FLAP, Part 1: Server Provisioning
We have reached the state where end-to-end data center provisioning is a reality. It’s early yet, so there is a certain amount of work involved, but today a DevOps team essentially can turn on the automation and move on to other DevOps priorities. It takes some effort, depending upon the solution chosen, but the end result is an infrastructure that provides for installation of operating system (OS), hardware (if needed) and apps, along with configuration of the whole, at the push of a button.
There are a number of solutions ready for your data center today, and this three-part series will explore them. In the first part, we’ll talk about server provisioning―the part that takes you from uninstalled server or virtual to a functioning OS configured for your environment. The following two articles will cover application provisioning and merging the two to achieve FLAP. (Yes, I made up FLAP. Use it or not, as you see fit.)
Disclaimer:I work for a vendor in this space. While I do not believe that impacts my objectivity, I will note where my employer is mentioned, and leave it to the reader to decide if I’m blinded to some items/issues based upon my association.Server Provisioning: What and Who
A server provisioning system takes a physical or virtual server from nothing to fully installed OS. This layer of FLAP is fundamental to automating the entire process. If the system has to be installed manually, using tools and scripts to install applications just doesn’t offer the overall benefit as when the entire process is automated.
For this discussion, we will be sticking with the major provisioning tools out there. To be sure there are more, and I have information about them, but for this short blog post, we’ll stick with the ones that hold something special―market share, history, integrations, associations―that make them a good long-term bet. Our list is alphabetical, and does not show preference by ordering.Cobbler
Cobbler is one of the original server automation tool sets, and definitely has the history and stability to warrant your attention. For shops that use a lot of Fedora and CentOS, Cobbler in combination with Spacewalk is particularly appealing, as we’ll talk about later. Support includes most linux distributions. Users have created ways to include windows in the list of installable OSes, but there is not yet an official solution for Windows.
Cobbler is integrated with Ansible, Spacewalk, Saltstack, Puppet(user created), and older versions of Satellite. There is some amount of concern about Cobbler’s future growth, simply because Red Hat moved Satellite off of Cobbler with release 6.0, though Red Hat still supports Cobbler. It is too soon after the split to predict how this will fall out, but currently it seems to have motivated the Cobbler core team to do more. Users concerned should check GitHub analytics to see what the trends are for committers and commits at the time they are evaluating (good advice for all of these products, but more pertinent for one where there is a question of its future).
Cobbler’s hardware support is better than most, and in terms of application support it is a pure-play server automation tool; there is no support for applications at all―application provisioning is expected to deal with that aspect.Foreman
Foreman is an open source project that is currently enjoying the sponsorship of Red Hat, but support is not limited to Red Hat OSes. In fact, Foreman will install just about any flavor of Linux, and can target most physical/virtual/cloud platforms. Using WDS, Foreman can also install Windows.
One of the big strengths of Foreman is its interoperability―it doesn’t much care which application provisioning tool you are using. It is integrated into Satellite (with Puppet), and has support for all of the other major application provisioning tools. This means that no matter what you’re using to get your apps installed, Foreman is worth looking at for getting your servers installed.
Like most products out there, Foreman provides CLI, API and GUI. They’re relatively stable in relation to the market, simply because Foreman implemented them earlier than most competitors, and is constantly improving them.
In short, if you are in an environment that has a wide selection of OS, architecture and application requirements, Foreman should be at the top of your short list. For more focused solutions (in terms of OS, whether or not cloud, or application provisioning tools), it makes more sense to compare specific features/functionality with some of the more focused tools in this list.MaaS
MaaS was the sleeping giant of the automation world, but it does indeed look as though it is awakening. MaaS is part of Canonical’s Ubuntu project, so there is plenty of backing, but historically its goals have been modest and its documentation more so. That changed some time over the summer/fall, and MaaS is showing increased support for OSes, better documentation and a more focused attempt to get the word out. If you are primarily an Ubuntu shop, it is well worth considering.
Like most of the products in this offering, MaaS uses PXE to get the machines into its system, and then uses predefined images that have been imported (Ubuntu images don’t need importing) to install a machine from bare metal/virtual to working OS. MaaS proclaims support for CentOS, RedHat, SuSE, Ubuntu and Windows. For those unfamiliar with the space, that’s an impressive list. But the last time this author used MaaS, it was still only Ubuntu, so I cannot comment on the level/quality of support for each of the OSes. Due diligence should involve testing with those OSes your organization needs.
The weakest part of some installers is non-standard hardware, such as RAID controllers, specialized network cards and the like. MaaS supports these components and includes UCS support in its packaging. Directly mentioning UCS support is only to be found with MaaS and Stacki, so if you’re a UCS shop, it is worth considering.
In addition to CLI, MaaS touts an API and a GUI. These are important tools in the DevOps sense, because the API lets you tie MaaS into your automation architecture, and the GUI helps find issues specific to MaaS and its domain. Particularly interesting is the collection of logs that show install results and operations results clearly for each server.
The one major drawback to MaaS is its limited application provisioning support―it is well-integrated with Juju, but none of the other big names in the space.
In short, for Ubuntu shops using Juju, this is the tool to put at the top of your short list. For everyone else, the tool is viable, but should be considered against the features/functionality of other tools.Razor
Razor is Puppet’s newer bare metal installer. It is young yet, and there are still issues to be worked out, but the large cadre of developers that are dedicated to Puppet say that Razor will continue to improve as time moves on. At current it directly supports most flavors of Linux and Windows installations. The catch to Razor is on the other end: It is designed to work with Puppet, and support for other application provisioning tools is low―indeed, is limited to user-designed solutions. Needless to say, because it is sponsored by Puppet, it is expected that official work in this area will remain slow, as it is not a priority.
Razor does not have a dedicated GUI; instead, it uses Puppet’s GUI to report results. As with integration, this is okay for Puppet shops but pretty much eliminates Razor from consideration for other shops. (More on this in a future blog in this series.)
Because Razor is new, there are a couple of serious caveats with the product. First, install is one of the worst in the market, with a lot of pre-install steps, a lot of install steps, and configuration of an array of underlying systems by hand. Second, each currently installed server that you do not want Razor to re-install must be entered into Razor manually on the command line. This is so limiting in a generalized data center environment (where Puppet shines) that you can expect this limitation to be resolved quickly.
In short, for Puppet shops that do not see their application provisioning tool changing, this is the tool to put at the top of your short list. For other shops, it’s worth looking at competitors first, simply because Razor requires Puppet.Stacki
Stacki is an open source project sponsored by StackIQ (as promised, this is my employer). Having roots that stretch back more than a decade, Stacki specializes in RedHat/CentOS installations with additional support for clustered software. As of this writing, CoreOS and Ubuntu have been added to Stacki’s list of supported OSes, and expect that list to grow over time.
The biggest appeal of Stacki is the variety of ways to get systems under management. All of these apps will auto-detect a new server on the network, grab it and install it. Stacki adds the ability to list just the servers that should be clean-installed in a spreadsheet, the next time each of those machines boots they will be installed, but no other machine will. While there are ways in all of these systems to simulate this functionality―you can add exceptions to the “install all machines that boot on this subnet” rule via the command line in Razor, for example―using a spreadsheet to affirmatively manage what machines are to be installed and how gives an offline bulk way of managing installations and re-installations.
As of this writing, Stacki does not have an API, and only with commercial add-ons can a GUI be had, but expect one or both of these things to change as the community begins guiding development efforts. Stacki is optimized to spin out hundreds of servers in minutes or hours instead of weeks or months, utilizing a peer-to-peer parallel installer to service installations faster as more servers come online. While it works as well as others in smaller environments, it really comes to its own when there are a large number of servers under management. On the initial installation front, while the other systems in this list require hand-installing and/or configuring prerequisites and sub-systems, Stacki comes as an ISO with a UI that asks a few questions and configures everything.
Stacki has been used with most (Ansible, Puppet, Saltstack) of the major application provisioning tools this series of blogs will consider, making it versatile on the application side of the equation.
Overall, if you’re a Red Hat shop that uses CentOS a lot―particularly a larger shop―Stacki should be the first stop on your short list. For everyone else, the tool is viable, but should be considered against the features/functionality of other tools.
Stay tuned for part two of this series, which will cover application provisioning.
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