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mesh/merge-gate head 2130f9961291 merged into trunk c71c513027e5 — pass: builds new: modules/mesh-mail, sent nowhere; no bus step; every machine composes w…
mesh/repo-check head 2130f9961291 merged into trunk c71c513027e5 — pass: its merge-check.sh passed, each part in its toolchain: merge-check.sh (go), merge-…
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ADR 0359 asked for a stream of its own and a bus grant from the module's grants; ADR 0363 built both. The events leave the shared EVENTS stream, and one family pattern per change replaces the literal per-account emits, so a new account changes no manifest.
59 lines
3.7 KiB
Markdown
59 lines
3.7 KiB
Markdown
# mesh-mail — the operator's mail accounts, watched and said on the bus
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One module holds the operator's mail accounts, watches them, and says each change of a message on the bus for the
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modules the operator grants it to (novox/hq ADR 0359, research 049 document 02). One instance, on the control-node.
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This is the first stage: accounts of the kind `imap`, read-only. Nothing here flags, moves, deletes, drafts or sends.
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## What it does
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- **Watches.** For each account it keeps one connection: IDLE on the inbox, ended and begun again every two minutes
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(which proves the server still answers), and a look at every other folder every five minutes. Folders are opened
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read-only and bodies are peeked, so watching never marks a message seen.
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- **Indexes.** One row per message and folder in its own database (`postgres-database`): metadata, flags, the text
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for search, and the attachments' references. Each attachment is kept once, by its SHA-256, in its bucket
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(`s3-bucket`, from `minio`).
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- **Says each change.** A message added, its flags changed, or removed is said as the event
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`mail.<account>.message.<added|changed|removed>`: account, folder, uid, message id, date, sender, recipients,
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subject, size, flags and attachment references; never the body, never an attachment's bytes. The events go to the
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module's own stream `MAIL`, kept seven days, never to the shared EVENTS stream (novox/hq ADR 0363); a module hears an
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account's part only when its `consumes` names mesh-mail and the setting `grants` names it for that account. The first look at a
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folder indexes what is there and says nothing: the bus hears what changed since the watch began. The keeper writes
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each event in the same step as the change it says; the bundle says it through the runtime and removes it once the
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bus took it.
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## Its settings, both trusted
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`accounts` — per account name (a lower-case token, which names the account on the bus and its secret):
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```json
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{"mesh": {"kind": "imap", "address": "<the address>",
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"incoming": {"host": "<the IMAP server>", "port": 993, "security": "tls"},
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"outgoing": {"host": "<the SMTP server>", "port": 465, "security": "tls"},
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"folders": ["optional: the folders watched besides the inbox; every folder when left out"]}}
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```
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`outgoing` is read and never used in this stage. A second `imap` account on another server is one more entry and one
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more password; no code changes. `user` signs in under another name than the address.
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`grants` — per account, who may read its mail: a module's name (on every machine), `<machine>.<module>`, or
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`person.<name>`. Nobody by default. It restricts the stream `MAIL` on the bus (a person's entry grants nothing there)
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and the tools `mail_search` and `mail_read`.
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The password of an account is the own secret `mail-credential-<account>`, given at the desk; the mesh never makes one.
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## Its tools
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| Tool | Answers |
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|---|---|
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| `mail_accounts` | each account's kind, state and why, when its server last answered, its folders; the address only to a caller granted it |
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| `mail_search` | messages of the accounts the caller is granted, by every word of a query, newest first, no body |
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| `mail_read` | one message's metadata and text, or one attachment's bytes, to a caller granted its account |
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| `mail_health` | healthy; unhealthy naming the account and why (connection down, or no answer for five minutes); waits naming `mail-credential-<account>` while its password is not given |
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The caller is the runtime's word, never an argument.
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## Its processes
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`prepare` brings the index's schema to this version's (numbered migrations, and `schema.sql` for a fresh database).
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`keep` watches the accounts and is judged by its unit. `watch` judges every minute and is judged by `mail_health`.
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