Google Gets Slack with Software Updates

An anonymous reader writes "While Google's open source project titled 'Slack' was released over a year ago, last week's Australian Unix Users Group Conference marks the first time that Google has ever discussed the system in public. Corporate systems administrator Michael Still helped to illuminate a little bit about how Google uses Slack and how their network of computers fits together. From the article: '"Slack is a source deployment system and it's the way we install applications on servers," Still said, adding Slack is based around a centralized configuration repository which is then deployed onto selected machines in a "pull" method. Each of the "worker" machines asks for its new configuration regularly or when a manual command is run.'"

Name infringement?

How closely is Google Slack, tied to Slackware? If it's not, why did they choose that name? The Slashdot icon and URL suggests this story has to do with Linux.

Re:Name infringement?

You mean... Google uses Slackware Linux? AH! I knew it! :-)

More seriously, re-read TFA summary: Google Slack is a configuration manager, and not necessarily Slackware-Linux-related. OTOH, The fact that the Google engineers used that adjective may be an hommage to the oldest surviving Linux distribution.

"Slack" is, after all, a perfectly valid ajective in the English language. Even though it has deep religious overtones for the Subgeniuses out there... This being said, Slackware is still, for me one of the best Linux distribution out there.

It may be an homage, true

Or maybe the googadmins have a sense of humor.

Naming an automated package management/software update system after Slackware? That's cute.

Here's the source code

Before anybody says "Hey! Where's the source?!", let me just provide a link right now:

http://www.sundell.net/~alan/projects/slack/ [sundell.net]

Do me a favor and don't destroy sundell's server, or he's likely to hurt me :-P

Coral Cache

I doubt it will get too slashdotted, but just in case, this is the link with the downloads coming from coral cache:

Index of /~alan/projects/slack

[TXT] COPYING 13-Oct-2006 00:09 1k
[TXT] ChangeLog 13-Oct-2006 00:09 7k
[ ] slack-0.13.1.tar.gz [nyud.net] 08-Jan-2005 20:01 28k
[ ] slack-0.13.2.tar.gz [nyud.net] 09-Feb-2005 11:27 28k
[ ] slack-0.14.0.tar.gz [nyud.net] 13-Oct-2006 00:09 47k

Short Description:

slack is a configuration management system designed to appeal to lazy
admins (like me). It's an evolution from the usual "put files in some
central directory" that is faily common practice. It's descended from an
earlier system I also wrote, called "subsets", and uses a multi-stage
rsync to fix some of the problems I had there.

Basically, it's a glorified wrapper around rsync.

License:
See the file COPYING.

Getting slack:
http://www.sundell.net/~alan/projects/slack/ [sundell.net]

Documentation:
Not much, but there's some in doc/

Reporting problems:
Send an email to <sundell (at gmail.com)>. Probably want to put
"slack" in the subject and be patient for replies. :)

$Id: README,v 1.5 2006/09/25 21:35:22 alan Exp $

Makes sense

Google has what, 700,000 servers? I would imagine that along the way they would have found existing solutions inadequate. Now they are making a version of their tool available other developers.

Re:Makes sense

You (and most others here) are largely missing the point. Slack is not a replacement for apt or rpm. It's more comparable to something like cfengine, although it's only vaguely in the same universe because Slack is so much simpler. Here's what goes in a slack role:

• a preinstall script
• a set of files (config files, little scripts, etc)
• a "fixfiles" script for setting permissions on the files before they're moved into place
• a postinstall script

That's it. You don't tar it up, you don't make a package, you don't have to learn a special language to describe your changes, etc. Nothing fancy. I know those four items sound similar to what you can do with a package management system, and they are, but that's not what this is for. You don't put binaries (for example) in a Slack role - slack is for higher-level stuff like your customized config files. You *could* roll custom packages for your config files and whatnot, but that's a lot of work (relatively speaking).

Say I've got a slack role for my web server. In the preinstall script, I'd make sure the right packages are installed, so I'd do something like "apt-get install apache2". Then in the files section, I'd have etc/apache2/httpd.conf along with whatever other config files I use for my installation. In the postinstall script I could check to see if I've just installed new config files and restart apache if I have.

That's all there is to it - it's purposely extremely simple, to make it easier than just copying files from an existing server to a new one when you set one up. Laziness usually wins out (a law of human nature, not a statement about google sysadmins :-P), so if config management is too much work, it either has to be forced upon everybody or it won't be used. Additionally, since you don't do anything with the files and scripts you put in a slack role, you can trivially put your slack repository in Subversion or CVS or your revision control du jour, so getting people to use Slack has the nice side effect of also getting them to use revision control for their config files!

And yes, I use it on my personal server with two admins :-P

Slackware

"I think SLackware sounds better than Microsoft" -- Pat.

Can't google come up with their own name?

--
Submit goats: http://www.historymatters.org.uk/output/page97.asp [historymatters.org.uk]

Sounds similar to our setup

We run Ubuntu in my department and ended up building an in-house Apt repository/svn/rsync system to maintain all our machines. We also use custom scripts that monitor NFS shares to emergency push operations. Obviously our down side is that an entire .deb package must be rebuilt for each change, but it's nice to see Google's method isn't out of this world after all.

Confusing title?

I'm sure I'm not the only one who immediately thought of this [slackware.com], am I?
I'd have chosen something else, even at the risk of it sounding ridiculous.
Like one of my projects [sf.net], for example.

Re:Confusing title?

FWIW, the name is an acronym: SLACK - Sysadmins' Lazy Auto-Configuration Kit

I knew it!

The SubGenius must have slack.
Google makes Slack.
Ergo,
Google is the corporate incarnation of 'Bob'!

... What? Someone had to say it!

So its part of the Active Directory for Unix

This sounds almost exactly like the Active Directory's ability to publish and/or assign software to Domain members.

Re:So its part of the Active Directory for Unix

You mean OpenLDAP, Samba, Kerberos, Bind.
I can give you one better.

I use Mandriva Linux as my Domain Controllers and workstations.

With urpmi's parallel operation with SSH support is a Godsend. See my Secure Shell server is GSSAPI enabled (Kerberos.) Because of the fact every machine is authorized by LDAP, and authenticated by Kerberos, I can do this:

urpmi samba-server --auto --parallel dcs

This will install Samba on all Domain Controllers

urpmi gnumeric --auto --parallel all

This will install gnumeric on every machine in my Domain.

urpmi.update -a
urpmi --auto --auto-select --parallel all

This will update every machine I have in my Domain while resolving dependancies. There are problems with doing it this way. The big one is, under AD, updates can be pushed to offline machines. For this to work, all machiess must be online.

Also this does not update the urpmi catalogue synthesis.

Not new

Sounds very much like CFEngine http://www.cfengine.org/ [cfengine.org] with subversion?

Kinda similar to APT

What they're describing there is like Debian's apt-get, or BSD's portage (also incorporated in Gentoo). Each of those technologies I listed are most commonly used to install packages from a common central repository over the internet (per distro). But, each of them can be configured to retrieve and install packages from a localized server. It's actually a very handy thing to have in large-scale networks because instead of installing and updating packages on each machine over the internet from a remote repository, you just update one machine from the internet and let all the rest of them update from it, thus cutting way back in internet usage and greatly reducing the time needed for the local machines to download and install updates.

Sounds like Slack is a simplified version of all of that.

Re:Kinda similar to APT

Some what. We use APT here in our department. One of the big changes from SLACK is that it doesn't require you to compile packages like RPMs or DEBs. We have a couple of very large applications that take up 1-3GB and it takes a very long time to rebuild the packages. Slack negates such a need.

BZZZT!

What they're describing there is like Debian's apt-get, or BSD's portage (also incorporated in Gentoo).

Gentoo is not Ports. Ports is not Gentoo. Gentoo is inspired by BSD's ports, which is why the Gentoo package manager is named portage. But there are huge differences.

Last I checked, Ports was primarily a distribution system. Portage is a full-fledged package manager that happens to use source packages, and happens to have a file called "make.conf".

Each of those technologies I listed are most commonly used to install packages from a common central repository over the internet (per distro). But, each of them can be configured to retrieve and install packages from a localized server.

True, and they mention this. Gentoo's probably the closest, but their main motivation for rolling their own is to be able to go into a filesystem and tweak it, instead of having to tweak, build an RPM (or Deb, or whatever), download that to the target machine, etc etc.

It's also simultaneously a like cfengine, which is used to manage configurations. That is, it's not just for packages, but also for app configurations. That is, if your webserver goes down, hard, you can bring a new one up in an hour, 100% automated, and it will be configured the exact same way as the old one. If you need to add a new webserver to the cluster, same process. Want to change the config on a webserver? Test it on a local machine, then put the new httpd.conf on the Slack server, and watch all the frontend machines download it.

Personally, I think they should've at least looked into cfengine, but APT alone is not enough. Saying APT could do it is like saying you can write a webserver in assembly -- yes, you can, but why would you want to?

Re:BZZZT!

Personally, I think they should've at least looked into cfengine [...]

Maybe they did ? I looked into cfengine for automating our server configurations and my head asploded.

Then I experimenting with it for a few weeks, but I could never quite grok how it was supposed to work and always had the feeling that "this is as much work as managing all the systems manually anyway". It seems extremely capable, but it's very difficult to use if you want to do anything that's more trivial than pushing (or pulling) a bunch of files (for which some rsync fiddling is _vastly_ easier).

the Cult of Bob

Bob says to get as much slack as you can!

radmind

As soon as I read this I immediately though of radmind [umich.edu], which, by the vague descriptions seems to do exactly what is going on above. I encourage everyone to take a look!

CFengine

How exactly does this compare to CFengine [cfengine.org]? From the short slack description it would seem like cfengine is a much more mature solution ...

how is that different/better than...

There are a bunch of widely used systems like this: rdist, cfengine, fai, ... In what way is "Slack" supposed to be better? Or is this simply a case of NIH?

Also Obligatory...

...deployed onto selected machines in a "pull" method.

So one machine says to the other, "Hey, give me some SLACK, will ya?"

Reply from Google:

"We're a busy company, give us some slack! Jeez!"

finallyy...

I get to sue google

Re:FP

Google is all over the news these days. They should go on vacation.

s/News/Slashdot is a little more accurate :)

Maybe Google bought OSTG when nobody was looking. Might help explain why Taco's omelet is a little heavy on the Google sauce lately.

Re:FP

Might help explain why Taco's omelet is a little heavy on the Google sauce lately.

Thanks. All the bleach in the world isn't going to help me with that mental image.

Re:open source ruined business for everybody

Awww! Poor 7 digiter is upset by OSS? Enjoy your Windows (you should probably not use the internet though, most versions of Windows uses FreeBSD's network stack)!

Re:open source ruined business for everybody

what?

Re:open source ruined business for everybody

OK, this is old news to everyone except ^, but how is open source "bad for business"? It creates jobs for graphics designers and web designers, among others. And plus, there's more to software than what it'll do to the economy. Users have a lot to gain from using Linux. Gamers could use a less-bloated OS, and even complete newbs could benefit from an XP-like desktop that doesn't crash as much and has better packaging. For most people, it's about sticking it to the man, not the man sticking it to everyone else. Linux is about rebellion- it's about burning the Windows flag.
PS: The only person who deserves immediate death is... well, I can't really think of anyone immediately.

Mod Parent Up; Not a troll

The parent is clearly not a troll, folks.

The distribution tarball is 28k. This is a tiny little one-man project that is little more than exactly what the parent said. There are 90234580928345 other dumb little rsync wrappers on sourceforge, many of which are MORE functional. Why focus on this one?

I'm not the only one who is getting sick and tired of everyone pulling out their e-penis at the slightest mention of Google and jerking vigorously. Nor am I the only one sick of half of all slashdot articles being nothing but spew from the Google spin machine.

Re:open source ruined business for everybody

I've seen better trolls from 10 year olds. C'mon, at least call RMS a smelly pot smoking hippie socialist that thinks we should all live in communes and wear clothing made from fig leaves. Or something.

Whatever happened to finely crafted trolls and flamebait? I'm tellin ya, these young'uns... there's no pride in their ruthless barbs anymore.