Table of Contents
Symbiosis will install well on a freshly-installed Debian 7.0 system. Currently it is only available for i386 and amd64 architectures, running on the Linux kernel.
It is designed to be as friendly as possible for beginners, whilst maintaining flexibility for more experienced systems administrators. Later in this chapter we’ll spell out a few basics to bear in mind when working with a system running Symbiosis.
Installing on a fresh Wheezy system is relatively simple. First, add the following to /etc/apt/sources.list.d/symbiosis.list:
# # Bytemark Symbiosis Packages # deb http://symbiosis.bytemark.co.uk/wheezy/ ./ deb-src http://symbiosis.bytemark.co.uk/wheezy/ ./
Once that is in your sources, run:
apt-get update apt-get install --install-recommends bytemark-symbiosis
At the end of this process, you should have a fully functioning Symbiosis system with all of the features documented here available to you for use.
Debian have comprehensive release notes, of which chapter 4 covers the recommended upgrade procedure. We have provided a shorter version for this, which is immediately below:
The first thing to do is make sure that you have backups. These should be kept in /var/backups/localhost, and they should be up to date.
Any modifications you may have made to Symbiosis scripts will likely be lost during the upgrade, so you should be prepared to reapply these changes after the upgrade.
Next, alter /etc/apt/sources.list. Change all instances of the word
squeeze to wheezy. If you have backports, you can remove them, and
any entries for Squeeze LTS should also be removed. Then change the
Symbiosis repository lines to match those shown in the previous section.
You can then proceed with the upgrade by running:
apt-get update apt-get dist-upgrade
If you see failures related to dovecot, refer to the release notes (Section 14.3, “Release notes”).
You may find that symbiosis-mysql symbiosis-phpmyadmin have been removed; if so, simply reinstall them:
apt-get install symbiosis-mysql symbiosis-phpmyadmin
You might get hourly php5 emails stating:
PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php5/20100525+lfs/suhosin.so
This may be fixed by running:
apt-get remove --purge php5-suhosin
That should be everything; you may have been asked other questions if you have installed extra packages on your system - answer them as you see fit.
This release of Symbiosis includes a number of new features that are summarised in Chapter 2, What’s new since the last release.
The backup regimen has changed. It is now set to 2 levels of 5 differential backups (from 3 levels of 8 differential backups) resulting in a new set of backups every 30 days, as opposed to every 584 days. Two sets of backups will be kept. This will mean that your machine will definitely need to have enough space for two full backups.
Dovecot has undergone a major upgrade since squeeze. If you’ve tweaked your dovecot config, it may need attention. If all else fails, try removing /etc/dovecot/dovecot.conf and then running:
apt-get install -f
There have been many command changes since the original Lenny release of Symbiosis. Not all of them made much sense, so commands have moved around quite a bit to follow the pattern symbiosis-package-command. The old commands have symbolic links in place pointing to the new commands:
symbiosis-check-mailbox-password -> symbiosis-email-check-password symbiosis-check-ftp-password -> symbiosis-ftpd-check-password symbiosis-create-sites -> symbiosis-httpd-configure symbiosis-create-mass-hosting-sites -> symbiosis-httpd-configure symbiosis-rotate-logs -> symbiosis-httpd-rotate-logs symbiosis-apache-logger -> symbiosis-httpd-logger symbiosis-generate-stats -> symbiosis-httpd-generate-stats
These links will be removed in jessie.
There were also commands left over from the Lenny release. These have been removed:
symbiosis-create-ssl -> symbiosis-httpd-configure checkpassword -> symbiosis-email-check-password symbiosis_checkpassword -> symbiosis-email-check-password firewall -> symbiosis-firewall firewall-whitelist -> symbiosis-firewall-whitelist firewall-blacklist -> symbiosis-firewall-blacklist
Each component that makes up Symbiosis is separately packaged as follows. Each package can be installed individually if needed.
sources.list file.
Symbiosis is an attempt to encourage best practice at all times in systems administration, whilst keeping things as simple as possible, and free of surprises. As a result there are a few general rules to bear in mind when tinkering with your system.
As far as possible Symbiosis will discourage you from using root
when logging in and configuring the system. This primarily applies to
/srv/ directory
/etc/symbiosis/firewall
For example, if a directory in /srv is owned by a system
user or group, i.e. one with a UID/GID less than 1000, then it will
not show up to various tasks, including, but not limited to,
config/crontab
public/logs/
In short, try not to use root if at all possible.
However it is perfectly possible to configure separate domains in
/srv/ to be owned by different users, as long as they are
non-system users, i.e. ones with user IDs greater than 1000. All
programs will respect these permissions.
Lots of configuration on the system is automatically generated to make Symbiosis work as it does. In previous releases of Symbiosis this meant that files would get overwritten without notice. However as of the Squeeze release in February 2012 configuration files are handled more conservatively.
Two things to watch out for. If a configuration file has
# DO NOT EDIT THIS FILE - CHANGES WILL BE OVERWRITTEN
written in it, then there is a high chance that any changes will be overwritten. It has to be the exact wording and spacing above for overwriting to take place, so if that sentence is removed from the configuration then it will not get overwritten.
Similarly many files are generated from templates, for example DNS and apache snippets. These will now have a checksum at the bottom of the file.
# Checksum MD5 586732ff59e60115d0ec1c4905c72773
This checksum allows Symbiosis scripts to establish if the template
used to generate the snippet has changed, if the data used in the
generation has changed, or if the file itself has been edited. For
example if an IP address is changed by editing config/ip, then that
would allow the apache snippet for that domain can be updated, as can
the DNS snippet.
This also means that sysadmins can edit the templates, and allow them to regenerate, or edit the snippets themselves safe in the knowledge that their changes will not get overwritten.
The Backup2l, Dovecot, and Exim configuration files are generated not with a template, but with a collection of snippets, which are joined and checked using a Makefile. This allows extra configuration snippets to be added in to the configuration.
If it is deemed necessary, sysadmins can add extra snippets to these configurations. The basic procedure is to read the configuration file, and decide where the extra directives need to go. This is made easier by the fact that through the configuration files comments are added showing where each part comes from.
# ------------------------------------------------------------------------------ # /etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/00-header # ------------------------------------------------------------------------------ # ACL that is used after the MAIL command acl_check_mail: # ------------------------------------------------------------------------------ # /etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/90-default # ------------------------------------------------------------------------------ # Allow anything not already denied to connect accept
In this example, if an extra directive were required in this ACL,
then a file could be created in
/etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/, maybe
with the filename 10-do-stuff. To create the new configuration,
we’d then need to run make in /etc/exim4/. This would
regenerate /etc/exim4/exim4.conf, and perform a basic syntax check.
If happy with the new configuration, then exim4 could be restarted.
The equivalent Dovecot configuration is in /etc/dovecot/symbiosis.d/
which generates /etc/dovecot/dovecot.conf. The Backup2l
configuration is in /etc/symbiosis/backup.d/conf.d/, which
generates /etc/symbiosis/backup.d/backup2l.conf.