commit 5e227dd8f494194284b4b545c02e09bc79909d41
author Philip Zeyliger <philip.zeyliger@gmail.com> Mon Apr 21 15:55:29 2025 -0700
committer Philip Zeyliger <philip.zeyliger@gmail.com> Mon Apr 21 20:04:53 2025 -0700
tree cbe3fb6cb160fea4379e822fcca2cfcbe5bc51cf
parent e8d6b80c8804353641c0d999d1897e29b068bbdc

sketch: Linux support

Together with 8a89e1cbd3e7c9bbe1c561e88141527a0c894e06, this
should resolve https://github.com/boldsoftware/sketch/issues/3,
in supporting Linux.

To test on a Mac, run "limactl shell default go run ./cmd/sketch -verbose", assuming
you have a lima default VM with sketch's dependencies already prepped.

The issues we encountered were:

1. Explicit checks for "is Colima installed", "is docker installed",
   etc. Easy enough to fix these.

2. When go's toolchain builds, it puts the output in different places
   depending whether it's cross-compiled or not. Fine, we adapt.
   Note that os.Rename() doesn't always work, and we fall back to
   copy/delete. Mode has to be set appropriately to, to make the
   /bin/sketch executable executable.

   Re-building is kind of silly: we could use /proc/self/exe, for
   example, or cross-mount the binary into the container, or any
   number of other things. That said, here we keep the paths the same.

3. Docker networking setup for the git server. The host git repo
   is served with git's cgi-bin wrapper. host.docker.internal
   seems to work different in colima vs Ubuntu's docker.io, so
   an extra command line flag to docker was added. Then,
   it turns out that our git server checks that the remote is
   127.0.0.1, which seems to be how Colima does its networking,
   but isn't the case for Docker in general. To handle this, we
   use HTTP Basic Auth with a random password. (Git also has
   an "http.extraHeader" configuration, but basic auth seems just
   as good and more obvious.)

Incidentally, I'm also adding the git remote as a git remote
named "sketch-host" to make it easier to work with in the terminal,
if necessary.