fix: worker to cache metrics result for the http service

Taskfile.yaml

@@ -16,3 +16,8 @@ tasks:
     silent: true
     cmds:
       - go run main.go query
+
+  serve:
+    desc: Run the http server
+    cmds:
+      - go run main.go serve

cmd/serve/serve.go

@@ -29,10 +29,12 @@ func NewServeCommand(app *app.App) *cobra.Command {
 				cancel()
 			}()
 
+			cache := http.NewResultCache(app)
 			http := http.NewHttp(app)
 
+			go cache.Work(ctx)
 			go func() {
-				if err := http.Serve(); err != nil {
+				if err := http.Start(); err != nil {
 					if !errors.Is(err, stdhttp.ErrServerClosed) {
 						fmt.Println(fmt.Errorf("http server failed: %v", err))
 						cancel()

internal/config/config.go

@@ -23,9 +23,10 @@ type Service struct {
 }
 
 type Config struct {
-	Port       int       `yaml:"port"`
-	Services   []Service `yaml:"services"`
-	Prometheus string    `yaml:"prometheus"`
+	Port       int           `yaml:"port"`
+	Services   []Service     `yaml:"services"`
+	Prometheus string        `yaml:"prometheus"`
+	Refresh    time.Duration `yaml:"refresh"`
 }
 
 func Load(path string) (*Config, error) {
@@ -61,6 +62,10 @@ func setDefaults(conf *Config) {
 		svc.Query.Name = "main"
 		conf.Services[i] = svc
 	}
+
+	if conf.Refresh == 0 {
+		conf.Refresh = time.Second * 30
+	}
 }
 
 func (c *Config) Validate() error {

internal/http/http.go

@@ -25,7 +25,7 @@ func NewHttp(app *app.App) *Http {
 	}
 }
 
-func (h *Http) Serve() error {
+func (h *Http) Start() error {
 	return h.e.Start(fmt.Sprintf(":%d", h.app.Config.Port))
 }
 

internal/http/results.go

@@ -1,11 +1,14 @@
 package http
 
 import (
+	"context"
+	"log"
 	"sync"
+	"time"
 
 	"github.com/henrywhitaker3/prompage/internal/app"
+	"github.com/henrywhitaker3/prompage/internal/collector"
 	"github.com/henrywhitaker3/prompage/internal/config"
-	"github.com/henrywhitaker3/prompage/internal/querier"
 )
 
 type Result struct {
@@ -14,15 +17,39 @@ type Result struct {
 }
 
 type ResultCache struct {
-	mu      *sync.Mutex
-	querier *querier.Querier
-	results map[string][]Result
+	mu        *sync.Mutex
+	collector *collector.Collector
+	interval  time.Duration
+	results   []collector.Result
 }
 
 func NewResultCache(app *app.App) *ResultCache {
 	return &ResultCache{
-		mu:      &sync.Mutex{},
-		querier: app.Querier,
-		results: map[string][]Result{},
+		mu:        &sync.Mutex{},
+		collector: app.Collector,
+		interval:  app.Config.Refresh,
+		results:   []collector.Result{},
+	}
+}
+
+func (c *ResultCache) Work(ctx context.Context) {
+	c.mu.Lock()
+	c.results = c.collector.Collect(ctx)
+	c.mu.Unlock()
+
+	ticker := time.NewTicker(c.interval)
+	defer ticker.Stop()
+
+	log.Printf("collecitng metrics every %s", c.interval)
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			c.mu.Lock()
+			c.results = c.collector.Collect(ctx)
+			c.mu.Unlock()
+		}
 	}
 }