mesh-controller/cmd/mesh-controller/merge_gate_test.go

package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/novox/mesh-controller/internal/catalogue"
	snapshot "github.com/novox/mesh-controller/internal/facts"
	"github.com/novox/mesh-controller/internal/inventory"
)

// The merge gate (novox/hq to-be 45 §9): a change judged against every machine of the snapshot, by the
// incidents it is written from. Each case raises a mesh, takes its snapshot, and judges a pull request's
// tree against it in throwaway stores of its own.

// catalogueMesh is two machines and a catalogue repository: a resolver and an object store on the
// anchor, and on the laptop a network manager requiring the resolver, an album requiring the object
// store, and a login manager. Every module is registered from novox/mesh-catalog, as the mesh's are.
func catalogueMesh(t *testing.T) (snapshot.Facts, map[string]string) {
	t.Helper()
	open := aMesh(t)
	ctx := t.Context()
	manifests := map[string]string{
		"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": `{"module":"resolver","version":"1",
			"provides":[{"name":"wildcard-resolution","scope":"mesh","identity":false}]}`,
		"networkmanager": `{"module":"networkmanager","version":"1","requires":["wildcard-resolution"]}`,
		"album":          `{"module":"album","version":"1","requires":["s3-bucket"]}`,
		"lemurs": `{"module":"lemurs","version":"1","capabilities":["systemd"],
			"resources":[{"id":"service","type":"service","unit":"lemurs.service","state":"running","boot":"enabled"}]}`,
	}
	for name, raw := range manifests {
		m, err := catalogue.ParseManifest([]byte(raw))
		if err != nil {
			t.Fatalf("%s: %v", name, err)
		}
		if err := open.inventory.RegisterModule(ctx, m, inventory.Source{Repository: "novox/mesh-catalog",
			Path: "modules/" + name, BuiltFrom: "c0ffee"}); err != nil {
			t.Fatal(err)
		}
	}
	for _, a := range [][2]string{{"anchor", "objects"}, {"anchor", "resolver"}, {"laptop", "networkmanager"},
		{"laptop", "album"}, {"laptop", "lemurs"}} {
		if _, err := assign(ctx, open, a[0], a[1]); err != nil {
			t.Fatalf("assign %s %s: %v", a[0], a[1], err)
		}
	}
	f, err := gatherFacts(ctx, open, "2.11.17")
	if err != nil {
		t.Fatal(err)
	}
	return f, manifests
}

// aTree is a checkout of the catalogue repository holding these manifests.
func aTree(t *testing.T, manifests map[string]string) string {
	t.Helper()
	dir := t.TempDir()
	for name, raw := range manifests {
		at := filepath.Join(dir, "modules", name)
		if err := os.MkdirAll(at, 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(filepath.Join(at, "module.json"), []byte(raw), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	return dir
}

func gateJudged(t *testing.T, f snapshot.Facts, tree string, changed ...string) mergeVerdict {
	t.Helper()
	admin := os.Getenv("MESH_TEST_POSTGRES")
	in := mergeCheckInput{facts: f, admin: admin, changed: changed}
	if tree != "" {
		in.repository, in.tree = "novox/mesh-catalog", tree
	}
	v, err := judgeChange(t.Context(), in)
	if err != nil {
		t.Fatal(err)
	}
	return v
}

func withEdit(manifests map[string]string, name, raw string) map[string]string {
	out := map[string]string{}
	for k, v := range manifests {
		out[k] = v
	}
	if raw == "" {
		delete(out, name)
	} else {
		out[name] = raw
	}
	return out
}

// The mesh as it is passes: every machine composes in the gate's store as the controller composed it.
func TestTheMeshAsItIsPassesTheGate(t *testing.T) {
	f, manifests := catalogueMesh(t)
	for _, m := range f.Machines {
		if !m.Declaration.Composes {
			t.Fatalf("the mesh itself does not compose: %+v", m.Declaration)
		}
	}
	v := gateJudged(t, f, aTree(t, manifests))
	if v.Verdict != "pass" {
		t.Fatalf("an unchanged catalogue does not pass:\n%s", v.Report())
	}
	for _, m := range v.Machines {
		if !m.Base.Composes || !m.Change.Composes {
			t.Errorf("%s does not compose in the gate's store as it does on the mesh: %+v / %+v", m.Described, m.Base, m.Change)
		}
	}
}

// **Issue 263**: a change makes the network manager require the object store's provision; on a machine
// whose name is six characters its identity is 26 against a bound of 20. Refused in the pull request,
// naming the module, and not on the anchor after it merged.
func TestIssue263AnIdentityARealMachineNameOverflowsFailsThePullRequest(t *testing.T) {
	f, manifests := catalogueMesh(t)
	tree := aTree(t, withEdit(manifests, "networkmanager",
		`{"module":"networkmanager","version":"1","requires":["wildcard-resolution","s3-bucket"]}`))
	v := gateJudged(t, f, tree)
	if v.Verdict != "fail" {
		t.Fatalf("the overflow passed the gate:\n%s", v.Report())
	}
	report := v.Report()
	if !strings.Contains(report, "networkmanager") || !strings.Contains(report, "s3-bucket") {
		t.Errorf("the refusal does not name the module and the provision:\n%s", report)
	}
}

// **Issue 236**: a login manager's service that omits its state passed the catalogue check and was
// refused whole by the node-engine on the first machine. A change to a module a machine runs, and a
// module nobody runs yet, are both refused before merge, naming the machine and the module.
func TestIssue236AManifestTheNodeEngineRefusesFailsThePullRequest(t *testing.T) {
	f, manifests := catalogueMesh(t)
	broken := `{"module":"lemurs","version":"1","capabilities":["systemd"],
		"resources":[{"id":"service","type":"service","unit":"lemurs.service","boot":"enabled"}]}`
	v := gateJudged(t, f, aTree(t, withEdit(manifests, "lemurs", broken)))
	if v.Verdict != "fail" || !strings.Contains(v.Report(), "lemurs") {
		t.Fatalf("a service the node-engine refuses passed the gate:\n%s", v.Report())
	}
	laptop := snapshot.Pseudonym("machine", "laptop")
	if !strings.Contains(v.Report(), laptop) {
		t.Errorf("the refusal does not name the machine it would be refused on:\n%s", v.Report())
	}

	// And as a new module, which no machine runs: tried on one that could.
	newcomer := strings.ReplaceAll(broken, `"lemurs"`, `"greeter"`)
	newcomer = strings.ReplaceAll(newcomer, "lemurs.service", "greeter.service")
	v = gateJudged(t, f, aTree(t, withEdit(manifests, "greeter", newcomer)))
	if v.Verdict != "fail" || !strings.Contains(v.Report(), "greeter, assigned to") {
		t.Fatalf("a new module the node-engine would refuse passed the gate:\n%s", v.Report())
	}
}

// **Version skew**: a manifest the controller judging it cannot read — the one the mesh runs, for a
// catalogue change — fails here, not at registration after the merge.
func TestAManifestTheRunningControllerCannotReadFailsThePullRequest(t *testing.T) {
	f, manifests := catalogueMesh(t)
	v := gateJudged(t, f, aTree(t, withEdit(manifests, "album",
		`{"module":"album","version":"1","requires":["s3-bucket"],"a-field-of-a-newer-controller":true}`)))
	if v.Verdict != "fail" || !strings.Contains(v.Report(), "refuses it") {
		t.Fatalf("a manifest this controller cannot read passed:\n%s", v.Report())
	}
}

// A module a machine runs, removed from its source, fails until it is unassigned (ADR 0236).
func TestAModuleAMachineRunsRemovedFromItsSourceFails(t *testing.T) {
	f, manifests := catalogueMesh(t)
	v := gateJudged(t, f, aTree(t, withEdit(manifests, "album", "")))
	if v.Verdict != "fail" || !strings.Contains(v.Report(), "album is removed") {
		t.Fatalf("removing a module a machine runs passed:\n%s", v.Report())
	}
}

// **Issue 278**: a file of a module nobody holds read as shared code, and the merge rebuilt the
// catalogue. The gate says how wide a merge's rebuild is, and warns when shared code makes it wide.
func TestIssue278AWideRebuildIsSaidBeforeTheMerge(t *testing.T) {
	f, manifests := catalogueMesh(t)
	was := wideRebuild
	wideRebuild = 2
	t.Cleanup(func() { wideRebuild = was })
	v := gateJudged(t, f, aTree(t, manifests), "modules/showcase/index.ts")
	if v.Width == nil || len(v.Width.Modules) < 5 || len(v.Width.Shared) != 1 {
		t.Fatalf("the width reads %+v", v.Width)
	}
	if v.Verdict != "warning" || !strings.Contains(v.Report(), "shared") {
		t.Fatalf("a rebuild of everything for one shared file is not said:\n%s", v.Report())
	}
	// The same file, with the reference module's definition in the tree: its directory is a module, held
	// or not, and the file is its business alone (the fix of 278, read from the tree as the announcer does).
	withShowcase := withEdit(manifests, "showcase", `{"module":"showcase","version":"1"}`)
	v = gateJudged(t, f, aTree(t, withShowcase), "modules/showcase/index.ts")
	if v.Width == nil || len(v.Width.Modules) != 0 || len(v.Width.Shared) != 0 {
		t.Fatalf("a file of a module nobody holds still reads as shared: %+v", v.Width)
	}
	v = gateJudged(t, f, aTree(t, manifests), "modules/album/module.json")
	if v.Width == nil || strings.Join(v.Width.Modules, ",") != "album" || v.Verdict != "pass" {
		t.Fatalf("a change to one module's directory reads %+v, %s", v.Width, v.Verdict)
	}
}