| 1 | // The one-shot sweep that finishes the senders migration (design §5). |
| 2 | package mail |
| 3 | |
| 4 | import ( |
| 5 | "context" |
| 6 | "errors" |
| 7 | "fmt" |
| 8 | "log" |
| 9 | "os" |
| 10 | "path" |
| 11 | "strings" |
| 12 | |
| 13 | "github.com/carlosframework/platform/internal/release" |
| 14 | ) |
| 15 | |
| 16 | // SweepLegacyRecords deletes apps/<acct>/<app>/email.json for every app that |
| 17 | // already has a senders/app.json, and nothing else. |
| 18 | // |
| 19 | // It is guarded by a flag that defaults OFF, and it is written now rather |
| 20 | // than a release from now because the thing that makes it safe is knowing, |
| 21 | // while the migration is fresh in view, exactly which object it may remove. |
| 22 | // The rule is one sentence: a legacy record is deletable when, and only |
| 23 | // when, the sender object that replaced it exists. An unmigrated app's |
| 24 | // email.json is still the only copy of its email and is left alone, so a |
| 25 | // deployment that turns the flag on early loses nothing. |
| 26 | // |
| 27 | // A failure on one app is logged and the sweep continues: one unreadable |
| 28 | // object must not stop the other five hundred, and every deletion is |
| 29 | // independent. |
| 30 | // |
| 31 | // It walks with ListDirs, twice, and never with List. List(ctx, "apps/") on |
| 32 | // a production bucket returns every object under every app, every release |
| 33 | // artifact of every version of every app, to find the handful of keys |
| 34 | // ending in /email.json, and it would do it at console start. ListDirs is |
| 35 | // the delimiter-aware listing (release/store.go:50-58): one page of |
| 36 | // accounts, one page of apps per account, then two Gets per app. |
| 37 | func SweepLegacyRecords(ctx context.Context, s release.Store, enabled bool) (int, error) { |
| 38 | if !enabled { |
| 39 | return 0, nil |
| 40 | } |
| 41 | accts, err := s.ListDirs(ctx, "apps/") |
| 42 | if err != nil { |
| 43 | return 0, fmt.Errorf("mail: sweep legacy records: %w", err) |
| 44 | } |
| 45 | deleted := 0 |
| 46 | for _, acctPrefix := range accts { |
| 47 | // ListDirs hands back a full prefix ending in "/", never a bare |
| 48 | // name, so the account is the last segment of it. |
| 49 | acct := path.Base(strings.TrimSuffix(acctPrefix, "/")) |
| 50 | if !release.ValidAccount(acct) { |
| 51 | continue |
| 52 | } |
| 53 | apps, err := s.ListDirs(ctx, acctPrefix) |
| 54 | if err != nil { |
| 55 | log.Printf("mail: sweep legacy records: listing %s -> %v", acctPrefix, err) |
| 56 | continue |
| 57 | } |
| 58 | for _, appPrefix := range apps { |
| 59 | app := path.Base(strings.TrimSuffix(appPrefix, "/")) |
| 60 | if !release.ValidApp(app) { |
| 61 | continue |
| 62 | } |
| 63 | if _, _, err := s.Get(ctx, SenderKey(acct, app, SenderAppID)); err != nil { |
| 64 | if !errors.Is(err, os.ErrNotExist) { |
| 65 | log.Printf("mail: sweep legacy records: reading %s -> %v", SenderKey(acct, app, SenderAppID), err) |
| 66 | } |
| 67 | continue // not migrated: this object is still the only copy |
| 68 | } |
| 69 | legacy := LegacyKey(acct, app) |
| 70 | if _, _, err := s.Get(ctx, legacy); err != nil { |
| 71 | if !errors.Is(err, os.ErrNotExist) { |
| 72 | log.Printf("mail: sweep legacy records: reading %s -> %v", legacy, err) |
| 73 | } |
| 74 | continue // nothing to remove, which is the steady state |
| 75 | } |
| 76 | if err := s.Delete(ctx, legacy); err != nil { |
| 77 | log.Printf("mail: sweep legacy records: deleting %s -> %v", legacy, err) |
| 78 | continue |
| 79 | } |
| 80 | deleted++ |
| 81 | } |
| 82 | } |
| 83 | return deleted, nil |
| 84 | } |
| 85 | |
amadan