The Google Cloud SDK commands are Python executables. However, the Google Cloud SDK may use third party libraries with their own CA certificate stores.

To add a CA certificate to the third party Google Cloud SDK libraries, execute something like the commands below, replacing CA_CERT_PATH with the path to the CA certificate file.

sudo -i

CA_CERT_PATH='CA_CERT_PATH'

CA_CERT=$(basename -- "${CA_CERT_PATH}")

cd /opt

for FILE in $(find google-cloud-sdk/ -type f -name 'cacert*')
do
    echo "${FILE}"

    cp \
        -a \
        -- \
        "${FILE}" \
        "${FILE}.orig"

    (
        echo
        echo "# ${CA_CERT}"
        cat -- "${CA_CERT_PATH}"
    ) >>"${FILE}"
done

for DIR in $(find google-cloud-sdk/ -type d -name 'cacert*')
do
    echo "${DIR}"

    cp \
        -a \
        -- \
        "${CA_CERT_PATH}" \
        "${DIR}"
done

exit