Add API_URL var to link to api instance

apps/block_scout_web/config/config.exs

@@ -29,7 +29,8 @@ config :block_scout_web,
     "Bloxy" => "https://bloxy.info/"
   },
   other_networks: System.get_env("SUPPORTED_CHAINS"),
-  webapp_url: System.get_env("WEBAPP_URL")
+  webapp_url: System.get_env("WEBAPP_URL"),
+  api_url: System.get_env("API_URL")
 
 config :block_scout_web, BlockScoutWeb.Counters.BlocksIndexedCounter, enabled: true
 

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

@@ -68,7 +68,7 @@
             <% end %>
           </li>
         <% end %>
-        <%= if Application.get_env(:block_scout_web, BlockScoutWeb.ApiRouter)[:enabled] do %>
+        <%= if Application.get_env(:block_scout_web, BlockScoutWeb.ApiRouter)[:enabled] or Application.get_env(:block_scout_web, :api_url) do %>
           <li class="nav-item dropdown">
             <a href="#" role="button" id="navbarAPIsDropdown" class="nav-link topnav-nav-link dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
               <span class="nav-link-icon">
@@ -80,17 +80,17 @@
               <%= link(
                     gettext("GraphQL"),
                     class: "dropdown-item #{tab_status("graphiql", @conn.request_path)}",
-                    to: "/graphiql"
+                    to: api_url() <> "/graphiql"
                   ) %>
               <%= link(
                     gettext("RPC"),
                     class: "dropdown-item #{tab_status("api_docs", @conn.request_path)}",
-                    to: api_docs_path(@conn, :index)
+                    to: api_url() <> api_docs_path(@conn, :index)
                   ) %>
               <%= link(
                     gettext("Eth RPC"),
                     class: "dropdown-item #{tab_status("api_docs", @conn.request_path)}",
-                    to: api_docs_path(@conn, :eth_rpc)
+                    to: api_url() <> api_docs_path(@conn, :eth_rpc)
                   ) %>
             </div>
           </li>

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

@@ -229,13 +229,23 @@ defmodule BlockScoutWeb.LayoutView do
     end
   end
 
-  defp webapp_url(conn) do
+  def webapp_url(conn) do
     :block_scout_web
     |> Application.get_env(:webapp_url)
     |> validate_url()
     |> case do
       :error -> chain_path(conn, :show)
-      url -> url
+      {:ok, url} -> url
+    end
+  end
+
+  def api_url do
+    :block_scout_web
+    |> Application.get_env(:api_url)
+    |> validate_url()
+    |> case do
+      :error -> ""
+      {:ok, url} -> url
     end
   end