Allow using a standard HTTP proxy in reddit widget

internal/glance/config-fields.go

@@ -1,7 +1,10 @@
 package glance
 
 import (
+	"crypto/tls"
 	"fmt"
+	"net/http"
+	"net/url"
 	"regexp"
 	"strconv"
 	"strings"
@@ -169,3 +172,50 @@ func (i *customIconField) UnmarshalYAML(node *yaml.Node) error {
 	*i = newCustomIconField(value)
 	return nil
 }
+
+type proxyOptionsField struct {
+	URL           string        `yaml:"url"`
+	AllowInsecure bool          `yaml:"allow-insecure"`
+	Timeout       durationField `yaml:"timeout"`
+	client        *http.Client  `yaml:"-"`
+}
+
+func (p *proxyOptionsField) UnmarshalYAML(node *yaml.Node) error {
+	type proxyOptionsFieldAlias proxyOptionsField
+	alias := (*proxyOptionsFieldAlias)(p)
+	var proxyURL string
+
+	if err := node.Decode(&proxyURL); err != nil {
+		if err := node.Decode(alias); err != nil {
+			return err
+		}
+	}
+
+	if proxyURL == "" && p.URL == "" {
+		return nil
+	}
+
+	if p.URL != "" {
+		proxyURL = p.URL
+	}
+
+	parsedUrl, err := url.Parse(proxyURL)
+	if err != nil {
+		return fmt.Errorf("parsing proxy URL: %v", err)
+	}
+
+	var timeout = defaultClientTimeout
+	if p.Timeout > 0 {
+		timeout = time.Duration(p.Timeout)
+	}
+
+	p.client = &http.Client{
+		Timeout: timeout,
+		Transport: &http.Transport{
+			Proxy:           http.ProxyURL(parsedUrl),
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: p.AllowInsecure},
+		},
+	}
+
+	return nil
+}