Add WEBAPP_URL var

apps/block_scout_web/config/config.exs

@@ -28,7 +28,8 @@ config :block_scout_web,
     "EtherChain" => "https://www.etherchain.org/",
     "Bloxy" => "https://bloxy.info/"
   },
-  other_networks: System.get_env("SUPPORTED_CHAINS")
+  other_networks: System.get_env("SUPPORTED_CHAINS"),
+  webapp_url: System.get_env("WEBAPP_URL")
 
 config :block_scout_web, BlockScoutWeb.Counters.BlocksIndexedCounter, enabled: true
 

apps/block_scout_web/lib/block_scout_web/templates/layout/_footer.html.eex

@@ -3,7 +3,7 @@
     <!-- Logo -->
     <div class="row footer-logo-row">
       <div class="col-md-12">
-        <%= link to: chain_path(@conn, :show), class: "footer-brand" do %>
+        <%= link to: webapp_url(@conn), class: "footer-brand" do %>
           <img class="footer-logo" src="<%= logo_footer() %>" alt="<%= subnetwork_title() %>" />
         <% end %>
       </div>

apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex

@@ -5,7 +5,7 @@
     }
   </script>
   <div class="container-fluid navbar-container">
-    <%= link to: chain_path(@conn, :show), class: "navbar-brand", "data-test": "header_logo" do %>
+    <%= link to: webapp_url(@conn), class: "navbar-brand", "data-test": "header_logo" do %>
       <img class="navbar-logo" id="navbar-logo" src="<%= logo() %>" alt="<%= subnetwork_title() %>" />
     <% end %>
     <script>

apps/block_scout_web/lib/block_scout_web/views/layout_view.ex

@@ -228,4 +228,23 @@ defmodule BlockScoutWeb.LayoutView do
       []
     end
   end
+
+  defp webapp_url(conn) do
+    :block_scout_web
+    |> Application.get_env(:webapp_url)
+    |> validate_url()
+    |> case do
+      :error -> chain_path(conn, :show)
+      url -> url
+    end
+  end
+
+  defp validate_url(url) when is_binary(url) do
+    case URI.parse(url) do
+      %URI{host: nil} -> :error
+      _ -> {:ok, url}
+    end
+  end
+
+  defp validate_url(_), do: :error
 end