[skip ci] Gate: Update docs w/ safer local command

Previously if you used the documented code validation command,
you would end up with your repository SELinux labels being changed.  In
many cases this is not desirable.  Update the documentation such that
the original source of the repository isn't touched in any way (prior
to making a copy of it in the container).

Also add a small (but important) note about building the container
image.

Signed-off-by: Chris Evich <cevich@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 8e921dcf3..32ed94ad4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -192,6 +192,8 @@ from the repository root, with the command:
 sudo podman build -t quay.io/libpod/gate:latest -f contrib/gate/Dockerfile .
 ```
 
+***N/B:*** **don't miss the dot (.) at the end, it's really important**
+
 The container executes 'make' by default, on a copy of the repository.
 This avoids changing or leaving build artifacts in your working directory.
 Execution does not require any special permissions from the host. However,
@@ -199,7 +201,7 @@ the repository root must be bind-mounted into the container at
 '/usr/src/libpod'. For example, running `make lint` is done (from
 the repository root) with the command:
 
-``sudo podman run -it --rm -v $PWD:/usr/src/libpod:z quay.io/libpod/gate:latest lint``
+``sudo podman run -it --rm -v $PWD:/usr/src/libpod:ro --security-opt label=disable quay.io/libpod/gate:latest lint``
 
 ### Integration Tests