TTP Requirements Specification

Suppose that a TTPForge user attempts to run a linux-only TTP on a macOS system. It is better for them to get an immediate, clear error of the form "this TTP can only be run on macOS" than for them to receive an obscure error such as "XYZ command not found" that pops up halfway through the execution of their TTP. The TTPForge requirements section solves this problem. By declaring a requirements section, you can clearly indicate to users of your TTP:

• With which platforms your TTP is compatible.
• Whether your TTP requires superuser privileges.

Specifying Compatible Platforms

The example below demonstrates how to tell TTPForge (and your TTP's users) that your TTP is only compatible with (and should therefore only be run) on certain platforms:

https://github.com/facebookincubator/TTPForge/blob/7634dc65879ec43a108a4b2d44d7eb2105a2a4b1/example-ttps/requirements/os-and-superuser.yaml#L1-L21

Each entry in the platforms list should contain one or both of the following fields:

• os: the target operating system.
• arch: the target architecture.

Since TTPForge is written in Go, you may specify any valid GOOS or GOARCH value for these fields - see here for the full list of allowed values.

Note that it is quite common to specify entries containing os but not arch - this simply means that the TTP is compatible with the specified os and that its implementation is not architecture specific. Conversely, the following entry indicates that the TTP is compatible with ARM-based macOS systems and x64-based Windows systems, but not with e.g. legacy intel-based macOS systems:

platforms:
  - os: darwin
    arch: arm64
  - os: windows
    arch: amd64

How TTPForge Determines the Current OS/Arch

TTPForge consults its runtime.GOOS and runtime.GOARCH constants to determine the OS and architecture on which it is currently running. These values are based on the GOOS and GOARCH settings with which that particular TTPForge executable was compiled. Note that these values may sometimes be misleading - for instance, if TTPForge was compiled with GOARCH=amd64, it will consider itself to be running on amd64 even if it is being run on an arm64 system using Rosetta.

Specifying Required Privileges

If your TTP requires superuser privileges to run, you should specify superuser: true in your requirements section, as demonstrated by the TTP above. This will ensure that your users get an immediate and unambiguous error message if they attempt to execute your TTP without the required privileges, rather than a "Permission Denied..." error midway through TTP execution.