[ixpmanager] Server rebuild

[Rowan Thorpe]

Quick Summary for the tl;dr people:

(A) Follow the IXP-M wiki exclusively if you have lots of free time,
and don't mind rediscovering platform quirks and having to recreate
your workarounds each time, and don't mind the risk of accidentally
re-creating settings incorrectly due to human-error each time

(B) Use it in parallel with reading the commands in the auto-installer
script if you wish to still be bullet-proof but want to save time (on
Debian, thus far) or if you can't think up workarounds that work for
you

(C) Only actually run the autoinstaller (on a bare or fully backed up
OS!) if you want to automate everything and you feel reckless, and don't
mind hacking it a bit to fit with latest IXP-M versions

====

Long version:

It seems that what my script actually does (and what it doesn't do)
has been a bit misunderstood...

> Probably best to stick with the standard installation process and
> restore the mysql dump.

I agree with this entirely, which doesn't conflict with also referring
to the auto-installer for tips. The script was designed to follow "the
standard installation process" with three extra vital distinctions:

 (1) automated (after editing the simple installer-conf once)
 (2) as forward-compatible as possible with future IXP-M versions
 (3) easily update-able to handle various platforms' quirks and
     differences

The script actually does restore the mysql dump, and the other steps
Brian mentioned in his first email, and in fact it automates "the
standard installation process" to the letter (as it appeared in the
IXP-M wiki on 29/09/2013), but it also takes (optional) extra steps to
attempt to have a fully functional, populated and running installation:

 (A) based on a potentially later version of IXP-M than was previously
     used
 (B) with configurable locations e.g. log files in /var/log/ixpmanager,
     cache files in /var/cache/ixpmanager (allowing a savvy sysadmin to
     gain security and performance benefits, etc)
 (C) even on a new server, without having to resort to
     fragile/maintenance-hell commands like
     "cd / && tar -x -f THE_PREVIOUS_FILESYSTEM_FOOTPRINT.tar" in order
     to catch subtle changes to locations like /usr/local/ixp,
     /opt/ixpmanager, /usr/local/share/perl/5.x.x/IXP-Manager,
     /etc/ixpmanager.conf, /var/cache/ixpmanager, /var/log/ixpmanager,
     etc...
 (D) by updating (rather than overwriting) the config from a
     fresh OS install on the fly, based on its simple key=value format
     config file, so that newer versions of IXP-M can hopefully still
     work without having to manually investigate and edit the entire
     application.ini.dist each time to discover additions,
     modifications and deletions that would be blitzed by just copying
     the old configs into place
 (E) by integrating things like sflow, smokeping, mrtg, etc without
     having to manually re-edit or copy-paste files at various points in
     the filesystem
 (F) by copying extra things like skinned templates and image files into
     place

Copy-pasted below is taken from
https://github.com/rowanthorpe/ixp-autoinstall/blob/master/ixp-autoinstall.sh#L157
and shows the steps it takes, which all default to "on" (=1), and can
all be independently turned off with flags (e.g. if you have already
manually edited or copied the config and trust it to be up-to-date, or
if you have already installed a system package for sflowtool, etc). If
you disable enough of the extra steps you will end up with exactly the
"standard installation process":

====
do_install_firewall=1
do_install_deps=1
do_setup_dirs=1
do_setup_permissions=1
do_install_ixpmanager=1
do_create_database=1
do_edit_base_confs=1
do_setup_schema=1
do_setup_webserver=1
do_setup_fixtures=1
do_unarchive_skin=1
do_unarchive_misc=1
do_unarchive_ext_images=1
do_setup_maintenance_file=1
do_populate_db_data=1
do_setup_perl_libs=1
do_integrate_mrtg=1
do_setup_mrtg=1
do_setup_mrtg_init=1
do_setup_periodic_update=1
do_setup_periodic_update_cron=1
do_setup_store_traffic_cron=1
do_setup_update_macs=1
do_setup_poll_switch_cron=1
do_install_sflowtool=1
do_setup_rrdcached=1
do_setup_sflow_to_rrd=1
do_setup_sflow_to_rrd_init=1
do_let_sflow_through_firewall=1
do_integrate_sflow=1
do_setup_smokeping=1
do_integrate_smokeping=1
do_remove_build_deps=1
do_start_webserver=1
do_let_web_through_firewall=1
====

I hoped that people would like to have that script around, even if only
as a quick "to do" reference regarding streamlining the installation
process (and showing what is not yet pointed out in the docs), but I've
not received any feedback or help with updating it yet (or integrating
any of its workarounds into IXP-M), so unfortunately it has already
fallen a few minor-versions behind IXP-M's master branch because I
don't have time to keep it synchronised by myself, so especially now it
should only be used as a reference rather than actually running it.
However it does serve as a good list of "gotcha's". A funny thing was
that a large part of it was originally dealing with hacks to make all
the mrtg perl-fu work correctly behind the scenes, and as I was about to
upload it IXP-M was updated to internalise much of that with PHP, so
that part became redundant. I believe that most of the rest of the
auto-installer can eventually be made redundant in the same fashion,
and if people check it out that may happen sooner...

> > Plugging away at your autoinstall script.  Most of it is tweaking
> > the conf.sh file.

If you already have a working config *for the present master HEAD
version of IXP-M* then it will be easier to copy that file and just
skip that step (as in what "--no-edit-base-confs" does)

> > I have found that it would be useful to include at least in the
> > documentation of all the package dependencies the script requires.

Of course those deps are all inside "case" statements because those
are the deps specifically needed in Debian Wheezy (and therefore
Ubuntu, etc). For example several platforms already have an sflowtool
package, but there is not one in Debian yet. However, I have packaged
and submitted it and am waiting for a Debian Developer to sponsor it
(when that happens sflowtool can become merely a dependency for Debian,
Ubuntu, etc too, rather than requiring the manual compilation step).

> > ..[snip]..
> >    10  apt-get install memcached
> >    11  apt-get install subversion
> >    12  apt-get install php5-memcache
> >    13  apt-get install php5-snmp
> >    14  apt-get install php-apc
> > ..[snip]..
> > Found pear was missing
> > 
> >  26  pear channel-discover pear.symfony.com
> >  27  apt-get install php-pear
> >  28  pear channel-discover pear.symfony.com
> >  29  pear channel-discover pear.doctrine-project.org
> >  30  pear install doctrine/DoctrineORM

A list of Debian Wheezy deps, separated into those with
version-requirements, interactive or not, etc, are at
https://github.com/rowanthorpe/ixp-autoinstall/blob/master/ixp-autoinstall.sh#L595
This should fall more-or-less in-line with what you need on Ubuntu.

> > ..[snip]..
> > Then found I needed to flip a switch in the install.sh for mysql
> > passwords.

The script processes the $with_root_db_password from the autoinstall
conf for this.

> > ..[snip]..
> > Discovered MRTG not installed.

It is included as a dep here:
https://github.com/rowanthorpe/ixp-autoinstall/blob/master/ixp-autoinstall.sh#L621

> > ..[snip]..
> > Currently I am still on MRTG with this error.
> > 
> > ixp-autoinstall.sh: setting up mrtg
> > sed: can't read /etc/mrtg-rrd.conf: No such file or directory
> > 
> > I haven't been able to determine where in the recipe this file gets
> > built.

mrtg-rrd is included as a dep here:
https://github.com/rowanthorpe/ixp-autoinstall/blob/master/ixp-autoinstall.sh#L622
I don't remember exactly any more but I think I included mrtg-rrd
because those who want to can push their mrtg data to rrd too using
this. The installer would bork at that point because the config file
won't exist if you didn't install the package. It is just trying to
update it to point to where IXP-manager has put its own mrtg config. I
am pretty sure it is an "optional extra" though. If in doubt ignore that
command (and that package).

> > > Setting variables is one thing,  Understanding the whole script
> > > might be another.

The "just setting variables" approach is when running the autoinstaller
with all steps enabled, having edited its config, but as mentioned
before it has already fallen slightly out of synch with the latest
IXP-M so you shouldn't rely on that approach any more. The way to use
it for now should be by reading through the script (just copying your
configs and ignoring all the sed-code for that if it makes you
cross-eyed) and manually entering its commands which either (1)
coincide with the latest version of the IXP-M wiki, or (2) take
steps which are missing from the wiki *and which still make sense with
the latest IXP-M version*.

The fully-automated aspect of the script attempts to cater to those who
want to effectively "provision" IXP-Manager to non-interactively
migrate VMs, etc.

-- 
Rowan Thorpe
mailto:rowan at rowanthorpe.com
PGP fingerprint:
 BB0A 0787 C0EE BDD8 7F97  3D30 49F2 13A5 265D CCBD
----
"There is a great difference between worry and concern. A worried
person sees a problem, and a concerned person solves a problem."
 - Harold Stephens