mesh-controller/examples/postgres-provisioner/where_test.go

package main

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

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

// The password comes from a file, because that is how the mesh delivers one.
//
// A provisioner told to take a superuser password from an environment variable needs somebody to
// read the sealed file and pass it in — a person in the middle of the one path that exists so
// there is not one. It is also the difference between a credential in a file and one in a process
// listing: `docker inspect` prints environment.
func TestTheSuperuserPasswordComesFromTheFileTheMeshWrote(t *testing.T) {
	path := filepath.Join(t.TempDir(), "superuser")
	if err := os.WriteFile(path, []byte("the-sealed-one\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("MESH_PROVISION_POSTGRES", "postgres://postgres@127.0.0.1:5433/postgres?sslmode=disable")
	t.Setenv("MESH_PROVISION_PASSWORD_FILE", path)

	where, err := connectionString()
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(where, "the-sealed-one") {
		t.Fatalf("the password the mesh wrote is not in the connection: %s", where)
	}
	if !strings.Contains(where, "127.0.0.1:5433") || !strings.Contains(where, "sslmode=disable") {
		t.Fatalf("the rest of the connection was lost: %s", where)
	}
}

// An empty file connects as nobody and is refused by the database three layers away, as an
// authentication problem with no cause anybody changed.
func TestAnEmptyPasswordFileIsRefusedHere(t *testing.T) {
	path := filepath.Join(t.TempDir(), "superuser")
	if err := os.WriteFile(path, []byte("\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("MESH_PROVISION_POSTGRES", "postgres://postgres@127.0.0.1:5433/postgres")
	t.Setenv("MESH_PROVISION_PASSWORD_FILE", path)
	if _, err := connectionString(); err == nil {
		t.Fatal("a provisioner with no password reported one")
	}
}

// And a provisioner somebody runs by hand still works with the URL alone.
func TestAConnectionWithNoPasswordFileIsLeftAlone(t *testing.T) {
	t.Setenv("MESH_PROVISION_POSTGRES", "postgres://postgres:typed@127.0.0.1:5433/postgres")
	t.Setenv("MESH_PROVISION_PASSWORD_FILE", "")
	where, err := connectionString()
	if err != nil {
		t.Fatal(err)
	}
	if where != "postgres://postgres:typed@127.0.0.1:5433/postgres" {
		t.Fatalf("the connection was rewritten when it should have been left alone: %s", where)
	}
}

func TestAProvisionerWithNoDatabaseSaysSo(t *testing.T) {
	t.Setenv("MESH_PROVISION_POSTGRES", "")
	t.Setenv("MESH_PROVISION_PASSWORD_FILE", "")
	if _, err := connectionString(); err == nil {
		t.Fatal("a provisioner that does not know which database it owns reported one")
	}
}

// PostgreSQL cuts an identifier at 63 bytes and says so only as a notice, so two consumers whose
// role names agree that far would quietly become one login — 022 again, at a length nobody tests.
func TestARoleNameTooLongToBeDistinctIsRefused(t *testing.T) {
	if err := usableRole("mesh_anchor_gitea"); err != nil {
		t.Fatalf("an ordinary name was refused: %v", err)
	}
	long := "mesh_" + strings.Repeat("n", 40) + "_" + strings.Repeat("m", 40)
	err := usableRole(long)
	if err == nil {
		t.Fatal("a role name PostgreSQL would shorten was accepted")
	}
	if !strings.Contains(err.Error(), "share the login") {
		t.Errorf("the refusal does not say what goes wrong: %v", err)
	}
}

// The prefix this provisioner removes by is the prefix the mesh names by.
//
// **Two definitions on purpose.** A provisioner is a separate program and anyone may write one, so
// the prefix is part of the contract rather than a symbol to import — the same reason the grant
// file's shape is written down rather than shared. But a contract with two copies and no check is
// a contract until somebody edits one: if the mesh named `nox_` and this removed `mesh_`, every
// login it created would be permanent, and nothing would report anything at all.
func TestTheMarkAgreesWithWhatTheMeshNamesBy(t *testing.T) {
	if mark != catalogue.IdentityPrefix {
		t.Fatalf(
			"this provisioner removes what begins with %q and the mesh names things %q, so it "+
				"would never remove anything it made", mark, catalogue.IdentityPrefix)
	}
}

// And a name the mesh would produce is one this provisioner accepts.
func TestWhatTheMeshNamesIsUsableAsARole(t *testing.T) {
	if err := usableRole(catalogue.ConsumerIdentity("home-server", "keycloak")); err != nil {
		t.Fatalf("the mesh named a consumer and this cannot make a role for it: %v", err)
	}
}