mesh-host/internal/apply/left_out_test.go

package apply

import (
	"context"
	"errors"
	"strings"
	"testing"

	"github.com/novox/mesh-host/internal/declaration"
	"github.com/novox/mesh-host/internal/store"
)

// A taken container keeps a found network by a per-machine setting (novox/hq ADR 0163, rule 4):
// joined once it runs, part of its spec, and refused when it cannot be joined.
func TestAContainerJoinsTheNetworksItKeeps(t *testing.T) {
	var ran []string
	connectFails := false
	run := func(_ context.Context, name string, args ...string) (string, error) {
		if name != "docker" {
			return "", errors.New("not installed")
		}
		ran = append(ran, strings.Join(args, " "))
		switch args[0] {
		case "info":
			return "29.0.0\n", nil
		case "container":
			if len(ran) > 2 {
				return "true\t" + specOfLast, nil
			}
			return "false\t\n", errors.New("no such container")
		case "run":
			return "deadbeef\n", nil
		case "network":
			if connectFails {
				return "", errors.New("network predecessor_default not found")
			}
		}
		return "", nil
	}
	d := parseTrusted(t, `{"declaration":1,"resources":[
	  {"id":"app","type":"container","name":"app","image":"`+pinned+`",
	   "networks":["predecessor_default"]}
	]}`)
	specOfLast = containerSpec(d.Resources[0].(*declaration.Container), inputs{})
	alone := *d.Resources[0].(*declaration.Container)
	alone.Networks = nil
	if specOfLast == containerSpec(&alone, inputs{}) {
		t.Fatal("the kept network is not part of the container's spec: kept or let go, the container would be left alone")
	}
	report, _, err := Apply(context.Background(), archHost(t), d, store.State{}, store.OriginCarried, run, nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	joined := false
	for i, line := range ran {
		if line == "network connect predecessor_default app" {
			joined = true
			if ran[i-1] != "container inspect --format {{.State.Running}}\t{{index .Config.Labels \""+specLabel+"\"}} app" &&
				!strings.HasPrefix(ran[i-1], "container inspect") {
				t.Errorf("joined before the container was read back as running: %v", ran)
			}
		}
	}
	if !joined || report.Outcomes[0].Action != "created" {
		t.Fatalf("the container did not join the kept network: %v\n%+v", ran, report.Outcomes)
	}

	connectFails, ran = true, nil
	if _, _, err := Apply(context.Background(), archHost(t), d, store.State{}, store.OriginCarried, run, nil, nil); err == nil ||
		!strings.Contains(err.Error(), "could not join the kept network predecessor_default") {
		t.Fatalf("a network that cannot be joined was passed over: %v", err)
	}
}

var specOfLast string

// A module the mesh left out of a declaration is not a module the mesh removed (novox/hq ADR 0163,
// rule 6): what the host wrote for it stays, recorded and said; what it holds for it stays held.
// A module simply absent is removed as it always was.
func TestALeftOutModuleIsNeitherRemovedNorForgotten(t *testing.T) {
	var removed []string
	gone := map[string]bool{}
	run := func(_ context.Context, name string, args ...string) (string, error) {
		if name != "docker" {
			return "", nil
		}
		switch args[0] {
		case "info":
			return "29.0.0\n", nil
		case "rm":
			removed = append(removed, args[len(args)-1])
			gone[args[len(args)-1]] = true
		case "container":
			if gone[args[len(args)-1]] {
				return "", errors.New("no such container")
			}
			return "true\tspec", nil
		}
		return "", nil
	}
	known := store.State{
		Resources: []store.Applied{
			{ID: "web.server", Type: "container", Target: "web", Origin: store.OriginDeclared},
			{ID: "old.server", Type: "container", Target: "old", Origin: store.OriginDeclared},
		},
		Held: []store.Held{{ID: "web.page", Module: "web", Kind: "file", Target: "/srv/web/index.html"}},
	}
	d := parse(t, `{"declaration":1,"left_out":["web"],"resources":[
	  {"id":"notes.conf","type":"file","path":"`+t.TempDir()+`/notes.conf","content":"x"}
	]}`)
	report, state, err := Apply(context.Background(), archHost(t), d, known, store.OriginDeclared, run, nil, nil)
	if err != nil {
		t.Fatal(err)
	}
	if len(removed) != 1 || removed[0] != "old" {
		t.Fatalf("removed %v; only the module that is absent goes", removed)
	}
	if _, kept := state.At("container", "web"); !kept {
		t.Fatal("the left-out module's record was forgotten")
	}
	if _, held := state.HeldAt("web.page"); !held {
		t.Fatal("the left-out module's hold was released")
	}
	said := false
	for _, o := range report.Outcomes {
		if o.ID == "web.server" && o.Action == "unchanged" && strings.Contains(o.Detail, "web was left out of this declaration by the mesh") {
			said = true
		}
		if o.ID == "web.server" && o.Action != "unchanged" {
			t.Errorf("the left-out module's container was %s", o.Action)
		}
	}
	if !said {
		t.Fatalf("keeping the left-out module's container was not said: %+v", report.Outcomes)
	}
}