COS tools: add .gitignore and a few testing instructions

This clarifies that `bazel` and `mtools` are required to run tests for
the COS tools repo, and that a `python` binary must be available on the
`$PATH`. It also mentions that ~10 K80 GPUs in us-west1 are needed to
successfully execute `./run_tests.sh`; my experience says that 5 is not
enough, but I'm told that 10 is.

The local Docker-build instructions for cos-customizer are also updated
to clarify that it refers to `//:cos_customizer`, not the target in the
same directory as the instructions,
`//src/cmd/cos_customizer:cos_customizer`.

Added a `.gitignore` file, as well, to exclude `bazel-*` directories at
the top level of the project from Git.

BUG=b/229419550
TEST=none; just doc updates

Change-Id: I0dc9065e76f78e5ffe91cdf0aaec0fc4619fa227
Reviewed-on: https://cos-review.googlesource.com/c/cos/tools/+/32100
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
Cloud-Build: GCB Service account <228075978874@cloudbuild.gserviceaccount.com>
4 files changed
tree: 9dfddbcf02cf9db64ac2c8a957bf6c9c75804c9e
  1. release/
  2. src/
  3. testing/
  4. .gitignore
  5. BUILD.bazel
  6. cloudbuild.yaml
  7. CONTRIBUTING.md
  8. deps.bzl
  9. go.mod
  10. go.sum
  11. LICENSE
  12. README.md
  13. run_tests.sh
  14. WORKSPACE
README.md

Tools for Container-Optimized OS

This is a repository of various tools developed for Container-Optimized OS. Examples include cos-gpu-installer, cos-toolbox, etc.

See CONTRIBUTING.md for how to contribute.