WIP status updates

pkg/config/server.go

@@ -2,13 +2,20 @@ package config
 
 import (
 	"fmt"
+	"time"
 )
 
 type ServerConfig struct {
 	SharedConfig
 
 	// ListenAddress is the address to listen on
 	ListenAddress string `split_words:"true" default:":8080"`
+
+	// UnhealthyTime is the amount of time since last ping before a host is marked unhealthy
+	UnhealthyTime time.Duration `split_words:"true" default:"5m"`
+
+	// UpdateFrequency is the amount of time between status updates
+	UpdateFrequency time.Duration `split_words:"true" default:"1m"`
 }
 
 func LoadServerConfig() (*ServerConfig, error) {

pkg/server/server.go

@@ -1,11 +1,14 @@
 package server
 
 import (
+	"context"
 	"net/http"
 	"sync"
+	"time"
 
 	"github.com/go-playground/validator/v10"
 	"github.com/labstack/echo/v4"
+	"github.com/rs/zerolog/log"
 
 	"github.com/nint8835/instatus-cluster-monitor/pkg/config"
 )
@@ -18,6 +21,21 @@ func (v *Validator) Validate(i any) error {
 	return v.validator.Struct(i)
 }
 
+type Status string
+
+const (
+	StatusNone      Status = ""
+	StatusHealthy   Status = "healthy"
+	StatusUnhealthy Status = "unhealthy"
+)
+
+type HostStatus struct {
+	Status     Status `json:"status"`
+	LastStatus Status `json:"-"`
+
+	ReportedAt time.Time `json:"reported_at"`
+}
+
 type Server struct {
 	config   *config.ServerConfig
 	echoInst *echo.Echo
@@ -26,9 +44,62 @@ type Server struct {
 }
 
 func (s *Server) Start() error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go s.monitorStatuses(ctx)
+
 	return s.echoInst.Start(s.config.ListenAddress)
 }
 
+func (s *Server) monitorStatuses(ctx context.Context) {
+	ticker := time.NewTicker(s.config.UpdateFrequency)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Debug().Msg("Stopping status monitor")
+			return
+		case <-ticker.C:
+			log.Debug().Msg("Updating statuses")
+
+			s.statuses.Range(func(key any, value any) bool {
+				identifier := key.(string)
+				status := value.(*HostStatus)
+
+				if time.Since(status.ReportedAt) >= s.config.UnhealthyTime {
+					status.Status = StatusUnhealthy
+				}
+
+				if status.Status == status.LastStatus {
+					return true
+				}
+
+				log.Info().
+					Str("identifier", identifier).
+					Str("last_status", string(status.LastStatus)).
+					Str("status", string(status.Status)).
+					Msg("Host status changed")
+
+				status.LastStatus = status.Status
+				return true
+			})
+		}
+	}
+}
+
+func (s *Server) getStatuses(c echo.Context) error {
+	statuses := map[string]*HostStatus{}
+
+	s.statuses.Range(func(key any, value any) bool {
+		statuses[key.(string)] = value.(*HostStatus)
+		return true
+	})
+
+	return c.JSON(http.StatusOK, statuses)
+}
+
 type PingBody struct {
 	Identifier string `json:"identifier" validate:"required"`
 }
@@ -48,6 +119,16 @@ func (s *Server) handlePing(c echo.Context) error {
 		return echo.NewHTTPError(http.StatusBadRequest, err.Error())
 	}
 
+	existingStatus, hasStatus := s.statuses.Load(body.Identifier)
+	if !hasStatus {
+		s.statuses.Store(body.Identifier, &HostStatus{ReportedAt: time.Now(), Status: StatusHealthy})
+		return c.JSON(http.StatusOK, map[string]any{})
+	}
+
+	status := existingStatus.(*HostStatus)
+	status.ReportedAt = time.Now()
+	status.Status = StatusHealthy
+
 	return c.JSON(http.StatusOK, map[string]any{})
 }
 
@@ -61,6 +142,7 @@ func New(c *config.ServerConfig) *Server {
 	echoInst.HideBanner = true
 	echoInst.Validator = &Validator{validator: validator.New()}
 
+	echoInst.GET("/statuses", serverInst.getStatuses)
 	echoInst.POST("/ping", serverInst.requireAuth(serverInst.handlePing))
 
 	return serverInst