Function for resolving the proxy server to be used for a HTTP connection from the proxy configuration specified through environment variables.
The following environment variables are taken into account:
http_proxy
https_proxy
no_proxy
HTTP_PROXY
HTTPS_PROXY
NO_PROXY
http_proxy and HTTP_PROXY specify the proxy server to use for
http:// urls. Use the format hostname:port. If no port is used a
default of 1080 will be used. If both are set the lower case one takes
precedence.
https_proxy and HTTPS_PROXY specify the proxy server to use for
https:// urls. Use the format hostname:port. If no port is used a
default of 1080 will be used. If both are set the lower case one takes
precedence.
no_proxy and NO_PROXY specify a comma separated list of
postfixes of hostnames for which not to use the proxy
server. E.g. the value "localhost,127.0.0.1" will make requests
to both "localhost" and "127.0.0.1" not use a proxy. If both are set
the lower case one takes precedence.
To activate this way of resolving proxies assign this function to the findProxy property on the HttpClient.
HttpClient client = new HttpClient();
client.findProxy = HttpClient.findProxyFromEnvironment;
If you don't want to use the system environment you can use a different one by wrapping the function.
HttpClient client = new HttpClient();
client.findProxy = (url) {
return HttpClient.findProxyFromEnvironment(
url, {"http_proxy": ..., "no_proxy": ...});
}
If a proxy requires authentication it is possible to configure
the username and password as well. Use the format
username:password@hostname:port to include the username and
password. Alternatively the API addProxyCredentials can be used
to set credentials for proxies which require authentication.
Source
static String findProxyFromEnvironment(Uri url,
{Map<String, String> environment}) {
return _HttpClient._findProxyFromEnvironment(url, environment);
}