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Editing: Quota.Dict.txt
Dictionary quota ================ *NOTE:* Using the <count> [Quota.Count.txt] backend (possibly together with <quota_clone> [Plugins.QuotaClone.txt] plugin) is now preferred to using this backend. It has less of a chance of quota usage becoming wrong. The /dictionary/ quota backend supports both *storage* and *messages* quota limits. The current quota is kept in the specified <dictionary> [Dictionary.txt]. The available dictionaries include: * SQL * Redis * Flat files See <Dictionary.txt> for full description of the available backends. The quota root format is: ---%<------------------------------------------------------------------------- quota = dict:<quota root name>:<username>[:<option>[...]]:<dictionary URI> ---%<------------------------------------------------------------------------- If /username/ is left empty, the logged in username is used (this is typically what you want). Another useful username is '%d' for supporting domain-wide quotas. The supported options are: * noenforcing: Don't enforce quota limits, only track them. * ignoreunlimited: If user has unlimited quota, don't track it. * ns=<prefix>: This quota root is tracked only for the given namespace. * hidden: Hide the quota root from IMAP GETQUOTA* commands. * no-unset: When recalculating quota, don't unset the quota first. This is needed if you wish to store the quota usage among other data in the same SQL row - otherwise the entire row could get deleted. Note that the unset is required with PostgreSQL or the merge_quota() trigger doesn't work correctly. (v2.2.20+) NOTE: The dictionary stores only the current quota usage. The quota limits are still configured in userdb the same way as with other quota backends. NOTE2: By default the quota dict may delete rows from the database when it wants to rebuild the quota. You must use a separate table that contains only the quota information, or you'll lose the other data. This can be avoided with the "no-unset" parameter. Examples -------- Simple per-user flat file ------------------------- This will create one quota-accounting file for each user. The Dovecot user process (imap, pop3 or lda) needs write access to this file, so %h or mail_location are good candidates to store it. *Warning*: if a user has shell or file access to this location, he can mangle his quota file, thus overcoming his quota limit by lying about his used capacity. ---%<------------------------------------------------------------------------- plugin { quota = dict:User quota::file:%h/mdbox/dovecot-quota quota_rule = *:storage=10M:messages=1000 } ---%<------------------------------------------------------------------------- Server-based dictionaries ------------------------- ---%<------------------------------------------------------------------------- plugin { # SQL backend: quota = dict:User quota::proxy::sqlquota # Redis backend (v2.1.9+): quota = dict:User quota::redis:host=127.0.0.1:prefix=user/ quota_rule = *:storage=10M:messages=1000 } dict { sqlquota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext } ---%<------------------------------------------------------------------------- The above SQL example uses dictionary proxy process (see below), because SQL libraries aren't linked to all Dovecot binaries. The file and Redis examples use direct access. Example 'dovecot-dict-sql.conf.ext': ---%<------------------------------------------------------------------------- connect = host=localhost dbname=mails user=sqluser password=sqlpass map { pattern = priv/quota/storage table = quota username_field = username value_field = bytes } map { pattern = priv/quota/messages table = quota username_field = username value_field = messages } ---%<------------------------------------------------------------------------- Create the table like this: ---%<------------------------------------------------------------------------- CREATE TABLE quota ( username varchar(100) not null, bytes bigint not null default 0, messages integer not null default 0, primary key (username) ); ---%<------------------------------------------------------------------------- MySQL uses the following queries to update the quota. You need suitable privileges. ---%<------------------------------------------------------------------------- INSERT INTO table (bytes,username) VALUES ('112497180','foo@example.com') ON DUPLICATE KEY UPDATE bytes='112497180'; INSERT INTO table (messages,username) VALUES ('1743','foo@example.com') ON DUPLICATE KEY UPDATE messages='1743'; UPDATE table SET bytes=bytes-14433,messages=messages-2 WHERE username = 'foo@example.com'; DELETE FROM table WHERE username = 'foo@example.com'; ---%<------------------------------------------------------------------------- If you're using SQLite, then take a look at the trigger in this post: http://dovecot.org/pipermail/dovecot/2013-July/091421.html If you're using PostgreSQL, you'll need a trigger: ---%<------------------------------------------------------------------------- CREATE OR REPLACE FUNCTION merge_quota() RETURNS TRIGGER AS $$ BEGIN IF NEW.messages < 0 OR NEW.messages IS NULL THEN -- ugly kludge: we came here from this function, really do try to insert IF NEW.messages IS NULL THEN NEW.messages = 0; ELSE NEW.messages = -NEW.messages; END IF; return NEW; END IF; LOOP UPDATE quota SET bytes = bytes + NEW.bytes, messages = messages + NEW.messages WHERE username = NEW.username; IF found THEN RETURN NULL; END IF; BEGIN IF NEW.messages = 0 THEN INSERT INTO quota (bytes, messages, username) VALUES (NEW.bytes, NULL, NEW.username); ELSE INSERT INTO quota (bytes, messages, username) VALUES (NEW.bytes, -NEW.messages, NEW.username); END IF; return NULL; EXCEPTION WHEN unique_violation THEN -- someone just inserted the record, update it END; END LOOP; END; $$ LANGUAGE plpgsql; CREATE TRIGGER mergequota BEFORE INSERT ON quota FOR EACH ROW EXECUTE PROCEDURE merge_quota(); ---%<------------------------------------------------------------------------- Dictionary proxy server ----------------------- To avoid each process making a new SQL connection, you can make all dictionary communications go through a dictionary server process which keeps the connections permanently open. The dictionary server is referenced with URI 'proxy:<dictionary server socket path>:<dictionary name>'. The socket path may be left empty if you haven't changed 'base_dir' setting in 'dovecot.conf'. Otherwise set it to '<base_dir>/dict-server'. The dictionary names are configured in 'dovecot.conf'. For example: ---%<------------------------------------------------------------------------- dict { quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext expire = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext } ---%<------------------------------------------------------------------------- See <Dict.txt> for more information, especially about permission issues. (This file was created from the wiki on 2019-06-19 12:42)
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