Docker compose extra_hosts does not change /etc/hosts file

I'm using the Nodejs app with docker to be deployed on AWS ecs.

The problem is that api call on private DNS record return error: getaddrinfo enotfound request

From research error looks like to be connected with DNS lookup (please feel free to comment if you have other theory), so I decided to set DNS servers and µextra_hostsµ on compose.

Even though everything builds, when I cat /etc/hosts in Dockerfile it's not changed.

Questions are:

1. Should /etc/hosts be modified by extra_hosts.
2. Can there be other reason for error: getaddrinfo enotfound request? All other api calls work except internal DNS which works once and after returns error: getaddrinfo enotfound.
3. What's the best way to configure DNS and host with docker?
4. Why is it working once and stops after?

this is how my docker-compose file looks:

version: '3'
services:
  nodejs:
    extra_hosts:
      - "<name here>:<ip here>"
      - "<name here>:<ip here>"
    dns:
      - <ip here>
      - <ip here>
      - <ip here>
    network_mode: 'host'
    build:
      context: .
      dockerfile: Dockerfile

Heres how docker file looks like

FROM alpine:latest
RUN apk add --update nodejs nodejs-npm && apk add g++ make python
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
COPY . .

RUN cat /etc/hosts
EXPOSE 80
CMD npm start

Here's the docker build output

Sending build context to Docker daemon  11.58MB
Step 1/11 : FROM alpine:latest
 ---> f70734b6a266
Step 2/11 : RUN apk add --update nodejs nodejs-npm && apk add g++ make python
 ---> Using cache
 ---> b173538c6ce5
Step 3/11 : WORKDIR /usr/src/app
 ---> Using cache
 ---> 0186bcca617d
Step 7/11 : RUN npm install
 ---> Using cache
 ---> 546f707d5fea
Step 8/11 : COPY . .
 ---> b66f4bec9d93
Step 9/11 : RUN cat /etc/hosts
 ---> Running in 1c48f0426713
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.2  1c48f0426713
Removing intermediate container 1c48f0426713
 ---> 858735acc4a6
Step 10/11 : EXPOSE 80
 ---> Running in dd7a8ae0669a
Removing intermediate container dd7a8ae0669a
 ---> 907a3dafb4fc
Step 11/11 : CMD npm start
 ---> Running in a3dd69c6ec3b
Removing intermediate container a3dd69c6ec3b
 ---> cda2214b2761
Successfully built cda2214b2761
Successfully tagged test:latest