More fixes for relative urls when running Grafana under a different sub path (#10470)

* Add nginx proxy docker container

Ease test/verification of running Grafana thru a reverse proxy

* Add apache proxy docker container

Ease test/verification of running Grafana thru a reverse proxy

* Fix relative urls for reset password page

* Fix relative urls for signup page

* Fix relative urls for login page

* Fix relative urls edit plugin page

docker/blocks/nginx_proxy/Dockerfile

@@ -0,0 +1,3 @@
+FROM nginx:alpine
+
+COPY nginx.conf /etc/nginx/nginx.conf

docker/blocks/nginx_proxy/docker-compose.yaml

@@ -0,0 +1,9 @@
+# This will proxy all requests for http://localhost:10080/grafana/ to
+# http://localhost:3000 (Grafana running locally)
+#
+# Please note that you'll need to change the root_url in the Grafana configuration:
+# root_url = %(protocol)s://%(domain)s:/grafana/
+
+  nginxproxy:
+    build: blocks/nginx_proxy
+    network_mode: host

docker/blocks/nginx_proxy/nginx.conf

@@ -0,0 +1,19 @@
+events { worker_connections 1024; }
+
+http {
+  sendfile on;
+
+  proxy_redirect     off;
+  proxy_set_header   Host $host;
+  proxy_set_header   X-Real-IP $remote_addr;
+  proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
+  proxy_set_header   X-Forwarded-Host $server_name;
+
+  server {
+    listen 10080;
+
+    location /grafana/ {
+      proxy_pass http://localhost:3000/;
+    }
+  }
+}