diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9738757cfb773..9be695daae43b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -192,7 +192,7 @@ repos:
         require_serial: true
       - id: build
         name: Check if image build is needed
-        entry: ./scripts/ci/local_ci_build.sh
+        entry: ./scripts/ci/pre_commit_ci_build.sh
         language: system
         always_run: true
         pass_filenames: false
diff --git a/BREEZE.rst b/BREEZE.rst
index 8b77b99a5a512..3df93e66a4623 100644
--- a/BREEZE.rst
+++ b/BREEZE.rst
@@ -79,11 +79,9 @@ images maintained on the Docker Hub in the ``apache/airflow`` repository.
 
 There are three images that we are currently managing:
 
-* **Slim CI** image that is used for static code checks (size of ~500MB). Its tag follows the pattern
-  of ``<BRANCH>-python<PYTHON_VERSION>-ci-slim`` (for example, ``apache/airflow:master-python3.6-ci-slim``).
-  The image is built using the `<Dockerfile>`_ Dockerfile.
-* **Full CI image*** that is used for testing. It contains a lot more test-related installed software
-  (size of ~1GB). Its tag follows the pattern of ``<BRANCH>-python<PYTHON_VERSION>-ci``
+* **CI image*** that is used for testing od both Unit tests and static check tests.
+  It contains a lot test-related packages (size of ~1GB).
+  Its tag follows the pattern of ``<BRANCH>-python<PYTHON_VERSION>-ci``
   (for example, ``apache/airflow:master-python3.6-ci``). The image is built using the
   `<Dockerfile>`_ Dockerfile.
 * **Checklicense image** that is used during license check with the Apache RAT tool. It does not
diff --git a/Dockerfile b/Dockerfile
index 28fc424ca335b..3ba54caee9350 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -15,16 +15,8 @@
 #
 # WARNING: THIS DOCKERFILE IS NOT INTENDED FOR PRODUCTION USE OR DEPLOYMENT.
 #
-# Base image for the whole Docker file
-ARG APT_DEPS_IMAGE="airflow-apt-deps-ci-slim"
 ARG PYTHON_BASE_IMAGE="python:3.6-slim-stretch"
-############################################################################################################
-# This is the slim image with APT dependencies needed by Airflow. It is based on a python slim image
-# Parameters:
-#    PYTHON_BASE_IMAGE - base python image (python:x.y-slim-stretch)
-############################################################################################################
-FROM ${PYTHON_BASE_IMAGE} as airflow-apt-deps-ci-slim
-
+FROM ${PYTHON_BASE_IMAGE} as main
 
 SHELL ["/bin/bash", "-o", "pipefail", "-e", "-u", "-x", "-c"]
 
@@ -121,116 +113,95 @@ RUN adduser airflow \
     && echo "airflow ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/airflow \
     && chmod 0440 /etc/sudoers.d/airflow
 
-############################################################################################################
-# This is an image with all APT dependencies needed by CI. It is built on top of the airlfow APT image
-# Parameters:
-#     airflow-apt-deps - this is the base image for CI deps image.
-############################################################################################################
-FROM airflow-apt-deps-ci-slim as airflow-apt-deps-ci
+ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/
 
-SHELL ["/bin/bash", "-o", "pipefail", "-e", "-u", "-x", "-c"]
+# Note missing man directories on debian-stretch
+# https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199
+RUN mkdir -pv /usr/share/man/man1 \
+    && mkdir -pv /usr/share/man/man7 \
+    && apt-get update \
+    && apt-get install --no-install-recommends -y \
+      gnupg \
+      apt-transport-https \
+      ca-certificates \
+      software-properties-common \
+      krb5-user \
+      ldap-utils \
+      less \
+      lsb-release \
+      net-tools \
+      openjdk-8-jdk \
+      openssh-client \
+      openssh-server \
+      postgresql-client \
+      python-selinux \
+      sqlite3 \
+      tmux \
+      unzip \
+      vim \
+    && apt-get autoremove -yqq --purge \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
-ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/
+ENV HADOOP_DISTRO="cdh" HADOOP_MAJOR="5" HADOOP_DISTRO_VERSION="5.11.0" HADOOP_VERSION="2.6.0" \
+    HADOOP_HOME="/tmp/hadoop-cdh"
+ENV HIVE_VERSION="1.1.0" HIVE_HOME="/tmp/hive"
+ENV HADOOP_URL="https://archive.cloudera.com/${HADOOP_DISTRO}${HADOOP_MAJOR}/${HADOOP_DISTRO}/${HADOOP_MAJOR}/"
+ENV MINICLUSTER_BASE="https://github.com/bolkedebruin/minicluster/releases/download/" \
+    MINICLUSTER_HOME="/tmp/minicluster" \
+    MINICLUSTER_VER="1.1"
 
-ARG APT_DEPS_IMAGE="airflow-apt-deps-ci-slim"
-ENV APT_DEPS_IMAGE=${APT_DEPS_IMAGE}
-ARG KUBERNETES_VERSION="v1.15.0"
-ENV KUBERNETES_VERSION=${KUBERNETES_VERSION}
-ARG KIND_VERSION="v0.5.0"
-ENV KIND_VERSION=${KIND_VERSION}
+RUN mkdir -pv "${HADOOP_HOME}" \
+    && mkdir -pv "${HIVE_HOME}" \
+    && mkdir -pv "${MINICLUSTER_HOME}" \
+    && mkdir -pv "/user/hive/warehouse" \
+    && chmod -R 777 "${HIVE_HOME}" \
+    && chmod -R 777 "/user/"
 
-RUN echo "${APT_DEPS_IMAGE}"
-
-# Note the ifs below might be removed if Buildkit will become usable. It should skip building this
-# image automatically if it is not used. For now we still go through all layers below but they are empty
-RUN if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then \
-        # Note missing man directories on debian-stretch
-        # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199
-        mkdir -pv /usr/share/man/man1 \
-        && mkdir -pv /usr/share/man/man7 \
-        && apt-get update \
-        && apt-get install --no-install-recommends -y \
-          gnupg \
-          apt-transport-https \
-          ca-certificates \
-          software-properties-common \
-          krb5-user \
-          ldap-utils \
-          less \
-          lsb-release \
-          net-tools \
-          openjdk-8-jdk \
-          openssh-client \
-          openssh-server \
-          postgresql-client \
-          python-selinux \
-          sqlite3 \
-          tmux \
-          unzip \
-          vim \
-        && apt-get autoremove -yqq --purge \
-        && apt-get clean \
-        && rm -rf /var/lib/apt/lists/* \
-        ;\
-    fi
+ENV HADOOP_DOWNLOAD_URL="${HADOOP_URL}hadoop-${HADOOP_VERSION}-${HADOOP_DISTRO}${HADOOP_DISTRO_VERSION}.tar.gz" \
+    HADOOP_TMP_FILE="/tmp/hadoop.tar.gz"
 
-# TODO: We should think about removing those and moving them into docker-compose dependencies.
-COPY scripts/ci/docker_build/ci_build_install_deps.sh /tmp/ci_build_install_deps.sh
+RUN curl -sL "${HADOOP_DOWNLOAD_URL}" >"${HADOOP_TMP_FILE}" \
+    && tar xzf "${HADOOP_TMP_FILE}" --absolute-names --strip-components 1 -C "${HADOOP_HOME}" \
+    && rm "${HADOOP_TMP_FILE}"
 
-# Kubernetes dependencies
-RUN \
-if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then \
-    curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add - \
-    && add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian stretch stable" \
-    && apt-get update \
-    && apt-get -y install --no-install-recommends docker-ce \
-    && apt-get autoremove -yqq --purge \
-    && apt-get clean && rm -rf /var/lib/apt/lists/* \
-    ;\
-fi
+ENV HIVE_URL="${HADOOP_URL}hive-${HIVE_VERSION}-${HADOOP_DISTRO}${HADOOP_DISTRO_VERSION}.tar.gz" \
+    HIVE_TMP_FILE="/tmp/hive.tar.gz"
 
-RUN \
-if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then \
-    curl -Lo kubectl \
-    "https://storage.googleapis.com/kubernetes-release/release/${KUBERNETES_VERSION}/bin/linux/amd64/kubectl" \
-    && chmod +x kubectl \
-    && mv kubectl /usr/local/bin/kubectl \
-    ;\
-fi
+RUN curl -sL "${HIVE_URL}" >"${HIVE_TMP_FILE}" \
+    && tar xzf "${HIVE_TMP_FILE}" --strip-components 1 -C "${HIVE_HOME}" \
+    && rm "${HIVE_TMP_FILE}"
 
-RUN \
-if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then \
-    curl -Lo kind \
-    "https://github.com/kubernetes-sigs/kind/releases/download/${KIND_VERSION}/kind-linux-amd64" \
-    && chmod +x kind \
-    && mv kind /usr/local/bin/kind \
-    ;\
-fi
-
-ENV HADOOP_DISTRO=cdh \
-    HADOOP_MAJOR=5 \
-    HADOOP_DISTRO_VERSION=5.11.0 \
-    HADOOP_VERSION=2.6.0 \
-    HIVE_VERSION=1.1.0
-ENV HADOOP_URL=https://archive.cloudera.com/${HADOOP_DISTRO}${HADOOP_MAJOR}/${HADOOP_DISTRO}/${HADOOP_MAJOR}/
-ENV HADOOP_HOME=/tmp/hadoop-cdh HIVE_HOME=/tmp/hive
-
-RUN if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then /tmp/ci_build_install_deps.sh; fi
+ENV MINICLUSTER_URL="${MINICLUSTER_BASE}${MINICLUSTER_VER}/minicluster-${MINICLUSTER_VER}-SNAPSHOT-bin.zip" \
+    MINICLUSTER_TMP_FILE="/tmp/minicluster.zip"
+
+RUN curl -sL "${MINICLUSTER_URL}" > "${MINICLUSTER_TMP_FILE}" \
+    && unzip "${MINICLUSTER_TMP_FILE}" -d "/tmp" \
+    && rm "${MINICLUSTER_TMP_FILE}"
 
 ENV PATH "${PATH}:/tmp/hive/bin"
 
-############################################################################################################
-# This is the target image - it installs PIP and NPM dependencies including efficient caching
-# mechanisms - it might be used to build the bare airflow build or CI build
-# Parameters:
-#    APT_DEPS_IMAGE - image with APT dependencies. It might either be base deps image with airflow
-#                     dependencies or CI deps image that contains also CI-required dependencies
-############################################################################################################
-FROM ${APT_DEPS_IMAGE} as main
+RUN curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add - \
+    && add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian stretch stable" \
+    && apt-get update \
+    && apt-get -y install --no-install-recommends docker-ce \
+    && apt-get autoremove -yqq --purge \
+    && apt-get clean && rm -rf /var/lib/apt/lists/*
 
-SHELL ["/bin/bash", "-o", "pipefail", "-e", "-u", "-x", "-c"]
+ARG KUBECTL_VERSION="v1.15.0"
+ENV KUBECTL_VERSION=${KUBECTL_VERSION}
+ARG KIND_VERSION="v0.5.0"
+ENV KIND_VERSION=${KIND_VERSION}
 
-RUN echo "Airflow version: ${AIRFLOW_VERSION}"
+RUN curl -Lo kubectl \
+  "https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl" \
+  && chmod +x kubectl \
+  && mv kubectl /usr/local/bin/kubectl
+
+RUN curl -Lo kind \
+   "https://github.com/kubernetes-sigs/kind/releases/download/${KIND_VERSION}/kind-linux-amd64" \
+   && chmod +x kind \
+   && mv kind /usr/local/bin/kind
 
 ARG AIRFLOW_USER=airflow
 ENV AIRFLOW_USER=${AIRFLOW_USER}
@@ -366,15 +337,11 @@ RUN if [[ -n "${ADDITIONAL_PYTHON_DEPS}" ]]; then \
 
 COPY --chown=airflow:airflow ./scripts/docker/entrypoint.sh /entrypoint.sh
 
-ARG APT_DEPS_IMAGE="airflow-apt-deps-ci-slim"
-ENV APT_DEPS_IMAGE=${APT_DEPS_IMAGE}
-
 COPY --chown=airflow:airflow .bash_completion run-tests-complete run-tests ${HOME}/
 COPY --chown=airflow:airflow .bash_completion.d/run-tests-complete \
      ${HOME}/.bash_completion.d/run-tests-complete
 
-RUN if [[ "${APT_DEPS_IMAGE}" == "airflow-apt-deps-ci" ]]; then \
-       ${AIRFLOW_SOURCES}/scripts/ci/docker_build/ci_build_extract_tests.sh; fi
+RUN ${AIRFLOW_SOURCES}/scripts/ci/docker_build/ci_build_extract_tests.sh
 
 USER ${AIRFLOW_USER}
 
diff --git a/breeze b/breeze
index d27cd5dfbafb4..442cb311698cb 100755
--- a/breeze
+++ b/breeze
@@ -105,10 +105,7 @@ export AIRFLOW_CONTAINER_PUSH_IMAGES=${AIRFLOW_CONTAINER_PUSH_IMAGES:="false"}
 # For local builds we fix file permissions only for setup-related files
 export AIRFLOW_FIX_PERMISSIONS=${AIRFLOW_FIX_PERMISSIONS:="setup"}
 
-# Skip building slim image locally - we only need full CI image
-export AIRFLOW_CONTAINER_SKIP_CI_SLIM_IMAGE="true"
-
-# Skip building full CI image locally - we only need slim image
+# Skip building full CI image locally
 export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="false"
 
 # Branch name of the base image used (usually master or v1-10-test or v1-10-stable)
@@ -682,7 +679,7 @@ echo
 CMDNAME="$(basename -- "$0")"
 
 # Cleans up the answer that was given last time, whether to force/
-cleanup_last_force_answer
+forget_last_answer
 
 export ENV="${ENV:=$(read_from_file ENV)}"
 export BACKEND="${BACKEND:=$(read_from_file BACKEND)}"
@@ -935,7 +932,6 @@ prepare_command_file "${BUILD_CACHE_DIR}/${LAST_DC_TEST_FILE}" "${DC_RUN_COMMAND
 prepare_command_file "${BUILD_CACHE_DIR}/${LAST_DC_FILE}" '"' "false"
 
 rebuild_ci_image_if_needed
-rebuild_ci_slim_image_if_needed
 rebuild_checklicence_image_if_needed
 
 export AIRFLOW_CONTAINER_DOCKER_IMAGE=\
diff --git a/hooks/build b/hooks/build
index 6f3b56fd1a630..91e0917c37d80 100755
--- a/hooks/build
+++ b/hooks/build
@@ -98,30 +98,18 @@ function build_python_image {
     NAME="${1}"
     MY_IMAGE_TAG="${2}"
     TARGET_IMAGE="${3}"
-    APT_DEPS_IMAGE="${4:-airflow-apt-deps-ci-slim}"
-    AIRFLOW_EXTRAS="${5:-all}"
-    AIRFLOW_USER="${6:-airflow}"
-    HOME="${7:-/home/airflow}"
+    AIRFLOW_EXTRAS="${4:-all}"
+    AIRFLOW_USER="${5:-airflow}"
+    HOME="${6:-/home/airflow}"
 
     echo "Build ${NAME} image: ${MY_IMAGE_TAG}"
     echo "Python base image: ${PYTHON_BASE_IMAGE}"
 
     set +u
-    if [[ "${MY_IMAGE_TAG}" == "${AIRFLOW_CI_IMAGE}" ]]; then
-        DOCKER_CACHE_DIRECTIVE=("${DOCKER_CACHE_DIRECTIVE_CI[@]}")
-    elif [[ "${MY_IMAGE_TAG}" == "${AIRFLOW_SLIM_CI_IMAGE}" ]]; then
-        DOCKER_CACHE_DIRECTIVE=("${DOCKER_CACHE_DIRECTIVE_CI_SLIM[@]}")
-    else
-        echo
-        echo "Don't know how to set cache directive for ${MY_IMAGE_TAG}. Exiting"
-        echo
-        exit 1
-    fi
     set -x
     docker build \
         --build-arg PYTHON_BASE_IMAGE="${PYTHON_BASE_IMAGE}" \
         --build-arg AIRFLOW_VERSION="${AIRFLOW_VERSION}" \
-        --build-arg APT_DEPS_IMAGE="${APT_DEPS_IMAGE}" \
         --build-arg AIRFLOW_EXTRAS="${AIRFLOW_EXTRAS}" \
         --build-arg AIRFLOW_USER="${AIRFLOW_USER}" \
         --build-arg AIRFLOW_BRANCH="${AIRFLOW_CONTAINER_BRANCH_NAME}" \
@@ -189,9 +177,6 @@ else
     NON_CI="true"
 fi
 
-# Extras used to to build slim airflow image
-AIRFLOW_SLIM_EXTRAS=${AIRFLOW_SLIM_EXTRAS:="all"}
-
 # Extras used to build cache and CI image
 AIRFLOW_CI_EXTRAS=${AIRFLOW_CI_EXTRAS:="devel_ci"}
 
@@ -212,13 +197,8 @@ export AIRFLOW_CONTAINER_FORCE_PULL_IMAGES=${AIRFLOW_CONTAINER_FORCE_PULL_IMAGES
 # In CI environment (and local force) we skip pulling latest python image
 export AIRFLOW_CONTAINER_SKIP_LATEST_PYTHON_PULL=${AIRFLOW_CONTAINER_SKIP_LATEST_PYTHON_PULL:=${CI}}
 
-# Skips downloading and building the slim image of airflow
-# This is set to true by default in CI test environment (we only need full CI image then)
-export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE=${AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE:=${CI}}
-echo "Skip slim image: ${AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE}"
-
 # Skips downloading and building the CI image, full CI-enabled image of airflow
-# This is set to true for pre-tests which do not need the whole CI image just the slim one
+# This is set to true for pre-tests which do not need the whole CI image
 export AIRFLOW_CONTAINER_SKIP_CI_IMAGE=${AIRFLOW_CONTAINER_SKIP_CI_IMAGE:="false"}
 echo "Skip CI image: ${AIRFLOW_CONTAINER_SKIP_CI_IMAGE}"
 
@@ -241,11 +221,6 @@ export PYTHON_BASE_IMAGE=python:${PYTHON_VERSION}-slim-stretch
 export CHECKLICENCE_BASE_IMAGE=debian:stretch-slim
 
 if [[ "${AIRFLOW_RELEASE_BUILD}" == "true" ]]; then
-    export AIRFLOW_SLIM_CI_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${AIRFLOW_VERSION}-python${PYTHON_VERSION}-ci-slim"
-    export AIRFLOW_SLIM_CI_IMAGE_DEFAULT="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${AIRFLOW_VERSION}-ci-slim"
-    export AIRFLOW_SLIM_CI_IMAGE_LATEST="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:latest-python${PYTHON_VERSION}-${TAG_PREFIX}-ci-slim"
-    export AIRFLOW_SLIM_CI_IMAGE_LATEST_DEFAULT="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:latest-${TAG_PREFIX}-ci-slim"
-
     export AIRFLOW_CI_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${AIRFLOW_VERSION}-python${PYTHON_VERSION}-ci"
     export AIRFLOW_CI_IMAGE_DEFAULT="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${AIRFLOW_VERSION}-ci"
     export AIRFLOW_CI_IMAGE_LATEST="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:latest-python${PYTHON_VERSION}-${TAG_PREFIX}-ci"
@@ -253,9 +228,6 @@ if [[ "${AIRFLOW_RELEASE_BUILD}" == "true" ]]; then
 
     export AIRFLOW_CHECKLICENCE_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:checklicence"
 else
-    export AIRFLOW_SLIM_CI_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${TAG_PREFIX}-python${PYTHON_VERSION}-ci-slim"
-    export AIRFLOW_SLIM_CI_IMAGE_DEFAULT="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${TAG_PREFIX}-ci-slim"
-
     export AIRFLOW_CI_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${TAG_PREFIX}-python${PYTHON_VERSION}-ci"
     export AIRFLOW_CI_IMAGE_DEFAULT="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${TAG_PREFIX}-ci"
     export AIRFLOW_CHECKLICENCE_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:checklicence"
@@ -280,7 +252,6 @@ if [[ "${AIRFLOW_CONTAINER_CLEANUP_IMAGES}" == "true" ]]; then
     start_step "Removing images"
     docker rmi "${PYTHON_BASE_IMAGE}" || true
     docker rmi "${CHECKLICENCE_BASE_IMAGE}" || true
-    docker rmi "${AIRFLOW_SLIM_CI_IMAGE}" || true
     docker rmi "${AIRFLOW_CI_IMAGE}" || true
     docker rmi "${AIRFLOW_CHECKLICENCE_IMAGE}" || true
     echo
@@ -297,7 +268,6 @@ fi
 start_step "Populating cache"
 
 DOCKER_CACHE_DIRECTIVE_CI=()
-DOCKER_CACHE_DIRECTIVE_CI_SLIM=()
 DOCKER_CACHE_DIRECTIVE_CHECKLICENCE=()
 
 if [[ "${AIRFLOW_CONTAINER_USE_PULLED_IMAGES_CACHE}" == "true" ]]; then
@@ -328,17 +298,12 @@ if [[ "${AIRFLOW_CONTAINER_USE_PULLED_IMAGES_CACHE}" == "true" ]]; then
         echo "Downloading the CI Airflow image"
         IMAGES_TO_PULL="${IMAGES_TO_PULL} ${AIRFLOW_CI_IMAGE}"
     fi
-    if [[ "${AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE}" != "true" ]]; then
-        echo "Downloading the slim Airflow image"
-        IMAGES_TO_PULL="${IMAGES_TO_PULL} ${AIRFLOW_SLIM_CI_IMAGE}"
-    fi
     if [[ "${AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE}" != "true" ]]; then
         echo "Downloading the CHECKLICENCE Airflow image"
         IMAGES_TO_PULL="${IMAGES_TO_PULL} ${AIRFLOW_CHECKLICENCE_IMAGE}"
     fi
 
     DOCKER_CACHE_DIRECTIVE_CI=()
-    DOCKER_CACHE_DIRECTIVE_CI_SLIM=()
     if [[ ${IMAGES_TO_PULL} == "" ]]; then
         echo
         echo "Skipping building of all images."
@@ -378,8 +343,6 @@ if [[ "${AIRFLOW_CONTAINER_USE_PULLED_IMAGES_CACHE}" == "true" ]]; then
             fi
             if [[ "${IMAGE}" == "${AIRFLOW_CI_IMAGE}" ]]; then
                 DOCKER_CACHE_DIRECTIVE_CI+=("--cache-from" "${IMAGE}")
-            elif [[ "${IMAGE}" == "${AIRFLOW_SLIM_CI_IMAGE}" ]]; then
-                DOCKER_CACHE_DIRECTIVE_CI_SLIM+=("--cache-from" "${IMAGE}")
             elif [[ "${IMAGE}" == "${AIRFLOW_CHECKLICENCE_IMAGE}" ]]; then
                 DOCKER_CACHE_DIRECTIVE_CHECKLICENCE+=("--cache-from" "${IMAGE}")
             else
@@ -396,14 +359,12 @@ start_step "Setting cache options"
 
 if [[ "${AIRFLOW_CONTAINER_USE_NO_CACHE}" == "true" ]]; then
     DOCKER_CACHE_DIRECTIVE_CI+=("--no-cache")
-    DOCKER_CACHE_DIRECTIVE_CI_SLIM+=("--no-cache")
     DOCKER_CACHE_DIRECTIVE_CHECKLICENCE+=("--no-cache")
     echo
     echo "Skip cache for builds. Everything will be rebuilt from scratch."
     echo
     echo "Cache directives used: "
     echo "CI build: ${DOCKER_CACHE_DIRECTIVE_CI[*]}"
-    echo "CI slim build: ${DOCKER_CACHE_DIRECTIVE_CI_SLIM[*]}"
     echo "CI checklicence build: ${DOCKER_CACHE_DIRECTIVE_CHECKLICENCE[*]}"
     echo
 elif [[ "${AIRFLOW_CONTAINER_USE_PULLED_IMAGES_CACHE}" == "true" ]]; then
@@ -412,13 +373,11 @@ elif [[ "${AIRFLOW_CONTAINER_USE_PULLED_IMAGES_CACHE}" == "true" ]]; then
     echo "Cache directives used: "
     set +u
     echo "CI build: ${DOCKER_CACHE_DIRECTIVE_CI[*]}"
-    echo "CI slim build: ${DOCKER_CACHE_DIRECTIVE_CI_SLIM[*]}"
     echo "CI checklicence build: ${DOCKER_CACHE_DIRECTIVE_CHECKLICENCE[*]}"
     set -u
     echo
 else
     DOCKER_CACHE_DIRECTIVE_CI=()
-    DOCKER_CACHE_DIRECTIVE_CI_SLIM=()
     DOCKER_CACHE_DIRECTIVE_CHECKLICENCE=()
     echo
     echo "Use default cache from locally built images."
@@ -426,7 +385,6 @@ else
     echo "Cache directives used: "
     set +u
     echo "CI build: ${DOCKER_CACHE_DIRECTIVE_CI[*]}"
-    echo "CI slim build: ${DOCKER_CACHE_DIRECTIVE_CI_SLIM[*]}"
     echo "CI checklicence build: ${DOCKER_CACHE_DIRECTIVE_CHECKLICENCE[*]}"
     set -u
     echo
@@ -443,7 +401,7 @@ BUILD_ID=${BUILD_ID:="local"}
 
 
 # directory where "deployment" artifacts should be placed
-DEPLOY_DIR=${AIRFLOW_SOURCES}/dist/${AIRFLOW_CONTAINER_BRANCH_NAME}/$(date +%Y-%m-%d)/${BUILD_ID}/${PYTHON_VERSION}
+DEPLOY_DIR="${AIRFLOW_SOURCES}/dist/${AIRFLOW_CONTAINER_BRANCH_NAME}/$(date "+%Y-%m-%d")/${BUILD_ID}/${PYTHON_VERSION}"
 
 mkdir -pv "${DEPLOY_DIR}"
 
@@ -483,29 +441,6 @@ echo "Group/other write access removed for ${FILES_FOR_REBUILD_CHECK[*]}"
 echo
 echo
 
-start_step "Build Airflow CI slim image"
-
-if [[ "${AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE}" == "true" ]]; then
-    echo "Skip building the Airflow CI slim image"
-else
-    build_python_image "Airflow" \
-                "${AIRFLOW_SLIM_CI_IMAGE}" \
-                "main" \
-                "airflow-apt-deps-ci-slim"
-    if [[ "${PYTHON_VERSION_FOR_DEFAULT_IMAGE}" == "${PYTHON_VERSION}" ]]; then
-        docker tag "${AIRFLOW_SLIM_CI_IMAGE}" "${AIRFLOW_SLIM_CI_IMAGE_DEFAULT}"
-        add_image_to_push "${AIRFLOW_SLIM_CI_IMAGE_DEFAULT}"
-    fi
-    if [[ "${AIRFLOW_RELEASE_BUILD}" == "true" ]]; then
-        docker tag "${AIRFLOW_SLIM_CI_IMAGE}" "${AIRFLOW_SLIM_CI_IMAGE_LATEST}"
-        add_image_to_push "${AIRFLOW_SLIM_CI_IMAGE_LATEST}"
-        if [[ "${PYTHON_VERSION_FOR_DEFAULT_IMAGE}" == "${PYTHON_VERSION}" ]]; then
-            docker tag "${AIRFLOW_SLIM_CI_IMAGE}" "${AIRFLOW_SLIM_CI_IMAGE_LATEST_DEFAULT}"
-            add_image_to_push "${AIRFLOW_SLIM_CI_IMAGE_LATEST_DEFAULT}"
-        fi
-    fi
-fi
-
 if [[ "${AIRFLOW_CONTAINER_SKIP_CI_IMAGE}" == "true" ]]; then
     echo "Skip building the CI full Airflow image"
 else
@@ -513,7 +448,6 @@ else
     build_python_image "Airflow CI" \
                 "${AIRFLOW_CI_IMAGE}" \
                 "main" \
-                "airflow-apt-deps-ci" \
                 "devel_ci" \
                 "root" \
                 "/root"
@@ -536,8 +470,10 @@ if [[ "${AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE}" == "true" ]]; then
     echo "Skip building the CHECKLICENCE image"
 else
     start_step "Build Airflow CHECKLICENCE image"
+    set +u
     docker build . -f Dockerfile-checklicence \
         "${DOCKER_CACHE_DIRECTIVE_CHECKLICENCE[@]}" -t "${AIRFLOW_CHECKLICENCE_IMAGE}"
+    set -u
     add_image_to_push "${AIRFLOW_CHECKLICENCE_IMAGE}"
 fi
 
diff --git a/scripts/ci/_utils.sh b/scripts/ci/_utils.sh
index 3a12c0c3b4cd7..0daa85027654c 100644
--- a/scripts/ci/_utils.sh
+++ b/scripts/ci/_utils.sh
@@ -33,7 +33,7 @@ export BUILD_CACHE_DIR
 
 LAST_FORCE_ANSWER_FILE="${BUILD_CACHE_DIR}/last_force_answer.sh"
 
-IMAGES_TO_CHECK=("SLIM_CI" "CI" "CHECKLICENCE")
+IMAGES_TO_CHECK=("CI" "CHECKLICENCE")
 export IMAGES_TO_CHECK
 
 mkdir -p "${AIRFLOW_SOURCES}/.mypy_cache"
@@ -236,11 +236,8 @@ function update_all_md5_files() {
 # or the Dockerfile itself changes.
 #
 # Another reason to skip rebuilding Docker is thar currently it takes a bit longer time than simple Docker
-# files. There are the following, problems with the current Dockerfiles that need longer build times:
-# 1) We need to fix group permissions of files in Docker because different linux build services have
-#    different default umask and Docker uses group permissions in checking for cache invalidation.
-# 2) we use multi-stage build and in case of slim image we needlessly build a full CI image because
-#    support for this only comes with the upcoming buildkit: https://github.com/docker/cli/issues/1134
+# We need to fix group permissions of files in Docker because different linux build services have
+# different default umask and Docker uses group permissions in checking for cache invalidation.
 #
 # As result of this check - most of the static checks will start pretty much immediately.
 #
@@ -355,29 +352,29 @@ function assert_not_in_container() {
     fi
 }
 
-function cleanup_last_force_answer() {
-    # Removes the "Force answer" (yes/no/quit) given previously, unles you specifically want to use it.
+function forget_last_answer() {
+    # Removes the "Forced answer" (yes/no/quit) given previously, unles you specifically want to remember it.
     #
     # This is the default behaviour of all rebuild scripts to ask independently whether you want to
-    # rebuild the image or not. Sometimes however we want to reuse answer previously given. For
+    # rebuild the image or not. Sometimes however we want to remember answer previously given. For
     # example if you answered "no" to rebuild the image, the assumption is that you do not
-    # want to rebuild image for other rebuilds in the same pre-commit execution.
+    # want to rebuild image also for other rebuilds in the same pre-commit execution.
     #
-    # All the pre-commit checks therefore have `export SKIP_CLEANUP_OF_LAST_ANSWER="true"` set
+    # All the pre-commit checks therefore have `export REMEMBER_LAST_ANSWER="true"` set
     # So that in case they are run in a sequence of commits they will not rebuild. Similarly if your most
     # recent answer was "no" and you run `pre-commit run mypy` (for example) it will also reuse the
     # "no" answer given previously. This happens until you run any of the breeze commands or run all
     # precommits `pre-commit run` - then the "LAST_FORCE_ANSWER_FILE" will be removed and you will
     # be asked again.
-    if [[ ${SKIP_CLEANUP_OF_LAST_ANSWER:=""} != "true" ]]; then
+    if [[ ${REMEMBER_LAST_ANSWER:="false"} != "true" ]]; then
         print_info
-        print_info "Removing last answer from ${LAST_FORCE_ANSWER_FILE}"
+        print_info "Forgetting last answer from ${LAST_FORCE_ANSWER_FILE}:"
         print_info
         rm -f "${LAST_FORCE_ANSWER_FILE}"
     else
         if [[ -f "${LAST_FORCE_ANSWER_FILE}" ]]; then
             print_info
-            print_info "Retaining last answer from ${LAST_FORCE_ANSWER_FILE}"
+            print_info "Still remember last answer from ${LAST_FORCE_ANSWER_FILE}:"
             print_info "$(cat "${LAST_FORCE_ANSWER_FILE}")"
             print_info
         fi
@@ -493,47 +490,10 @@ EOF
     fi
 }
 
-#
-# Rebuilds the slim image for static checks if needed. In order to speed it up, it's built without NPM
-#
-function rebuild_ci_slim_image_if_needed() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="false"
-    export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="true"
-    export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="true"
-
-    # Temporary force python version 3.5 for static checks
-    export OLD_PYTHON_VERSION=${PYTHON_VERSION=""}
-    export PYTHON_VERSION=3.5
-
-    export THE_IMAGE_TYPE="SLIM_CI"
-
-    rebuild_image_if_needed
-
-    export AIRFLOW_SLIM_CI_IMAGE="${DOCKERHUB_USER}/${DOCKERHUB_REPO}:${DEFAULT_BRANCH}-python${PYTHON_VERSION}-ci-slim"
-    export PYTHON_VERSION=${OLD_PYTHON_VERSION}
-}
-
-#
-# Cleans up the CI slim image
-#
-function cleanup_ci_slim_image() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="false"
-    export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="true"
-    export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="true"
-    export AIRFLOW_CONTAINER_CLEANUP_IMAGES="true"
-
-    export PYTHON_VERSION=3.5  # Always use python version 3.5 for static checks
-
-    export THE_IMAGE_TYPE="SLIM_CI"
-
-    rebuild_image_if_needed
-}
-
 #
 # Rebuilds the image for tests if needed.
 #
 function rebuild_ci_image_if_needed() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="false"
 
@@ -546,10 +506,9 @@ function rebuild_ci_image_if_needed() {
 
 
 #
-# Cleans up the CI slim image
+# Cleans up the CI image
 #
 function cleanup_ci_image() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="false"
     export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="true"
     export AIRFLOW_CONTAINER_CLEANUP_IMAGES="true"
@@ -563,7 +522,6 @@ function cleanup_ci_image() {
 # Rebuilds the image for licence checks if needed.
 #
 function rebuild_checklicence_image_if_needed() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="false"
     export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="true"
 
@@ -575,10 +533,9 @@ function rebuild_checklicence_image_if_needed() {
 }
 
 #
-# Cleans up the CI slim image
+# Cleans up the checklicence image
 #
 function cleanup_checklicence_image() {
-    export AIRFLOW_CONTAINER_SKIP_SLIM_CI_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CI_IMAGE="true"
     export AIRFLOW_CONTAINER_SKIP_CHECKLICENCE_IMAGE="false"
     export AIRFLOW_CONTAINER_CLEANUP_IMAGES="true"
@@ -648,7 +605,7 @@ function basic_sanity_checks() {
     go_to_airflow_sources
     check_if_coreutils_installed
     create_cache_directory
-    cleanup_last_force_answer
+    forget_last_answer
 }
 
 
@@ -664,7 +621,7 @@ function run_flake8() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_flake8.sh" \
             | tee -a "${OUTPUT_LOG}"
     else
@@ -676,7 +633,7 @@ function run_flake8() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_flake8.sh" "${FILES[@]}" \
             | tee -a "${OUTPUT_LOG}"
     fi
@@ -691,7 +648,7 @@ function run_docs() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/docs/build.sh" \
             | tee -a "${OUTPUT_LOG}"
 }
@@ -721,7 +678,7 @@ function run_mypy() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_mypy.sh" "airflow" "tests" "docs" \
             | tee -a "${OUTPUT_LOG}"
     else
@@ -733,7 +690,7 @@ function run_mypy() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_mypy.sh" "${FILES[@]}" \
             | tee -a "${OUTPUT_LOG}"
     fi
@@ -750,7 +707,7 @@ function run_pylint_main() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_pylint_main.sh" \
             | tee -a "${OUTPUT_LOG}"
     else
@@ -762,7 +719,7 @@ function run_pylint_main() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_pylint_main.sh" "${FILES[@]}" \
             | tee -a "${OUTPUT_LOG}"
     fi
@@ -780,7 +737,7 @@ function run_pylint_tests() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_pylint_tests.sh" \
             | tee -a "${OUTPUT_LOG}"
     else
@@ -792,7 +749,7 @@ function run_pylint_tests() {
             --env HOST_USER_ID="$(id -ur)" \
             --env HOST_GROUP_ID="$(id -gr)" \
             --rm \
-            "${AIRFLOW_SLIM_CI_IMAGE}" \
+            "${AIRFLOW_CI_IMAGE}" \
             "--" "/opt/airflow/scripts/ci/in_container/run_pylint_tests.sh" "${FILES[@]}" \
             | tee -a "${OUTPUT_LOG}"
     fi
@@ -852,7 +809,7 @@ function refresh_pylint_todo() {
         --env AIRFLOW_CI_SILENT \
         --env HOST_USER_ID="$(id -ur)" \
         --env HOST_GROUP_ID="$(id -gr)" \
-        "${AIRFLOW_SLIM_CI_IMAGE}" | tee -a "${OUTPUT_LOG}"
+        "${AIRFLOW_CI_IMAGE}" | tee -a "${OUTPUT_LOG}"
 }
 
 function rebuild_all_images_if_needed_and_confirmed() {
@@ -861,15 +818,7 @@ function rebuild_all_images_if_needed_and_confirmed() {
 
     for THE_IMAGE_TYPE in "${IMAGES_TO_CHECK[@]}"
     do
-        if [[ "${THE_IMAGE_TYPE}" == "SLIM_CI" ]]; then
-            # Temporary force python version 3.5 for static checks
-            export OLD_PYTHON_VERSION=${PYTHON_VERSION=""}
-            export PYTHON_VERSION=3.5
-
-            check_if_docker_build_is_needed
-
-            export PYTHON_VERSION=${OLD_PYTHON_VERSION}
-        fi
+        check_if_docker_build_is_needed
     done
 
     if [[ ${AIRFLOW_CONTAINER_DOCKER_BUILD_NEEDED} == "true" ]]; then
@@ -901,7 +850,6 @@ function rebuild_all_images_if_needed_and_confirmed() {
 
         if [[ ${SKIP_REBUILD} != "true" ]]; then
             rebuild_ci_image_if_needed
-            rebuild_ci_slim_image_if_needed
             rebuild_checklicence_image_if_needed
         fi
     fi
@@ -969,16 +917,16 @@ function build_image_on_ci() {
     elif [[ ${TRAVIS_JOB_NAME} == "Check lic"* ]]; then
         rebuild_checklicence_image_if_needed
     elif [[ ${TRAVIS_JOB_NAME} == "Static"* ]]; then
-        rebuild_ci_slim_image_if_needed
+        rebuild_ci_image_if_needed
     elif [[ ${TRAVIS_JOB_NAME} == "Pylint"* ]]; then
         match_files_regexp '.*\.py'
         if [[ ${FILE_MATCHES} == "true" || ${TRAVIS_PULL_REQUEST:=} == "false" ]]; then
-            rebuild_ci_slim_image_if_needed
+            rebuild_ci_image_if_needed
         else
             touch "${BUILD_CACHE_DIR}"/.skip_tests
         fi
     elif [[ ${TRAVIS_JOB_NAME} == "Build documentation"* ]]; then
-        rebuild_ci_slim_image_if_needed
+        rebuild_ci_image_if_needed
     else
         echo
         echo "Error! Unexpected Travis job name: ${TRAVIS_JOB_NAME}"
diff --git a/scripts/ci/ci_docs.sh b/scripts/ci/ci_docs.sh
index 603f19b86811c..bc6c48cffd7cd 100755
--- a/scripts/ci/ci_docs.sh
+++ b/scripts/ci/ci_docs.sh
@@ -31,7 +31,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 run_docs
 
diff --git a/scripts/ci/ci_flake8.sh b/scripts/ci/ci_flake8.sh
index 958305171b9f8..553043090db61 100755
--- a/scripts/ci/ci_flake8.sh
+++ b/scripts/ci/ci_flake8.sh
@@ -31,7 +31,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 run_flake8 "$@"
 
diff --git a/scripts/ci/ci_isort.sh b/scripts/ci/ci_isort.sh
index a8ada59956858..01e7b1163da31 100755
--- a/scripts/ci/ci_isort.sh
+++ b/scripts/ci/ci_isort.sh
@@ -32,7 +32,7 @@ force_python_3_5
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 run_flake8 "$@"
 
diff --git a/scripts/ci/ci_mypy.sh b/scripts/ci/ci_mypy.sh
index 6f0837c83a82b..8d4dd22b4cb17 100755
--- a/scripts/ci/ci_mypy.sh
+++ b/scripts/ci/ci_mypy.sh
@@ -31,7 +31,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 run_mypy "$@"
 
diff --git a/scripts/ci/ci_pylint_main.sh b/scripts/ci/ci_pylint_main.sh
index 8c2d533047801..430effd0d2b83 100755
--- a/scripts/ci/ci_pylint_main.sh
+++ b/scripts/ci/ci_pylint_main.sh
@@ -31,7 +31,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 if [[ "${#@}" != "0" ]]; then
     filter_out_files_from_pylint_todo_list "$@"
diff --git a/scripts/ci/ci_pylint_tests.sh b/scripts/ci/ci_pylint_tests.sh
index 2edc53f5ebd26..df7c189929700 100755
--- a/scripts/ci/ci_pylint_tests.sh
+++ b/scripts/ci/ci_pylint_tests.sh
@@ -31,7 +31,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 if [[ "${#@}" != "0" ]]; then
     filter_out_files_from_pylint_todo_list "$@"
diff --git a/scripts/ci/ci_refresh_pylint_todo.sh b/scripts/ci/ci_refresh_pylint_todo.sh
index bbeed2c843ab6..46716c3150884 100755
--- a/scripts/ci/ci_refresh_pylint_todo.sh
+++ b/scripts/ci/ci_refresh_pylint_todo.sh
@@ -30,7 +30,7 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 refresh_pylint_todo
 
diff --git a/scripts/ci/ci_run_all_static_tests.sh b/scripts/ci/ci_run_all_static_tests.sh
index 6e80267556d34..03ae9aca5057c 100755
--- a/scripts/ci/ci_run_all_static_tests.sh
+++ b/scripts/ci/ci_run_all_static_tests.sh
@@ -39,10 +39,10 @@ if [[ -f ${BUILD_CACHE_DIR}/.skip_tests ]]; then
     exit
 fi
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 rebuild_checklicence_image_if_needed
 
-IMAGES_TO_CHECK=("SLIM_CI" "CHECKLICENCE")
+IMAGES_TO_CHECK=("CI" "CHECKLICENCE")
 export IMAGES_TO_CHECK
 
 pre-commit run --all-files --show-diff-on-failure
diff --git a/scripts/ci/ci_run_all_static_tests_except_pylint.sh b/scripts/ci/ci_run_all_static_tests_except_pylint.sh
index ec26b0679ba4f..e6943b79b2111 100755
--- a/scripts/ci/ci_run_all_static_tests_except_pylint.sh
+++ b/scripts/ci/ci_run_all_static_tests_except_pylint.sh
@@ -39,10 +39,10 @@ if [[ -f ${BUILD_CACHE_DIR}/.skip_tests ]]; then
     exit
 fi
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 rebuild_checklicence_image_if_needed
 
-IMAGES_TO_CHECK=("SLIM_CI" "CHECKLICENCE")
+IMAGES_TO_CHECK=("CI" "CHECKLICENCE")
 export IMAGES_TO_CHECK
 
 SKIP=pylint pre-commit run --all-files --show-diff-on-failure
diff --git a/scripts/ci/ci_run_all_static_tests_except_pylint_licence.sh b/scripts/ci/ci_run_all_static_tests_except_pylint_licence.sh
index 55e71b1ac60aa..0899eb6210222 100755
--- a/scripts/ci/ci_run_all_static_tests_except_pylint_licence.sh
+++ b/scripts/ci/ci_run_all_static_tests_except_pylint_licence.sh
@@ -39,9 +39,9 @@ if [[ -f ${BUILD_CACHE_DIR}/.skip_tests ]]; then
     exit
 fi
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
-IMAGES_TO_CHECK=("SLIM_CI")
+IMAGES_TO_CHECK=("CI")
 export IMAGES_TO_CHECK
 
 SKIP=pylint,check-apache-license pre-commit run --all-files --show-diff-on-failure
diff --git a/scripts/ci/ci_run_all_static_tests_pylint.sh b/scripts/ci/ci_run_all_static_tests_pylint.sh
index 2b9fd03fb6667..5bb8a655e552e 100755
--- a/scripts/ci/ci_run_all_static_tests_pylint.sh
+++ b/scripts/ci/ci_run_all_static_tests_pylint.sh
@@ -39,9 +39,9 @@ if [[ -f ${BUILD_CACHE_DIR}/.skip_tests ]]; then
     exit
 fi
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
-IMAGES_TO_CHECK=("SLIM_CI")
+IMAGES_TO_CHECK=("CI")
 export IMAGES_TO_CHECK
 
 pre-commit run pylint --all-files --show-diff-on-failure
diff --git a/scripts/ci/docker_build/ci_build_install_deps.sh b/scripts/ci/docker_build/ci_build_install_deps.sh
deleted file mode 100755
index eb690822872e3..0000000000000
--- a/scripts/ci/docker_build/ci_build_install_deps.sh
+++ /dev/null
@@ -1,68 +0,0 @@
-#!/usr/bin/env bash
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-
-# Bash sanity settings (error on exit, complain for undefined vars, error when pipe fails)
-set -euxo pipefail
-
-# TODO: We should think about removing those and moving them into docker-compose dependencies.
-# TODO: We might come up with just one airflow CI image not the SLIM/CI versions. That would simplify a lot.
-# TODO: We could likely get rid of the multi-staging approach. It introduces a number of limitations
-# TODO: As long as we decrease the size of the CI image, we should be fine with using single CI image for
-# TODO: everything. Currently the CI image is about 1GB where CI_SLIM is around 0.5 GB.
-
-export HADOOP_DISTRO="${HADOOP_DISTRO:="cdh"}"
-export HADOOP_MAJOR="${HADOOP_MAJOR:="5"}"
-export HADOOP_DISTRO_VERSION="${HADOOP_DISTRO_VERSION:="5.11.0"}"
-export HADOOP_VERSION="${HADOOP_VERSION:="2.6.0"}"
-export HIVE_VERSION="${HIVE_VERSION:="1.1.0"}"
-export HADOOP_URL="${HADOOP_URL:="https://archive.cloudera.com/${HADOOP_DISTRO}${HADOOP_MAJOR}/${HADOOP_DISTRO}/${HADOOP_MAJOR}/"}"
-export HADOOP_HOME="${HADOOP_HOME:="/tmp/hadoop-cdh"}"
-export HIVE_HOME="${HIVE_HOME:="/tmp/hive"}"
-export MINICLUSTER_BASE="${MINICLUSTER_BASE:="https://github.com/bolkedebruin/minicluster/releases/download/"}"
-export MINICLUSTER_HOME="${MINICLUSTER_HOME:="/tmp/minicluster"}"
-export MINICLUSTER_VER="${MINICLUSTER_VER:="1.1"}"
-
-mkdir -pv "${HADOOP_HOME}"
-mkdir -pv "${HIVE_HOME}"
-mkdir -pv "${MINICLUSTER_HOME}"
-mkdir -pv "/user/hive/warehouse"
-chmod -R 777 "${HIVE_HOME}"
-chmod -R 777 "/user/"
-
-export HADOOP_DOWNLOAD_URL="${HADOOP_URL}hadoop-${HADOOP_VERSION}-${HADOOP_DISTRO}${HADOOP_DISTRO_VERSION}.tar.gz"
-export HADOOP_TMP_FILE="/tmp/hadoop.tar.gz"
-
-curl -sL "${HADOOP_DOWNLOAD_URL}" >"${HADOOP_TMP_FILE}"
-
-tar xzf "${HADOOP_TMP_FILE}" --absolute-names --strip-components 1 -C "${HADOOP_HOME}"
-
-rm "${HADOOP_TMP_FILE}"
-
-export HIVE_URL="${HADOOP_URL}hive-${HIVE_VERSION}-${HADOOP_DISTRO}${HADOOP_DISTRO_VERSION}.tar.gz"
-export HIVE_TMP_FILE="/tmp/hive.tar.gz"
-
-curl -sL "${HIVE_URL}" >"${HIVE_TMP_FILE}"
-tar xzf "${HIVE_TMP_FILE}" --strip-components 1 -C "${HIVE_HOME}"
-rm "${HIVE_TMP_FILE}"
-
-MINICLUSTER_URL="${MINICLUSTER_BASE}${MINICLUSTER_VER}/minicluster-${MINICLUSTER_VER}-SNAPSHOT-bin.zip"
-MINICLUSTER_TMP_FILE="/tmp/minicluster.zip"
-
-curl -sL "${MINICLUSTER_URL}" > "${MINICLUSTER_TMP_FILE}"
-unzip "${MINICLUSTER_TMP_FILE}" -d "/tmp"
-rm "${MINICLUSTER_TMP_FILE}"
diff --git a/scripts/ci/in_container/run_pylint_main.sh b/scripts/ci/in_container/run_pylint_main.sh
index f8935c973e704..198636ca8d1f1 100755
--- a/scripts/ci/in_container/run_pylint_main.sh
+++ b/scripts/ci/in_container/run_pylint_main.sh
@@ -41,6 +41,7 @@ if [[ ${#@} == "0" ]]; then
     -path "./airflow/www/node_modules" -prune -o \
     -path "./airflow/www_rbac/node_modules" -prune -o \
     -path "./airflow/_vendor" -prune -o \
+    -path "./airflow/migrations/versions" -prune -o \
     -path "./.eggs" -prune -o \
     -path "./docs/_build" -prune -o \
     -path "./build" -prune -o \
diff --git a/scripts/ci/local_ci_build_ci_slim_image.sh b/scripts/ci/local_ci_build_ci_slim_image.sh
index 6c0635551b42a..b632f0009e2cf 100755
--- a/scripts/ci/local_ci_build_ci_slim_image.sh
+++ b/scripts/ci/local_ci_build_ci_slim_image.sh
@@ -30,6 +30,6 @@ basic_sanity_checks
 
 script_start
 
-rebuild_ci_slim_image_if_needed
+rebuild_ci_image_if_needed
 
 script_end
diff --git a/scripts/ci/local_ci_cleanup.sh b/scripts/ci/local_ci_cleanup.sh
index 388731b9619bd..9600c5d3b5609 100755
--- a/scripts/ci/local_ci_cleanup.sh
+++ b/scripts/ci/local_ci_cleanup.sh
@@ -32,8 +32,6 @@ script_start
 
 cleanup_ci_image
 
-cleanup_ci_slim_image
-
 cleanup_checklicence_image
 
 script_end
diff --git a/scripts/ci/pre_commit_check_license.sh b/scripts/ci/pre_commit_check_license.sh
index da38ea7fb50bd..fbcff1497cb7e 100755
--- a/scripts/ci/pre_commit_check_license.sh
+++ b/scripts/ci/pre_commit_check_license.sh
@@ -20,6 +20,6 @@ set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export FORCE_ANSWER_TO_QUESTIONS=${FORCE_ANSWER_TO_QUESTIONS:="quit"}
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_check_license.sh" "${@}"
diff --git a/scripts/ci/pre_commit_ci_build.sh b/scripts/ci/pre_commit_ci_build.sh
new file mode 100755
index 0000000000000..217434ba77240
--- /dev/null
+++ b/scripts/ci/pre_commit_ci_build.sh
@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+set -uo pipefail
+
+MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+export REMEMBER_LAST_ANSWER="false"
+export PYTHON_VERSION=3.5
+
+"${MY_DIR}/local_ci_build.sh"
diff --git a/scripts/ci/pre_commit_flake8.sh b/scripts/ci/pre_commit_flake8.sh
index c8fc2f6c6d1af..5108751d5d39e 100755
--- a/scripts/ci/pre_commit_flake8.sh
+++ b/scripts/ci/pre_commit_flake8.sh
@@ -20,6 +20,6 @@ set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export FORCE_ANSWER_TO_QUESTIONS=${FORCE_ANSWER_TO_QUESTIONS:="quit"}
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_flake8.sh" "${@}"
diff --git a/scripts/ci/pre_commit_lint_dockerfile.sh b/scripts/ci/pre_commit_lint_dockerfile.sh
index e742a6d672471..bb729c114f6f6 100755
--- a/scripts/ci/pre_commit_lint_dockerfile.sh
+++ b/scripts/ci/pre_commit_lint_dockerfile.sh
@@ -19,6 +19,6 @@
 set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_lint_dockerfile.sh" "${@}"
diff --git a/scripts/ci/pre_commit_mypy.sh b/scripts/ci/pre_commit_mypy.sh
index 116a410ebec2f..d137d20fce9c0 100755
--- a/scripts/ci/pre_commit_mypy.sh
+++ b/scripts/ci/pre_commit_mypy.sh
@@ -20,6 +20,6 @@ set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export FORCE_ANSWER_TO_QUESTIONS=${FORCE_ANSWER_TO_QUESTIONS:="quit"}
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_mypy.sh" "${@}"
diff --git a/scripts/ci/pre_commit_pylint_main.sh b/scripts/ci/pre_commit_pylint_main.sh
index 58b48e1c7af27..70f496fe91fbc 100755
--- a/scripts/ci/pre_commit_pylint_main.sh
+++ b/scripts/ci/pre_commit_pylint_main.sh
@@ -20,6 +20,6 @@ set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export FORCE_ANSWER_TO_QUESTIONS=${FORCE_ANSWER_TO_QUESTIONS:="quit"}
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_pylint_main.sh" "${@}"
diff --git a/scripts/ci/pre_commit_pylint_tests.sh b/scripts/ci/pre_commit_pylint_tests.sh
index 7ff27ac65bd1d..dcb7386118e60 100755
--- a/scripts/ci/pre_commit_pylint_tests.sh
+++ b/scripts/ci/pre_commit_pylint_tests.sh
@@ -20,6 +20,6 @@ set -uo pipefail
 
 MY_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 export FORCE_ANSWER_TO_QUESTIONS=${FORCE_ANSWER_TO_QUESTIONS:="quit"}
-export SKIP_CLEANUP_OF_LAST_ANSWER="true"
+export REMEMBER_LAST_ANSWER="true"
 
 "${MY_DIR}/ci_pylint_tests.sh" "${@}"
diff --git a/tests/test_impersonation.py b/tests/test_impersonation.py
index cc723d9bd480d..c3013e9436ed9 100644
--- a/tests/test_impersonation.py
+++ b/tests/test_impersonation.py
@@ -80,11 +80,11 @@ def revoke_permissions():
 
 
 def check_original_docker_image():
-    if not os.path.isfile('/.dockerenv') or os.environ.get('APT_DEPS_IMAGE') is None:
+    if not os.path.isfile('/.dockerenv') or os.environ.get('PYTHON_BASE_IMAGE') is None:
         raise unittest.SkipTest("""Adding/removing a user as part of a test is very bad for host os
 (especially if the user already existed to begin with on the OS), therefore we check if we run inside a
 the official docker container and only allow to run the test there. This is done by checking /.dockerenv
-file (always present inside container) and checking for APT_DEPS_IMAGE variable.
+file (always present inside container) and checking for PYTHON_BASE_IMAGE variable.
 """)