be used")
+		}
+		if len(readinessChecks) > 1 {
+			common.LogWarn("Multiple readiness checks are not supported, only the first one will be used")
+		}
+		if len(startupChecks) > 1 {
+			common.LogWarn("Multiple startup checks are not supported, only the first one will be used")
+		}
+		if len(uptimeSeconds) > 1 {
+			common.LogWarn("Multiple uptime checks are not supported, only the first one will be used")
+		}
+
+		if len(livenessChecks) > 0 {
+			deployment.Spec.Template.Spec.Containers[0].LivenessProbe = &livenessChecks[0]
+		}
+		if len(readinessChecks) > 0 {
+			deployment.Spec.Template.Spec.Containers[0].ReadinessProbe = &readinessChecks[0]
+		}
+		if len(startupChecks) > 0 {
+			deployment.Spec.Template.Spec.Containers[0].StartupProbe = &startupChecks[0]
+		}
+		if len(uptimeSeconds) > 0 {
+			deployment.Spec.MinReadySeconds = uptimeSeconds[0]
+		}
+	}
+
 	if input.ProcessType == "web" {
 		for _, portMap := range input.PortMaps {
 			protocol := "TCP"

plugins/scheduler-k3s/triggers.go

@@ -16,6 +16,7 @@ import (
 	"syscall"
 	"time"
 
+	appjson "github.com/dokku/dokku/plugins/app-json"
 	"github.com/dokku/dokku/plugins/common"
 	"github.com/dokku/dokku/plugins/config"
 	"github.com/dokku/dokku/plugins/cron"
@@ -221,6 +222,11 @@ data:
 		}
 	}
 
+	appJSON, err := appjson.GetAppJSON(appName)
+	if err != nil {
+		return fmt.Errorf("Error getting app.json for deployment: %w", err)
+	}
+
 	workingDir := common.GetWorkingDir(appName, image)
 	deployments := map[string]appsv1.Deployment{}
 	i := 0
@@ -239,7 +245,11 @@ data:
 		i++
 		replicaCountPlaceholder := int32(i * 1000)
 
-		// todo: implement healthchecks
+		healthchecks, ok := appJSON.Healthchecks[processType]
+		if !ok {
+			healthchecks = []appjson.Healthcheck{}
+		}
+
 		// todo: implement deployment annotations
 		// todo: implement pod annotations
 		// todo: implement volumes
@@ -249,6 +259,7 @@ data:
 			Image:            image,
 			ImagePullSecrets: imagePullSecrets,
 			ImageSourceType:  imageSourceType,
+			Healthchecks:     healthchecks,
 			Namespace:        namespace,
 			PrimaryPort:      primaryPort,
 			PortMaps:         portMaps,