Cloud Native PHYSICAL PROVISIONING? Come on! Really?!

We believe Cloud Native development disciplines are essential regardless of the infrastructure.

imageToday, RackN announce very low entry level support for Digital Rebar Provisioning – the RESTful Cobbler PXE/DHCP replacement.  Having a company actually standing behind this core data center function with support is a big deal; however…

We’re making two BIG claims with Provision: breaking DevOps bottlenecks and cloud native physical provisioning.  We think both points are critical to SRE and Ops success because our current approaches are not keeping pace with developer productivity and hardware complexity.

I’m going to post more about Provision can help address the political struggles of SRE and DevOps that I’ve been watching in our industry.   A hint is in the release, but the Cloud Native comment needs to be addressed.

First, Cloud Native is an architecture, not an infrastructure statement.

There is no requirement that we use VMs or AWS in Cloud Native.  From that perspective, “Cloud” is a useful but deceptive adjective.  Cloud Native is born from applications that had to succeed in hands-off, lower SLA infrastructure with fast delivery cycles on untrusted systems.  These are very hostile environments compared to “legacy” IT.

What makes Digital Rebar Provision Cloud Native?  A lot!

The following is a list of key attributes I consider essential for Cloud Native design.

Micro-services Enabled: The larger Digital Rebar project is a micro-services design.  Provision reflects a stand-alone bundling of two services: DHCP and Provision.  The new Provision service is designed to both stand alone (with embedded UX) and be part of a larger system.

Swagger RESTful API: We designed the APIs first based on years of experience.  We spent a lot of time making sure that the API conformed to spec and that includes maintaining the Swagger spec so integration is easy.

Remote CLI: We build and test our CLI extensively.  In fact, we expect that to be the primary user interface.

Security Designed In: We are serious about security even in challenging environments like PXE where options are limited by 20 year old protocols.  HTTPS is required and user or bearer token authentication is required.  That means that even API calls from machines can be secured.

12 Factor & API Config: There is no file configuration for Provision.  The system starts with command line flags or environment variables.  Deeper configuration is done via API/CLI.  That ensures that the system can be fully managed by remote and configured securely becausee credentials are required for configuration.

Fast Start / Golang:  Provision is a totally self-contained golang app including the UX.  Even so, it’s very small.  You can run it on a laptop from nothing in about 2 minutes including download.

CI/CD Coverage: We committed to deep test coverage for Provision and have consistently increased coverage with every commit.  It ensures quality and prevents regressions.

Documentation In-project Auto-generated: On-boarding is important since we’re talking about small, API-driven units.  A lot of Provisioning documentation is generated directly from the code into the actual project documentation.  Also, the written documentation is in Restructured Text in the project with good indexes and cross-references.  We regenerate the documentation with every commit.

We believe these development disciplines are essential regardless of the infrastructure.  That’s why we made sure the v3 Provision (and ultimately every component of Digital Rebar as we iterate to v3) was built to these standards.

What do you think?  Is this Cloud Native?  What did we miss?

Cloud-first Physical Provisioning? 10 ways that the DR is in to fix your PXE woes.


Why has it been so hard to untie from Cobbler? Why can’t we just REST-ify these 1990s Era Protocols? Dealing with the limits of PXE, DHCP and TFTP in wide-ranging data centers is tricky and Cobbler’s manual pre-defined approach was adequate in legacy data centers.

Now, we have to rethink Physical Ops in Cloud-first terms. DevOps and SRE minded operators services that have need real APIs, day-2 ops, security and control as primary design requirements.

The Digital Rebar team at RackN is hunting for Cobbler, Stacki, MaaS and Forman users to evaluate our RESTful, Golang, Template-based PXE Provisioning utility. Deep within the Digital Rebar full life-cycle hybrid control was a cutting-edge bare metal provisioning utility. As part of our v3 roadmap, we carved out the Provisioner to also work as a stand-alone service.

Here’s 10 reasons why DR Provisioning kicks aaS:

  1. Swagger REST API & CLI. Cloud-first means having a great, tested API. Years of provisioning experience went into this 3rd generation design and it shows. That includes a powerful API-driven DHCP.
  2. Security & Authenticated API. Not an afterthought, we both HTTPS and user authentication for using the API. Our mix of basic and bearer token authentication recognizes that both users and automation will use the API. This brings a new level of security and control to data center provisioning.
  3. Stand-alone multi-architecture Golang binary. There are no dependencies or prerequisites, plus upgrades are drop in replacements. That allows users to experiment isolated on their laptop and then easily register it as a SystemD service.
  4. Nested Template Expansion. In DR Provision, Boot Environments are composed of reusable template snippets. These templates can incorporate global, profile or machine specific properties that enable users to set services, users, security or scripting extensions for their environment.
  5. Configuration at Global, Group/Profile and Node level. Properties for templates can be managed in a wide range of ways that allows operators to manage large groups of servers in consistent ways.
  6. Multi-mode (but optional) DHCP. Network IP allocation is a key component of any provisioning infrastructure; however, DHCP needs are highly site dependant. DR Provision works as a multi-interface DHCP listener and can also resolve addresses from DHCP forwarders. It can even be disabled if your environment already has a DHCP service that can configure a the “next boot” provider.
  7. Dynamic Provisioner templates for TFTP and HTTP. For security and scale, DR Provision builds provisioning files dynamically based on the Boot Environment Template system. This means that critical system information is not written to disk and files do not have to be synchronized. Of course, when you need to just serve a file that works too.
  8. Node Discovery Bootstrapping. Digital Rebar’s long-standing discovery process is enabled in the Provisioner with the included discovery boot environment. That process includes an integrated secure token sequence so that new machines can self-register with the service via the API. This eliminates the need to pre-populate the DR Provision system.
  9. Multiple Seeding Operating Systems. DR Provision comes with a long list of Boot Environments and Templates including support for many Linux flavors, Windows, ESX and even LinuxKit. Our template design makes it easy to expand and update templates even on existing deployments.
  10. Two-stage TFTP/HTTP Boot. Our specialized Sledgehammer and Discovery images are designed for speed with optimized install cycles the improve boot speed by switching from PXE TFTP to IPXE HTTP in a two stage process. This ensures maximum hardware compatibility without creating excess network load.

Digital Rebar Provision is a new generation of data center automation designed for operators with a cloud-first approach. Data center provisioning is surprisingly complex because it’s caught between cutting edge hardware and arcane protocols embedded in firmware requirements that are still very much alive.

We invite you to try out Digital Rebar Provision yourself and let us know what you think. It only takes a few minutes. If you want more help, contact RackN for a $1000 Quick Start offer.

Packet Pushers 333: Orchestration v Automation < YES, this is what we are doing!

Iix34grhy_400x400 highly recommend catching Packet Pushers 333 “Automation & Orchestration In Networking” by Drew Conry-Murray and guests Pete Lumbis and Michael Damkot.

While the discussion is all about NETWORK DevOps, they do a good job of decrying WHY current state of system orchestration is so sad – in a word: heterogeneity.  It’s not going away because the alternative is lock-in.  They also do a good job of describing the difference between automation and orchestration; however, I think there’s a middle tier  of resource “scheduling” that better describes OpenStack and Kubernetes.

Around 5:00 minutes into the podcast, they effectively describe the composable design of Digital Rebar and the rationale for the way that we’ve abstracted interfaces for automation.  If you guys really do want to cash in by consulting with it (at 10 minutes), just give me a call.

It’s great to hear acknowledgement of both the complexity and need for solving these problems.   Thanks for the great podcast Drew, Pete and Michael!

Oh… and I’m going to be presenting at Interop ITX also.  Hopefully, I’ll get a chance to talk 1×1 with Drew.

10x Faster Today but 10x Harder to Maintain Tomorrow: the Cul-De-Sac problem

I’ve been digging into what it means to be a site reliability engineer (SRE) and thinking about my experience trying to automate infrastructure in a way to scales dramatically better.  I’m not thinking about scale in number of nodes, but in operator efficiency.  The primary way to create that efficiency is limit site customization and to improve reuse.  Those changes need to start before the first install.

As an industry, we must address the “day 2” problem in collaboratively developed open software before users’ first install.

Recently, RackN asked the question “Shouldn’t we have Shared Automation for Commodity Infrastructure?” which talked about fact that we, as an industry, keep writing custom automation for what should be commodity servers.  This “snow flaking” happens because there’s enough variation at the data center system level that it’s very difficult to share and reuse automation on an ongoing basis.

Since variation enables innovation, we need to solve this problem without limiting diversity of choice.


Happily, platforms like Kubernetes are designed to hide these infrastructure variations for developers.  That means we can expect a productivity explosion for the huge number of applications that can narrowly target platforms.  Unfortunately, that does nothing for the platforms or infrastructure bound applications.  For this lower level software, we need to accept that operations environments are heterogeneous.


I realized that we’re looking at a multidimensional problem after watching communities like OpenStack struggle to evolve operations practice.

It’s multidimensional because we are building the operations practice simultaneously with the software itself.  To make things even harder, the infrastructure and dependencies are also constantly changing.  Since this degree of rapid multi-factor innovation is the new normal, we have to plan that our operations automation itself must be as upgradable.

If we upgrade both the software AND the related deployment automation then each deployment will become a cul-de-sac after day 1.

For open communities, that cul-de-sac challenge limits projects’ ability to feed operational improvements back into the user base and makes it harder for early users to stay current.  These challenges limit the virtuous feedback cycles that help communities grow.  

The solution is to approach shared project deployment automation as also being continuously deployed.

This is a deceptively hard problem.

This is a hard problem because each deployment is unique and those differences make it hard to absorb community advances without being constantly broken.  That is one of the reasons why company opt out of the community and into vendor distributions. While Vendors are critical to the ecosystem, the practice ultimately limits the growth and health of the community.

Our approach at RackN, as reflected in open Digital Rebar, is to create management abstractions that isolate deployment variables based on system level concerns.  Unlike project generated templates, this approach absorbs heterogeneity and brings in the external information that often complicate project deployment automation.  

We believe that this is a general way to solve the broader problem and invite you to participate in helping us solve the Day 2 problems that limit our open communities.

Beyond Expectations: OpenStack via Kubernetes Helm (Fully Automated with Digital Rebar)

RackN revisits OpenStack deployments with an eye on ongoing operations.

I’ve been an outspoken skeptic of a Joint OpenStack Kubernetes Environment (my OpenStack BCN presoSuper User follow-up and BOS Proposal) because I felt that the technical hurdles of cloud native architecture would prove challenging.  Issues like stable service positioning and persistent data are requirements for OpenStack and hard problems in Kubernetes.

I was wrong: I underestimated how fast these issues could be addressed.

youtube-thumb-nail-openstackThe Kubernetes Helm work out of the AT&T Comm Dev lab takes on the integration with a “do it the K8s native way” approach that the RackN team finds very effective.  In fact, we’ve created a fully integrated Digital Rebar deployment that lays down Kubernetes using Kargo and then adds OpenStack via Helm.  The provisioning automation includes a Ceph cluster to provide stateful sets for data persistence.  

This joint approach dramatically reduces operational challenges associated with running OpenStack without taking over a general purpose Kubernetes infrastructure for a single task.

sre-seriesGiven the rise of SRE thinking, the RackN team believes that this approach changes the field for OpenStack deployments and will ultimately dominate the field (which is already  mainly containerized).  There is still work to be completed: some complex configuration is required to allow both Kubernetes CNI and Neutron to collaborate so that containers and VMs can cross-communicate.

We are looking for companies that want to join in this work and fast-track it into production.  If this is interesting, please contact us at

Why should you sponsor? Current OpenStack operators facing “fork-lift upgrades” should want to find a path like this one that ensures future upgrades are baked into the plan.  This approach provide a fast track to a general purpose, enterprise grade, upgradable Kubernetes infrastructure.

Closing note from my past presentations: We’re making progress on the technical aspects of this integration; however, my concerns about market positioning remain.

Surgical Ansible & Script Injections before, during or after deployment.

I’ve been posting about the unique composable operations approach the RackN team has taken with Digital Rebar to enable hybrid infrastructure and mix-and-match underlay tooling.  The orchestration design (what we call annealing) allows us to dynamically add roles to the environment and execute them as single role/node interactions in operational chains.

ansiblemtaWith our latest patches (short demo videos below), you can now create single role Ansible or Bash scripts dynamically and then incorporate them into the node execution.

That makes it very easy to extend an existing deployment on-the-fly for quick changes or as part of a development process.

You can also run an ad hoc bash script against one or groups of machines.  If that script is something unique to your environment, you can manage it without having to push it back upsteam because Digital Rebar workloads are composable and designed to be safely integrated from multiple sources.

Beyond tweaking running systems, this is fastest script development workflow that I’ve ever seen.  I can make fast, surgical iterative changes to my scripts without having to rerun whole playbooks or runlists.  Even better, I can build multiple operating system environments side-by-side and test changes in parallel.

For secure environments, I don’t have to hand out user SSH access to systems because the actions run in Digital Rebar context.  Digital Rebar can limit control per user or tenant.

I’m very excited about how this capability can be used for dev, test and production systems.  Check it out and let me know what you think.




Provisioned Secure By Default with Integrated PKI & TLS Automation

Today, I’m presenting this topic (PKI automation & rotation) at Defragcon  so I wanted to share this background more broadly as a companion for that presentation.  I know this is a long post – hang with me, PKI is complex.

Building automation that creates a secure infrastructure is as critical as it is hard to accomplish. For all the we talk about repeatable automation, actually doing it securely is a challenge. Why? Because we cannot simply encode passwords, security tokens or trust into our scripts. Even more critically, secure configuration is antithetical to general immutable automation: it requires that each unit is different and unique.

Over the summer, the RackN team expanded open source Digital Rebar to include roles that build a service-by-service internal public key infrastructure (PKI).

untitled-drawingThis is a significant advance in provisioning infrastructure because it allows bootstrapping transport layer security (TLS) encryption without having to assume trust at the edges.  This is not general PKI: the goal is for internal trust zones that have no external trust anchors.

Before I explain the details, it’s important to understand that RackN did not build a new encryption model!  We leveraged the ones that exist and automated them.  The challenge has been automating PKI local certificate authorities (CA) and tightly scoped certificates with standard configuration tools.  Digital Rebar solves this by merging service management, node configuration and orchestration.

I’ll try and break this down into the key elements of encryption, keys and trust.

The goal is simple: we want to be able to create secure communications (that’s TLS) between networked services. To do that, they need to be able to agree on encryption keys for dialog (that’s PKI). These keys are managed in public and private pairs: one side uses the public key to encrypt a message that can only be decoded with the receiver’s private key.

To stand up a secure REST API service, we need to create a private key held by the server and a public key that is given to each client that wants secure communication with the server.

Now the parties can create secure communications (TLS) between networked services. To do that, they need to be able to agree on encryption keys for dialog. These keys are managed in public and private pairs: one side uses the public key to encrypt a message that can only be decoded with the receiver’s private key.

Unfortunately, point-to-point key exchange is not enough to establish secure communications.  It too easy to impersonate a service or intercept traffic.  

Part of the solution is to include holder identity information into the key itself such as the name or IP address of the server.  The more specific the information, the harder it is to break the trust.  Unfortunately, many automation patterns simply use wildcard (or unspecific) identity because it is very difficult for them to predict the IP address or name of a server.   To address that problem, we only generate certificates once the system details are known.  Even better, it’s then possible to regenerate certificates (known as key rotation) after initial deployment.

While identity improves things, it’s still not sufficient.  We need to have a trusted third party who can validate that the keys are legitimate to make the system truly robust.  In this case, the certificate authority (CA) that issues the keys signs them so that both parties are able to trust each other.  There’s no practical way to intercept communications between the trusted end points without signed keys from the central CA.  The system requires that we can build and maintain these three way relationships.  For public websites, we can rely on root certificates; however, that’s not practical or desirable for dynamic internal encryption needs.

So what did we do with Digital Rebar?  We’ve embedded a certificate authority (CA) service into the core orchestration engine (called “trust me”).  

The Digital Rebar CA can be told to generate a root certificate on a per service basis.  When we add a server for that service, the CA issues a unique signed certificate matching the server identity.  When we add a client for that service, the CA issues a unique signed public key for the client matching the client’s identity.  The server will reject communication from unknown public keys.  In this way, each service is able to ensure that it is only communicating with trusted end points.

Wow, that’s a lot of information!  Getting security right is complex and often neglected.  Our focus is provisioning automation, so these efforts do not cover all PKI lifecycle issues or challenges.  We’ve got a long list of integrations, tools and next steps that we’d like to accomplish.

Our goal was to automate building secure communication as a default.  We think these enhancements to Digital Rebar are a step in that direction.  Please let us know if you think this approach is helpful.