| 1 | //go:build linux |
| 2 | |
| 3 | package instancectl |
| 4 | |
| 5 | import ( |
| 6 | "context" |
| 7 | "errors" |
| 8 | "fmt" |
| 9 | "os" |
| 10 | "path/filepath" |
| 11 | "strings" |
| 12 | "sync" |
| 13 | "testing" |
| 14 | |
| 15 | "github.com/carlosframework/platform/internal/cgroup" |
| 16 | "github.com/carlosframework/platform/internal/provision" |
| 17 | "github.com/carlosframework/platform/internal/release" |
| 18 | ) |
| 19 | |
| 20 | // With generations on, the agent names the serving generation's staged |
| 21 | // build for a run's command, as it does for the legacy sidecar |
| 22 | // (zero-downtime spec §7.5). Root validates it before the host's executable |
| 23 | // mount is pointed at it, and a refusal answers 403 having started nothing. |
| 24 | // A command that names none binds the live link, as before. Only a cold |
| 25 | // slice gets the tier: a populated one belongs to the instance's owner, and |
| 26 | // during an overlap it is the raised parent of two generations (§7.3). |
| 27 | func TestCmdStartMountsTheServingStagedExe(t *testing.T) { |
| 28 | opt, exeRoot, cgroupRoot := t.TempDir(), t.TempDir(), t.TempDir() |
| 29 | staged := release.VersionPath(opt, release.OpsAccount, "v2", "blog") |
| 30 | digest := writeStaged(t, staged, "build v2") |
| 31 | good := StagedExe{Path: staged, Version: "v2", Digest: digest} |
| 32 | ctl := &fakeCtl{answers: map[string]string{ |
| 33 | "show -p ActiveState --value": "inactive\n", |
| 34 | "show -p InvocationID --value": "old\n", |
| 35 | }} |
| 36 | arm := func(inv string) { |
| 37 | ctl.onStart = func() { ctl.set("show -p InvocationID --value", inv+"\n") } |
| 38 | } |
| 39 | _, sock := serveOnSocket(t, ctl, fastCmd, func(s *Server) { |
| 40 | s.ExeRoot, s.OptDir, s.CgroupRoot = exeRoot, opt, cgroupRoot |
| 41 | s.HostApp = func(string) (string, string, error) { return release.OpsAccount, "blog", nil } |
| 42 | }) |
| 43 | c := NewClient(sock) |
| 44 | ctx := context.Background() |
| 45 | // The command's own source (merge ruling M4), not the host's app. |
| 46 | app := filepath.Join(exeRoot, provision.InstanceID(genHost), CmdExeApp) |
| 47 | |
| 48 | arm("inv-1") |
| 49 | if inv, err := c.CmdExe(ctx, genHost, cgroup.TierDefault.MemoryMax, good); err != nil || inv != "inv-1" { |
| 50 | t.Fatalf("CmdExe = %q, %v; want inv-1", inv, err) |
| 51 | } |
| 52 | if got, err := os.Readlink(app); err != nil || got != staged { |
| 53 | t.Fatalf("the command's exe = %q (%v), want the staged %q", got, err, staged) |
| 54 | } |
| 55 | if !ctlCalled(ctl, "set-property --runtime "+SliceName(genHost)) { |
| 56 | t.Fatal("a cold slice got no tier") |
| 57 | } |
| 58 | |
| 59 | for name, x := range map[string]StagedExe{ |
| 60 | "bytes that differ": {Path: staged, Version: "v2", Digest: strings.Repeat("0", 64)}, |
| 61 | "a path outside": {Path: "/etc/passwd", Version: "v2", Digest: digest}, |
| 62 | } { |
| 63 | ctl.reset() |
| 64 | if _, err := c.CmdExe(ctx, genHost, cgroup.TierDefault.MemoryMax, x); !errors.Is(err, ErrStagedExe) { |
| 65 | t.Errorf("%s: %v, want ErrStagedExe", name, err) |
| 66 | } |
| 67 | if ctlCalled(ctl, "start") || ctlCalled(ctl, "set-property") { |
| 68 | t.Errorf("%s: a refused command reached systemd:\n%s", name, ctl.joined()) |
| 69 | } |
| 70 | if got, _ := os.Readlink(app); got != staged { |
| 71 | t.Errorf("%s: a refused command moved the mount to %q", name, got) |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | events := filepath.Join(cgroupRoot, parentSlices, SliceName(genHost), "cgroup.events") |
| 76 | if err := os.MkdirAll(filepath.Dir(events), 0o755); err != nil { |
| 77 | t.Fatal(err) |
| 78 | } |
| 79 | if err := os.WriteFile(events, []byte("populated 1\nfrozen 0\n"), 0o644); err != nil { |
| 80 | t.Fatal(err) |
| 81 | } |
| 82 | ctl.reset() |
| 83 | arm("inv-2") |
| 84 | if _, err := c.CmdExe(ctx, genHost, cgroup.TierDefault.MemoryMax, good); err != nil { |
| 85 | t.Fatal(err) |
| 86 | } |
| 87 | if ctlCalled(ctl, "set-property") { |
| 88 | t.Fatal("a command rewrote the populated slice's limit") |
| 89 | } |
| 90 | |
| 91 | ctl.reset() |
| 92 | arm("inv-3") |
| 93 | if _, err := c.Cmd(ctx, genHost, cgroup.TierDefault.MemoryMax); err != nil { |
| 94 | t.Fatal(err) |
| 95 | } |
| 96 | if got, err := os.Readlink(app); err != nil || got != filepath.Join(LiveDir, genHost) { |
| 97 | t.Fatalf("a command naming no build has exe %q (%v), want the live link", got, err) |
| 98 | } |
| 99 | if ctlCalled(ctl, "set-property") { |
| 100 | t.Fatal("a command without a build rewrote the populated slice's limit") |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | // bindRecorder is a systemctl that reads, at each start, the source the |
| 105 | // starting unit binds as its /opt/carlos/app, which is what systemd would |
| 106 | // bind at that moment: cmd-app for a command, app for a sidecar. |
| 107 | type bindRecorder struct { |
| 108 | mu sync.Mutex |
| 109 | dir string // <ExeRoot>/<instance id> |
| 110 | inv int |
| 111 | cmd []string // what each command start would bind |
| 112 | sidecar []string // what each sidecar start would bind |
| 113 | } |
| 114 | |
| 115 | func (r *bindRecorder) run(_ context.Context, args ...string) (string, error) { |
| 116 | line := strings.Join(args, " ") |
| 117 | switch { |
| 118 | case args[0] == "start": |
| 119 | unit := args[len(args)-1] |
| 120 | src, into := "app", &r.sidecar |
| 121 | if strings.HasPrefix(unit, UnitPrefixCmd) { |
| 122 | src, into = CmdExeApp, &r.cmd |
| 123 | } |
| 124 | got, err := os.Readlink(filepath.Join(r.dir, src)) |
| 125 | if err != nil { |
| 126 | got = err.Error() |
| 127 | } |
| 128 | r.mu.Lock() |
| 129 | *into = append(*into, got) |
| 130 | r.inv++ |
| 131 | r.mu.Unlock() |
| 132 | case strings.HasPrefix(line, "show -p InvocationID --value"): |
| 133 | r.mu.Lock() |
| 134 | defer r.mu.Unlock() |
| 135 | return fmt.Sprintf("inv-%d\n", r.inv), nil |
| 136 | case strings.HasPrefix(line, "show -p ActiveState --value"): |
| 137 | return "inactive\n", nil |
| 138 | } |
| 139 | return "", nil |
| 140 | } |
| 141 | |
| 142 | // A command and a sidecar of one instance start at the same time on |
| 143 | // different builds, as around a swap: each start binds its own build, |
| 144 | // because the command's source is its own (merge ruling M4). With one |
| 145 | // shared source, either start could repoint the other's before systemd |
| 146 | // binds it. A stopped command's source is removed. |
| 147 | func TestConcurrentCmdAndSidecarStartsBindTheirOwnBuilds(t *testing.T) { |
| 148 | const host = "shop.example.com" |
| 149 | opt, exeRoot := t.TempDir(), t.TempDir() |
| 150 | stage := func(v string) StagedExe { |
| 151 | path := release.VersionPath(opt, release.OpsAccount, v, "blog") |
| 152 | return StagedExe{Path: path, Version: v, Digest: writeStaged(t, path, "build "+v)} |
| 153 | } |
| 154 | cmdBuild, sidecarBuild := stage("v2"), stage("v3") |
| 155 | rec := &bindRecorder{dir: filepath.Join(exeRoot, provision.InstanceID(host))} |
| 156 | _, sock := serveOnSocket(t, &fakeCtl{answers: map[string]string{}}, fastCmd, func(s *Server) { |
| 157 | s.Systemctl = rec.run |
| 158 | s.ExeRoot, s.OptDir = exeRoot, opt |
| 159 | s.HostApp = func(string) (string, string, error) { return release.OpsAccount, "blog", nil } |
| 160 | }) |
| 161 | c := NewClient(sock) |
| 162 | ctx := context.Background() |
| 163 | const rounds = 40 |
| 164 | var wg sync.WaitGroup |
| 165 | errs := make(chan error, 2*rounds) |
| 166 | wg.Add(2) |
| 167 | go func() { |
| 168 | defer wg.Done() |
| 169 | for range rounds { |
| 170 | if _, err := c.CmdExe(ctx, host, cgroup.TierDefault.MemoryMax, cmdBuild); err != nil { |
| 171 | errs <- fmt.Errorf("CmdExe: %w", err) |
| 172 | } |
| 173 | } |
| 174 | }() |
| 175 | go func() { |
| 176 | defer wg.Done() |
| 177 | for range rounds { |
| 178 | if _, err := c.StartSidecarExe(ctx, host, cgroup.TierDefault.MemoryMax, sidecarBuild); err != nil { |
| 179 | errs <- fmt.Errorf("StartSidecarExe: %w", err) |
| 180 | } |
| 181 | } |
| 182 | }() |
| 183 | wg.Wait() |
| 184 | close(errs) |
| 185 | for err := range errs { |
| 186 | t.Fatal(err) |
| 187 | } |
| 188 | rec.mu.Lock() |
| 189 | defer rec.mu.Unlock() |
| 190 | if len(rec.cmd) != rounds || len(rec.sidecar) != rounds { |
| 191 | t.Fatalf("starts: %d commands, %d sidecars; want %d each", len(rec.cmd), len(rec.sidecar), rounds) |
| 192 | } |
| 193 | for i, got := range rec.cmd { |
| 194 | if got != cmdBuild.Path { |
| 195 | t.Fatalf("command start %d would bind %q, want its own build %q", i, got, cmdBuild.Path) |
| 196 | } |
| 197 | } |
| 198 | for i, got := range rec.sidecar { |
| 199 | if got != sidecarBuild.Path { |
| 200 | t.Fatalf("sidecar start %d would bind %q, want its own build %q", i, got, sidecarBuild.Path) |
| 201 | } |
| 202 | } |
| 203 | if err := c.Stop(ctx, host, RoleCmd); err != nil { |
| 204 | t.Fatal(err) |
| 205 | } |
| 206 | for _, name := range []string{CmdExeApp, CmdExeLive} { |
| 207 | if _, err := os.Lstat(filepath.Join(rec.dir, name)); !os.IsNotExist(err) { |
| 208 | t.Errorf("%s survived the command's stop (%v)", name, err) |
| 209 | } |
| 210 | } |
| 211 | if got, err := os.Readlink(filepath.Join(rec.dir, "app")); err != nil || got != sidecarBuild.Path { |
| 212 | t.Errorf("the command's stop touched the host's app: %q (%v)", got, err) |
| 213 | } |
| 214 | } |
| 215 | |
amadan