Update Dockerfile, .gitlab-ci.yml files

.gitlab-ci.yml

+build:
+  stage: build
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  script:
+    - mkdir -p /kaniko/.docker
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile $CI_PROJECT_DIR/Dockerfile --destination $CI_REGISTRY_IMAGE:$CI_COMMIT_TAG

Dockerfile

+FROM gcr.io/kaniko-project/executor:arm64-v1.3.0
+
+COPY --from=arm64v8/busybox:1.32.0 /bin /busybox
+# Declare /busybox as a volume to get it automatically in the path to ignore
+VOLUME /busybox
+ENV PATH /usr/local/bin:/kaniko:/busybox
+
+# via https://github.com/GoogleContainerTools/kaniko/issues/1488