Notes for Packagers¶
Sample configuration files¶
There are several samples of cyrus.conf(5) and
imapd.conf(5) located in the doc/examples
directory of
the distribution tarball. Please install these to your preferred
documentation directory (i.e. /usr/share/doc/cyrus-imapd
) as a
reference for your users.
Predefined configurations¶
The configuration file for master: cyrus.conf¶
When installing a predefined cyrus.conf(5) for your users, please pay attention to new features and how these may impact users. For example, for some time now, Cyrus has supported placing several standard DB files in temporary, or ephemeral, storage, such as memory backed filesystems like tmpfs (see below). This both boosts efficiency and ensures DB consistency in event of a crash or other system disruptive events. But, in light of this, actions which depend on the existence of these database files should not be placed in the START section of cyrus.conf(5).
Section Purpose¶
A new section, DAEMON, was added to cyrus.conf(5) in version 2.5. Please consult cyrus.conf(5) for details. Please refer to the notes in Section Descriptions pertaining to the distinctions between START, EVENTS and DAEMON sections.
In brief, the sorts of things which should go into the different sections are:
- START
- Programs which should be spawned by cyrusmaster(8) which are expected to cleanup after themselves
- do not rely on any ephemeral files or resources
- cyrusmaster(8) will not start until all entries in START have either ended or backgrounded themselves.
- SERVICES
- Service daemons managed by cyrusmaster(8)
- cyrusmaster(8) will listen on ports or sockets as specified and dispatch new child processes as needed, destroy old or stale processes, etc.
- EVENTS
- Periodic processes which will be started by cyrusmaster(8) as specified.
- DAEMON
- Programs which should be spawned by cyrusmaster(8) which it should shut down and clean up after.
The configuration file for the various programs: imapd.conf¶
The sample imapd.conf(5) files must be adapted for use from site to site. Here, therefore, we’ll attempt to point you towards some reasonable settings which take advantage of recent improvements and features, and may help guide you and your users to a better performing Cyrus installation.
Ephemeral files and temporary filesystems¶
In addition to Unix domain sockets and lock files, several databases
used by Cyrus programs may be located in temporary filesystems, such as
those backed by RAM (i.e. tmpfs, md, etc.). Here’s a list of such
files. In this example, the filesystem /run
is on tmpfs:
proc_path: /run/cyrus/proc
mboxname_lockpath: /run/cyrus/lock
duplicate_db_path: /run/cyrus/deliver.db
statuscache_db_path: /run/cyrus/statuscache.db
ptscache_db_path: /run/cyrus/ptscache.db
tls_sessions_db_path: /run/cyrus/tls_sessions.db
lmtpsocket: /run/cyrus/socket/lmtp
idlesocket: /run/cyrus/socket/idle
notifysocket: /run/cyrus/socket/notify
Note
Any process which depends on these files already existing should not be placed in the START section of cyrus.conf(5), or the server will not start as expected.
New default settings¶
With the introduction of version 3.0, the defaults for some settings have changed. Please consult Upgrading to 3.0 for details.
New features¶
There are several features either new to version 3.0, or newly improved. Some of these may be features which previously were not considered ripe for packaging, but merit new consideration.
Please see the release notes Major changes since the 2.5.x series for more details and other recent changes.
- Conversations
- Server-side threading with reduced protocol chatter for mobile or other high-latency clients.
- Required for JMAP support.
- See the
conversations
options in imapd.conf(5)
- JMAP
- JSON Mail Access Protocol
- Follow-on successor to IMAP (“J comes after I”) with a special focus on mobile and other clients with high-latency or unreliable connectivity.
- Includes Calendaring, Contacts, Conversations, message delivery.
- See
httpmodules
in imapd.conf(5)
- Xapian
- Higher quality full-text search support.
- Required for JMAP support.
- See the
search_engine
option in imapd.conf(5) anddoc/README.xapian
in the source distribution.
- Archive partitions
- Automatically migrate messages from posh, fast storage (think SSD) to cheap, slow storage (spinning rust).
- Requires addition of an archive partition for each data partition.
- See
archive_*
options in imapd.conf(5)
- Backup
- Replication-based backup to dedicated instance with efficient, compact scheme.
- See Cyrus Backups
Please consider enabling these features in the imapd.conf(5) you ship in your packages.
Services in /etc/services
¶
Listing named services through /etc/services
aids in cross-system consistency and cross-platform interoperability. Furthermore, it enables administrators and users to refer to the service by name (for example in /etc/cyrus.conf
, ‘listen=mupdate’ can be specified instead of ‘listen=3905’).
Some of the services Cyrus IMAP would like to see available through /etc/services
have not been assigned an IANA port number, and few have configuration options.
The Cyrus IMAP server provides service interfaces via either TCP/IP
ports or Unix domain sockets. For the former, Cyrus requires that there
are proper entries in the host’s /etc/services
file. The following
are required for any host using the listed services:
pop3 110/tcp # Post Office Protocol v3
nntp 119/tcp # Network News Transport Protocol
imap 143/tcp # Internet Mail Access Protocol rev4
imsp 406/tcp # Internet Message Support Protocol (deprecated)
nntps 563/tcp # NNTP over TLS
imaps 993/tcp # IMAP over TLS
pop3s 995/tcp # POP3 over TLS
kpop 1109/tcp # Kerberized Post Office Protocol
lmtp 2003/tcp # Lightweight Mail Transport Protocol service
smmap 2004/tcp # Cyrus smmapd (quota check) service
csync 2005/tcp # Cyrus replication service
mupdate 3905/tcp # Cyrus mupdate service
sieve 4190/tcp # timsieved Sieve Mail Filtering Language service
Make sure that these lines are present or add them if they are missing.