Why Gitlab external_url is allways redirect to https automatically

Hello every one,

I’m working on running gitlab docker container ,

I’m using docker-compose file:

version: '2'
services:
redis:
restart: always
image: sameersbn/redis:latest
container_name: gitlab-redis
command:
- --loglevel warning
volumes:
- /srv/docker/gitlab/redis:/var/lib/redis
postgresql:
restart: always
image: sameersbn/postgresql:9.6-2
container_name: gitlab-postgresql
volumes:
- /srv/docker/gitlab/postgresql:/var/lib/postgresql
environment:
- DB_USER=user
- DB_PASS=userpass
- DB_NAME=database
- DB_EXTENSION=pg_trgm
gitlab:
image: sameersbn/gitlab:latest
container_name: gitlab
links:
- redis
- postgresql
ports:
- "8080:80"
- "8022:22"
- "8443:443"
volumes:
- /srv/docker/gitlab/gitlab/config:/etc/gitlab
- /srv/docker/gitlab//gitlab/logs:/var/log/gitlab
- /srv/docker/gitlab/gitlab/data:/home/git/data
- /srv/docker/gitlab/gitlab/opt:/var/opt/gitlab
environment:
- DB_ADAPTER=postgresql
- DB_HOST=postgresql
- DB_PORT=5432
- DB_USER=user
- DB_PASS=userpass
- DB_NAME=database
- REDIS_HOST=redis
- REDIS_PORT=6379
- GITLAB_HTTPS=false
- GITLAB_OMNIBUS_CONFIG="external_url 'http://gitlab.example.com:8080/';gitlab_rails['gitlab_shell_ssh_port'] =8022"
- GITLAB_SSH_PORT=8022
- GITLAB_HOST=http://gitlab.exmaple.com
- GITLAB_ROOT_PASSWORD=root
- GITLAB_SECRETS_DB_KEY_BASE=xxxxxxxxxxxxxxxxxxx
- GITLAB_SECRETS_SECRET_KEY_BASE=xxxxxxxxxxxxxxx
- GITLAB_SECRETS_OTP_KEY_BASE=xxxxxxxxxxxxxxxxxx

When i connect using gitlab.example.com:8080 automatically it’s redirect to https://gitlab.example.com:8080

Why i’m facing this behavior