1 files changed, 83 insertions, 0 deletions
diff --git a/services/docker/mail-server/relay/dovecot.ts b/services/docker/mail-server/relay/dovecot.ts
new file mode 100644
index 0000000..0528968
--- /dev/null
+++ b/services/docker/mail-server/relay/dovecot.ts
@@ -0,0 +1,83 @@
+import { getConfig } from "./config.ts";
+import { getLogger } from "./logger.ts";
+import {
+  Mail,
+  MailDeliverContext,
+  MailDeliverer,
+  MailDeliverReceiptResult,
+} from "./mail.ts";
+
+export class DovecotMailDeliverer extends MailDeliverer {
+  readonly name = "dovecot";
+  readonly ldaBin = "dovecot-lda";
+
+  protected override async doDeliver(
+    mail: Mail,
+    context: MailDeliverContext,
+  ): Promise<void> {
+    const { ldaBin } = this;
+    const utf8Stream = mail.toUtf8Bytes();
+    const receipts = mail.simpleParseReceipts({
+      domain: getConfig().getValue("mailDomain"),
+    });
+
+    if (receipts.length === 0) {
+      throw new Error("No receipts detected from mail headers.");
+    }
+
+    getLogger().log(`Deliver to (from headers) ${receipts.join(", ")}.`);
+
+    for (const receipt of receipts) {
+      getLogger().log(`Call ${ldaBin} for ${receipt}...`);
+
+      const result: MailDeliverReceiptResult = {
+        kind: "done",
+        message: `${ldaBin} exited with success.`,
+      };
+
+      try {
+        const ldaCommand = new Deno.Command(ldaBin, {
+          args: ["-d", receipt],
+          stdin: "piped",
+          stdout: "piped",
+          stderr: "piped",
+        });
+
+        const ldaProcess = ldaCommand.spawn();
+        getLogger().logProgramOutput(ldaProcess, ldaBin);
+
+        const stdinWriter = ldaProcess.stdin.getWriter();
+        await stdinWriter.ready;
+        await stdinWriter.write(utf8Stream);
+        await stdinWriter.ready;
+        const status = await ldaProcess.status;
+
+        if (!status.success) {
+          result.kind = "fail";
+          result.message = `${ldaBin} exited with error code ${status.code}`;
+
+          if (status.signal != null) {
+            result.message += ` (signal ${status.signal})`;
+          }
+
+          // https://doc.dovecot.org/main/core/man/dovecot-lda.1.html
+          switch (status.code) {
+            case 67:
+              result.message += ", receipt user not known";
+              break;
+            case 75:
+              result.kind = "retry";
+              break;
+          }
+
+          result.message += ".";
+        }
+      } catch (e) {
+        result.kind = "fail";
+        result.message = "An error was thrown when running lda process.";
+        result.cause = e;
+      }
+      context.result.set(receipt, result);
+    }
+  }
+}