Revert "add node exporter"

This reverts commit 13044fb997.

docker-compose.exporter.yml

@@ -1,18 +0,0 @@
-version: '3.2'
-services:
-  node_exporter:
-    container_name: node_exporter
-    # Always check if there is a newer stable release:
-    # https://hub.docker.com/r/prom/node-exporter/tags
-    image: prom/node-exporter:v0.18.1
-    command:
-    - "--path.rootfs=/host"
-    - "--web.listen-address=127.0.0.1:9100"
-    network_mode: "host"
-    pid: "host"
-    volumes:
-    - type: "bind"
-      source: "/"
-      target: "/host"
-      read_only: true
-    restart: unless-stopped