DinD configuration for Gitlab CI with private Docker registry in Sonatype Nexus 3 - docker

Question

I have done a setup of my own Gitlab(-p 7022:22, 7080:9080), Gitlab Runner(-p 7093:8093), Sonatype Nexus3(Maven, Docker, Helm)(-p 10081:8081, 10082:10082, 10083:10083, 10084:10084). All are running as docker images of their own. And till docker build everything runs great(below code snippets doesn't have docker build related code). Problem is, I want to upload the final docker image to my Nexus3 Docker Registry which I am unable to do so.
My Gitlab Runner config is below
concurrent = 1
check_interval = 0
[session_server]
session_timeout = 1800
[[runners]]
name = "testing dind runner"
url = "http://192.168.0.250:7080/" ----> Gitlab git repo external url
token = "SOME TOKEN"
executor = "docker"
[runners.custom_build_dir]
[runners.cache]
[runners.cache.s3]
[runners.cache.gcs]
[runners.cache.azure]
[runners.docker]
tls_verify = false
image = "docker:19.03.12"
privileged = true
disable_entrypoint_overwrite = false
oom_kill_disable = false
disable_cache = false
volumes = ["/var/run/docker.sock:/var/run/docker.sock", "/cache"]
shm_size = 0
My Docker registry in Nexus3 is hosted as below
Web UI = http://192.168.0.250:10081/ (container internal port is 8081 and exposed to host on 10081)
Docker(Group) = 10084 (exposed as the same port through docker)
Docker(Hosted) = 10082 (exposed as the same port through docker)
Docker(Proxy) = 10083 (exposed as the same port through docker)
My project CI config is below
image: docker:19.03.12
services:
- name: docker:19.03.12-dind
variables:
DOCKER_HOST: tcp://docker:2375
DOCKER_TLS_CERTDIR: ""
before_script:
- docker info
- docker login -u nx-uploader -p 1234 192.168.0.250:10082
stages:
- test docker reg
test-docker:
stage: test docker reg
script:
- docker images
- docker search httpd
I am constantly getting errors as
$ docker login -u nx-uploader -p 1234 192.168.0.250:10082
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
error during connect: Post http://docker:2376/v1.40/auth: dial tcp: lookup docker on 192.168.0.1:53: no such host
ERROR: Job failed: exit code 1
Need help/pointers to fix this.
Thanks in advance.