nginx: Add `nginx-serve-volume` service

This service allows for easy serving of static content in a volume,
typically HTML files in directory structures mapping to the navigation
structure for the content served.

config/service/nginx/service/nginx-serve-volume.conf.template

@@ -0,0 +1,7 @@
+server {
+    listen 8080;
+    server_name ${SERVER_NAME};
+
+    root ${SERVER_ROOT};
+    include server.conf;
+}

config/service/nginx/systemd/nginx-serve-volume@.service

@@ -0,0 +1,25 @@
+[Unit]
+Description=NGINX Web Service for Volume %I
+Wants=nginx.service
+After=nginx.service
+
+[Service]
+Type=notify
+NotifyAccess=all
+SyslogIdentifier=%N
+Restart=on-failure
+Environment=PODMAN_SYSTEMD_UNIT=%n
+Environment=SERVER_NAME=%p-%i SERVER_ROOT=/srv
+Environment=NGINX_CONF=%E/coreos-home-server/nginx/service/%p.conf.template
+ExecStartPre=/bin/podman create --replace --name $SERVER_NAME --net internal --sdnotify=conmon \
+                                --volume %i:/srv:z,ro \
+                                localhost/nginx:latest
+ExecStartPre=/bin/sh -c "envsubst '$SERVER_NAME $SERVER_ROOT' < ${NGINX_CONF} > /tmp/%i.conf"
+ExecStartPre=/bin/sh -c 'podman cp /tmp/%i.conf ${SERVER_NAME}:/etc/nginx/conf.d/%i.conf && rm -f /tmp/%i.conf'
+ExecStart=/bin/podman start --attach $SERVER_NAME
+ExecStop=/bin/podman stop --ignore --time 10 $SERVER_NAME
+ExecStopPost=/bin/podman rm --ignore --force $SERVER_NAME
+
+[Install]
+Alias=%i.service
+WantedBy=multi-user.target

host/virtual/spec.bu

@@ -72,6 +72,16 @@ systemd:
     - name: nginx-proxy-http@php.localhost.service
       enabled: true
 
+    - name: nginx-serve-volume@git-serve.service
+      enabled: true
+    - name: nginx-proxy-http@git.localhost.service
+      enabled: true
+      dropins:
+        - name: git-volume-upstream.conf
+          contents: |
+            [Service]
+            Environment=UPSTREAM_HOST=nginx-serve-volume-git-serve UPSTREAM_PORT=8080
+
     - name: nginx-proxy-http@dav.localhost.service
       enabled: true
       dropins: