Custom filebeat docker image error

Elastic Stack Beats
,
1

The custom image configuration section on the docs says that we can do the following to create a customized image:

FROM docker.elastic.co/beats/filebeat:8.10.0
COPY --chown=root:filebeat filebeat.yml /usr/share/filebeat/filebeat.yml

So I created the Dockerfile just like this, but when I start the container, I have the following error logged:

error loading config file: config file ("filebeat.yml") can only be writable by the owner but the permissions are "-rw-rw-r--" (to fix the permissions use: 'chmod go-w /usr/share/filebeat/filebeat.yml')

Maybe RUN chmod go-w /usr/share/filebeat/filebeat.yml should be added to the Dockerfile?
Let's try:

FROM docker.elastic.co/beats/filebeat:8.10.0
COPY --chown=root:filebeat filebeat.yml /usr/share/filebeat/filebeat.yml
RUN chmod go-w /usr/share/filebeat/filebeat.yml

$ docker build --tag xyz $("pwd")/filebeat-custom-img
[+] Building 0.2s (7/7) FINISHED                                                                                                                                                                            docker:default
 => [internal] load .dockerignore                                                                                                                                                                                     0.0s
 => => transferring context: 2B                                                                                                                                                                                       0.0s
 => [internal] load build definition from Dockerfile                                                                                                                                                                  0.0s
 => => transferring dockerfile: 204B                                                                                                                                                                                  0.0s
 => [internal] load metadata for docker.elastic.co/beats/filebeat:8.10.0                                                                                                                                              0.0s
 => [internal] load build context                                                                                                                                                                                     0.0s
 => => transferring context: 34B                                                                                                                                                                                      0.0s
 => [1/3] FROM docker.elastic.co/beats/filebeat:8.10.0                                                                                                                                                                0.0s
 => CACHED [2/3] COPY --chown=root:filebeat filebeat.yml /usr/share/filebeat/filebeat.yml                                                                                                                             0.0s
 => ERROR [3/3] RUN chmod go-w /usr/share/filebeat/filebeat.yml                                                                                                                                                       0.2s
------
 > [3/3] RUN chmod go-w /usr/share/filebeat/filebeat.yml:
0.226 chmod: changing permissions of '/usr/share/filebeat/filebeat.yml': Operation not permitted

chmod: changing permissions of '/usr/share/filebeat/filebeat.yml': Operation not permitted

What to do in this situation?

2

So I solved by changing my Dockerfile to:

FROM docker.elastic.co/beats/filebeat:8.10.0
COPY --chown=filebeat filebeat.yml /usr/share/filebeat/filebeat.yml
RUN chmod go-w /usr/share/filebeat/filebeat.yml

I don't know if this is the best way to do, but it worked.
If this configuration poses any risk, please, let me know.