use custom dind to build doc container image

.drone.yml

@@ -40,20 +40,23 @@ steps:
   - cd docs
   - make html
 
-- name: build-docs
-  image: banzaicloud/drone-kaniko
-  settings:
-    registry: registry.kmlabz.com
-    dockerfile: docs/Dockerfile
-    context: ${PWD}/docs/
-    repo: goldenpogacsa/consumer-api-docs
-    username:
+- name: build_docs
+  image: docker:stable-dind
+  volumes:
+    - name: dockersock
+      path: /var/run
+  environment:
+    DOCKER_USERNAME:
       from_secret: DOCKER_USERNAME
-    password:
+    DOCKER_PASSWORD:
       from_secret: DOCKER_PASSWORD
-    tags:
-      - latest
-      - ${DRONE_BUILD_NUMBER}
+  commands:
+    - cd docs
+    - echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin registry.kmlabz.com
+    - docker build -t="registry.kmlabz.com/goldenpogacsa/producer-docs" .
+    - docker build -t="registry.kmlabz.com/goldenpogacsa/producer-docs:$DRONE_BUILD_NUMBER" .
+    - docker push "registry.kmlabz.com/goldenpogacsa/producer-docs"
+    - docker push "registry.kmlabz.com/goldenpogacsa/producer-docs:$DRONE_BUILD_NUMBER"
 
 - name: slack
   image: plugins/slack
@@ -64,3 +67,15 @@ steps:
     icon_url: https://cloudcdn.tormakristof.eu/static/drone.svg
   when:
     status: [ failure ]
+
+services:
+- name: docker
+  image: docker:stable-dind
+  privileged: true
+  volumes:
+  - name: dockersock
+    path: /var/run
+
+volumes:
+- name: dockersock
+  temp: {}