How to add ip allias to GKE + GitLab Runner?

Question

I deployed Heml Chart gitlab/gitlab on GKE

helm install gitlab gitlab/gitlab \
  --set global.hosts.domain=**my.domain.tld** \
  --set certmanager-issuer.email=me@example.com

then integrated GKE with GitLab. Integration succeed But automatically created Runner's pod fails on registration with error

ERROR: Registering runner... failed                 
status=couldn't execute POST against https://gitlab.my.domain.tld/api/v4/runners: 
Post https://gitlab.my.domain.tld/api/v4/runners: dial tcp: 
lookup gitlab.my.domain.tld on 10.0.0.10:53: no such host

How i can change Runner's /etc/hosts? Or add some system variable with ip to gitlab.my.domain.tld?

P.S. Also i tried to use Helm Chart gitlab/gitlab-runner with config,

helm install gitlab-runner -f values.yaml gitlab/gitlab-runner

# values.yaml

gitlabUrl: https://gitlab.my.domain.tld/
runnerRegistrationToken: <token>
concurrent: 10
rbac:
  create: true
  clusterWideAccess: false
runners:
  image: ubuntu:18.04

hostAliases:
  - ip: <ip_of_my_gitlab>
    hostnames:
      - "gitlab.my.domain.tld"

but it fails on registration with another error

ERROR: Registering runner... failed                 
runner=ipdNGq79 status=couldn't execute POST against https://gitlab.my.domain.tld/api/v4/runners: 
Post https://gitlab.my.domain.tld/api/v4/runners: 
x509: certificate signed by unknown authority

May be fix this issue easier then configure automatically created Runner's pod? Where i can get needed certificate? Thanks!