faas-cli build to select architecture automatically

[Lewiscowles1986]

Provide a mechanism for FaaS CLI / Docker to detect CPU type and attempt to build Dockerfile.{cputype} if exists, with fallback to Dockerfile.

Expected Behaviour

This is an improvement AFAIK, I've not been able to find anywhere that mentions how to do this. I was going to have a cascade from Dockerfile.$(arch) (most specific) Dockerfile.$(arch-short) (semi-generic) to the default Dockerfile

Current Behaviour

When I build, it looks like Dockerfile.armhf needs to be named Dockerfile

Possible Solution

I was going to code a build utility with tests that provides either

• The ability to pass arguments to docker build $(args) . -t
• Cascade checking for file existence

Steps to Reproduce (for bugs)

Not a bug

Context

This issue is raised as it's really messing with my laziness, and after checking, it looks like I just imagined docker handled this (not sure why)

Your Environment

• Docker version docker version :

  $ docker version
  Client:
   Version:      17.05.0-ce
   API version:  1.29
   Go version:   go1.7.5
   Git commit:   89658be
   Built:        Thu May  4 22:30:54 2017
   OS/Arch:      linux/arm
  
  Server:
   Version:      17.05.0-ce
   API version:  1.29 (minimum version 1.12)
   Go version:   go1.7.5
   Git commit:   89658be
   Built:        Thu May  4 22:30:54 2017
   OS/Arch:      linux/arm
   Experimental: false
  

• Are you using Docker Swarm or Kubernetes (FaaS-netes)? docker-swarm

• Operating System and version (e.g. Linux, Windows, MacOS): Linux

• Link to your project or a code example to reproduce issue: N/A

[austinfrey]

Derek add label: proposal

[alexellis]

We haven't done this yet because we didn't have a good / standard way of doing it. Don't want to really end up managing this in the project if possible. Multi-arch builds may solve this.. worth re-visting when Alpine Linux is multi-arch (currently blocked).

[alexellis]

Derek add label: revisit

[Lewiscowles1986]

I do have a way of doing it on Linux, but I must admit I hadn't considered anything outside of arm, arm64 and amd64 (only architectures I have access to)

[alexellis]

Which architectures do you need? I think two is enough to come up with a solution.

I'm going to close this issue but mark it as revisit when multi-arch support is finished by Docker Inc.