An update to @sourcesimian 's and @kunal-b's answer which dynamically sets the username and password if configured in the system properties.
The following sets the username and password if provided or just adds the host and port if no username and password is set.
task setHttpProxyFromEnv {
def map = ['HTTP_PROXY': 'http', 'HTTPS_PROXY': 'https']
for (e in System.getenv()) {
def key = e.key.toUpperCase()
if (key in map) {
def base = map[key]
//Get proxyHost,port, username, and password from http system properties
// in the format http://username:password@proxyhost:proxyport
def (val1,val2) = e.value.tokenize( '@' )
def (val3,val4) = val1.tokenize( '//' )
def(userName, password) = val4.tokenize(':')
def url = e.value.toURL()
//println " - systemProp.${base}.proxy=${url.host}:${url.port}"
System.setProperty("${base}.proxyHost", url.host.toString())
System.setProperty("${base}.proxyPort", url.port.toString())
System.setProperty("${base}.proxyUser", userName.toString())
System.setProperty("${base}.proxyPassword", password.toString())
}
}
}