Accept and ignore a file's trusted, and give each runtime its own time to answer

The fourth review (hq issue 339): `trusted` is the catalogue's word and the
controller takes it out, but a controller that passes it on, an older one or
one rolled back to, must not cost a node its whole declaration. A file now
accepts it and nothing reads it; any other resource still refuses it. And a
podman that hangs no longer eats docker's ten seconds.

internal/apply/placement_guard.go

@@ -152,14 +152,15 @@ func readRuntimeRoots(ctx context.Context, run Runner) []string {
 		}
 	}
 	if run != nil {
-		ask, cancel := context.WithTimeout(ctx, 10*time.Second)
-		if root, err := run(ask, "docker", "info", "--format", "{{.DockerRootDir}}"); err == nil {
-			add(root)
+		// Each runtime has its own ten seconds: one that hangs costs the other nothing.
+		for _, q := range [][]string{{"docker", "info", "--format", "{{.DockerRootDir}}"},
+			{"podman", "info", "--format", "{{.Store.GraphRoot}}"}} {
+			ask, cancel := context.WithTimeout(ctx, 10*time.Second)
+			if root, err := run(ask, q[0], q[1:]...); err == nil {
+				add(root)
+			}
+			cancel()
 		}
-		if root, err := run(ask, "podman", "info", "--format", "{{.Store.GraphRoot}}"); err == nil {
-			add(root)
-		}
-		cancel()
 	}
 	daemonJSON := func(path string) {
 		raw, err := os.ReadFile(path)

internal/declaration/declaration.go

@@ -198,6 +198,12 @@ type File struct {
 	// by looking rather than by knowing which field won.
 	Sealed string `json:"sealed,omitempty"`
 
+	// Trusted is the catalogue's word on whether the settings this file's content took are trusted (novox/hq
+	// issue 339). It is the controller's to act on, and a controller takes it out before it sends a declaration.
+	// Accepted here, and nothing is done with it, so that a controller that passes it on — an older one, or one
+	// rolled back to — never costs a node its whole declaration. Not part of the file's digest.
+	Trusted *bool `json:"trusted,omitempty"`
+
 	// Secrets are sealed values put into Content where it says `${secret:name}`.
 	//
 	// **The one place a secret and a configuration meet, and it happens on the machine.** A

internal/declaration/trusted_test.go

@@ -0,0 +1,23 @@
+package declaration
+
+import "testing"
+
+// `trusted` is the catalogue's word on a file (novox/hq issue 339): a controller takes it out before it sends a
+// declaration, and one that does not — an older one, or one rolled back to — must not cost the node its whole
+// declaration. So a file accepts it and the engine does nothing with it; any other resource still refuses it.
+func TestAFileAcceptsAndIgnoresTrusted(t *testing.T) {
+	for _, v := range []string{"true", "false"} {
+		d, err := Parse([]byte(`{"declaration":1,"resources":[{"id":"m.f","type":"file","path":"/etc/m.conf",` +
+			`"content":"x","trusted":` + v + `}]}`))
+		if err != nil {
+			t.Fatalf("trusted %s: %v", v, err)
+		}
+		if f, ok := d.Resources[0].(*File); !ok || f.Content != "x" {
+			t.Fatalf("trusted %s: %+v", v, d.Resources[0])
+		}
+	}
+	if _, err := Parse([]byte(`{"declaration":1,"resources":[{"id":"m.d","type":"directory","path":"/srv/m",` +
+		`"trusted":true}]}`)); err == nil {
+		t.Fatal("a directory took trusted")
+	}
+}