feat(master): POLL_INTERVAL, poller wiring and version picker in the UI (#9)

cmd/master/main.go

@@ -11,6 +11,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"strings"
 	"syscall"
 	"time"
@@ -20,6 +21,8 @@ import (
 	"github.com/shcizo/package-updater/internal/master/events"
 	"github.com/shcizo/package-updater/internal/master/hub"
 	"github.com/shcizo/package-updater/internal/master/jobs"
+	"github.com/shcizo/package-updater/internal/master/poller"
+	"github.com/shcizo/package-updater/internal/master/registry"
 	"github.com/shcizo/package-updater/internal/master/store"
 	"github.com/shcizo/package-updater/internal/master/web"
 	"github.com/shcizo/package-updater/internal/master/webauth"
@@ -37,6 +40,29 @@ func main() {
 	}
 }
 
+// pollFirstDelay is how long the master runs before its first registry
+// polling cycle, so agents have reported their inventory.
+const pollFirstDelay = time.Minute
+
+// pollWorkers is how many registry lookups run at once.
+const pollWorkers = 4
+
+// registryCredentialsDir returns the directory the registry client reads
+// credentials from (DOCKER_CONFIG, else ~/.docker) and whether a config.json
+// is in it. Only the path is logged, never the file.
+func registryCredentialsDir() (dir string, found bool) {
+	dir = os.Getenv("DOCKER_CONFIG")
+	if dir == "" {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", false
+		}
+		dir = filepath.Join(home, ".docker")
+	}
+	_, err := os.Stat(filepath.Join(dir, "config.json"))
+	return dir, err == nil
+}
+
 func run() error {
 	cfg, err := config.Load()
 	if err != nil {
@@ -81,6 +107,7 @@ func run() error {
 
 	ui, err := web.New(st, agentHub, jobService, broker, web.Config{
 		AgentURL: cfg.AgentURL, MasterKey: fingerprint, AgentImage: cfg.AgentImage,
+		PollInterval: cfg.PollInterval,
 	}, logger)
 	if err != nil {
 		return err
@@ -127,22 +154,39 @@ func run() error {
 		BaseContext: baseContext,
 	}
 
+	credDir, credFound := registryCredentialsDir()
+	logger.Info("registry_credentials", "docker_config", credDir, "config_json_found", credFound)
+	pollCtx, stopPolling := context.WithCancel(ctx)
+	defer stopPolling()
+	registryPoller := poller.New(st, jobService, registry.New("package-updater-master/"+version), broker, poller.Config{
+		Interval: cfg.PollInterval, FirstDelay: pollFirstDelay, Workers: pollWorkers,
+	}, logger)
+	pollDone := make(chan struct{})
+	go func() {
+		defer close(pollDone)
+		registryPoller.Run(pollCtx)
+	}()
+
 	errCh := make(chan error, 2)
 	go func() { errCh <- webSrv.ListenAndServe() }()
 	go func() { errCh <- agentSrv.ListenAndServeTLS("", "") }()
 	logger.Info("listening", "web", webSrv.Addr, "agents", agentSrv.Addr)
 
+	var serveErr error
 	select {
 	case <-ctx.Done():
 		logger.Info("shutdown_signal")
 	case err := <-errCh:
 		if !errors.Is(err, http.ErrServerClosed) {
-			return err
+			serveErr = err
 		}
 	}
 	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	_ = webSrv.Shutdown(shutdownCtx)
 	_ = agentSrv.Shutdown(shutdownCtx)
-	return nil
+	// The poller writes to the store, which is closed when run returns.
+	stopPolling()
+	<-pollDone
+	return serveErr
 }