I have a managed k8s cluster based on VK Cloud.

1. I have installed to him gitlab-agent by Helm:

helm repo add gitlab https://charts.gitlab.io
helm repo update
helm upgrade --install icebreakers-router-k8s-agent gitlab/gitlab-agent 
--namespace gitlab-agent-icebreakers-router-k8s-agent 
--create-namespace 
--set image.tag=v17.1.0-rc5 
--set config.token=*TOKEN* 
--set config.kasAddress=wss://kas.gitlab.com

Empty Gitlab-agent config created in root of repository:
.gitlab/agents/icebreakers-router-k8s-agent/config.yaml

2. Gitlab-runner is installed as follows:

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

values.yaml:

gitlabUrl: https://gitlab.com
runnerRegistrationToken: *TOKEN*
rbac:
  serviceAccountName: gitlab-admin
runners:
  config: |
    [[runners]]
      [runners.kubernetes]
        service_account = "gitlab-admin"
        namespace = "gitlab-runner"
        image = "ubuntu:20.04"
        privileged = true
  tags: "icebreakers-router-gitlab-runner"
  serviceAccountName: gitlab-admin
  cloneUrl: https://gitlab.com/

kubectl apply -f 1-gitlab-runner-service-account.yaml

1-gitlab-runner-service-account.yaml:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: gitlab-admin
  namespace: gitlab-runner

---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  namespace: gitlab-runner
  name: gitlab-admin
rules:
  - apiGroups: ['']
    resources: ['*']
    verbs: ['*']

---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: gitlab-admin
  namespace: gitlab-runner
subjects:
  - kind: ServiceAccount
    name: gitlab-admin
    namespace: gitlab-runner
roleRef:
  kind: Role
  name: gitlab-admin
  apiGroup: rbac.authorization.k8s.io

3. Gitlab-job based on docs:

build-and-release-docker-image:
  stage: release
  image: docker:26.1.3
  services:
    - docker:26.1.3-dind
  variables:
    GIT_STRATEGY: none
    DOCKER_HOST: tcp://docker:2375
    DOCKER_TLS_CERTDIR: ""
  needs:
    - job: build-jar
      artifacts: true
  script:
    - ls
    - docker build .

I am unsuccessfully trying create Docker-In-Docker Job for build in them docker images.

As a result of starting a job, I get:

$ docker build .
ERROR: Cannot connect to the Docker daemon at tcp://docker:2375. Is the docker daemon running?

What am I doing wrong?