sysupdate: run a second update pass when the refresh changed the tags

cmd/quarry-sysupdate/update.go

@@ -5,12 +5,13 @@ package sysupdate
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"log/slog"
+	"slices"
 
 	"github.com/urfave/cli/v3"
 
+	"go.amutable.dev/quarry/internal/hostnamed"
 	"go.amutable.dev/quarry/internal/third_party/assert"
 	"go.amutable.dev/quarry/internal/tufclient"
 	"go.amutable.dev/quarry/internal/xsysupdate"
@@ -24,14 +25,6 @@ var updateCommand = withExtensionDirFlag(withQuarryUserFlag(withQuarryProxyFlag(
 			&xsysupdate.TransferFileExtension{
 				OverrideSourcePathURL: ctxQuarryProxyURL(ctx),
 			},
-			&xsysupdate.TagsExtension{
-				// TODO: There is no ownership model for machine tags yet, so
-				// as a temporary workaround we take full control of the acp.*
-				// and amutable.* tag namespaces. These tags always exactly
-				// match the set shipped by the configured repositories, and
-				// tags outside them are never touched.
-				AllowedNamespaces: []string{"acp.", "amutable."},
-			},
 		}
 		ctx, err := exts.DoInit(ctx)
 		if err != nil {
@@ -106,37 +99,47 @@ var updateCommand = withExtensionDirFlag(withQuarryUserFlag(withQuarryProxyFlag(
 		// the extension application, clean up the successfully installed
 		// components, and force-downgrade to the old versions.
 
-		components, err := listComponents(ctx)
-		if err != nil {
-			return fmt.Errorf("get list of sysupdate components: %w", err)
-		}
-		slog.Info("Spawning 'systemd-sysupdate update'...",
-			"components", components)
-		var errs []error
-		for _, component := range components {
-			if err := sysupdate(ctx, component); err != nil {
-				slog.Error("sysupdate for component failed.",
-					"err", err.Error(), "component", component)
-				// FIXME: If we hit an error, continue on because we don't have
-				// a decent revert story at the moment.
-				errs = append(errs, err)
-			}
-		}
-		if err := errors.Join(errs...); err != nil {
-			return fmt.Errorf("sysupdate failed: %w", err)
+		if err := sysupdateAll(ctx); err != nil {
+			return err
 		}
-		slog.Info("'systemd-sysupdate update' completed.")
 
 		if err := exts.Close(); err != nil {
 			return fmt.Errorf("post-update extension cleanup: %w", err)
 		}
 
+		// A merged confext may ship tags.d(5) files, which systemd applies as
+		// part of the refresh. Features gated on those tags were evaluated
+		// with the old tags above, so they need another update pass.
+		tagsBefore, err := hostnamed.CurrentTags(ctx, "")
+		if err != nil {
+			return fmt.Errorf("fetch machine tags before refresh: %w", err)
+		}
+
 		// Do online-reload of sysexts and confexts.
 		slog.Info("Trigger online-reload of new components.")
 		if err := sysupdateRefresh(ctx); err != nil {
 			return fmt.Errorf("online-reload components: %w", err)
 		}
 
+		tagsAfter, err := hostnamed.CurrentTags(ctx, "")
+		if err != nil {
+			return fmt.Errorf("fetch machine tags after refresh: %w", err)
+		}
+		if slices.Equal(tagsBefore, tagsAfter) {
+			return nil
+		}
+		slog.Info("Machine tags changed by refresh, running a second update pass.",
+			"before", tagsBefore, "after", tagsAfter)
+		if err := enableSuggested(ctx); err != nil {
+			return err
+		}
+		if err := sysupdateAll(ctx); err != nil {
+			return err
+		}
+		if err := sysupdateRefresh(ctx); err != nil {
+			return fmt.Errorf("online-reload components after second pass: %w", err)
+		}
+
 		return nil
 	},
 })))

cmd/quarry-sysupdate/utils_sysupdate.go

@@ -53,6 +53,40 @@ func sysupdate(ctx context.Context, component string) error {
 	return systemdcmd.Call(ctx, "sysupdate", args...)
 }
 
+// sysupdateAll runs "systemd-sysupdate update" for every component.
+func sysupdateAll(ctx context.Context) error {
+	components, err := listComponents(ctx)
+	if err != nil {
+		return fmt.Errorf("get list of sysupdate components: %w", err)
+	}
+	slog.Info("Spawning 'systemd-sysupdate update'...",
+		"components", components)
+	var errs []error
+	for _, component := range components {
+		if err := sysupdate(ctx, component); err != nil {
+			slog.Error("sysupdate for component failed.",
+				"err", err.Error(), "component", component)
+			// FIXME: If we hit an error, continue on because we don't have
+			// a decent revert story at the moment.
+			errs = append(errs, err)
+		}
+	}
+	if err := errors.Join(errs...); err != nil {
+		return fmt.Errorf("sysupdate failed: %w", err)
+	}
+	slog.Info("'systemd-sysupdate update' completed.")
+	return nil
+}
+
+// enableSuggested enables the components and features whose SuggestOn*
+// conditions now hold, e.g. after the machine tags changed.
+func enableSuggested(ctx context.Context) error {
+	if err := systemdcmd.Call(ctx, "systemctl", "start", "systemd-sysupdate-auto-enable.service"); err != nil {
+		return fmt.Errorf("failed to trigger systemd-sysupdate-auto-enable service: %w", err)
+	}
+	return nil
+}
+
 func sysupdateRefresh(ctx context.Context) error {
 	errs := []error{
 		// systemd-confext refresh

contrib/systemd/quarry-sysupdate.service

@@ -7,6 +7,12 @@
 Description=Quarry-Based Automatic System Update
 Wants=network-online.target
 After=network-online.target
+# Features gated on machine tags (SuggestOnMachineTag=) become enabled only
+# when `systemd-sysupdate enable-feature --feature-suggested` runs, which is
+# what systemd-sysupdate-auto-enable.service does. Run it ahead of every
+# update: a tag that arrives with this run's confext is picked up by the next.
+Wants=systemd-sysupdate-auto-enable.service
+After=systemd-sysupdate-auto-enable.service
 
 # For containers we assume that the manager will handle updates. And we likely
 # can't even access our backing block device anyway.

docs/getting-started.md

@@ -392,8 +392,8 @@ directly, but for those who are interested:
    local HTTP server as a source in transfer files.
 
  * `quarry sysupdate update` wraps `systemd-sysupdate` and does some pre-update
-   and post-update steps (such as installing tags and instantiating transfer
-   files from the TUF repository).
+   and post-update steps (such as instantiating transfer files from the TUF
+   repository).
 
 In most cases, you should avoid interacting with these tools -- these are
 intended to be used by a `systemd-sysupdate`-managed operating system directly.