Go Alone is a brief experiment into running Go as an appliance-oriented operating system.

We do not run Go on bare metal, nor did we write a kernel in Go -- we use Linux, and just replace userspace with a Go app. All of the userspace.

The single Go application just becames the init, PID 1, of the machine. There is nothing really difficult here, it just works.

The scripts included build a minimal kernel, intended to run inside a KVM. They don't even include support for block devices. Take that, 12-factor apps!

Here's how to run them:

# if you have a local clone of linux.git, put it in ~/src/linux/
# to speed up first run
./do-build-kernel

# build and run the hello world example app
./do-run-hello-word

# build and run the network app and forward port 8000 to it
./do-run-network
# in a browser, open http://localhost:8000/
# when done, type control-A x

This assumes x86_64 platform and a working install of qemu-system-x86_64.

The output should look like this:

...
Unpacking initramfs...
Freeing initrd memory: 580K (ffff880007f5f000 - ffff880007ff0000)
io scheduler noop registered (default)
ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11
Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
Freeing unused kernel memory: 648K (ffffffff81279000 - ffffffff8131b000)
Hello, world! I have 4 CPUs
ACPI: Preparing to enter system sleep state S5
reboot: Power down

• play more with network configuration

• maybe set up virtfs

• maybe bundle asset files and/or config in the initramfs

• migrate from ad hoc scripts to utility commands, with configurability such as RAM size.. open questions:

  • what to do with generated files that are needed?
  • where to store them?
  • cache invisibly or make that part of the UI?
  • kernel can be shared between many apps, initramfs is per app (version)

• quick cli ideas

  # build kernel
  alone build-kernel [--version=VER] [--mirror=PATH] OUT_PATH
  
  # create initramfs
  alone take INITRAMFS_PATH_TO_CREATE GO_PACKAGE
  
  # run the previously-created kernel and initramfs
  alone exec [--ram=512M] KERNEL INITRAMFS
  
  # sort of like `go run`, but takes package. builds kernel if needed
  alone run [--kernel-version=VER] [--ram=512M] GO_PACKAGE