Boot me up! out-of-band IPMI rocks then shuts up and waits

It’s hard to get excited about re-implementing functionality from v1 unless the v2 happens to also be freaking awesome.   It’s awesome because the OpenCrowbar architecture allows us to it “the right way” with real out-of-band controls against the open WSMAN APIs.

gangnam styleWith out-of-band control, we can easily turn systems on and off using OpenCrowbar orchestration.  This means that it’s now standard practice to power off nodes after discovery & inventory until they are ready for OS installation.  This is especially interesting because many servers RAID and BIOS can be configured out-of-band without powering on at all.

Frankly, Crowbar 1 (cutting edge in 2011) was a bit hacky.  All of the WSMAN control was done in-band but looped through a gateway on the admin server so we could access the out-of-band API.  We also used the vendor (Dell) tools instead of open API sets.

That means that OpenCrowbar hardware configuration is truly multi-vendor.  I’ve got Dell & SuperMicro servers booting and out-of-band managed.  Want more vendors?  I’ll give you my shipping address.

OpenCrowbar does this out of the box and in the open so that everyone can participate.  That’s how we solve this problem as an industry and start to cope with hardware snowflaking.

And this out-of-band management gets even more interesting…

Since we’re talking to servers out-of-band (without the server being “on”) we can configure systems before they are even booted for provisioning.  Since OpenCrowbar does not require a discovery boot, you could pre-populate all your configurations via the API and have the Disk and BIOS settings ready before they are even booted (for models like the Dell iDRAC where the BMCs start immediately on power connect).

Those are my favorite features, but there’s more to love:

  • the new design does not require network gateway (v1 did) between admin and bmc networks (which was a security issue)
  • the configuration will detect and preserves existing assigned IPs.  This is a big deal in lab configurations where you are reusing the same machines and have scripted remote consoles.
  • OpenCrowbar offers an API to turn machines on/off using the out-of-band BMC network.
  • The system detects if nodes have IPMI (VMs & containers do not) and skip configuration BUT still manage to have power control using SSH (and could use VM APIs in the future)
  • Of course, we automatically setup BMC network based on your desired configuration

 

OpenCrowbar Design Principles: Reintroduction [Series 1 of 6]

While “ready state” as a concept has been getting a lot of positive response, I forget that much of the innovation and learning behind that concept never surfaced as posts here.  The Anvil (2.0) release included the OpenCrowbar team cataloging our principles in docs.  Now it’s time to repost the team’s work into a short series over the next three days.

In architecting the Crowbar operational model, we’ve consistently twisted adapted traditional computer science concepts like late binding, simulated annealing, emergent behavior, attribute injection and functional programming to create a repeatable platform for sharing open operations practice (post 2).

Functional DevOps aka “FuncOps”

Ok, maybe that’s not going to be the 70′s era hype bubble name, but… the operational model behind Crowbar is entering its third generation and its important to understand the state isolation and integration principles behind that model is closer to functional than declarative programming.

Parliament is Crowbar’s official FuncOps sound track

The model is critical because it shapes how Crowbar approaches the infrastructure at a fundamental level so it makes it easier to interact with the platform if you see how we are approaching operations. Crowbar’s goal is to create emergent services.

We’ll expore those topics in this series to explain Crowbar’s core architectural principles.  Before we get into that, I’d like to review some history.

The Crowbar Objective

Crowbar delivers repeatable best practice deployments. Crowbar is not just about installation: we define success as a sustainable operations model where we continuously improve how people use their infrastructure. The complexity and pace of technology change is accelerating so we must have an approach that embraces continuous delivery.

Crowbar’s objective is to help operators become more efficient, stable and resilient over time.

Background

When Greg Althaus (github @GAlhtaus) and Rob “zehicle” Hirschfeld (github @CloudEdge) started the project, we had some very specific targets in mind. We’d been working towards using organic emergent swarming (think ants) to model continuous application deployment. We had also been struggling with the most routine foundational tasks (bios, raid, o/s install, networking, ops infrastructure) when bringing up early scale cloud & data applications. Another key contributor, Victor Lowther (github @VictorLowther) has critical experience in Linux operations, networking and dependency resolution that lead to made significant contributions around the Annealing and networking model. These backgrounds heavily influenced how we approached Crowbar.

First, we started with best of field DevOps infrastructure: Opscode Chef. There was already a remarkable open source community around this tool and an enthusiastic following for cloud and scale operators . Using Chef to do the majority of the installation left the Crowbar team to focus on

crowbar_engineKey Features

  • Heterogeneous Operating Systems – chose which operating system you want to install on the target servers.
  • CMDB Flexibility (see picture) – don’t be locked in to a devops toolset. Attribute injection allows clean abstraction boundaries so you can use multiple tools (Chef and Puppet, playing together).
  • Ops Annealer –the orchestration at Crowbar’s heart combines the best of directed graphs with late binding and parallel execution. We believe annealing is the key ingredient for repeatable and OpenOps shared code upgrades
  • Upstream Friendly – infrastructure as code works best as a community practice and Crowbar use upstream code
  • without injecting “crowbarisms” that were previously required. So you can share your learning with the broader DevOps community even if they don’t use Crowbar.
  • Node Discovery (or not) – Crowbar maintains the same proven discovery image based approach that we used before, but we’ve streamlined and expanded it. You can use Crowbar’s API outside of the PXE discovery system to accommodate Docker containers, existing systems and VMs.
  • Hardware Configuration – Crowbar maintains the same optional hardware neutral approach to RAID and BIOS configuration. Configuring hardware with repeatability is difficult and requires much iterative testing. While our approach is open and generic, the team at Dell works hard to validate a on specific set of gear: it’s impossible to make statements beyond that test matrix.
  • Network Abstraction – Crowbar dramatically extended our DevOps network abstraction. We’ve learned that a networking is the key to success for deployment and upgrade so we’ve made Crowbar networking flexible and concise. Crowbar networking works with attribute injection so that you can avoid hardwiring networking into DevOps scripts.
  • Out of band control – when the Annealer hands off work, Crowbar gives the worker implementation flexibility to do it on the node (using SSH) or remotely (using an API). Making agents optional means allows operators and developers make the best choices for the actions that they need to take.
  • Technical Debt Paydown - We’ve also updated the Crowbar infrastructure to use the latest libraries like Ruby 2, Rails 4, Chef 11. Even more importantly, we’re dramatically simplified the code structure including in repo documentation and a Docker based developer environment that makes building a working Crowbar environment fast and repeatable.

OpenCrowbar (CB2) vs Crowbar (CB1)?

Why change to OpenCrowbar? This new generation of Crowbar is structurally different from Crowbar 1 and we’ve investing substantially in refactoring the tooling, paying down technical debt and cleanup up documentation. Since Crowbar 1 is still being actively developed, splitting the repositories allow both versions to progress with less confusion. The majority of the principles and deployment code is very similar, I think of Crowbar as a single community.

Continue Reading > post 2

Crowbar HK Hack Report

Purple Fuzzy H for Hackathon (and Havana)Overall, I’m happy with our three days of hacking on Crowbar 2.  We’ve reached the critical “deploys workload” milestone and I’m excited about well the design is working and how clearly we’ve been able to articulate our approach in code & UI.

Of course, it’s worth noting again that Crowbar 1 has also had significant progress on OpenStack Havana workloads running on Ubuntu, Centos/RHEL, and SUSE/SLES

Here are the focus items from the hack:

  • Documentation – cleaned up documentation specifically by updating the README in all the projects to point to the real documentation in an effort to help people find useful information faster.  Reminder: if unsure, put documentation in barclamp-crowbar/doc!
  • Docker Integration for Crowbar 2 progress.  You can now install Docker from internal packages on an admin node.  We have a strategy for allowing containers be workload nodes.
  • Ceph installed as workload is working.  This workload revealed the need for UI improvements and additional flags for roles (hello “cluster”)
  • Progress on OpenSUSE and Fedora as Crowbar 2 install targets.  This gets us closer to true multi-O/S support.
  • OpenSUSE 13.1 setup as a dev environment including tests.  This is a target working environment.
  • Being 12 hours offset from the US really impacted remote participation.

One thing that became obvious during the hack is that we’ve reached a point in Crowbar 2 development where it makes sense to move the work into distinct repositories.  There are build, organization and packaging changes that would simplify Crowbar 2 and make it easier to start using; however, we’ve been trying to maintain backwards compatibility with Crowbar 1.  This is becoming impossible; consequently, it appears time to split them.  Here are some items for consideration:

  1. Crowbar 2 could collect barclamps into larger “workload” repos so there would be far fewer repos (although possibly still barclamps within a workload).  For example, there would be a “core” set that includes all the current CB2 barclamps.  OpenStack, Ceph and Hadoop would be their own sets.
  2. Crowbar 2 would have a clearly named “build” or “tools” repo instead of having it called “crowbar”
  3. Crowbar 2 framework would be either part of “core” or called “framework”
  4. We would put these in a new organization (“Crowbar2″ or “Crowbar-2″) so that the clutter of Crowbar’s current organization is avoided.

While we clearly need to break apart the repo, this suggestion needs community more discussion!

Crowbar 2 Status Update > I can feel the rumble of the engines

two

Crowbar Two

While I’ve been more muted on our Crowbar 2 progress since our pivot back to CB1 for Grizzly, it has been going strong and steady.  We took advantage of the extra time to do some real analysis about late-binding, simulated annealing, emergent services and functional operations that are directly reflected in Crowbar’s operational model (yes, I’m working on posted explaining each concept).

We’re planning Crowbar 2 hack-a-thon in Hong Kong before the OpenStack Ice House Summit (11/1-3).  We don’t expect a big crowd on site, but the results will be fun to watch remote and it should be possible to play along (watch the crowbar list for details).

In the mean time, I wanted to pass along this comprehensive status update by Crowbar’s leading committer, Victor Lowther:

It has been a little over a month since my last status report on
Crowbar 2.0, so now that we have hit the next major milestone
(installing the OS on a node and being able to manage it afterwards),
it is time for another status report.

Major changes since the initial status report:

* The Crowbar framework understands node aliveness and availability.
* The Network barclamp is operational, and can manage IPv4 and IPv6 in
  the same network.
* delayed_jobs + a stupidly thin queuing layer handle all our
  long-running tasks.
* We have migrated to postgresql 9.3 for all our database needs.
* DHCP and DNS now utilize the on_node_* role hooks to manage their
  databases.
* We support a 2 layer deployment tree -- system on top, everything
  else in the second layer.
* The provisioner can install Ubuntu 12.04 on other nodes.
* The crowbar framework can manage other nodes that are not in
  Sledgehammer.
* We have a shiny installation wizard now.

In more detail:

Aliveness and availability:

Nodes in the Crowbar framework have two related flags that control
whether the annealer can operate on them.

Aliveness is under the control of the Crowbar framework and
encapsulates the framework's idea of whether any given node is
manageable or not.  If a node is pingable and can be SSH'ed into as
root without a password using the credentials of the root user on
the admin node, then the node is alive, otherwise it is dead.
Aliveness is tested everytime a jig tries to do something on a node
-- if a node cannot be pinged and SSH'ed into from at least one of
its addresses on the admin network, it will be marked as
dead.  When a node is marked as dead, all of the noderoles on that
node will be set to either blocked or todo (depending on the state of
their parent noderoles), and those changes will ripple down the
noderole dependency graph to any child noderoles.

Nodes will also mark themselves as alive and dead in the course of
their startup and shutdown routines.

Availability is under the control of the Crowbar cluster
administrators, and should be used by them to tell Crowbar that it
should stop managing noderoles on the node.  When a node is not
available, the annealer will not try to perform any jig runs on a
node, but it will leave the state of the noderoles alone.

A node must be both alive and available for the annealer to perform
operations on it.

The Network Barclamp:

The network barclamp is operational, with the following list of
features:

* Everything mentioned in Architecture for the Network Barclamp in
  Crowbar 2.0
* IPv6 support.  You can create ranges and routers for IPv6 addresses
  as well as IPv4 addresses, and you can tell a network that it should
  automatically assign IPv6 addresses to every node on that network by
  setting the v6prefix setting for that network to either:
  * a /64 network prefix, or
  * "auto", which will create a globally unique RFC4193 IPv6 network
    prefix from a randomly-chosen 40 bit number (unique per cluster
    installation) followed by a subnet ID based on the ID of the
    Crowbar network.
  Either way, nodes in a Crowbar network that has a v6prefix will get
  an interface ID that maps back to their FQDN via the last 64 bits of
  the md5sum of that FQDN. For now, the admin network will
  automatically create an RFC4193 IPv6 network if it is not passed a
  v6prefix so that we can easily test all the core Crowbar components
  with IPv6 as well as IPv4.  The DNS barclamp has been updated to
  create the appropriate AAAA records for any IPv6 addresses in the
  admin network.

Delayed Jobs and Queuing:

The Crowbar framework runs all jig actions in the background using
delayed_jobs + a thin queuing layer that ensures that only one task is
running on a node at any given time.  For now, we limit ourselves to
having up to 10 tasks running in the background at any given time,
which should be enough for the immediate future until we come up with
proper tuning guidelines or auto-tuning code for significantly larger
clusters.

Postgresql 9.3:

Migrating to delayed_jobs for all our background processing made it
immediatly obvious that sqlite is not at all suited to handling real
concurrency once we started doing multiple jig runs on different nodes
at a time. Postgresql is more than capable of handling our forseeable
concurrency and HA use cases, and gives us lots of scope for future
optimizations and scalability.

DHCP and DNS:

The roles for DHCP and DNS have been refactored to have seperate
database roles, which are resposible for keeping their respective
server roles up to date.  Theys use the on_node_* roles mentioned in
"Roles, nodes, noderoles, lifeycles, and events, oh my!" along with a
new on_node_change event hook create and destroy DNS and DHCP database
entries, and (in the case of DHCP) to control what enviroment a node
will PXE/UEFI boot into.  This gives us back the abiliy to boot into
something besides Sledgehammer.

Deployment tree:

Until now, the only deployment that Crowbar 2.0 knew about was the
system deployment.  The system deployment, however, cannot be placed
into proposed and therefore cannot be used for anything other than
initial bootstrap and discovery.  To do anything besides
bootstrap the admin node and discover other nodes, we need to create
another deployment to host the additional noderoles needed to allow
other workloads to exist on the cluster.  Right now, you can only
create deployments as shildren of the system deployment, limiting the
deployment tree to being 2 layers deep.

Provisioner Installing Ubuntu 12.04:

Now, we get to the first of tqo big things that were added in the last
week -- the provisioner being able to install Ubuntu 12.04 and bring
the resulting node under management by the rest of the CB 2.0
framework.  This bulds on top of the deployment tree and DHCP/DNS
database role work.  To install Ubuntu 12.04 on a node from the web UI:

1: Create a new deployment, and add the provisioner-os-install role to
that deployment.  In the future you will be able to edit the
deployment role information to change what the default OS for a
deployment should be.
2: Drag one of the non-admin nodes onto the provisioner-os-install
role.  This will create a proposed noderole binding the
provisioner-os-install role to that node, and in the future you would
be able to change what OS would be installed on that node by editing
that noderole before committing the deployment.
3: Commit the snapshot.  This will cause several things to happen:
  * The freshly-bound noderoles will transition to TODO, which will
    trigger an annealer pass on the noderoles.
  * The annealer will grab all the provisioner-os-install roles that
    are in TODO, set them in TRANSITION, and hand them off to
    delayed_jobs via the queuing system.
  * The delayed_jobs handlers will use the script jig to schedule a
    reboot of the nodes for 60 seconds in the future and then return,
    which will transition the noderole to ACTIVE.
  * In the crowbar framework, the provisioner-os-install role has an
    on_active hook which will change the boot environment of the node
    passed to it via the noderole to the appropriate os install state
    for the OS we want to install, and mark the node as not alive so
    that the annealer will ignore the node while it is being
    installed.
  * The provisioner-dhcp-database role has an on_node_change handler
    that watches for changes in the boot environment of a node.  It
    will see the bootenv change, update the provisioner-dhcp-database
    noderoles with the new bootenv for the node, and then enqueue a
    run of all of the provisioner-dhcp-database roles.
  * delayed_jobs will see the enqueued runs, and run them in the order
    they were submitted.  All the runs sholuld happen before the 60
    seconds has elapsed.
  * When the nodes finally reboot, the DHCP databases should have been
    updated and the nodes will boot into the Uubntu OS installer,
    install, and then set their bootenv to local, which will tell the
    provisioner (via the provisioner-dhcp-database on_node_change
    hook) to not PXE boot the node anymore.
  * When the nodes reboot off their freshly-installed hard drive, they
    will mark themselves as alive, and the annealer will rerun all of
    the usual discovery roles.
The semi-astute observer will have noticed some obvious bugs and race
conditions in the above sequence of steps.  These have been left in
place in the interest of expediency and as learning oppourtunities for
others who need to get familiar with the Crowbar codebase.

Installation Wizard:

We have a shiny installation that you can use to finish bootstrapping
your admin node.  To use it, pass the --wizard flag after your FQDN to
/opt/dell/bin/install-crowbar when setting up the admin node, and the
install script will not automatically create an admin network or an
entry for the admin node, and logging into the web UI will let you
customize things before creating the initial admin node entry and
committing the system deployment.  

Once we get closer to releasing CB 2.0, --wizard will become the default.

OpenStack Deploy Day generates lots of interest, less coding

Last week, my team at Dell led a world-wide OpenStack Essex Deploy event. Kamesh Pemmaraju, our OpenStack-powered solution product manager, did a great summary of the event results (200+ attendees!). What started as a hack-a-thon for deploy scripts morphed into a stunning 14+ hour event with rotating intro content and an ecosystem showcase (videos).  Special kudos to Kamesh, Andi Abes, Judd Maltin, Randy Perryman & Mike Pittaro for leadership at our regional sites.

Clearly, OpenStack is attracting a lot of interest. We’ve been investing time in content to help people who are curious about OpenStack to get started.

While I’m happy to be fueling the OpenStack fervor with an easy on-ramp, our primary objective for the Deploy Day was to collaborate on OpenStack deployments.

On that measure, we have room for improvement. We had some great discussions about how to handle upgrades and market drivers for OpenStack; however, we did not spend the time improving Essex deployments that I was hoping to achieve. I know it’s possible – I’ve talked with developers in the Crowbar community who want this.

If you wanted more expert interaction, here are some of my thoughts for future events.

  • Expert track did not get to deploy coding. I think that we need to simply focus more even tightly on to Crowbar deployments. That means having a Crowbar Hack with an OpenStack focus instead of vice versa.
  • Efforts to serve OpenStack n00bs did not protect time for experts. If we offer expert sessions then we won’t try to have parallel intro sessions. We’ll simply have to direct novices to the homework pages and videos.
  • Combining on-site and on-line is too confusing. As much as I enjoy meeting people face-to-face, I think we’d have a more skilled audience if we kept it online only.
  • Connectivity! Dropped connections, sigh.
  • Better planning for videos (not by the presenters) to make sure that we have good results on the expert track.
  • This event was too long. It’s just not practical to serve Europe, US and Asia in a single event. I think that 2-3 hours is a much more practical maximum. 10-12am Eastern or 6-8pm Pacific would be much more manageable.

Do you have other comments and suggestions? Please let me know!

OpenStack Essex Deploy Day: First Steps to Production

One March 8th, 70 people from around the world gathered on the Crowbar IM channel to begin building a production grade OpenStack Essex deployment. The event was coordinated as meet-ups by the Dell OpenStack/Crowbar team (my team) in two physical locations: the Nokia offices in Boston and the TechRanch in Austin.

My objective was to enable the community to begin collaboration on Essex Deployment. At that goal, we succeeded beyond my expectations.

IMHO, the top challenge for OpenStack Essex is to build a community of deploying advocates. We have a strong and dynamic development community adding features to the project. Now it is time for us to build a comparable community of deployers. By providing a repeatable, shared and open foundation for OpenStack deployments, we create a baseline that allows collaboration and co-development. Not only must we make deployments easy and predictable, we must also ensure they are scalable and production ready.

Having solid open production deployment infrastructure drives OpenStack adoption.

Our goal on the 8th was not to deliver finished deployments; it was to the start of Essex deployment community collaboration. To ensure that we could focus on getting to an Essex baseline, our team invested substantial time before the event to make sure that participants had a working Essex reference deployment.

By the nature of my team’s event leadership and our approach to OpenStack, the event was decidedly Crowbar focused. I feel like this is an acceptable compromise because Crowbar is open and provides a repeatable foundation. If everyone has the same foundation then we can focus on the truly critical challenges of ensuring consistent OpenStack deployments. Even using Crowbar, we waste a lot of time trying to figure out the differences between configurations. Lack of baseline consistency seriously impedes collaboration.

The fastest way to collaborate on OpenStack deployment is to have a reference deployment as a foundation.

Success By The Numbers

This was a truly international community collaborative event. Here are some of the companies that participated:

Dell (sponsor), Nokia (sponsor), Rackspace, Opscode, Canonical, Fedora, Mirantis, Morphlabs, Nicira, Enstratus, Deutsche Telekom Innovation Laboratories, Purdue University, Orbital Software Solutions, XepCloud and others.

PLEASE COMMENT here if I missed your company and I will add it to the list.

On the day of the event, we collected the following statistics:

  • 70 people on Skype IM channel (it’s not too late to join by pinging DellCrowbar with “Essex barclamps”).
  • 14+ companies
  • 2 physical sites with 10-15 people at each
  • 4 fold increase in traffic on the Crowbar Github to 813 hits.
  • 66 downloads of the Deploy day ISO
  • 8 videos capture from deploy day sessions.
  • World-wide participation

For over 70 people to spend a day together at this early stage in deployment is a truly impressive indication of the excitement that is building around OpenStack.

Improvements for Next Deploy Day

This was a first time that Andi Abes (Boston event lead), Rob Hirschfeld (Austin event lead) or Jean-Marie Martini (Dell event lead) had ever coordinated an event like this. We owe much of the success to efforts by Greg Althaus, Victor Lowther and the Canonical 12.04/Essex team before the event. Also, having physical sites was very helpful.

We are planning to do another event, so we are carefully tracking ways to improve.

Here are some issues we are tracking.

  • Issues with setting up a screen and voice share that could handle 70 people.
  • Lack of test & documentation on Crowbar meant too much time focused on Crowbar
  • Connectivity issues distributed voice
  • Should have started with DevStack as a baseline
  • more welcome in the comments!

Thank you!

I want to thank everyone who participated in making this event a huge success!

OpenStack Essex Deploy Day 3/8 – Get involved and install with us

My team at Dell has been avidly tracking the upsdowns, and breakthroughs of the OpenStack Essex release.  While we still have a few milestones before the release is cut, we felt like the E4 release was a good time to begin the work on Essex deployment.  Of course, the final deployment scripts will need substantial baking time after the final release on April 5th; however, getting deployments working will help influence the quality efforts and expand the base of possible testers.

To rally behind Essex Deployments, we are hosting a public work day on Thursday March 8th.

For this work day, we’ll be hosting all-day community events online and physically in Austin and Boston.  We are getting commitments from other Dell teams, partners and customers around the world to collaborate.  The day is promising to deliver some real Essex excitement.

The purpose of these events is to deliver the core of a working OpenStack Essex deployment.  While my team is primarily focused on deploys via Crowbar/Chef, we are encouraging anyone interested in laying down OpenStack Essex to participate.  We will be actively engaged on the OpenStack IRC and mailing lists too.

We have experts in OpenStack, Chef, Crowbar and Operating Systems (Canonical, SUSE, and RHEL) engaged in these activities.

This is a great time to start learning about OpenStack (or Crowbar) with hands-on work.  We are investing substantial upfront time (checkout out the Crowbar wiki for details) to ensure that there is a working base OpenStack Essex deploy on Ubuntu 12.04 beta.  This deploy includes the Crowbar 1.3 beta with some new features specifically designed to make testing faster and easier than ever before.

In the next few days, I’ll cut a 12.04 ISO and OpenStack Barclamp TARs as the basis for the deploy day event.  I’ll also be creating videos that help you quickly get a test lab up and running.  Visit the wiki or meetup sites to register and stay tuned for details!

Barclamps: now with added portability!

I had a question about moving barclamps between solutions.  Since Victor just changed the barclamp build to create a tar for each barclamp (with the debs/rpms), I thought it was the perfect time to explain the new feature.

You can find the barclamps on the Crowbar ISO under “/dell/barclamps” and you can install the TAR onto a Crowbar system using “./barclamp_install foo.tar.gz” where foo is the name of your barclamp.

Here’s a video of how to find and install barclamp tars:

Note: while you can install OpenStack into a Hadoop system, that combination is NOT tested.  We only test OpenStack on Ubuntu 10.10 and Hadoop on RHEL 5.7.   Community help in expanding support is always welcome!

Build Sledgehammer, the Crowbar discovery image / build prerequisite

Note: This content has been copied to the Crowbar Wiki.
Victor “got your back” Lowther, CI & build automation czar on our team at Dell, spent a lot of time cleaning up the open source build to make it MUCH easier.  The latest build only requires ONE server for all components.  To make it repeatable and fast, I’m using a hosted VM from Rackspace Cloud.
Here are the steps that you should follow (cool: if you build before the prereqs are in place, the script will tell you what’s missing).
Note: You must build the discovery image (build_sledgehammer.sh) before building Crowbar.  This image does not change very often, so it’s helpful to cache it somewhere (like in the Crowbar cache where it normally lives) and save time.
  1. Starting from a Rackspace Cloud Ubuntu 10.10 image (512 RAM is OK, $0.03/hr)
  2. Get libraries for git, RPM, & Ruby: apt-get install git rpm ruby
  3. Get the sledgehammer repo: git clone git://github.com/dellcloudedge/crowbar-sledgehammer.git
  4. Go to sledgehammer: cd crowbar-sledgehammer
  5. Download the CentOS image: curl -o ../CentOS-5.6-x86_64-bin-DVD-1of2.iso http://mirror.cs.vt.edu/pub/CentOS/5.6/isos/x86_64/CentOS-5.6-x86_64-bin-DVD-1of2.iso
    1. takes some time (10+ mins) even in the cloud
  6. Tell the build where to look for the CentOS image: CENTOS_ISO=~/CentOS-5.6-x86_64-bin-DVD-1of2.iso ./build_sledgehammer.sh
    1. you may need to change the path of the image if you did not put it in your home directory
    1. wait a long time while magic happens and the tar gets created
    2. check out the tar ball in the /bin directory!
  7. Create the cache location for Sledgehammer: mkdir -p ~/.crowbar-build-cache
  8. Move the the cache location: cd ~/.crowbar-build-cache
  9. Extract the Sledgehammer tar: tar xzvf ~/crowbar-sledgehammer/bin/sledgehammer-tftpboot.tar.gz 
Or, use the tar copy that I’ve cached it on zehicle.com!  Then you can start at step 8.
Now you can build crowbar as per instructions (duplicated below)
  1. cd ~
  2. git clone git://github.com/dellcloudedge/crowbar.git
  3. apt-get update
  4. apt-get install build-essential mkisofs debootstrap
  5. crowbar/build_crowbar.sh
    1. kicks off a long download to create the cache (first time only!)
    2. look in the home directory for the openstack-dev.iso

Of course, you still need to INSTALL CROWBAR (as root, /tftpboot/ubuntu_dvd/extra/install) after you use the ISO to boot a VM.  Instructions on that shortly…