Allow override with own authentication if provided (rpardini#61)

Dockerfile

@@ -94,6 +94,9 @@ ENV MANIFEST_CACHE_SECONDARY_TIME="60d"
 # In the default config, :latest and other frequently-used tags will get this value.
 ENV MANIFEST_CACHE_DEFAULT_TIME="1h"
 
+# Should we allow overridding with own authentication, default to false.
+ENV ALLOW_OWN_AUTH="false"
+
 # Should we allow actions different than pull, default to false.
 ENV ALLOW_PUSH="false"
 

README.md

@@ -79,6 +79,7 @@ for this to work it requires inserting a root CA certificate into system trusted
 - Expose port 3128 to the network
 - Map volume `/docker_mirror_cache` for up to `CACHE_MAX_SIZE` (32gb by default) of cached images across all cached registries
 - Map volume `/ca`, the proxy will store the CA certificate here across restarts. **Important** this is security sensitive.
+- Env `ALLOW_OWN_AUTH` (default `false`): Allow overridding the `AUTH_REGISTRIES` authentication with own Docker credentials if provided (to support `docker login` as another user).
 - Env `ALLOW_PUSH` : This bypasses the proxy when pushing, default to false - if kept to false, pushing will not work. For more info see this [commit](https://github.com/rpardini/docker-registry-proxy/commit/536f0fc8a078d03755f1ae8edc19a86fc4b37fcf).
 - Env `CACHE_MAX_SIZE` (default `32g`): set the max size to be used for caching local Docker image layers. Use [Nginx sizes](http://nginx.org/en/docs/syntax.html).
 - Env `ENABLE_MANIFEST_CACHE`, see the section on pull rate limiting.

entrypoint.sh

@@ -137,6 +137,17 @@ echo -e "\nManifest caching config: ---\n"
 cat /etc/nginx/nginx.manifest.caching.config.conf
 echo "---"
 
+if [[ "a${ALLOW_OWN_AUTH}" == "atrue" ]]; then
+    cat << 'EOF' > /etc/nginx/conf.d/allowed_override_auth.conf
+    if ($http_authorization != "") {
+        # override with own authentication if provided
+        set $finalAuth $http_authorization;
+    }
+EOF
+else
+    echo '' > /etc/nginx/conf.d/allowed_override_auth.conf
+fi
+
 if [[ "a${ALLOW_PUSH}" == "atrue" ]]; then
     cat <<EOF > /etc/nginx/conf.d/allowed.methods.conf
     # allow to upload big layers

nginx.conf

@@ -245,6 +245,7 @@ echo "Docker configured with HTTPS_PROXY=$scheme://$http_host/"
         proxy_ignore_headers   X-Accel-Expires Expires Cache-Control Set-Cookie;
 
         # Add the authentication info, if the map matched the target domain.
+        include "/etc/nginx/conf.d/allowed_override_auth.conf";
         proxy_set_header Authorization $finalAuth;
 
         # Use SNI during the TLS handshake with the upstream.