support for http_proxy variables

environ/proxy.go

@@ -0,0 +1,41 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Parity Public License
+// that can be found in the LICENSE file.
+
+package environ
+
+import (
+	"strings"
+)
+
+// Proxy returns the http_proxy variables.
+func Proxy() map[string]string {
+	environ := map[string]string{}
+	if value := envAnyCase("no_proxy"); value != "" {
+		environ["no_proxy"] = value
+		environ["NO_PROXY"] = value
+	}
+	if value := envAnyCase("http_proxy"); value != "" {
+		environ["http_proxy"] = value
+		environ["HTTP_PROXY"] = value
+	}
+	if value := envAnyCase("https_proxy"); value != "" {
+		environ["https_proxy"] = value
+		environ["HTTPS_PROXY"] = value
+	}
+	return environ
+}
+
+// helper function returns the environment variable value
+// using a case-insenstive environment name.
+func envAnyCase(name string) (value string) {
+	name = strings.ToUpper(name)
+	if value := getenv(name); value != "" {
+		return value
+	}
+	name = strings.ToLower(name)
+	if value := getenv(name); value != "" {
+		return value
+	}
+	return
+}

environ/proxy_test.go

@@ -0,0 +1,81 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Parity Public License
+// that can be found in the LICENSE file.
+
+package environ
+
+import (
+	"os"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestProxy(t *testing.T) {
+	defer func() {
+		getenv = os.Getenv
+	}()
+
+	getenv = func(s string) string {
+		switch s {
+		case "no_proxy":
+			return "http://dummy.no.proxy"
+		case "http_proxy":
+			return "http://dummy.http.proxy"
+		case "https_proxy":
+			return "http://dummy.https.proxy"
+		default:
+			return ""
+		}
+	}
+
+	a := map[string]string{
+		"no_proxy":    "http://dummy.no.proxy",
+		"NO_PROXY":    "http://dummy.no.proxy",
+		"http_proxy":  "http://dummy.http.proxy",
+		"HTTP_PROXY":  "http://dummy.http.proxy",
+		"https_proxy": "http://dummy.https.proxy",
+		"HTTPS_PROXY": "http://dummy.https.proxy",
+	}
+	b := Proxy()
+	if diff := cmp.Diff(a, b); diff != "" {
+		t.Fail()
+		t.Log(diff)
+	}
+}
+
+func Test_envAnyCase(t *testing.T) {
+	defer func() {
+		getenv = os.Getenv
+	}()
+
+	getenv = func(s string) string {
+		switch s {
+		case "foo":
+			return "bar"
+		default:
+			return ""
+		}
+	}
+
+	if envAnyCase("FOO") != "bar" {
+		t.Errorf("Expect environment variable sourced from lowercase variant")
+	}
+
+	getenv = func(s string) string {
+		switch s {
+		case "FOO":
+			return "bar"
+		default:
+			return ""
+		}
+	}
+
+	if envAnyCase("foo") != "bar" {
+		t.Errorf("Expect environment variable sourced from uppercase variant")
+	}
+
+	if envAnyCase("bar") != "" {
+		t.Errorf("Expect zero value string when environment variable does not exit")
+	}
+}