To install gcloud sdk on Linux, run
# curl https://sdk.cloud.google.com | bash
If you get the following error. Most probably IPv6 is enabled on Linux.
ERROR: (gcloud.components.update) Failed to fetch component listing from server. Check your network settings and try again.
I disabled it temporarily and installed gcloud successfully. Run the following command to disable IPv6.
# sysctl net.ipv6.conf.all.disable_ipv6=1