Add three new helpers to the existing progresstracking package:
- Ticker: spawns a 1 Hz goroutine that calls a report function with
the current value of an atomic counter and a total. Returns a stop
function (safe to call multiple times via sync.OnceFunc) that fires
one final report and blocks until the goroutine exits.
- NewWriter: wraps an io.Writer and calls onProgress at most once per
interval with the cumulative byte count.
- CountingWriter: an io.Writer that atomically counts bytes written,
for use with Ticker.
These will be used by the appliance flash and OTA update code in
subsequent commits.
Updates #1866
Change-Id: If353cea6506f5351b6fb19bfdb7bc9b78fe7855e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Adds a CLI subcommand that downloads a signed Tailscale appliance
image (Gokrazy archive format, GAF) from pkgs.tailscale.com,
constructs a fresh GPT-partitioned disk from it (mbr.img + a
synthesized partition table + boot.img + root.img), formats /perm
as ext4 in pure Go via go-diskfs, and ejects the disk so a user
running on a regular workstation can flash an SD card or homelab
VM disk in one command without installing e2fsprogs.
On macOS the target disk is auto-discovered via diskutil, skipping
the boot disk and anything bigger than 256 GB out of paranoia. On
Linux the user passes --disk=/dev/sdX explicitly. Windows is not
supported yet and the command returns an error.
The GPT layout matches monogok's full-disk layout via the new
public github.com/bradfitz/monogok/disklayout package; a drift-
guard test inside monogok asserts the two implementations stay
byte-identical so OTA updates against monogok-built images keep
working.
Behind a ts_omit_flashappliance build tag (on by default).
Updates #1866
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: Ic1a8cd185e7039edccb7702ab4104544fcb58d29
Brad Fitzpatrick