| 1 | package hostops |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "context" |
| 6 | "encoding/json" |
| 7 | "errors" |
| 8 | "os" |
| 9 | "reflect" |
| 10 | "time" |
| 11 | |
| 12 | "github.com/carlosframework/platform/internal/hostclaim" |
| 13 | "github.com/carlosframework/platform/internal/release" |
| 14 | ) |
| 15 | |
| 16 | // PurgeRequestKey is the box-written automatic purge request. The console |
| 17 | // consumes it only through DiscardPurgeRequest or RemovePurgeJournal. |
| 18 | func PurgeRequestKey(account, app string) (string, error) { |
| 19 | if _, err := AdmissionKey(account, app); err != nil { |
| 20 | return "", err |
| 21 | } |
| 22 | return "apps/" + account + "/" + app + "/purge-request.json", nil |
| 23 | } |
| 24 | |
| 25 | func validNewJournal(j PurgeJournal) error { |
| 26 | if j.V != 1 || j.ID == "" || j.AppID == "" || j.Phase != "reserved" || j.Hosts == nil { |
| 27 | return ErrIdentity |
| 28 | } |
| 29 | if j.Tombstone.Key != release.AppTombstoneKey(j.Account, j.App) || j.Tombstone.ETag == "" || !json.Valid(j.Tombstone.Body) { |
| 30 | return ErrIdentity |
| 31 | } |
| 32 | return nil |
| 33 | } |
| 34 | |
| 35 | // ReservePurge registers the purge reservation, then writes the journal |
| 36 | // create-only. The journal is the durable intent BeginPurge transfers to the |
| 37 | // exclusive operation; losing that CAS leaves only an admitted reservation |
| 38 | // with no teardown authority. |
| 39 | func (w *ControlWriter) ReservePurge(ctx context.Context, j PurgeJournal, owner RegistrationOwner, now time.Time) (string, error) { |
| 40 | if err := w.ready(); err != nil { |
| 41 | return "", err |
| 42 | } |
| 43 | if !validRegistrationOwner(owner) { |
| 44 | return "", ErrIdentity |
| 45 | } |
| 46 | key, err := PurgeKey(j.Account, j.App) |
| 47 | if err != nil { |
| 48 | return "", err |
| 49 | } |
| 50 | a, err := w.read(ctx, j.Account, j.App, j.AppID) |
| 51 | if err != nil { |
| 52 | return "", err |
| 53 | } |
| 54 | if j.AdmissionEpoch == 0 { |
| 55 | j.AdmissionEpoch = a.Value.Epoch |
| 56 | } |
| 57 | if err = validNewJournal(j); err != nil || j.AdmissionEpoch != a.Value.Epoch { |
| 58 | return "", ErrIdentity |
| 59 | } |
| 60 | if existing, tag, gerr := w.raw.Get(ctx, key); gerr == nil { |
| 61 | var seen struct { |
| 62 | ID string `json:"id"` |
| 63 | AppID string `json:"app_id"` |
| 64 | } |
| 65 | if json.Unmarshal(existing, &seen) == nil && seen.ID == j.ID && seen.AppID == j.AppID && tag != "" { |
| 66 | return tag, nil |
| 67 | } |
| 68 | // Another purge's journal (or a malformed one) holds the name. |
| 69 | return "", ErrPending |
| 70 | } else if !errors.Is(gerr, os.ErrNotExist) { |
| 71 | return "", gerr |
| 72 | } |
| 73 | body, tag, err := w.raw.Get(ctx, j.Tombstone.Key) |
| 74 | if err != nil { |
| 75 | return "", err |
| 76 | } |
| 77 | if tag != j.Tombstone.ETag || !bytes.Equal(body, j.Tombstone.Body) { |
| 78 | return "", ErrPending |
| 79 | } |
| 80 | if a.Value.State != "open" || a.Value.Op != nil { |
| 81 | return "", ErrPending |
| 82 | } |
| 83 | if _, ok := a.Value.Registrations[j.ID]; !ok { |
| 84 | reg := Registration{Kind: registrationPurge, Owner: owner, AppID: j.AppID, Epoch: a.Value.Epoch} |
| 85 | if a, err = w.updateAdmission(ctx, a, func(v *AppAdmission) error { return registerStart(v, j.ID, reg, now) }); err != nil { |
| 86 | return "", err |
| 87 | } |
| 88 | } |
| 89 | reg := a.Value.Registrations[j.ID] |
| 90 | if reg.Kind != registrationPurge || reg.Owner != owner || !RegistrationLive(reg, now) { |
| 91 | return "", ErrPending |
| 92 | } |
| 93 | raw, err := json.Marshal(j) |
| 94 | if err != nil { |
| 95 | return "", err |
| 96 | } |
| 97 | return w.raw.Put(ctx, key, raw, "") |
| 98 | } |
| 99 | |
| 100 | // BeginPurge transfers the reserved journal into the exclusive purging |
| 101 | // operation, removing its own reservation registration in the same CAS. |
| 102 | // Replays return a handle for the existing operation. |
| 103 | func (w *ControlWriter) BeginPurge(ctx context.Context, account, app, appID, id string, owner RegistrationOwner) (*OperationHandle, error) { |
| 104 | if !validRegistrationOwner(owner) { |
| 105 | return nil, ErrIdentity |
| 106 | } |
| 107 | j, _, err := ReadPurgeJournal(ctx, w.raw, account, app, id, appID) |
| 108 | if err != nil { |
| 109 | return nil, err |
| 110 | } |
| 111 | a, err := w.read(ctx, account, app, appID) |
| 112 | if err != nil { |
| 113 | return nil, err |
| 114 | } |
| 115 | if op := a.Value.Op; op != nil { |
| 116 | if a.Value.State == "closed" && op.ID == id && op.Kind == OpPurging { |
| 117 | return &OperationHandle{w: w, account: account, app: app, appID: appID, id: id, kind: OpPurging, owner: owner}, nil |
| 118 | } |
| 119 | return nil, ErrPending |
| 120 | } |
| 121 | if j.Phase != "reserved" || j.AdmissionEpoch != a.Value.Epoch { |
| 122 | return nil, ErrPending |
| 123 | } |
| 124 | if _, err = w.updateAdmission(ctx, a, func(v *AppAdmission) error { |
| 125 | op := AppOperation{ID: id, Kind: OpPurging, AppID: appID, Phase: "draining", Intent: map[string]string{"account": account, "app": app}} |
| 126 | if err := exclusiveAdmission(v, op); err != nil { |
| 127 | return err |
| 128 | } |
| 129 | if r, ok := v.Registrations[id]; ok && r.Kind == registrationPurge { |
| 130 | delete(v.Registrations, id) |
| 131 | } |
| 132 | return nil |
| 133 | }); err != nil { |
| 134 | return nil, err |
| 135 | } |
| 136 | return &OperationHandle{w: w, account: account, app: app, appID: appID, id: id, kind: OpPurging, owner: owner}, nil |
| 137 | } |
| 138 | |
| 139 | // SavePurgeJournal is a validated replacement, not a generic write: |
| 140 | // identity is immutable, the phase never moves backwards, cleanup flags only |
| 141 | // set, host entries are never removed, and the journal's own purging |
| 142 | // operation must still own admission. |
| 143 | func (w *ControlWriter) SavePurgeJournal(ctx context.Context, next PurgeJournal, tag string) (string, error) { |
| 144 | if err := w.ready(); err != nil { |
| 145 | return "", err |
| 146 | } |
| 147 | if tag == "" { |
| 148 | return "", ErrIdentity |
| 149 | } |
| 150 | key, err := PurgeKey(next.Account, next.App) |
| 151 | if err != nil { |
| 152 | return "", err |
| 153 | } |
| 154 | cur, curTag, err := ReadPurgeJournal(ctx, w.raw, next.Account, next.App, next.ID, next.AppID) |
| 155 | if err != nil { |
| 156 | return "", err |
| 157 | } |
| 158 | if curTag != tag { |
| 159 | return "", release.ErrCASConflict |
| 160 | } |
| 161 | if next.V != cur.V || next.RequestedBy != cur.RequestedBy || next.RequestedAt != cur.RequestedAt || next.Reason != cur.Reason || |
| 162 | !reflect.DeepEqual(next.Tombstone, cur.Tombstone) || next.AdmissionEpoch != cur.AdmissionEpoch { |
| 163 | return "", ErrIdentity |
| 164 | } |
| 165 | if phaseIndex(next.Phase) < phaseIndex(cur.Phase) { |
| 166 | return "", ErrIdentity |
| 167 | } |
| 168 | for id, reg := range next.IngestRegistrations { |
| 169 | if !validIngestRegistration(id, reg, next.AppID, next.AdmissionEpoch) { |
| 170 | return "", ErrIdentity |
| 171 | } |
| 172 | } |
| 173 | for id, reg := range cur.IngestRegistrations { |
| 174 | if next.IngestRegistrations[id] != reg { |
| 175 | return "", ErrIdentity |
| 176 | } |
| 177 | } |
| 178 | for host := range cur.Hosts { |
| 179 | if _, ok := next.Hosts[host]; !ok { |
| 180 | return "", ErrIdentity |
| 181 | } |
| 182 | } |
| 183 | c, n := cur.Cleanup, next.Cleanup |
| 184 | if (c.Tombstone && !n.Tombstone) || (c.AppRow && !n.AppRow) || (c.Fences && !n.Fences) || (c.Admission && !n.Admission) || |
| 185 | (c.Sweep.Verified && !n.Sweep.Verified) || n.Sweep.Batch < c.Sweep.Batch { |
| 186 | return "", ErrIdentity |
| 187 | } |
| 188 | a, err := w.read(ctx, next.Account, next.App, next.AppID) |
| 189 | if err != nil { |
| 190 | return "", err |
| 191 | } |
| 192 | if a.Value.State != "closed" || a.Value.Op == nil || a.Value.Op.ID != next.ID || a.Value.Op.Kind != OpPurging { |
| 193 | return "", ErrPending |
| 194 | } |
| 195 | body, err := json.Marshal(next) |
| 196 | if err != nil { |
| 197 | return "", err |
| 198 | } |
| 199 | MarkAppMutationIssued(ctx) |
| 200 | return w.raw.Put(ctx, key, body, tag) |
| 201 | } |
| 202 | |
| 203 | // DrainPurgeRegistrations journals each saved registration into the purge |
| 204 | // journal, fences or witnesses its host, and only then removes it. |
| 205 | func (w *ControlWriter) DrainPurgeRegistrations(ctx context.Context, account, app, appID, id string, now time.Time, recoverCreate func(context.Context, string) error) error { |
| 206 | a, err := w.read(ctx, account, app, appID) |
| 207 | if err != nil { |
| 208 | return err |
| 209 | } |
| 210 | if a.Value.State != "closed" || a.Value.Op == nil || a.Value.Op.ID != id || a.Value.Op.Kind != OpPurging { |
| 211 | return ErrPending |
| 212 | } |
| 213 | for regID, registration := range a.Value.Registrations { |
| 214 | if registration.Kind == RegistrationIngest { |
| 215 | j, tag, err := ReadPurgeJournal(ctx, w.raw, account, app, id, appID) |
| 216 | if err != nil { |
| 217 | return err |
| 218 | } |
| 219 | if j.Phase != "reserved" { |
| 220 | return ErrPending |
| 221 | } |
| 222 | if j.IngestRegistrations == nil { |
| 223 | j.IngestRegistrations = map[string]Registration{} |
| 224 | } |
| 225 | if old, ok := j.IngestRegistrations[regID]; ok && old != registration { |
| 226 | return ErrIdentity |
| 227 | } |
| 228 | j.IngestRegistrations[regID] = registration |
| 229 | if _, err = w.SavePurgeJournal(ctx, j, tag); err != nil { |
| 230 | return err |
| 231 | } |
| 232 | out, _, err := w.judgeRegistration(ctx, &a.Value, account, app, regID, registration, now, nil) |
| 233 | if err != nil { |
| 234 | return err |
| 235 | } |
| 236 | if out != drainRemove { |
| 237 | return ErrPending |
| 238 | } |
| 239 | } else if registration.Kind == registrationPurge { |
| 240 | // A different purge's reservation: drained once it lapses. |
| 241 | if !RegistrationDrained(registration, now) { |
| 242 | return ErrPending |
| 243 | } |
| 244 | } else { |
| 245 | j, tag, err := ReadPurgeJournal(ctx, w.raw, account, app, id, appID) |
| 246 | if err != nil { |
| 247 | return err |
| 248 | } |
| 249 | if j.Phase != "reserved" { |
| 250 | return ErrPending |
| 251 | } |
| 252 | h := j.Hosts[registration.Host] |
| 253 | if h.Registrations == nil { |
| 254 | h.Registrations = map[string]json.RawMessage{} |
| 255 | } |
| 256 | body, err := json.Marshal(registration) |
| 257 | if err != nil { |
| 258 | return err |
| 259 | } |
| 260 | h.Registrations[regID] = body |
| 261 | j.Hosts[registration.Host] = h |
| 262 | if _, err = w.SavePurgeJournal(ctx, j, tag); err != nil { |
| 263 | return err |
| 264 | } |
| 265 | obs, err := hostclaim.Read(ctx, w.raw, registration.Host) |
| 266 | if err != nil { |
| 267 | return err |
| 268 | } |
| 269 | if !obs.Absent && obs.Claim.Op.ID == regID { |
| 270 | if obs.Claim.Op.Kind == hostclaim.KindCreating && recoverCreate != nil { |
| 271 | if err = recoverCreate(ctx, registration.Host); err != nil && !errors.Is(err, ErrPending) { |
| 272 | return err |
| 273 | } |
| 274 | } |
| 275 | return ErrPending |
| 276 | } |
| 277 | if !RegistrationDrained(registration, now) { |
| 278 | return ErrPending |
| 279 | } |
| 280 | changed := obs.Absent != registration.Claim.Absent || (!obs.Absent && (obs.ETag != registration.Claim.ETag || obs.Claim.Gen != registration.Claim.Gen)) |
| 281 | switch { |
| 282 | case registration.Kind == RegistrationWakeRetryReset: |
| 283 | case obs.Absent || obs.Claim.Free(): |
| 284 | if obs, err = hostclaim.Update(ctx, w.raw, obs, FencePurge(id, now)); err != nil { |
| 285 | return err |
| 286 | } |
| 287 | h.FenceState, h.FenceGen, h.FenceETag = "held", obs.Claim.Gen, obs.ETag |
| 288 | case obs.Claim.Holder == nil && obs.Claim.Op.Kind == hostclaim.KindPurging && obs.Claim.Op.ID == id: |
| 289 | h.FenceState, h.FenceGen, h.FenceETag = "held", obs.Claim.Gen, obs.ETag |
| 290 | default: |
| 291 | if !changed { |
| 292 | return ErrPending |
| 293 | } |
| 294 | // A foreign revision proves only that the delayed CAS cannot |
| 295 | // succeed; it grants no authority over that holder. |
| 296 | h.FenceState, h.FenceGen, h.FenceETag = "changed", obs.Claim.Gen, obs.ETag |
| 297 | } |
| 298 | if j, tag, err = ReadPurgeJournal(ctx, w.raw, account, app, id, appID); err != nil { |
| 299 | return err |
| 300 | } |
| 301 | if j.Phase != "reserved" { |
| 302 | return ErrPending |
| 303 | } |
| 304 | j.Hosts[registration.Host] = h |
| 305 | if _, err = w.SavePurgeJournal(ctx, j, tag); err != nil { |
| 306 | return err |
| 307 | } |
| 308 | } |
| 309 | // Retried: the mutate re-checks the op and the exact saved registration. |
| 310 | if _, err = w.retryAdmission(ctx, account, app, appID, AdmissionObserved{}, func(v *AppAdmission) error { |
| 311 | if v.Op == nil || v.Op.ID != id || v.Op.Kind != OpPurging || v.State != "closed" { |
| 312 | return ErrPending |
| 313 | } |
| 314 | saved, ok := v.Registrations[regID] |
| 315 | if !ok { |
| 316 | return nil |
| 317 | } |
| 318 | if saved != registration || !effectsSettled(v, regID) { |
| 319 | return ErrPending |
| 320 | } |
| 321 | delete(v.Registrations, regID) |
| 322 | return nil |
| 323 | }); err != nil { |
| 324 | return err |
| 325 | } |
| 326 | } |
| 327 | fresh, err := w.read(ctx, account, app, appID) |
| 328 | if err != nil { |
| 329 | return err |
| 330 | } |
| 331 | if len(fresh.Value.Registrations) != 0 || !effectsSettled(&fresh.Value, "") { |
| 332 | return ErrPending |
| 333 | } |
| 334 | return nil |
| 335 | } |
| 336 | |
| 337 | // CompletePurge closes the incarnation: last_purge is set exactly here. |
| 338 | func (h *OperationHandle) CompletePurge(ctx context.Context) error { |
| 339 | if h.kind != OpPurging { |
| 340 | return ErrIdentity |
| 341 | } |
| 342 | j, _, err := ReadPurgeJournal(ctx, h.w.raw, h.account, h.app, h.id, h.appID) |
| 343 | if err != nil { |
| 344 | return err |
| 345 | } |
| 346 | if j.Phase != "done" || !j.Cleanup.Fences || !j.Cleanup.Tombstone || !j.Cleanup.AppRow || !j.Cleanup.Sweep.Verified { |
| 347 | return ErrPending |
| 348 | } |
| 349 | a, err := h.w.read(ctx, h.account, h.app, h.appID) |
| 350 | if err != nil { |
| 351 | return err |
| 352 | } |
| 353 | if lp := a.Value.LastPurge; a.Value.Op == nil && lp != nil && lp.ID == h.id && lp.AppID == h.appID { |
| 354 | return nil |
| 355 | } |
| 356 | if err = h.mine(&a.Value); err != nil { |
| 357 | return err |
| 358 | } |
| 359 | _, err = h.w.retryAdmission(ctx, h.account, h.app, h.appID, a, func(v *AppAdmission) error { |
| 360 | if err := h.mine(v); err != nil { |
| 361 | return err |
| 362 | } |
| 363 | if len(v.Registrations) != 0 || !effectsSettled(v, "") { |
| 364 | return ErrPending |
| 365 | } |
| 366 | v.State = "closed" |
| 367 | v.LastPurge = &PurgeMark{ID: h.id, AppID: h.appID} |
| 368 | v.Op = nil |
| 369 | return nil |
| 370 | }) |
| 371 | return err |
| 372 | } |
| 373 | |
| 374 | // RemovePurgeJournal deletes the journal last, and with it a box purge |
| 375 | // request that named the same retired incarnation. |
| 376 | func (w *ControlWriter) RemovePurgeJournal(ctx context.Context, account, app, id string) error { |
| 377 | a, err := ReadCanonicalAdmission(ctx, w.raw, account, app) |
| 378 | if err != nil { |
| 379 | return err |
| 380 | } |
| 381 | if !CompletedAdmission(a.Value) || a.Value.LastPurge.ID != id { |
| 382 | return ErrPending |
| 383 | } |
| 384 | j, tag, err := ReadPurgeJournal(ctx, w.raw, account, app, id, a.Value.AppID) |
| 385 | if errors.Is(err, os.ErrNotExist) { |
| 386 | _, err = w.DiscardPurgeRequest(ctx, account, app) |
| 387 | return err |
| 388 | } |
| 389 | if err != nil { |
| 390 | return err |
| 391 | } |
| 392 | if j.Phase != "done" || !j.Cleanup.Fences { |
| 393 | return ErrPending |
| 394 | } |
| 395 | if _, err = w.DiscardPurgeRequest(ctx, account, app); err != nil { |
| 396 | return err |
| 397 | } |
| 398 | key, err := PurgeKey(account, app) |
| 399 | if err != nil { |
| 400 | return err |
| 401 | } |
| 402 | return release.DeleteIfMatch(ctx, w.raw, key, tag) |
| 403 | } |
| 404 | |
| 405 | // DiscardPurgeRequest removes a box request only when it names a retired |
| 406 | // incarnation; a request for the live app is left for SweepRequests. |
| 407 | func (w *ControlWriter) DiscardPurgeRequest(ctx context.Context, account, app string) (bool, error) { |
| 408 | key, err := PurgeRequestKey(account, app) |
| 409 | if err != nil { |
| 410 | return false, err |
| 411 | } |
| 412 | body, tag, err := w.raw.Get(ctx, key) |
| 413 | if errors.Is(err, os.ErrNotExist) { |
| 414 | return false, nil |
| 415 | } |
| 416 | if err != nil { |
| 417 | return false, err |
| 418 | } |
| 419 | var request release.ClaimPurgeRequest |
| 420 | if err = json.Unmarshal(body, &request); err != nil { |
| 421 | return false, err |
| 422 | } |
| 423 | if request.V != 1 || request.Account != account || request.App != app || request.AppID == "" || tag == "" { |
| 424 | return false, ErrIdentity |
| 425 | } |
| 426 | a, err := ReadCanonicalAdmission(ctx, w.raw, account, app) |
| 427 | if err != nil { |
| 428 | return false, err |
| 429 | } |
| 430 | if a.Value.LastPurge == nil || a.Value.LastPurge.AppID != request.AppID { |
| 431 | return false, nil |
| 432 | } |
| 433 | if err = release.DeleteIfMatch(ctx, w.raw, key, tag); err != nil { |
| 434 | return false, err |
| 435 | } |
| 436 | return true, nil |
| 437 | } |
| 438 | |
amadan