Add support for providing PyPI connection properties

Author: sutaakar

support/environment.go

@@ -47,6 +47,10 @@ const (
 
 	// URL for downloading MNIST dataset
 	mnistDatasetURL = "MNIST_DATASET_URL"
+
+	// URL for PiPI index containing all the required test Python packages
+	pipIndexURL    = "PIP_INDEX_URL"
+	pipTrustedHost = "PIP_TRUSTED_HOST"
 )
 
 type ClusterType string
@@ -117,6 +121,14 @@ func GetMnistDatasetURL() string {
 	return lookupEnvOrDefault(mnistDatasetURL, "http://yann.lecun.com/exdb/mnist/")
 }
 
+func GetPipIndexURL() string {
+	return lookupEnvOrDefault(pipIndexURL, "https://pypi.python.org/simple")
+}
+
+func GetPipTrustedHost() string {
+	return lookupEnvOrDefault(pipTrustedHost, "")
+}
+
 func lookupEnvOrDefault(key, value string) string {
 	if v, ok := os.LookupEnv(key); ok {
 		return v