| 1 | // The console's own email, for when Keymail cannot carry a message (today: |
| 2 | // invites to someone with no Keymail mailbox). The From identity is made by |
| 3 | // the platform's own mail layer, mail.EnsureDomain, owned by the ops |
| 4 | // account under the reserved referrer app consoleMailApp. Sends go out on |
| 5 | // the console's own AWS role, so no SMTP credential exists to store. |
| 6 | package console |
| 7 | |
| 8 | import ( |
| 9 | "context" |
| 10 | "errors" |
| 11 | "fmt" |
| 12 | "log" |
| 13 | "strings" |
| 14 | "time" |
| 15 | |
| 16 | "github.com/carlosframework/platform/internal/dnsrec" |
| 17 | "github.com/carlosframework/platform/internal/mail" |
| 18 | "github.com/carlosframework/platform/internal/release" |
| 19 | ) |
| 20 | |
| 21 | // consoleMailApp is the referrer name on the console's domain record. |
| 22 | // reservedAppName refuses it in the ops account, and the mail layer refuses |
| 23 | // to tear down its domain, so no app delete can take the identity with it. |
| 24 | const consoleMailApp = mail.ConsoleMailApp |
| 25 | |
| 26 | // consoleMailPendingRecheck is how long a not-yet-verified answer is trusted. |
| 27 | const consoleMailPendingRecheck = 5 * time.Minute |
| 28 | |
| 29 | // ErrConsoleMailNotReady: the identity is not verified (or could not be |
| 30 | // made). The caller falls back to the next channel. |
| 31 | var ErrConsoleMailNotReady = errors.New("console mail: sending identity not verified yet") |
| 32 | |
| 33 | type ConsoleMailer interface { |
| 34 | Send(ctx context.Context, to, subject, body string) error |
| 35 | // Ready reports whether a Send would go out now: the sending identity is |
| 36 | // verified. It makes no SES call, and gives up after two seconds. |
| 37 | Ready(ctx context.Context) bool |
| 38 | } |
| 39 | |
| 40 | // ConsoleMailFrom resolves the From address: the operator's explicit choice, |
| 41 | // else noreply at console-mail under the ops account's platform name, else |
| 42 | // "" (no email). Not "console.bab": that is also the platform mail name of |
| 43 | // an ops app called "console". |
| 44 | func ConsoleMailFrom(explicit, platformSuffix string) string { |
| 45 | if e := strings.ToLower(strings.TrimSpace(explicit)); e != "" { |
| 46 | return e |
| 47 | } |
| 48 | if platformSuffix == "" { |
| 49 | return "" |
| 50 | } |
| 51 | return "noreply@" + mail.ConsoleMailApp + "." + release.OpsAccount + "." + platformSuffix |
| 52 | } |
| 53 | |
| 54 | type sesConsoleMailer struct { |
| 55 | from, domain string |
| 56 | store release.Store |
| 57 | prov mail.Provisioner |
| 58 | dns dnsrec.Writer |
| 59 | dep mail.Deployment |
| 60 | ses mail.EmailSender |
| 61 | now func() time.Time |
| 62 | |
| 63 | // lock is a one-slot mutex a waiter can give up on: an ensure stalled |
| 64 | // inside an AWS call must not hold a Send past its own deadline. |
| 65 | // Everything below it is guarded by it. |
| 66 | lock chan struct{} |
| 67 | ensured bool |
| 68 | verified bool |
| 69 | configSet string |
| 70 | checkedAt time.Time |
| 71 | } |
| 72 | |
| 73 | func newSESConsoleMailer(from string, s release.Store, p mail.Provisioner, w dnsrec.Writer, d mail.Deployment, ses mail.EmailSender) *sesConsoleMailer { |
| 74 | _, domain, _ := strings.Cut(from, "@") |
| 75 | return &sesConsoleMailer{from: from, domain: domain, store: s, prov: p, dns: w, dep: d, ses: ses, now: time.Now, |
| 76 | lock: make(chan struct{}, 1)} |
| 77 | } |
| 78 | |
| 79 | // NewConsoleMailer builds the console's mailer, or nil when this deployment |
| 80 | // has no From address or no mail provisioner. The returned func runs the |
| 81 | // identity ensure; serve() starts it in the background. |
| 82 | func NewConsoleMailer(from string, s release.Store, p mail.Provisioner, w dnsrec.Writer, d mail.Deployment, ses mail.EmailSender) (ConsoleMailer, func(context.Context)) { |
| 83 | if from == "" || p == nil || ses == nil || s == nil { |
| 84 | return nil, func(context.Context) {} |
| 85 | } |
| 86 | m := newSESConsoleMailer(from, s, p, w, d, ses) |
| 87 | return m, func(ctx context.Context) { |
| 88 | if err := m.Ensure(ctx); err != nil { |
| 89 | log.Printf("console mail: %v (retried on the next send)", err) |
| 90 | } |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | // Ensure makes (or re-reads) the identity. Idempotent. Pending DNS records |
| 95 | // for a custom domain are logged for the operator to publish. |
| 96 | func (m *sesConsoleMailer) Ensure(ctx context.Context) error { |
| 97 | if err := m.acquire(ctx); err != nil { |
| 98 | return err |
| 99 | } |
| 100 | defer m.unlock() |
| 101 | return m.ensureLocked(ctx) |
| 102 | } |
| 103 | |
| 104 | // acquire takes m.lock, or gives up with ErrConsoleMailNotReady when ctx |
| 105 | // ends first. |
| 106 | func (m *sesConsoleMailer) acquire(ctx context.Context) error { |
| 107 | select { |
| 108 | case m.lock <- struct{}{}: |
| 109 | return nil |
| 110 | case <-ctx.Done(): |
| 111 | return fmt.Errorf("%w: %w", ErrConsoleMailNotReady, ctx.Err()) |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | func (m *sesConsoleMailer) unlock() { <-m.lock } |
| 116 | |
| 117 | func (m *sesConsoleMailer) ensureLocked(ctx context.Context) error { |
| 118 | if m.ensured { |
| 119 | return nil |
| 120 | } |
| 121 | _, pending, err := mail.EnsureDomain(ctx, m.store, m.prov, m.dns, m.dep, |
| 122 | release.OpsAccount, consoleMailApp, m.domain, m.now()) |
| 123 | if err != nil { |
| 124 | return fmt.Errorf("console mail: ensure %s: %w", m.domain, err) |
| 125 | } |
| 126 | for _, r := range pending { |
| 127 | log.Printf("console mail: publish %s %s %s so %s can verify", r.Type, r.Name, strings.Join(r.Values, " "), m.domain) |
| 128 | } |
| 129 | m.ensured = true |
| 130 | return nil |
| 131 | } |
| 132 | |
| 133 | func (m *sesConsoleMailer) ready(ctx context.Context) (string, error) { |
| 134 | if err := m.acquire(ctx); err != nil { |
| 135 | return "", err |
| 136 | } |
| 137 | defer m.unlock() |
| 138 | if m.verified { |
| 139 | return m.configSet, nil |
| 140 | } |
| 141 | if !m.checkedAt.IsZero() && m.now().Sub(m.checkedAt) < consoleMailPendingRecheck { |
| 142 | return "", ErrConsoleMailNotReady |
| 143 | } |
| 144 | m.checkedAt = m.now() |
| 145 | if err := m.ensureLocked(ctx); err != nil { |
| 146 | return "", fmt.Errorf("%w: %v", ErrConsoleMailNotReady, err) |
| 147 | } |
| 148 | rec, err := mail.VerifyDomain(ctx, m.store, m.prov, m.dep, release.OpsAccount, m.domain, m.dep.Region, m.now()) |
| 149 | if err != nil { |
| 150 | // The domain record (or its claim) is gone — e.g. an unverified |
| 151 | // claim lapsed (mail.ClaimLapse) and was taken, or the record was |
| 152 | // otherwise removed from under this mailer. m.ensured must not |
| 153 | // stay true: left set, every future call would short-circuit |
| 154 | // ensureLocked and this mailer would refuse forever, with no |
| 155 | // recheck ever able to repair it. Clearing it here means the NEXT |
| 156 | // recheck (after consoleMailPendingRecheck) re-runs EnsureDomain |
| 157 | // instead. |
| 158 | m.ensured = false |
| 159 | return "", fmt.Errorf("%w: %v", ErrConsoleMailNotReady, err) |
| 160 | } |
| 161 | st := rec.Regions[m.dep.Region] |
| 162 | if st == nil || st.Status != mail.StatusVerified { |
| 163 | return "", ErrConsoleMailNotReady |
| 164 | } |
| 165 | m.verified, m.configSet = true, st.ConfigSet |
| 166 | return m.configSet, nil |
| 167 | } |
| 168 | |
| 169 | // Ready is the check a page runs before it promises an email: it shares |
| 170 | // ready's cache and its pending-recheck window, and returns false rather |
| 171 | // than waiting on a stalled ensure. |
| 172 | func (m *sesConsoleMailer) Ready(ctx context.Context) bool { |
| 173 | if ctx.Err() != nil { |
| 174 | // acquire picks at random when the lock is free and ctx is over. |
| 175 | return false |
| 176 | } |
| 177 | ctx, cancel := context.WithTimeout(ctx, 2*time.Second) |
| 178 | defer cancel() |
| 179 | _, err := m.ready(ctx) |
| 180 | return err == nil |
| 181 | } |
| 182 | |
| 183 | func (m *sesConsoleMailer) Send(ctx context.Context, to, subject, body string) error { |
| 184 | configSet, err := m.ready(ctx) |
| 185 | if err != nil { |
| 186 | return err |
| 187 | } |
| 188 | _, err = m.ses.SendEmail(ctx, mail.SimpleEmailInput(m.from, to, subject, body, |
| 189 | mail.TenantName(release.OpsAccount), configSet)) |
| 190 | if err != nil { |
| 191 | return fmt.Errorf("console mail: send to %s: %w", to, err) |
| 192 | } |
| 193 | return nil |
| 194 | } |
| 195 | |
amadan