client: make install step a bit more resilient

change private keys on client earlier to avoid race conditions,
and attempt the fetch call multiple times to avoid spurious issues,
while also not failing the entire command if fetch doesn't succeed.

client/src/main.rs

@@ -237,7 +237,16 @@ fn install(invite: &Path, hosts_file: Option<PathBuf>, opts: InstallOpts) -> Res
         e
     })?;
 
-    fetch(&iface, false, hosts_file)?;
+    let mut fetch_success = false;
+    for _ in 0..3 {
+        if fetch(&iface, false, hosts_file).is_ok() {
+            fetch_success = true;
+            break;
+        }
+    }
+    if !fetch_success {
+        println!("{} Failed to fetch peers from server, you will need to manually run the 'up' command.", "[!]".red());
+    }
 
     if opts.delete_invite
         || Confirm::with_theme(&*prompts::THEME)
@@ -319,15 +328,15 @@ fn redeem_invite(
         "[*]".dimmed(),
         target_conf.to_string_lossy().yellow()
     );
+
     println!(
-        "{} Waiting for server's WireGuard interface to transition to new key.",
+        "{} Changing keys and waiting for server's WireGuard interface to transition.",
         "[*]".dimmed(),
     );
-    thread::sleep(*REDEEM_TRANSITION_WAIT);
-
     DeviceConfigBuilder::new()
         .set_private_key(keypair.private)
         .apply(&iface)?;
+    thread::sleep(*REDEEM_TRANSITION_WAIT);
 
     Ok(())
 }