feat(agent): Add docker image update available flag (#2211)

Co-authored-by: henrygd <hank@henrygd.me>

internal/hub/systems/container_records_test.go

@@ -0,0 +1,46 @@
+//go:build testing
+
+package systems
+
+import (
+	"testing"
+
+	"github.com/henrygd/beszel/internal/entities/container"
+	"github.com/pocketbase/dbx"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateContainerRecordsPersistsImageUpdateAvailability(t *testing.T) {
+	_, app := newTestSystemWithHub(t)
+
+	const (
+		systemID    = "system123"
+		containerID = "abcdef123456"
+		image       = "nginx:latest"
+	)
+
+	data := &container.Stats{
+		Id:              containerID,
+		Name:            "web",
+		Image:           image,
+		UpdateAvailable: true,
+	}
+	require.NoError(t, createContainerRecords(app, []*container.Stats{data}, systemID))
+
+	var record struct {
+		Image           string `db:"image"`
+		UpdateAvailable bool   `db:"updatable"`
+	}
+	require.NoError(t, app.DB().Select("image", "updatable").From("containers").
+		Where(dbx.HashExp{"id": containerID}).One(&record))
+	assert.Equal(t, image, record.Image)
+	assert.True(t, record.UpdateAvailable)
+
+	data.UpdateAvailable = false
+	require.NoError(t, createContainerRecords(app, []*container.Stats{data}, systemID))
+	require.NoError(t, app.DB().Select("image", "updatable").From("containers").
+		Where(dbx.HashExp{"id": containerID}).One(&record))
+	assert.Equal(t, image, record.Image)
+	assert.False(t, record.UpdateAvailable)
+}