• relates to 🚧 Add support for OAuth device-code login 🚧  docker/cli#5221

I was, erm, curious where all the extra dependencies originated from 🙈;

• github.com/tklauser/go-sysconf
• github.com/tklauser/go-sysconf (number of online CPUs?)
• github.com/shoenig/go-m1cpu (CPU info for m1 CPUs)
• github.com/power-devops/perfstat (handling of libperfstat ??
• github.com/go-ole/go-ole (loading of Windows OLE objects)
• github.com/yusufpapurcu/wmi (WQL interface to Windows Management Instrumentation (WMI))

And those all look to be related to this single host.Info(); gopsutil/host.Info() is doing a lot of things; https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/host/host.go#L65-L117

• Getting information about the distro-version, which;
  • on Linux involves trying to parse /etc/os-release and more; https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/host/host_linux.go#L173-L321
  • on macOS involves shelling out to sw_vers -productVersion https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/host/host_darwin.go#L98-L124
  • and on Windows invoking the infamous tricks to try to get a version, because there is no official API for this https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/host/host_windows.go#L146-L234
  • ^^ on Windows that's invoked twice because it uses PlatformVersion as KernelVersion
• Getting the kernel architecture, which on Linux/Darwin is just unix.Utsname, but on Windows involves parsing processor architectures; https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/host/host_windows.go#L251-L280
• Trying to detect Virtualization, which is only implemented on Linux, but there it's a lot, including (again) parsing /etc/os-release; enough for the library author to implement caching, but that won't do much for a short-lived process like the CLI; https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/internal/common/common_linux.go#L168-L346
• It also tries to get BootTime, and UpTime, which again do a lot, including shelling out to various binaries, and it even has special cases for docker; caching was implemented there as well, but won't help us here; https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/internal/common/common_linux.go#L63-L119
• It tries to obtain the number of running processes on the machine, which on Linux means listing all files in /proc, and for each of them trying to see if it can convert them to an Integer (in which case it's a process-id); https://github.com/shirou/gopsutil/blob/865b8c3f58d6ee4c47dab074fbf3c4b037abfd96/internal/common/common_linux.go#L41-L61
  • ☝️ which makes me want to sit in a corner and cry
• It tries to obtain a HostID (sys/kernel/random/boot_id, on Linux, but shelling out to ioreg -rd1 -c IOPlatformExpertDevice on Darwin, and using the registry on Windows)

So I went looking "What information do we really need here?"

• cliVersion - ⚠️ this function is set at compile time; there is no formal definition of the format (and can be set to anything)
• hostinfo.OS - this is hardcoded to runtime.GOOS in gopsutil/host.Info()
• hostVersion - this comes from PlatformVersion. Is it a strong requirement to know the version of the OS? On Linux it will be useless without distro. On Windows, it will be "guesswork" (no official API); if really needed, we could also use pkg/parsers/kernel.GetKernelVersion() from the docker code.
• hostinfo.KernelArch - do we need detailed architecture (including CPU sub-variants), which could even be "off" when running with QEMU emulation; could we use runtime.GOARCH instead?

Can we get rid of this dependency, and replace host.Info() with something more basic?

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