mesh-host/internal/compose/resolution/own_name_test.go

package resolution

import (
	"encoding/json"
	"strings"
	"testing"

	mcat "git.novox.be/novox/mesh-sdk/go/catalogue"
)

// selfAware contributes a labelled route, binds the requirement, and writes its own name into a file.
func selfAware(label string) mcat.Manifest {
	m := labelled("board", label, 8080)
	m.Requires = []string{"reverse-proxy"}
	m.Binds = map[string]string{"reverse-proxy": "/var/lib/board/route.json"}
	m.Resources = []map[string]any{
		{"id": "conf", "type": "file", "path": "/var/lib/board/app.conf",
			"content": "root = https://${bound:reverse-proxy:name}/\ninternal = ${bound:reverse-proxy:internal-name}\n"},
	}
	return m
}

// servingProxy is proxy() as the catalogue's route providers are declared: the provision scoped to
// the mesh, serving nothing a consumer must know (route-adapter, route-proxy: `"serves": {"route": {}}`).
func servingProxy() mcat.Manifest {
	p := proxy()
	p.Provides = []mcat.Offer{{Name: "reverse-proxy", Scope: mcat.ScopeMesh}}
	p.Serves = map[string]map[string]any{"reverse-proxy": {}}
	return p
}

// nodeProxy is the same provider scoped to its node, whose answer on the same machine comes from
// `here` rather than from the mesh's needs — the other path a binding is written by.
func nodeProxy() mcat.Manifest {
	p := proxy()
	p.Serves = map[string]map[string]any{"reverse-proxy": {"scheme": "http"}}
	return p
}

// onBoth is a node with a public domain and a private-network address, so both names compose.
func onBoth(domain string) mcat.Node {
	n := withDomain(domain)
	n.At = "anchor.internal"
	return n
}

func fileAt(t *testing.T, out []map[string]any, path string) string {
	t.Helper()
	for _, r := range out {
		if r["path"] == path {
			return r["content"].(string)
		}
	}
	t.Fatalf("nothing was declared at %s", path)
	return ""
}

func TestAModuleIsToldTheNameItsProviderServes(t *testing.T) {
	got, err := Resolve(shelf(servingProxy(), selfAware("git")), []string{"traefik", "board"},
		onBoth("example.tld"), mcat.World{})
	if err != nil {
		t.Fatal(err)
	}
	out := mustDeclare(t, got)
	served := received(t, out)[0].Values

	var binding map[string]any
	if err := json.Unmarshal([]byte(fileAt(t, out, "/var/lib/board/route.json")), &binding); err != nil {
		t.Fatal(err)
	}
	if binding["name"] != served["name"] || binding["name"] != "git.example.tld" {
		t.Fatalf("the module was told %v, the provider serves %v", binding["name"], served["name"])
	}
	if binding["internal-name"] != served["internal-name"] || binding["internal-name"] == nil {
		t.Fatalf("internal name: module told %v, provider serves %v",
			binding["internal-name"], served["internal-name"])
	}

	conf := fileAt(t, out, "/var/lib/board/app.conf")
	want := "root = https://git.example.tld/\ninternal = " + served["internal-name"].(string) + "\n"
	if conf != want {
		t.Fatalf("the file was rendered as\n%s\nwant\n%s", conf, want)
	}
}

func TestTheNameAModuleIsToldFollowsTheNodesDomain(t *testing.T) {
	// The whole point: the same definition, two machines, two names — nothing edited.
	for _, domain := range []string{"example.tld", "other.example"} {
		got, err := Resolve(shelf(servingProxy(), selfAware("git")), []string{"traefik", "board"},
			onBoth(domain), mcat.World{})
		if err != nil {
			t.Fatal(err)
		}
		conf := fileAt(t, mustDeclare(t, got), "/var/lib/board/app.conf")
		if !strings.HasPrefix(conf, "root = https://git."+domain+"/") {
			t.Fatalf("on %s the module wrote %q", domain, conf)
		}
	}
}

func TestAModuleWithNoPublicNameIsNotToldOne(t *testing.T) {
	// No public domain on the node: nothing composed, so no `name` — and a file asking for one is
	// refused rather than rendered with a placeholder or an empty host.
	m := selfAware("git")
	m.Resources[0]["content"] = "root = https://${bound:reverse-proxy:name}/\n"
	got, err := Resolve(shelf(servingProxy(), m), []string{"traefik", "board"}, workstation(), mcat.World{})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := Declaration(got, mcat.Rendering{}); err == nil ||
		!strings.Contains(err.Error(), `"name"`) {
		t.Fatalf("a file asking for a name that was never composed was not refused: %v", err)
	}
}

func TestAModuleIsToldItsNameByANodeScopedProviderToo(t *testing.T) {
	m := selfAware("git")
	m.Resources[0]["content"] = "root = https://${bound:reverse-proxy:name}/\n"
	got, err := Resolve(shelf(nodeProxy(), m), []string{"board"},
		withDomain("example.tld"), mcat.World{})
	if err != nil {
		t.Fatal(err)
	}
	conf := fileAt(t, mustDeclare(t, got), "/var/lib/board/app.conf")
	if !strings.HasPrefix(conf, "root = https://git.example.tld/") {
		t.Fatalf("a same-machine, node-scoped answer did not tell the module its name: %q", conf)
	}
}