Modify /etc/default/gamma

1. Change CATALINA_OPTS environment variable with given settings:

export CATALINA_OPTS="-Dhttps.proxyHost=PROXY_IP -Dhttps.proxyPort=PROXY_PORT -Dhttp.proxyHost=PROXY_IP -Dhttp.proxyPort=PROXY_PORT -DGAMMA_ROOT=/opt/gamma -Xmx1024m -Djava.awt.headless=true -Djava.library.path=/usr/lib/x86_64-linux-gnu/jni/:/usr/lib64/"

2. Also add new environment variables as below:

export https_proxy=http://PROXY_IP:PROXY_PORT
export http_proxy=http://PROXY_IP:PROXY_PORT
export no_proxy='127.0.0.1,localhost'
Note: Use your proxy host and port by replacing text “PROXY_IP” and “PROXY_PORT” respectively.