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Cloud · head to head

Buildah vs Nebula

Buildah logo

Buildah

Cloud

Build OCI container images without a daemon or a Dockerfile

From
Free
Rated
-
Full reviewWebsite
Nebula logo

Nebula

Networking

Certificate based overlay network from Slack, with identity and firewall rules carried in the certificate

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Buildah linux only, with no native macOS or Windows support; Nebula the open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.
  • They diverge on capability: Buildah covers Daemonless builds, Nebula covers Certificate carried identity.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Buildah and Nebula actually diverge.

Attributes where Buildah and Nebula differ
AttributeBuildahNebula
PlatformsLinuxLinux, macOS, Windows, iOS, Android, FreeBSD
CategoryCloudNetworking

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Buildah

  • Daemonless builds
  • Rootless
  • Dockerfile compatible
  • Scriptable builds

Only in Nebula

  • Certificate carried identity
  • Group based host firewall
  • Lighthouse discovery
  • Noise protocol encryption
  • Unsafe routes
  • Managed option

What people use each for

The jobs each tool is most often brought in to do.

Buildah

  • Building images in CI without a privileged Docker daemonnot Nebula
  • Producing minimal images with tighter layer control than a Dockerfile givesnot Nebula
  • Scripted image assembly where a Dockerfile is the wrong abstractionnot Nebula

Nebula

  • Flattening a network across several clouds and datacentres without VPC peering or route tablesnot Buildah
  • Very large fleets where a central policy service on the connection path is unacceptablenot Buildah
  • Environments that already run an internal certificate authority and want the network to use itnot Buildah
  • Replacing per host iptables rules with policy written against roles that follow the hostnot Buildah

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Buildah

  • Linux only, with no native macOS or Windows support
  • Scriptable builds are powerful but less portable and less familiar than a Dockerfile
  • Narrow by design: it builds images and does not run them, so it needs Podman or another runtime alongside

Nebula

  • The open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.
  • Revoking a compromised host means distributing a blocklist entry to every other host and reloading them, which is a fleet wide operation rather than a click, and easy to get wrong under pressure.
  • Changing a host group membership means reissuing and redeploying its certificate, so policy changes are a deployment rather than a configuration edit.
  • There is no identity provider integration or single sign on in the open source version, so it maps well to servers and badly to a fleet of user laptops.
  • NAT traversal is best effort and hosts behind symmetric NAT need a relay configured deliberately, so connectivity failures show up as intermittent rather than immediate and are awkward to diagnose.

Pricing, plan by plan

Buildah

Free
  • BuildahFree
    • Full functionality
    • No usage limits
    • Community support

Nebula

Free
  • NebulaFree
    • Full functionality under the MIT licence
    • No host limit
    • You operate the certificate authority and lighthouses
  • Defined Networking$undefined/month
    • Hosted control plane and enrolment
    • Managed certificate lifecycle and revocation
    • Policy and DNS interface

Which should you pick?

Choose Buildah if

  • You need daemonless builds.
  • You want to start without paying.
  • You work on Linux.
  • You also want rootless.
Buildah review

Choose Nebula if

  • You need certificate carried identity.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, iOS, Android, FreeBSD.
  • You also want group based host firewall.
Nebula review

Questions people ask

Is Buildah or Nebula better?
Neither clearly leads. Buildah starts at Free and Nebula at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Buildah or Nebula?
Buildah starts at Free and Nebula at Free.
Does Buildah or Nebula run on more platforms?
Buildah runs on Linux. Nebula runs on Linux, macOS, Windows, iOS, Android, FreeBSD.
Can I use Buildah for free?
Both have a free tier, so you can try either at no cost before committing.
What is Buildah best used for?
Buildah is most often used for building images in ci without a privileged docker daemon, producing minimal images with tighter layer control than a dockerfile gives, scripted image assembly where a dockerfile is the wrong abstraction. Of those, building images in ci without a privileged docker daemon and producing minimal images with tighter layer control than a dockerfile gives are not what Nebula is typically brought in for.
What can Buildah do that Nebula cannot?
Buildah covers Daemonless builds, Rootless, Dockerfile compatible, Scriptable builds. Nebula covers Certificate carried identity, Group based host firewall, Lighthouse discovery, Noise protocol encryption.

Answered from the vendors’ own pages

Buildah: Is Buildah free?

Yes, open source with no licence fee.

Nebula: Does it use WireGuard?

No. Nebula predates the common WireGuard mesh tools and uses the Noise protocol framework with its own certificate format.

Buildah: Do I still need a Dockerfile?

No. Buildah reads Dockerfiles if you have them, but images can be built entirely from shell commands instead.

Nebula: Can I run it without Defined Networking?

Yes, entirely. Defined Networking sells the control plane conveniences, not the network itself.

Buildah: How is Buildah different from Podman?

Buildah builds images; Podman runs them. Podman actually embeds Buildah for its build command, and the two are designed to be used together.

Nebula: How do I revoke a host?

Add its certificate fingerprint to the blocklist in the configuration of the other hosts and reload them. There is no online revocation check.

Nebula: Is it a good fit for laptops?

Less so than the identity provider based tools. There is no single sign on, so every laptop needs a certificate issued and renewed by whatever process you build.

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