| 1 | // The instance config layer (tenant-email senders design §6.2): a third |
| 2 | // bundle, one object per route host, resolved after the named environment. |
| 3 | // Same Manifest shape, same sealed envelopes, same name and value rules as |
| 4 | // the other two — a per-instance bundle is not a new format, just a third |
| 5 | // bucket key the same shape is written to. |
| 6 | // |
| 7 | // Bucket layout addition: |
| 8 | // |
| 9 | // apps/<acct>/<app>/instances-config/<host>.json CAS-guarded, schema-1 manifest |
| 10 | // |
| 11 | // It exists so a credential can be scoped to ONE instance. #148's shape is |
| 12 | // one instance per customer under a single app, and everything the platform |
| 13 | // delivers today lands in a bundle every instance of the app renders, so a |
| 14 | // per-customer secret delivered through the default bundle reaches every |
| 15 | // other customer's process. |
| 16 | // |
| 17 | // Manifest.ExecDelivery is NOT read from this layer. That is the ruling at |
| 18 | // appconfig.go's ExecDelivery doc comment, unchanged: a per-route delivery |
| 19 | // flag would need a registry column, a record field and reconcile |
| 20 | // convergence, and two routes resolving through the same bundle could |
| 21 | // disagree about whether they are delivered. A per-host bundle is exactly |
| 22 | // the granularity that ruling refused, so resolveExecDelivery is never |
| 23 | // handed one of these manifests and a field that somehow appears in one is |
| 24 | // inert. |
| 25 | package appconfig |
| 26 | |
| 27 | import ( |
| 28 | "context" |
| 29 | "fmt" |
| 30 | "regexp" |
| 31 | "strings" |
| 32 | "sync" |
| 33 | |
| 34 | "github.com/carlosframework/platform/internal/release" |
| 35 | ) |
| 36 | |
| 37 | // InstancesConfigPrefix is the list prefix behind "which instances of this |
| 38 | // app have an overlay" — every instances-config/<host>.json key shares it. |
| 39 | // Inside apps/<acct>/<app>/ on purpose: release.PurgeApp's prefix sweep |
| 40 | // reaches it, so a purged app cannot leave an object full of sealed |
| 41 | // secrets behind. |
| 42 | func InstancesConfigPrefix(acct, app string) string { |
| 43 | return release.AppPrefix(acct, app) + "instances-config/" |
| 44 | } |
| 45 | |
| 46 | // InstanceConfigKey is the bucket key of one instance's overlay. host is a |
| 47 | // route's Host column verbatim, which is what makes the key derivable from |
| 48 | // a registry row with nothing to look up. |
| 49 | func InstanceConfigKey(acct, app, host string) string { |
| 50 | return InstancesConfigPrefix(acct, app) + host + ".json" |
| 51 | } |
| 52 | |
| 53 | // instanceHostRe is a bare lowercase hostname: labels of letters, digits |
| 54 | // and hyphens, joined by dots, never starting or ending with a hyphen or a |
| 55 | // dot. Case-restricted like ValidEnvironmentName and for the same reason, |
| 56 | // with one more: this string is also the file name sync derives on the box |
| 57 | // (sync.go's filepath.Base guard), so one convention keeps a bucket key and |
| 58 | // a file name from disagreeing about which host they belong to. |
| 59 | var instanceHostRe = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$`) |
| 60 | |
| 61 | // ValidInstanceHost reports whether host is usable as an instance overlay |
| 62 | // key. A separator or a traversal is refused at the one gate every caller |
| 63 | // passes through, because this string is concatenated into a bucket key: a |
| 64 | // host of "../config" would otherwise name the app's default bundle. |
| 65 | func ValidInstanceHost(host string) bool { |
| 66 | if host == "" || len(host) > 253 || strings.Contains(host, "..") { |
| 67 | return false |
| 68 | } |
| 69 | // Per-label bound as well as the whole-name one, matching DNS and |
| 70 | // launchctx/controlname's label rule. Without it a single 200-character |
| 71 | // label passes here and is refused everywhere else that handles the same |
| 72 | // host, which is a disagreement between two gates rather than one rule. |
| 73 | for _, label := range strings.Split(host, ".") { |
| 74 | if len(label) > 63 { |
| 75 | return false |
| 76 | } |
| 77 | } |
| 78 | return instanceHostRe.MatchString(host) |
| 79 | } |
| 80 | |
| 81 | // LoadInstanceConfig reads one instance's overlay, returning the manifest, |
| 82 | // the etag it was read at, and whether the object exists at all. |
| 83 | // |
| 84 | // The etag is the point of this signature. The delivery ack (design §6.5) |
| 85 | // carries the etag the agent actually rendered, and the console compares it |
| 86 | // with the one its own Put returned: that comparison is decidable, where a |
| 87 | // map of delivered key names cannot tell an old agent apart from a new one |
| 88 | // rendering a route with no overlay vars. |
| 89 | // |
| 90 | // Not-found is (nil, "", false, nil): an instance with no overlay is the |
| 91 | // normal case and the state every instance is in until something writes one. |
| 92 | func LoadInstanceConfig(ctx context.Context, s release.Store, acct, app, host string) (*Manifest, string, bool, error) { |
| 93 | if !release.ValidAccount(acct) { |
| 94 | return nil, "", false, fmt.Errorf("config: invalid account %q", acct) |
| 95 | } |
| 96 | if !release.ValidApp(app) { |
| 97 | return nil, "", false, fmt.Errorf("config: invalid app %q", app) |
| 98 | } |
| 99 | if !ValidInstanceHost(host) { |
| 100 | return nil, "", false, fmt.Errorf("config: invalid instance host %q", host) |
| 101 | } |
| 102 | return getIfExistsAtETag(ctx, s, InstanceConfigKey(acct, app, host)) |
| 103 | } |
| 104 | |
| 105 | // ApplyInstance writes sets and removes unsets from ONE instance's overlay |
| 106 | // in one CAS write, returning how many of unsets were actually present and |
| 107 | // THE ETAG IT WROTE AT. |
| 108 | // |
| 109 | // That etag is the contract with the box. The console keeps it, the agent |
| 110 | // reports the etag it rendered in its config ack, and the two are compared |
| 111 | // (design §6.5, InstanceConfigDelivery). A map of delivered key names would |
| 112 | // not do: it cannot tell an agent too old to render this layer apart from a |
| 113 | // new agent rendering a route whose overlay sets nothing it recognises. |
| 114 | // |
| 115 | // There is no CLI verb and no console door onto this function, by design |
| 116 | // (§6.2, "only the platform writes this layer"). It exists so a credential |
| 117 | // can be scoped to one instance, and the only caller that scopes one is the |
| 118 | // email walk in step 5. |
| 119 | // |
| 120 | // Unset-only against an overlay that does not exist is refused, not turned |
| 121 | // into a create, for the reason applyAt's own doc comment gives: an empty |
| 122 | // manifest that EXISTS is a state the sweeps converge a file to, and |
| 123 | // minting one to hold nothing would deliver an empty file to a live |
| 124 | // instance. |
| 125 | func claimRawApplyInstance(ctx context.Context, s release.Store, acct, app, host string, sets map[string]Var, unsets []string) (int, string, error) { |
| 126 | if !release.ValidAccount(acct) { |
| 127 | return 0, "", fmt.Errorf("config: invalid account %q", acct) |
| 128 | } |
| 129 | if !release.ValidApp(app) { |
| 130 | return 0, "", fmt.Errorf("config: invalid app %q", app) |
| 131 | } |
| 132 | if !ValidInstanceHost(host) { |
| 133 | return 0, "", fmt.Errorf("config: invalid instance host %q", host) |
| 134 | } |
| 135 | removed, etag, err := applyAt(ctx, s, InstanceConfigKey(acct, app, host), app, "instance "+host, sets, unsets) |
| 136 | if err != nil { |
| 137 | return 0, "", err |
| 138 | } |
| 139 | // The generation object is the ONLY signal this layer has. |
| 140 | // ConfigRouteFingerprints (routefingerprint.go) digests registry columns |
| 141 | // and cannot see a bucket-side change, so an overlay written without |
| 142 | // this touch would wait out configSyncLoop's hourly floor. Same |
| 143 | // best-effort demotion every other write here makes: the manifest has |
| 144 | // landed, so a failed touch is logged, never returned. |
| 145 | touchLogged(ctx, s, acct, app) |
| 146 | return removed, etag, nil |
| 147 | } |
| 148 | |
| 149 | // DeleteInstanceConfig removes one instance's overlay outright, which |
| 150 | // converges that route back to its group's merge on the next pass. Absent |
| 151 | // is success: a retried teardown must converge rather than fail, and |
| 152 | // release.Store.Delete is already idempotent. |
| 153 | // |
| 154 | // The generation is touched even when nothing was removed. Branching on it |
| 155 | // would mean a Get before every delete to find out, and one redundant touch |
| 156 | // costs a tiny object write where a missed one costs an hour of a live |
| 157 | // instance holding config nothing meant it to have. |
| 158 | func claimRawDeleteInstanceConfig(ctx context.Context, s release.Store, acct, app, host string) error { |
| 159 | if !release.ValidAccount(acct) { |
| 160 | return fmt.Errorf("config: invalid account %q", acct) |
| 161 | } |
| 162 | if !release.ValidApp(app) { |
| 163 | return fmt.Errorf("config: invalid app %q", app) |
| 164 | } |
| 165 | if !ValidInstanceHost(host) { |
| 166 | return fmt.Errorf("config: invalid instance host %q", host) |
| 167 | } |
| 168 | if err := s.Delete(ctx, InstanceConfigKey(acct, app, host)); err != nil { |
| 169 | return err |
| 170 | } |
| 171 | touchLogged(ctx, s, acct, app) |
| 172 | return nil |
| 173 | } |
| 174 | |
| 175 | // LoadMergedHost is LoadMerged plus the instance layer: default < |
| 176 | // environment < instance, the instance winning per key, and the overlay's |
| 177 | // etag returned alongside so a caller can check delivery against it later |
| 178 | // (design §6.2, §6.5). An empty etag means this host has no overlay, which |
| 179 | // is a different statement from an agent that never rendered one. |
| 180 | // |
| 181 | // LoadMerged keeps its signature and its meaning. Everything that asks |
| 182 | // "what does this APP's environment resolve to" still gets two layers, and |
| 183 | // only a caller that names a host gets three. |
| 184 | // |
| 185 | // The two sync sweeps do NOT call this function, deliberately: they resolve |
| 186 | // one group base for every route that shares it and would re-fetch |
| 187 | // config.json per route if they came through here. They reach the same |
| 188 | // answer through instanceOverlays and applyInstanceOverlay instead, and the |
| 189 | // equivalence for a VALID host is pinned by a test rather than by hope — |
| 190 | // TestSyncRendersTheInstanceOverlayForItsOwnRouteOnly compares a sweep's |
| 191 | // rendered file against this function's own answer for the same host. |
| 192 | // |
| 193 | // That equivalence does NOT extend to a host that fails ValidInstanceHost. |
| 194 | // This function refuses one outright (see the guard below): a hostname a |
| 195 | // caller cannot even ask about is an error here. The sweeps never make that |
| 196 | // call at all — instanceOverlayLoader treats such a host as "not named by |
| 197 | // the listing", which reads as "no overlay", and the route converges on its |
| 198 | // group's merge same as any other unconfigured instance. A caller that |
| 199 | // wants the sweep's own answer for a host it cannot yet prove valid (step |
| 200 | // 5's write path, before ApplyInstance's own ValidInstanceHost gate runs) |
| 201 | // must not substitute this function for that reason: the two disagree here, |
| 202 | // on purpose, and only one of them is what a box will actually deliver. |
| 203 | func LoadMergedHost(ctx context.Context, s release.Store, acct, app, envName, host string) (*Manifest, string, error) { |
| 204 | m, v, err := LoadMergedHostVersions(ctx, s, acct, app, envName, host) |
| 205 | return m, v.Overlay, err |
| 206 | } |
| 207 | |
| 208 | // MergedVersions names the version (etag) of each object a three-layer |
| 209 | // merge actually read: the app's default bundle, the route's named |
| 210 | // environment, and the host's instance overlay. "" means that layer was |
| 211 | // absent or not part of the merge (an unbound route reads no environment). |
| 212 | type MergedVersions struct { |
| 213 | Default, Environment, Overlay string |
| 214 | } |
| 215 | |
| 216 | // LoadMergedHostVersions is LoadMergedHost returning the etag of every |
| 217 | // object it merged, each taken from the very read that returned its bytes |
| 218 | // (getIfExistsAtETag). It is the one loader a move's held render and T3 |
| 219 | // use (moves design §9.1): a later, independent read could not establish |
| 220 | // which versions were rendered, because a bundle written in between would |
| 221 | // answer with the new etag over the old bytes. LoadMergedHost is this |
| 222 | // function with everything but the overlay's etag discarded. |
| 223 | func LoadMergedHostVersions(ctx context.Context, s release.Store, acct, app, envName, host string) (*Manifest, MergedVersions, error) { |
| 224 | if !ValidInstanceHost(host) { |
| 225 | return nil, MergedVersions{}, fmt.Errorf("config: invalid instance host %q", host) |
| 226 | } |
| 227 | // The host's overlay is read beside the app's layers (loadMergedETags), |
| 228 | // not after them; the answers are taken in the old order. |
| 229 | var ( |
| 230 | inst *Manifest |
| 231 | etag string |
| 232 | found bool |
| 233 | instErr error |
| 234 | wg sync.WaitGroup |
| 235 | ) |
| 236 | wg.Add(1) |
| 237 | go func() { |
| 238 | defer wg.Done() |
| 239 | inst, etag, found, instErr = LoadInstanceConfig(ctx, s, acct, app, host) |
| 240 | }() |
| 241 | base, defETag, envETag, err := loadMergedETags(ctx, s, acct, app, envName) |
| 242 | wg.Wait() |
| 243 | if err != nil { |
| 244 | return nil, MergedVersions{}, err |
| 245 | } |
| 246 | v := MergedVersions{Default: defETag, Environment: envETag} |
| 247 | if err := instErr; err != nil { |
| 248 | return nil, MergedVersions{}, err |
| 249 | } |
| 250 | if !found { |
| 251 | return base, v, nil |
| 252 | } |
| 253 | v.Overlay = etag |
| 254 | return applyInstanceOverlay(app, base, inst), v, nil |
| 255 | } |
| 256 | |
| 257 | // applyInstanceOverlay lays inst over base, per key. base may be nil (the |
| 258 | // app has no default bundle and the route is unbound), in which case the |
| 259 | // merged view is the overlay ALONE — which the callers treat as the |
| 260 | // wholesale replacement it is, see sync.go's defaultMissing guard. |
| 261 | // |
| 262 | // A nil overlay returns base untouched, pointer and all: that is the path |
| 263 | // every instance without an overlay takes, and rebuilding the manifest |
| 264 | // there would strip exec_delivery off the default bundle object LoadMerged |
| 265 | // hands back for an unbound route. |
| 266 | // |
| 267 | // The merged view never carries exec_delivery FROM the overlay. See this |
| 268 | // file's own doc comment: a per-host delivery flag is the granularity the |
| 269 | // #195 ruling refused, and the merged manifest is what gets rendered into a |
| 270 | // file, where a delivery flag has no business appearing anyway. |
| 271 | func applyInstanceOverlay(app string, base, inst *Manifest) *Manifest { |
| 272 | if inst == nil { |
| 273 | return base |
| 274 | } |
| 275 | merged := &Manifest{Schema: 1, App: app, Vars: map[string]Var{}} |
| 276 | if base != nil { |
| 277 | for k, v := range base.Vars { |
| 278 | merged.Vars[k] = v |
| 279 | } |
| 280 | } |
| 281 | for k, v := range inst.Vars { |
| 282 | merged.Vars[k] = v |
| 283 | } |
| 284 | return merged |
| 285 | } |
| 286 | |
| 287 | // instanceOverlays lists which of this app's instances have an overlay at |
| 288 | // all: one listing per (account, app), cached by the caller for a whole |
| 289 | // pass, so a sweep pays one List per app and then one Get per instance that |
| 290 | // actually has one. Reading every route's key blind would cost a bucket |
| 291 | // round trip per instance on a box where nothing has an overlay, which is |
| 292 | // every box in the fleet the day this ships. |
| 293 | // |
| 294 | // A key that does not end in .json, or whose host does not survive |
| 295 | // ValidInstanceHost, is skipped rather than reported: nothing can have |
| 296 | // written it through this package, so it is not this app's overlay |
| 297 | // whatever it is. |
| 298 | func instanceOverlays(ctx context.Context, s release.Store, acct, app string) (map[string]bool, error) { |
| 299 | prefix := InstancesConfigPrefix(acct, app) |
| 300 | keys, err := s.List(ctx, prefix) |
| 301 | if err != nil { |
| 302 | return nil, err |
| 303 | } |
| 304 | out := make(map[string]bool, len(keys)) |
| 305 | for _, k := range keys { |
| 306 | host := strings.TrimSuffix(strings.TrimPrefix(k, prefix), ".json") |
| 307 | if host == strings.TrimPrefix(k, prefix) || !ValidInstanceHost(host) { |
| 308 | continue |
| 309 | } |
| 310 | out[host] = true |
| 311 | } |
| 312 | return out, nil |
| 313 | } |
| 314 | |
| 315 | // instanceOverlayListErr marks an error as coming from instanceOverlayLoader's |
| 316 | // cached LISTING (instanceOverlays) rather than from a per-host Get. The |
| 317 | // listing is the one call every route of an app shares, so every route |
| 318 | // fails identically and for the same reason when it errors — a caller may |
| 319 | // dedup on that. A per-host Get or parse failure carries no such guarantee: |
| 320 | // two routes can have two separately corrupt overlay objects, each failing |
| 321 | // for its own reason, and folding both into one line would hide the second |
| 322 | // one's failure entirely. errors.As is how a caller tells the two apart. |
| 323 | type instanceOverlayListErr struct{ error } |
| 324 | |
| 325 | // Unwrap lets errors.Is/errors.As see through the wrapper to the listing |
| 326 | // failure itself, the same courtesy every %w wrap in this package gives. |
| 327 | func (e *instanceOverlayListErr) Unwrap() error { return e.error } |
| 328 | |
| 329 | // instanceOverlayLoader is one pass's instance-layer reader, shared by both |
| 330 | // sweeps (Sync and SyncExec) so neither can drift from the other about what |
| 331 | // a host gets or what it costs. One List per (account, app), cached for the |
| 332 | // pass including its failure, then a Get only for a host that listing |
| 333 | // named. |
| 334 | // |
| 335 | // A listing FAILURE is returned to the caller wrapped in |
| 336 | // instanceOverlayListErr, never folded into "no overlay". The two sweeps |
| 337 | // treat it the way they treat a bundle fetch failure: leave the file |
| 338 | // exactly as it is, say so, retry next pass. Folding it away would silently |
| 339 | // deliver the app-wide merge to an instance that is meant to have its own |
| 340 | // credential, which is the one outcome this layer exists to prevent. |
| 341 | // |
| 342 | // A host the listing named but whose object is gone by the time of the Get |
| 343 | // is simply "no overlay": a delete racing the pass converges the route back |
| 344 | // to its group's merge, which is what the delete asked for. |
| 345 | // |
| 346 | // The index map below has no lock. That's safe only because each call to |
| 347 | // this function returns a fresh closure over its own map, and both Sync and |
| 348 | // SyncExec build one loader per pass and drive it from their own single |
| 349 | // route loop — never two goroutines sharing one closure. A caller that ever |
| 350 | // shared one instanceOverlayLoader value across concurrently running sweeps |
| 351 | // would race on this map; don't. |
| 352 | func instanceOverlayLoader(ctx context.Context, s release.Store) func(acct, app, host string) (*Manifest, string, error) { |
| 353 | type appKey struct{ acct, app string } |
| 354 | type indexRes struct { |
| 355 | hosts map[string]bool |
| 356 | err error |
| 357 | } |
| 358 | index := map[appKey]indexRes{} |
| 359 | return func(acct, app, host string) (*Manifest, string, error) { |
| 360 | ak := appKey{acct, app} |
| 361 | idx, done := index[ak] |
| 362 | if !done { |
| 363 | hosts, err := instanceOverlays(ctx, s, acct, app) |
| 364 | if err != nil { |
| 365 | err = &instanceOverlayListErr{fmt.Errorf("%s/%s: instance config listing failed: %w", acct, app, err)} |
| 366 | } |
| 367 | idx = indexRes{hosts: hosts, err: err} |
| 368 | index[ak] = idx |
| 369 | } |
| 370 | if idx.err != nil { |
| 371 | return nil, "", idx.err |
| 372 | } |
| 373 | if !idx.hosts[host] { |
| 374 | return nil, "", nil |
| 375 | } |
| 376 | m, etag, found, err := LoadInstanceConfig(ctx, s, acct, app, host) |
| 377 | if err != nil { |
| 378 | return nil, "", fmt.Errorf("%s/%s: instance config for %s: %w", acct, app, host, err) |
| 379 | } |
| 380 | if !found { |
| 381 | return nil, "", nil |
| 382 | } |
| 383 | return m, etag, nil |
| 384 | } |
| 385 | } |
| 386 | func ApplyInstance(ctx context.Context, s release.Store, acct, app, host string, sets map[string]Var, unsets []string) (claimResult0 int, claimResult1 string, claimResult2 error) { |
| 387 | claimResult2 = release.WithAppMutation(ctx, s, acct, app, "appconfig.ApplyInstance", func(claimContext context.Context) error { |
| 388 | claimResult0, claimResult1, claimResult2 = claimRawApplyInstance(claimContext, s, acct, app, host, sets, unsets) |
| 389 | return claimResult2 |
| 390 | }) |
| 391 | return |
| 392 | } |
| 393 | func DeleteInstanceConfig(ctx context.Context, s release.Store, acct, app, host string) (claimResult0 error) { |
| 394 | claimResult0 = release.WithAppMutation(ctx, s, acct, app, "appconfig.DeleteInstanceConfig", func(claimContext context.Context) error { |
| 395 | claimResult0 = claimRawDeleteInstanceConfig(claimContext, s, acct, app, host) |
| 396 | return claimResult0 |
| 397 | }) |
| 398 | return |
| 399 | } |
| 400 | |
amadan