AWS cloud-config not setting dns-nameservers - amazon-web-services

Question

Here is the cloud.cfg on my instance (I had tampered it manually when provisioning the ami from which I launched the instance)
root#ip-10-17-0-121:~# cat /etc/cloud/cloud.cfg | grep -i resol -C 3
# Network configuration for ami
manage_resolv_conf: true
resolv_conf:
nameservers: ['10.11.4.1']
However this is never taken into account given that:
# cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 10.17.0.2
search eu-west-1.compute.internal
I have tried with and without creating the following file
# cat /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg
network: {config: disabled}

Answer 1

I managed to make my instance obtain my custom dns-nameserver as follows
- name: pre_tasks --> Add my custom dns-nameserver
lineinfile:
path: /etc/dhcp/dhclient.conf
regexp: '^#prepend domain-name-servers'
line: 'prepend domain-name-servers 10.11.4.1;'
become: yes
However now I am getting the following warning:
pkara#ip-10-17-0-35:~$ sudo -i
sudo: unable to resolve host ip-10-17-0-35
not accepting my answer until / unless I address this;
edit_1: adding this to my cloud-config.yml which I am setting as user data did not help much:
hostname: localhost
manage_etc_hosts: true
edit_2: adding this to my cloud-config.cfg helped me to address the above unable to resolve host problemn
bootcmd:
- echo "127.0.0.1 $(hostname)" >> /etc/hosts