Fixed

Dockerfile

@@ -1,7 +1,6 @@
 FROM prom/node-exporter:latest
 
+USER root
 COPY entrypoint.sh /etc/node-exporter/
-RUN chmod +x /etc/node-exporter/entrypoint.sh
+ENTRYPOINT ["sh", "/etc/node-exporter/entrypoint.sh"]
-
+CMD ["/bin/node_exporter"]
-ENTRYPOINT  [ "/etc/node-exporter/docker-entrypoint.sh" ]
-CMD [ "/bin/node_exporter" ]

README.md

@@ -4,7 +4,7 @@ This is a copy of [prom/node-exporter](https://hub.docker.com/r/prom/node-export
 
 ## Example
 
-For the hostname to be detected, you must load the host filesystem into the container's `/host` directory as seen here.
+For the hostname to be detected, you must mount the host's `rootfs` into the container's `/host` directory as seen here:
 
 ```
 version: '3.8'
@@ -21,5 +21,3 @@ services:
     deploy:
       mode: global
 ```
-
-Otherwise use the `$HOSTNAME` variable to specify the path to the *hostname file* & ensure it's mounted.

entrypoint.sh

@@ -1,8 +1,6 @@
 #!/bin/sh
 
-if [ -z "$HOSTNAME" ]; then $HOSTNAME="/host/hostname"; fi
+NODE_NAME=$(cat "/host/etc/hostname")
-
-NODE_NAME=$(cat "$HOSTNAME")
 echo "node_meta{node_name=\"$NODE_NAME\"} 1" > /etc/node-exporter/node-meta.prom
 set -- /bin/node_exporter "$@"
 exec "$@"