add configuration for cli httpclient

Author: hdiniz

httpclient/httpclient_config.go

@@ -0,0 +1,49 @@
+package httpclient
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"runtime"
+
+	"github.com/arduino/arduino-cli/cli/globals"
+	"github.com/spf13/viper"
+)
+
+// Config is the configuration of the http client
+type Config struct {
+	UserAgent string
+	Proxy     *url.URL
+}
+
+// DefaultConfig returns the default http client config
+func DefaultConfig() (*Config, error) {
+	var proxy *url.URL
+	var err error
+	if viper.IsSet("network.proxy") {
+		proxyConfig := viper.GetString("network.proxy")
+		if proxy, err = url.Parse(proxyConfig); err != nil {
+			return nil, errors.New("Invalid network.proxy '" + proxyConfig + "': " + err.Error())
+		}
+	}
+
+	return &Config{
+		UserAgent: UserAgent(),
+		Proxy:     proxy,
+	}, nil
+}
+
+// UserAgent returns the user agent for the cli http client
+func UserAgent() string {
+	subComponent := viper.GetString("network.user_agent_ext")
+	if subComponent != "" {
+		subComponent = " " + subComponent
+	}
+
+	return fmt.Sprintf("%s/%s%s (%s; %s; %s) Commit:%s",
+		globals.VersionInfo.Application,
+		globals.VersionInfo.VersionString,
+		subComponent,
+		runtime.GOARCH, runtime.GOOS, runtime.Version(),
+		globals.VersionInfo.Commit)
+}