Follow http redirects for autoconfigure (#3208)

src/configure/read_url.rs

@@ -1,20 +1,40 @@
 use crate::context::Context;
 
-#[derive(Debug, thiserror::Error)]
-pub enum Error {
-    #[error("URL request error")]
-    GetError(surf::Error),
-}
+use anyhow::format_err;
+use anyhow::Context as _;
 
-pub async fn read_url(context: &Context, url: &str) -> Result<String, Error> {
-    info!(context, "Requesting URL {}", url);
-
-    match surf::get(url).recv_string().await {
-        Ok(res) => Ok(res),
-        Err(err) => {
-            info!(context, "Can\'t read URL {}: {}", url, err);
-
-            Err(Error::GetError(err))
+pub async fn read_url(context: &Context, url: &str) -> anyhow::Result<String> {
+    match read_url_inner(context, url).await {
+        Ok(s) => {
+            info!(context, "Successfully read url {}", url);
+            Ok(s)
+        }
+        Err(e) => {
+            info!(context, "Can't read URL {}: {:#}", url, e);
+            Err(format_err!("Can't read URL {}: {:#}", url, e))
         }
     }
 }
+
+pub async fn read_url_inner(context: &Context, mut url: &str) -> anyhow::Result<String> {
+    let mut _temp; // For the borrow checker
+
+    // Follow up to 10 http-redirects
+    for _i in 0..10 {
+        let mut response = surf::get(url).send().await.map_err(|e| e.into_inner())?;
+        if response.status().is_redirection() {
+            _temp = response
+                .header("location")
+                .context("Redirection doesn't have a target location")?
+                .last()
+                .to_string();
+            info!(context, "Following redirect to {}", _temp);
+            url = &_temp;
+            continue;
+        }
+
+        return response.body_string().await.map_err(|e| e.into_inner());
+    }
+
+    Err(format_err!("Followed 10 redirections"))
+}