be clever about docker "-it" args

kokoro/linux/aarch64/dockcross_helpers/run_dockcross_manylinux2014_aarch64.sh

@@ -5,11 +5,18 @@ set -e
 # go to the repo root
 cd $(dirname $0)/../../../..
 
+if [[ -t 0 ]]; then
+  DOCKER_TTY_ARGS="-it"
+else
+  # The input device on kokoro is not a TTY, so -it does not work.
+  DOCKER_TTY_ARGS=
+fi
+
 # running dockcross image without any arguments generates a wrapper
 # scripts that can be used to run commands under the dockcross image
 # easily.
 # See https://github.com/dockcross/dockcross#usage for details
-docker run --rm -it dockcross/manylinux2014-aarch64 >dockcross-manylinux2014-aarch64.sh
+docker run $DOCKER_TTY_ARGS --rm dockcross/manylinux2014-aarch64 >dockcross-manylinux2014-aarch64.sh
 chmod +x dockcross-manylinux2014-aarch64.sh
 
 # the wrapper script has CRLF line endings and bash doesn't like that

kokoro/linux/aarch64/test_python_aarch64.sh

@@ -5,6 +5,13 @@ set -e
 # go to the repo root
 cd $(dirname $0)/../../..
 
+if [[ -t 0 ]]; then
+  DOCKER_TTY_ARGS="-it"
+else
+  # The input device on kokoro is not a TTY, so -it does not work.
+  DOCKER_TTY_ARGS=
+fi
+
 # crosscompile python extension and the binary wheel under dockcross/manylinux2014-aarch64 image
 kokoro/linux/aarch64/dockcross_helpers/run_dockcross_manylinux2014_aarch64.sh kokoro/linux/aarch64/python_crosscompile_aarch64.sh
 
@@ -16,4 +23,4 @@ kokoro/linux/aarch64/dockcross_helpers/run_dockcross_manylinux2014_aarch64.sh ko
 #   running under current user's UID and GID. To be able to do that, we need to provide a home directory for the user
 #   otherwise the UID would be homeless under the docker container and pip install wouldn't work. For simplicity,
 #   we just run map the user's home to a throwaway temporary directory
-docker run -it --rm --user "$(id -u):$(id -g)" -e "HOME=/home/fake-user" -v "$(mktemp -d):/home/fake-user" -v "$(pwd)":/work -w /work quay.io/pypa/manylinux_2_24_aarch64 kokoro/linux/aarch64/python_run_tests_with_qemu_aarch64.sh
+docker run $DOCKER_TTY_ARGS --rm --user "$(id -u):$(id -g)" -e "HOME=/home/fake-user" -v "$(mktemp -d):/home/fake-user" -v "$(pwd)":/work -w /work quay.io/pypa/manylinux_2_24_aarch64 kokoro/linux/aarch64/python_run_tests_with_qemu_aarch64.sh