From 3a385fc08d4a48da1f2ae5bca3ab59b605174ba8 Mon Sep 17 00:00:00 2001
From: Joxit <joxit972@gmail.com>
Date: Mon, 8 Nov 2021 05:28:39 +0100
Subject: [PATCH] feat(nginx): add support for `proxy_pass_header` directive
 via `NGINX_PROXY_PASS_HEADER_*`

fixes #206
---
 README.md          |  6 ++++--
 bin/entrypoint     | 17 +++++++++++++++++
 nginx/default.conf |  1 +
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 1a14a284..8f95bdd7 100644
--- a/README.md
+++ b/README.md
@@ -46,7 +46,8 @@ This web user interface uses [Riot](https://github.com/Riot/riot) the react-like
 -   Multi arch support in history page (see [#130](https://github.com/Joxit/docker-registry-ui/issues/130) and [#134](https://github.com/Joxit/docker-registry-ui/pull/134))
 -   Set a list of default registries with `DEFAULT_REGISTRIES` (see [#219](https://github.com/Joxit/docker-registry-ui/pull/219)).
 -   Desactivate add and remove regisitries with `READ_ONLY_REGISTRIES` (see [#219](https://github.com/Joxit/docker-registry-ui/pull/219)).
--   Filter images and tags with a search bar. You can select the search bar with the shortcut `CRTL` + `F` or `F3`. When the search bar is already focused, the shortcut will fallback to the default behavior (see [#213](https://github.com/Joxit/docker-registry-ui/issues/213)). 
+-   Filter images and tags with a search bar. You can select the search bar with the shortcut `CRTL` + `F` or `F3`. When the search bar is already focused, the shortcut will fallback to the default behavior (see [#213](https://github.com/Joxit/docker-registry-ui/issues/213)).
+-   **Forward** custom header to your backend registry via environment variable and file via `NGINX_PROXY_PASS_HEADER_*` (see [#206](https://github.com/Joxit/docker-registry-ui/pull/206)).
 
 ## FAQ
 
@@ -90,7 +91,8 @@ Some env options are available for use this interface for **only one server**.
 - `CATALOG_ELEMENTS_LIMIT`: Limit the number of elements in the catalog page. (default: `100000`).
 - `SINGLE_REGISTRY`: Remove the menu that show the dialogs to add, remove and change the endpoint of your docker registry. (default: `false`).
 - `NGINX_PROXY_PASS_URL`: Update the default Nginx configuration and set the **proxy_pass** to your backend docker registry (this avoid CORS configuration). This is usually the name of your registry container in the form `http://registry:5000`.
-- `NGINX_PROXY_HEADER_*`: Update the default Nginx configuration and set **custom headers** for your backend docker registry. Only when `NGINX_PROXY_PASS_URL` is used.
+- `NGINX_PROXY_HEADER_*`: Update the default Nginx configuration and **set custom headers** for your backend docker registry. Only when `NGINX_PROXY_PASS_URL` is used.
+- `NGINX_PROXY_HEADER_*`: Update the default Nginx configuration and **forward custom headers** to your backend docker registry. Only when `NGINX_PROXY_PASS_URL` is used.
 - `DEFAULT_REGISTRIES`: List of comma separated registry URLs (e.g `http://registry.example.com,http://registry:5000`), available only when `SINGLE_REGISTRY=false`. (default: ` `).
 - `READ_ONLY_REGISTRIES`: Desactivate dialog for remove and add new registries, available only when `SINGLE_REGISTRY=false`. (default: `false`).
 
diff --git a/bin/entrypoint b/bin/entrypoint
index 1cb40e5a..15218b11 100755
--- a/bin/entrypoint
+++ b/bin/entrypoint
@@ -32,8 +32,25 @@ get_nginx_proxy_headers() {
   done
 }
 
+get_nginx_proxy_pass_headers() {
+  (
+    env &&
+    if [ -f "/etc/nginx/.env" ]; then
+      cat /etc/nginx/.env
+      # Force new line
+      echo ""
+    fi
+  ) | while read e; do
+    if [ -n "$(echo $e | grep -o '^NGINX_PROXY_PASS_HEADER_')" ]; then
+      key=$(echo ${e%%=*} | sed 's/^NGINX_PROXY_PASS_HEADER_//' | sed 's/_/-/g')
+      echo -n "proxy_pass_header \"${key}\"; "
+    fi
+  done
+}
+
 if [ -n "${NGINX_PROXY_PASS_URL}" ] ; then
   sed -i "s,\${NGINX_PROXY_PASS_URL},${NGINX_PROXY_PASS_URL}," /etc/nginx/conf.d/default.conf
   sed -i "s^\${NGINX_PROXY_HEADERS}^$(get_nginx_proxy_headers)^" /etc/nginx/conf.d/default.conf
+  sed -i "s^\${NGINX_PROXY_PASS_HEADERS}^$(get_nginx_proxy_pass_headers)^" /etc/nginx/conf.d/default.conf
   sed -i "s,#!,," /etc/nginx/conf.d/default.conf
 fi
diff --git a/nginx/default.conf b/nginx/default.conf
index 3f7bf0c9..c6a8e39f 100644
--- a/nginx/default.conf
+++ b/nginx/default.conf
@@ -27,6 +27,7 @@ server {
 #!            return 404;
 #!        }
 #!        ${NGINX_PROXY_HEADERS}
+#!        ${NGINX_PROXY_PASS_HEADERS}
 #!        proxy_pass ${NGINX_PROXY_PASS_URL};
 #!    }