fix: don't bump a deployment's updated_on when a reconcile leaves its status unchanged

admin/jobs/river/reconcile_deployment.go

@@ -124,11 +124,20 @@ func (w *ReconcileDeploymentWorker) Work(ctx context.Context, job *river.Job[Rec
 		return nil
 	}
 
-	// Update the deployment status
-	depl, err = w.admin.DB.UpdateDeploymentStatus(ctx, depl.ID, newStatus, "")
+	// Update the deployment status.
+	// We skip the update when the status is unchanged (as on the periodic reconcile of a running deployment) because it bumps updated_on,
+	// which the runtime treats as a change to the deployment: it forces a repo pull and a full re-parse of the project (see runtime.configReloader).
+	// We re-fetch the deployment first since the status may have changed while we were working (e.g. UpdateDeploymentInner sets it to updating).
+	depl, err = w.admin.DB.FindDeployment(ctx, depl.ID)
 	if err != nil {
 		return err
 	}
+	if depl.Status != newStatus || depl.StatusMessage != "" {
+		depl, err = w.admin.DB.UpdateDeploymentStatus(ctx, depl.ID, newStatus, "")
+		if err != nil {
+			return err
+		}
+	}
 
 	// If current depl.DesiredStatusUpdatedOn != desiredStatusUpdatedOn when job started, then the deployment changed while we were working and we should reschedule another job.
 	if !depl.DesiredStatusUpdatedOn.Equal(desiredStatusUpdatedOn) {

cli/cmd/project/deployment/deployments_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/rilldata/rill/admin/testadmin"
 	"github.com/rilldata/rill/cli/testcli"
 	adminv1 "github.com/rilldata/rill/proto/gen/rill/admin/v1"
+	"github.com/rilldata/rill/runtime"
 	"github.com/rilldata/rill/runtime/drivers"
 	"github.com/rilldata/rill/runtime/pkg/gitutil"
 	"github.com/rilldata/rill/runtime/testruntime/testmode"
@@ -72,6 +73,32 @@ vars:
 		return modelOutputFn == 1
 	}, 10*time.Second, 100*time.Millisecond, "unexpected model output")
 
+	// reconcile the unchanged deployment twice: neither should bump updated_on,
+	// and the second should not make the runtime re-parse the project
+	// (the first may, since the runtime has not seen the deployment's updated_on before)
+	ctrl, err := adm.Runtime.Controller(t.Context(), depl.RuntimeInstanceID)
+	require.NoError(t, err)
+	parserStateVersion := func() int64 {
+		require.NoError(t, ctrl.WaitUntilIdle(t.Context(), false))
+		pp, err := ctrl.Get(t.Context(), runtime.GlobalProjectParserName, false)
+		require.NoError(t, err)
+		return pp.Meta.StateVersion
+	}
+	depl2 := adm.TriggerDeployment(t, "reload-configs-test", "rill-mgd-deploy")
+	require.True(t, depl.UpdatedOn.Equal(depl2.UpdatedOn), "updated_on changed from %v to %v", depl.UpdatedOn, depl2.UpdatedOn)
+	stateVersion := parserStateVersion()
+	depl2 = adm.TriggerDeployment(t, "reload-configs-test", "rill-mgd-deploy")
+	require.True(t, depl.UpdatedOn.Equal(depl2.UpdatedOn), "updated_on changed from %v to %v", depl.UpdatedOn, depl2.UpdatedOn)
+	require.Equal(t, stateVersion, parserStateVersion(), "the project was re-parsed")
+
+	// changing the slots reprovisions the runtime and marks the deployment as updating while that happens;
+	// the reconcile should still leave it running
+	result = u1.Run(t, "project", "edit", "--prod-slots=3", "--org=reload-configs-test", "--project=rill-mgd-deploy")
+	require.Equal(t, 0, result.ExitCode, result.Output)
+	depl = adm.TriggerDeployment(t, "reload-configs-test", "rill-mgd-deploy")
+	require.Equal(t, database.DeploymentStatusRunning, depl.Status)
+	require.Empty(t, depl.StatusMessage)
+
 	// set env via `rill env set limit 10`
 	result = u1.Run(t, "env", "set", "limit", "10", "--org=reload-configs-test", "--project=rill-mgd-deploy")
 	require.Equal(t, 0, result.ExitCode, result.Output)