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

internal/master/web/views.go

@@ -5,7 +5,9 @@ import (
 	"time"
 
 	"github.com/shcizo/package-updater/internal/imageref"
+	"github.com/shcizo/package-updater/internal/master/jobs"
 	"github.com/shcizo/package-updater/internal/master/model"
+	"github.com/shcizo/package-updater/internal/master/poller"
 	"github.com/shcizo/package-updater/internal/protocol"
 )
 
@@ -54,6 +56,51 @@ func shortRef(ref string) string {
 	return r.String()
 }
 
+// followsNoTag says the service's image reference has a digest but no tag,
+// so there is no tag to poll or update.
+func followsNoTag(svc model.Service) bool {
+	return jobs.FollowedRef(svc.ActualRef) == ""
+}
+
+// versionRow is an image version as shown on the service page.
+type versionRow struct {
+	model.ImageVersion
+	Running bool // the service runs exactly this digest
+}
+
+// versionRows marks the version the service runs now, by digest.
+func versionRows(versions []model.ImageVersion, actualDigest string) []versionRow {
+	rows := make([]versionRow, len(versions))
+	for i, v := range versions {
+		rows[i] = versionRow{ImageVersion: v, Running: v.Digest != "" && v.Digest == actualDigest}
+	}
+	return rows
+}
+
+// pollingStatus is the text of the "Polling" row on the service page and
+// whether it is a registry error.
+func pollingStatus(svc model.Service, interval time.Duration) (text string, failed bool) {
+	switch {
+	case poller.SkipReason(svc) != "":
+		return "not polled: " + poller.SkipReason(svc), false
+	case svc.LastPollError != "":
+		return "last check failed: " + svc.LastPollError, true
+	}
+	return "every " + shortDuration(interval), false
+}
+
+// shortDuration formats d without trailing zero units: "6h", "1h30m", "90s".
+func shortDuration(d time.Duration) string {
+	s := d.String()
+	if strings.HasSuffix(s, "m0s") {
+		s = s[:len(s)-2]
+	}
+	if strings.HasSuffix(s, "h0m") {
+		s = s[:len(s)-2]
+	}
+	return s
+}
+
 type agentRow struct {
 	model.Agent
 	Online bool