[Core] Add ~/.local/bin to make which ray work if ray is installed in ~/.local

[Michaelvll]

To reproduce:

1. docker build -t mydockerrepo/image-name:v1 .; docker push mydockerrepo/image-name:v1

FROM berkeleyskypilot/skypilot-k8s

# Use a RUN command to modify PATH and write to a temporary file
RUN echo "export PATH=$(echo $PATH | sed -e 's|/home/sky/.local/bin:||g' -e 's|:/home/sky/.local/bin||g')" > ~/.bashrc

2. sky launch -c test --image-id docker:mydockerrepo/image-name:v1 echo hi

Another Dockerfile to test:

FROM berkeleyskypilot/skypilot-k8s

# Use a RUN command to modify PATH and write to a temporary file
RUN echo "export PATH=$(echo $PATH | sed -e 's|/home/sky/.local/bin:||g' -e 's|:/home/sky/.local/bin||g')" > ~/.bashrc

RUN pip uninstall ray -y

Tested (run the relevant ones):

• Code formatting: bash format.sh
• Any manual or new tests for this PR (please specify below)
  • Reproducible code above.
• All smoke tests: pytest tests/test_smoke.py (except TPU tests [Examples] TPU example fail examples/tpu/tpuvm_mnist.yaml #3425)
• Relevant individual smoke tests: pytest tests/test_smoke.py::test_fill_in_the_name
• Backward compatibility tests: bash tests/backward_comaptibility_tests.sh

[concretevitamin]

LGTM with a question, thanks @Michaelvll.

[concretevitamin]

Is this for debugging? Worth a comment.

[Michaelvll]

Yes, just added the comment.

[concretevitamin]

Do I understand correctly:

• The issue is in some envs, our own Ray is by default installed into ~/.local/bin
• In that env, this path is not in $PATH by default
• So, previously we touch the SKY_RAY_PATH_FILE file, which is empty
• Bug is, later on when we do our_ray start, our_ray is basically empty string?

[Michaelvll]

Yes, this is exactly the issue. Tried to elaborate the comments a bit. PTAL : )