Merge pull request 'Bound a consumer's identity by the provision it requires (hq issue 263, ADR 0225)' (#76) from fix/263-identity-bound-per-provision into main

cmd/mesh-controller/build.go

@@ -679,6 +679,10 @@ type answers struct {
 	// failing is every consumer a provider says it keeps failing (novox/hq ADR 0224): a provider's
 	// journal was the only place that said so for a day (04-ISSUES/179).
 	failing []inventory.ProviderStanding
+	// overflowing is every module whose identity overflows the bound of a provision it requires
+	// (novox/hq ADR 0225): its provider leaves it out of the grants and composes everything else, so
+	// this is the one place it is said across the mesh. Not well while there is any.
+	overflowing []catalogue.Overflow
 }
 
 // heldBy is every artifact this mesh has built, for a build that may need one as its base.

cmd/mesh-controller/check.go

@@ -25,7 +25,17 @@ import (
 // mesh seat is judged fully only at registration. A seat another module declares is unknown unless
 // that module's manifest is passed too. Both are printed as a note, not as a problem — a check that
 // refused what it could not see would teach people to ignore it.
+//
+// **And every identity against every bound it meets** (novox/hq ADR 0225, issue 263): each module's
+// identity, on a machine whose name is `longestMachine` characters, against the bound of every
+// provision it wants that a manifest given here offers. An overflow is refused in the pull request
+// that introduces it — a new requirement, a lowered bound, a longer slug — instead of on the
+// provider's machine when a real machine's name first meets the module's.
 func moduleCheck(paths []string, out io.Writer) error {
+	return moduleCheckFor(paths, catalogue.DefaultLongestMachine, out)
+}
+
+func moduleCheckFor(paths []string, longestMachine int, out io.Writer) error {
 	if len(paths) == 0 {
 		return errors.New("module check <manifest.json>... — one file per module; pass every " +
 			"manifest of a repository together so the rules between them are checked too")
@@ -74,6 +84,15 @@ func moduleCheck(paths []string, out io.Writer) error {
 	}
 	failed += len(problems)
 
+	// Between the manifests too: an identity against the bounds of the provisions it wants, which
+	// only the provider's manifest states.
+	identities := catalogue.IdentityProblems(shelf, longestMachine)
+	sort.Strings(identities)
+	for _, p := range identities {
+		fmt.Fprintln(out, p)
+	}
+	failed += len(identities)
+
 	var names []string
 	for name := range shelf {
 		names = append(names, name)
@@ -109,7 +128,8 @@ func moduleCheck(paths []string, out io.Writer) error {
 	}
 	fmt.Fprintf(out, "%d manifest(s) checked. Judged against the seats this binary carries; a claim on "+
 		"one of the mesh's own seats is judged fully at registration, and a seat declared by a "+
-		"module not given here reads as unknown\n", len(paths))
+		"module not given here reads as unknown. Identities judged on a %d-character machine name, "+
+		"against the bounds of the providers given here\n", len(paths), longestMachine)
 	return nil
 }
 

cmd/mesh-controller/identity_bound_test.go

@@ -0,0 +1,150 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// novox/hq ADR 0225, issue 263: a consumer's identity is bounded by the provision it requires, an
+// overflow is refused before merge by `module check`, and a provider's machine is never refused for
+// one consumer's identity.
+
+// `module check` refuses the pull request that introduces an overflow, naming the module.
+func TestModuleCheckRefusesAnIdentityThatOverflowsWhatItRequires(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name, body string) string {
+		p := filepath.Join(dir, name+".json")
+		if err := os.WriteFile(p, []byte(body), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		return p
+	}
+	objects := write("objects", `{"module":"objects","version":"1",
+		"provides":[{"name":"s3-bucket","scope":"mesh","identity":{"max":20,"in":"an S3 access key"}}],
+		"receives":{"s3-bucket":"/var/lib/mesh/objects/mesh.json"}}`)
+	resolver := write("resolver", `{"module":"resolver","version":"1",
+		"provides":[{"name":"wildcard-resolution","scope":"mesh","identity":false}]}`)
+	album := write("photoalbum", `{"module":"photoalbum","version":"1","requires":["s3-bucket"]}`)
+	nm := write("networkmanager", `{"module":"networkmanager","version":"1","requires":["wildcard-resolution"]}`)
+
+	var out bytes.Buffer
+	if err := moduleCheckFor([]string{resolver, nm}, 6, &out); err != nil {
+		t.Fatalf("a long name requiring a keyless provision was refused (issue 263): %v\n%s", err, out.String())
+	}
+	out.Reset()
+	err := moduleCheckFor([]string{objects, album, resolver, nm}, 6, &out)
+	if err == nil {
+		t.Fatalf("an identity overflowing an S3 access key passed:\n%s", out.String())
+	}
+	if !strings.Contains(out.String(), "photoalbum wants s3-bucket") ||
+		!strings.Contains(out.String(), "`slug` of at most 8 characters") ||
+		strings.Contains(out.String(), "networkmanager wants") {
+		t.Fatalf("the refusal does not name the one overflowing module and its remedy:\n%s", out.String())
+	}
+}
+
+// Tonight's case, through the commands: networkmanager on a six-character machine requires the
+// resolver provision, and a second consumer there overflows an object store's access key. The
+// provider's machine still composes; the overflowing consumer is left out of its grants and named,
+// by push and by `status`, and the keyless consumer is granted with its long name.
+func TestAnOverflowingConsumerNeverRefusesItsProvidersMachine(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, catalogue.Manifest{Module: "objects", Version: "1",
+		Provides: []catalogue.Offer{{Name: "s3-bucket", Scope: catalogue.ScopeMesh,
+			Identity: &catalogue.OfferIdentity{Max: 20, In: "an S3 access key"}}},
+		Receives: map[string]string{"s3-bucket": "/var/lib/mesh/objects/mesh.json"}})
+	register(t, open, catalogue.Manifest{Module: "resolver", Version: "1",
+		Provides: []catalogue.Offer{{Name: "wildcard-resolution", Scope: catalogue.ScopeMesh}}})
+	register(t, open, catalogue.Manifest{Module: "networkmanager", Version: "1",
+		Requires: []string{"wildcard-resolution"}})
+	register(t, open, catalogue.Manifest{Module: "photoalbum", Version: "1", Requires: []string{"s3-bucket"}})
+	register(t, open, catalogue.Manifest{Module: "files", Version: "1", Requires: []string{"s3-bucket"}})
+	for _, a := range [][2]string{{"anchor", "objects"}, {"anchor", "resolver"},
+		{"laptop", "networkmanager"}, {"laptop", "photoalbum"}, {"laptop", "files"}} {
+		if _, err := assign(ctx, open, a[0], a[1]); err != nil {
+			t.Fatalf("assign %s %s: %v", a[0], a[1], err)
+		}
+	}
+
+	// The consumer's machine resolves, and says which of its modules no provider will grant.
+	consumer, _, err := planFor(ctx, open, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	over := consumer.Overflowing()
+	if len(over) != 1 || over[0].Module != "photoalbum" || over[0].Provision != "s3-bucket" {
+		t.Fatalf("the consumer's side does not name exactly photoalbum: %+v", over)
+	}
+
+	// The provider's machine composes. Under ADR 0049's one bound this was a refusal naming
+	// networkmanager, and no push to the provider could go through.
+	plan, settings, err := planFor(ctx, open, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	declared, err := declarationFor(ctx, open, "anchor", plan, settings)
+	if err != nil {
+		t.Fatalf("one consumer's identity refused its provider's whole machine: %v", err)
+	}
+	if len(declared.withheld) != 1 || declared.withheld[0].Identity != "mesh_laptop_photoalbum" {
+		t.Fatalf("the overflowing consumer is not the one withheld: %+v", declared.withheld)
+	}
+	grants, _, err := grantsFor(ctx, open, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var keyless bool
+	for _, g := range grants {
+		keyless = keyless || g.Provision == "wildcard-resolution" && g.From == "networkmanager"
+	}
+	if !keyless {
+		t.Fatalf("networkmanager, 26 characters, is not granted the keyless resolver provision: %+v", grants)
+	}
+	var granted []string
+	for _, c := range declared.Received["objects"]["s3-bucket"] {
+		granted = append(granted, c.From)
+	}
+	if strings.Join(granted, ",") != "files" {
+		t.Fatalf("the object store grants %v; files and only files fit", granted)
+	}
+	said := printed(t, func() error { reportLeftOut("anchor", declared); return nil })
+	if !strings.Contains(said, `photoalbum on laptop requires s3-bucket from anchor`) ||
+		!strings.Contains(said, "left out of anchor's grants") {
+		t.Fatalf("the push does not say whom it leaves out:\n%s", said)
+	}
+
+	// And `status` names it, and does not call the mesh well while it stands.
+	asked, err := theThreeQuestions(ctx, open)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(asked.overflowing) != 1 || asked.overflowing[0].Module != "photoalbum" {
+		t.Fatalf("status does not carry the overflow: %+v", asked.overflowing)
+	}
+	if asked.well() {
+		t.Fatal("a mesh with a consumer left out of its grants reads as well")
+	}
+	shown := printed(t, func() error { return printStatus(asked) })
+	if !strings.Contains(shown, "identified too long for a provision they require") ||
+		!strings.Contains(shown, "mesh_laptop_photoalbum") {
+		t.Fatalf("status does not say it:\n%s", shown)
+	}
+	body, err := statusAsJSON(asked)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var doc struct {
+		Overflowing []catalogue.Overflow `json:"overflowing"`
+	}
+	if err := json.Unmarshal(body, &doc); err != nil || len(doc.Overflowing) != 1 ||
+		doc.Overflowing[0].Bound.Max != 20 {
+		t.Fatalf("the document does not carry it: %v\n%s", err, body)
+	}
+}

cmd/mesh-controller/modules.go

@@ -59,8 +59,19 @@ func moduleCommand(ctx context.Context, args []string) error {
 	// `check` needs no mesh, and must not: it is what somebody runs in their own repository before
 	// there is a mesh in reach (novox/hq issue 148). A directory expands to every manifest under it.
 	if args[0] == "check" {
+		set := flag.NewFlagSet("module check", flag.ContinueOnError)
+		// The longest machine name an identity must fit on (novox/hq ADR 0225): a mesh passes its own.
+		longest := set.Int("longest-machine-name", catalogue.DefaultLongestMachine,
+			"judge each module's identity on a machine name this many characters long")
+		given, err := parseAround(set, args[1:])
+		if err != nil {
+			return err
+		}
+		if *longest < 1 {
+			return errors.New("--longest-machine-name is a length, at least 1")
+		}
 		var paths []string
-		for _, a := range args[1:] {
+		for _, a := range given {
 			if info, err := os.Stat(a); err == nil && info.IsDir() {
 				under, err := manifestsUnder(a)
 				if err != nil {
@@ -71,7 +82,7 @@ func moduleCommand(ctx context.Context, args []string) error {
 			}
 			paths = append(paths, a)
 		}
-		return moduleCheck(paths, os.Stdout)
+		return moduleCheckFor(paths, *longest, os.Stdout)
 	}
 	open, err := openStores(ctx)
 	if err != nil {

cmd/mesh-controller/plan.go

@@ -399,7 +399,7 @@ func declarationWith(ctx context.Context, open *stores, node string,
 	}
 	out := sendable{Resources: composed.Resources, Adoption: adoption,
 		Received: composed.Received, Mesh: with.Mesh, BusUsers: with.BusUsers,
-		LeftOut: sortedKeysOf(composed.LeftOut), leftOutWhy: composed.LeftOut}
+		LeftOut: sortedKeysOf(composed.LeftOut), leftOutWhy: composed.LeftOut, withheld: with.Withheld}
 	// And which build of each module it carries, for the send to record (novox/hq issue 259, ADR
 	// 0221). Read only on the send path: a question about what would be sent records nothing.
 	if choosing == Allocating {
@@ -464,6 +464,11 @@ func reportLeftOut(node string, declared sendable) {
 			"what the machine holds for it is kept and its containers are untouched. %s\n",
 			node, m, declared.leftOutWhy[m])
 	}
+	// And whom it serves nothing, because their identity overflows what the provision keeps (ADR
+	// 0225): the machine is sent everything else, and the consumer is named.
+	for _, o := range declared.withheld {
+		fmt.Printf("%s: %s\n", node, o)
+	}
 }
 
 // renderingFor is everything a node's declaration is composed with, and the node's record.
@@ -471,7 +476,7 @@ func renderingFor(ctx context.Context, open *stores, node string,
 	plan catalogue.Resolution, settings catalogue.SettingsBy,
 	gens map[string]catalogue.Generator, choosing Choosing) (catalogue.Rendering, inventory.Node, error) {
 	inv := open.inventory
-	grants, err := grantsFor(ctx, open, node)
+	grants, withheld, err := grantsFor(ctx, open, node)
 	if err != nil {
 		return catalogue.Rendering{}, inventory.Node{}, err
 	}
@@ -794,7 +799,7 @@ func renderingFor(ctx context.Context, open *stores, node string,
 		Suffix: overlay.Suffix(), MeshRange: meshRange, TunnelInterface: overlay.Interface, Accounts: accounts, Foundation: foundation,
 		Kept: kept, Adopted: record.Adopted, OutwardLinks: outwardLinks,
 		Given: given, Taken: taken, Seats: seats, ArtifactStore: artifactStore, SeatReach: reach, Built: built,
-		BusUsers: busUsers,
+		BusUsers: busUsers, Withheld: withheld,
 	}, record, nil
 }
 
@@ -930,28 +935,34 @@ func certificateFor(ctx context.Context, open *stores, node string) (string, str
 // The mirror of what a consumer is given, and the half that makes the credential real: a password
 // nothing was told to create is a password that authenticates nowhere. Sealed to this node, so
 // the mesh hands over something it cannot itself use.
-func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Grant, error) {
+//
+// **One consumer's identity never refuses the provider's machine** (novox/hq ADR 0225, issue 263).
+// A consumer whose identity overflows the provision's bound is left out of the grants and returned
+// beside them, for push, plan and `status` to say; every other consumer is granted and the provider's
+// declaration composes. Refusing here once made a whole machine unpushable for one module elsewhere.
+func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Grant, []catalogue.Overflow, error) {
 	inv := open.inventory
 	issued, err := inv.SecretsFrom(ctx, node)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Where each consumer is, so a provider that must reach back to one does not have to know how
 	// the mesh names machines.
 	shelf, err := inv.Catalogue(ctx)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	onNetwork, err := whereEveryoneIs(ctx, inv, shelf)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// What each consumer actually asked for, taken from that machine's own resolution rather than
 	// from a record beside it. A provider told to create a password and not what to create it for
 	// can do nothing with it, and the name a consumer wants is the consumer's to say.
 	out := make([]catalogue.Grant, 0, len(issued))
+	var withheld []catalogue.Overflow
 	for _, s := range issued {
 		plan, settings, err := planFor(ctx, open, s.Consumer)
 		switch {
@@ -964,11 +975,11 @@ func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Gran
 			// The mesh could not be asked what they wanted, which is not the same as their wanting
 			// nothing — and withholding a grant on that reading takes a consumer's access away
 			// (novox/hq 04-ISSUES/152).
-			return nil, fmt.Errorf("what %s asked of %s cannot be read: %w", s.Consumer, s.Name, err)
+			return nil, nil, fmt.Errorf("what %s asked of %s cannot be read: %w", s.Consumer, s.Name, err)
 		}
 		values, asks, err := plan.ContributionsFrom(s.Name, s.ConsumerModule, settings)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 		// A port in there is the consumer's software port until this. The consumer is on another
 		// machine, so the assignment that moved it is that machine's — fetched here rather than
@@ -976,7 +987,7 @@ func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Gran
 		// this case (novox/hq 04-ISSUES/038, the cross-node half).
 		published, err := portsOn(ctx, inv, s.Consumer, s.ConsumerModule)
 		if err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 		values = catalogue.AtPublishedPort(values, s.ConsumerModule, published)
 		from := s.ConsumerModule
@@ -987,9 +998,10 @@ func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Gran
 			from = ""
 		}
 		// The consumer's identity slug, from its own manifest, carried on the grant so the provider
-		// derives the same login the consumer does (novox/hq ADR 0049). Refused here if it still would
-		// not fit the tightest backend — the mesh chose the name, so the mesh refuses it, with the
-		// remedy a short slug rather than a login a provider silently shortened.
+		// derives the same login the consumer does (novox/hq ADR 0049). Judged against the bound of
+		// this provision, as the consumer's resolution states it from the provider's offer (ADR
+		// 0225): a consumer it would not fit is left out of the grants and said, rather than a login a
+		// provider silently shortened — and rather than this whole machine refused for it.
 		slug := ""
 		for _, mm := range plan.Modules {
 			if mm.Module == s.ConsumerModule {
@@ -998,15 +1010,32 @@ func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Gran
 			}
 		}
 		if from != "" {
-			if err := catalogue.CheckIdentity(s.Consumer, catalogue.IdentitySource(slug, s.ConsumerModule)); err != nil {
-				return nil, err
+			bound := boundOfGrant(plan, s, node)
+			source := catalogue.IdentitySource(slug, s.ConsumerModule)
+			if catalogue.CheckIdentityWithin(s.Consumer, source, bound) != nil {
+				withheld = append(withheld, catalogue.Overflow{Provision: s.Name, Provider: node,
+					Consumer: s.Consumer, Module: s.ConsumerModule,
+					Identity: catalogue.ConsumerIdentity(s.Consumer, source), Bound: bound})
+				continue
 			}
 		}
 		out = append(out, catalogue.Grant{
 			Provision: s.Name, Consumer: s.Consumer, At: onNetwork[s.Consumer],
 			From: from, Values: values, Slug: slug, Sealed: s.ForProvider, Local: s.Local})
 	}
-	return out, nil
+	return out, withheld, nil
+}
+
+// boundOfGrant is the identity bound the consumer's own resolution states for the requirement this
+// grant answers. A requirement not found there is held to the tightest bound the mesh knows rather
+// than to none: what the provider keeps of it is not known here.
+func boundOfGrant(consumer catalogue.Resolution, s inventory.Secret, provider string) catalogue.IdentityBound {
+	for _, n := range consumer.Needs {
+		if n.Name == s.Name && n.For == s.ConsumerModule && n.From == provider {
+			return n.Identity
+		}
+	}
+	return catalogue.DefaultIdentityBound
 }
 
 // listensLines is what a person is told about what this module would open, and why — the same
@@ -1082,6 +1111,11 @@ func planCommand(ctx context.Context, args []string) error {
 		left := plan.LeftOut(settings, record.Adopted)
 		reportLeftOut(args[0], sendable{LeftOut: sortedKeysOf(left), leftOutWhy: left})
 	}
+	// And which of its modules no provider will grant, because the identity overflows the bound of
+	// what it requires (novox/hq ADR 0225) — said on the machine the remedy is for.
+	for _, o := range plan.Overflowing() {
+		fmt.Printf("%s: %s\n", args[0], o)
+	}
 	// And a setting that reaches nothing — refused where it is stored, and said here for one
 	// stored before its definition moved from under it.
 	for _, m := range plan.Modules {

cmd/mesh-controller/readable.go

@@ -83,6 +83,9 @@ type meshStatus struct {
 	// document without this called the mesh well while the identity provider refused every consumer
 	// for a day (04-ISSUES/179).
 	Failing []inventory.ProviderStanding `json:"failing,omitempty"`
+	// Overflowing is every module whose identity overflows the bound of a provision it requires, and
+	// so is left out of its provider's grants (novox/hq ADR 0225). Absent when every identity fits.
+	Overflowing []catalogue.Overflow `json:"overflowing,omitempty"`
 }
 
 // machineFiltered is one rule set on a converged machine that the mesh did not write and that
@@ -216,6 +219,7 @@ func statusAsJSON(asked answers) ([]byte, error) {
 	}
 	out.Unheld = asked.unheld
 	out.Failing = asked.failing
+	out.Overflowing = asked.overflowing
 	for name := range asked.refused {
 		out.Unresolved = append(out.Unresolved, machineUnresolved{
 			Node: name, Problem: asked.refused[name]})

cmd/mesh-controller/sendable.go

@@ -43,6 +43,9 @@ type sendable struct {
 	LeftOut []string
 	// leftOutWhy is why each was, for push and plan to say; never on the wire.
 	leftOutWhy map[string]string
+	// withheld is every consumer this machine's grants leave out, because its identity overflows the
+	// provision's bound (novox/hq ADR 0225); for push and plan to say, never on the wire.
+	withheld []catalogue.Overflow
 	// Builds is the build of each module this declaration carries — module to the commit its build
 	// was made from — recorded with the send and never on the wire (novox/hq issue 259, ADR 0221).
 	// Composed only on the send path; nil records that it is not known.

cmd/mesh-controller/status.go

@@ -302,6 +302,19 @@ func printStatus(asked answers) error {
 		fmt.Printf("\n  `assign <node> <holder>` meets it; reported until every machine has its holders, then refused\n\n")
 	}
 
+	if len(asked.overflowing) > 0 {
+		// **Reported, and the provider still pushed** (novox/hq ADR 0225, issue 263). Each is left
+		// out of its provider's grants, so the module holds a login nothing created; the provider's
+		// machine is sent everything else rather than refused for one consumer elsewhere.
+		fmt.Printf("%d module(s) identified too long for a provision they require, and not granted it:\n",
+			len(asked.overflowing))
+		for _, o := range asked.overflowing {
+			fmt.Printf("  %-12s %-20s %-22s %q is %d, %s keeps %d\n", o.Consumer, o.Module, o.Provision,
+				o.Identity, len(o.Identity), o.Bound.In, o.Bound.Max)
+		}
+		fmt.Printf("\n  a shorter `slug` in the module's definition fits it; `module check` refuses one before merge\n\n")
+	}
+
 	if adopted := adoptedNodes(nodes); len(adopted) > 0 {
 		// Said, because nothing forces the flip: a node left adopted is visible here rather than
 		// read as converged (novox/hq ADR 0100). Not a fault, so it does not break "all well".
@@ -419,6 +432,10 @@ func theThreeQuestions(ctx context.Context, open *stores) (answers, error) {
 			return answers{}, err
 		}
 		out.unheld = append(out.unheld, plan.Unheld...)
+		// And which of its modules a provider leaves out of its grants, for an identity too long
+		// for what the provision keeps (novox/hq ADR 0225) — judged from the consumer's own
+		// resolution, as the provider's composition judges it.
+		out.overflowing = append(out.overflowing, plan.Overflowing()...)
 	}
 	// And every consumer a provider says it keeps failing (novox/hq ADR 0224). Read from what the
 	// providers announced: nothing else in the mesh knows whether a provision is being made.
@@ -538,7 +555,7 @@ func untakenModules(ctx context.Context, inv *inventory.Inventory, nodes []inven
 func (a answers) well() bool {
 	return len(a.wrong) == 0 && len(a.quiet) == 0 && len(a.behind) == 0 &&
 		len(a.waiting) == 0 && len(a.refused) == 0 && a.network == "" && len(a.untaken) == 0 &&
-		len(a.filtered) == 0 && len(a.unheld) == 0 && len(a.failing) == 0
+		len(a.filtered) == 0 && len(a.unheld) == 0 && len(a.failing) == 0 && len(a.overflowing) == 0
 }
 
 // hostSplit is which machines report which host version, for every version more than one machine