Have genesis trust its registry before pushing to it (issue 92)

Genesis pushed the control plane's image to the mesh's plain-HTTP registry
before anything told the container runtime to trust it; the docker module
that writes that trust is applied long after. Genesis now writes the trust
itself at the registry step, with the same into-json writer and a reload,
for the address given and the node's mesh name on the node's registry
port, and refuses before any push unless the runtime says it trusts each.
The docker module later finds the mesh name there and takes it over
without a change.

internal/bootstrap/bootstrap.go

@@ -292,12 +292,14 @@ type Result struct {
 	Agent     string `json:"host-agent,omitempty"`
 
 	// Registry is the mesh's own artifact store, once it answers.
-	Registry         string `json:"registry,omitempty"`
-	RegistryReplied  int    `json:"registry-replied,omitempty"`
-	RegistryKnown    bool   `json:"registry-already-registered,omitempty"`
-	RegistryRunning  string `json:"registry-container,omitempty"`
-	PublishedAs      string `json:"control-plane-image,omitempty"`
-	PublishedAlready bool   `json:"control-plane-image-already-published,omitempty"`
+	Registry        string `json:"registry,omitempty"`
+	RegistryReplied int    `json:"registry-replied,omitempty"`
+	RegistryKnown   bool   `json:"registry-already-registered,omitempty"`
+	RegistryRunning string `json:"registry-container,omitempty"`
+	// RegistryTrusted are the names the runtime was told to trust the registry by, before the push.
+	RegistryTrusted  []string `json:"registry-trusted,omitempty"`
+	PublishedAs      string   `json:"control-plane-image,omitempty"`
+	PublishedAlready bool     `json:"control-plane-image-already-published,omitempty"`
 
 	// Permanent is the control plane as an ordinary module.
 	Permanent          string   `json:"permanent-container,omitempty"`
@@ -555,7 +557,9 @@ func Run(ctx context.Context, o Options, d Deps, say func(string)) (Result, erro
 			// Named rather than attempted. Everything from step 6 on is a conversation with a
 			// control plane that a dry run has not raised, so there is nothing to ask and nothing
 			// honest to report about the answers.
-			say("  would then        enrol " + o.Node + ", install the registry from " +
+			say("  would then        enrol " + o.Node + ", have the runtime trust the registry as " +
+				strings.Join(RegistryNames(o), ", ") + ",")
+			say("                    install the registry from " +
 				o.Catalogue + ", push the control plane's image into it,")
 			say("                    reinstall the control plane as a module, and drop " +
 				rewritten.TempName)
@@ -656,6 +660,13 @@ func Run(ctx context.Context, o Options, d Deps, say func(string)) (Result, erro
 
 	// ---- 7. registry ----------------------------------------------------------------------
 	say("registry — somewhere for this mesh to keep its own images")
+	// Trusted by the runtime before anything is pushed to it, by every name the mesh will use for
+	// it here: the module that writes this trust is applied long after the push (novox/hq issue 92).
+	trusted, err := TrustTheRegistry(ctx, o, sys, d.Run, say)
+	result.RegistryTrusted = trusted
+	if err != nil {
+		return result, failed(StepRegistry, err)
+	}
 	registry, err := InstallRegistry(ctx, o, d, temporary, say)
 	result.Registry, result.RegistryRunning = registry.Address, registry.Container
 	result.RegistryKnown, result.RegistryReplied = registry.Known, registry.Answered