Avoid creation of multiple layers during build

Containerfile

@@ -2,54 +2,17 @@ FROM quay.io/devfile/universal-developer-image:ubi8-latest
 
 ARG PYV=3.11
 
-LABEL org.opencontainers.image.source https://github.com/ansible/ansible-workspace-env-reference-image
-LABEL org.opencontainers.image.authors "Ansible DevTools"
-LABEL org.opencontainers.image.vendor "Red Hat"
-LABEL org.opencontainers.image.licenses "GPL-3.0"
-LABEL org.opencontainers.image.description "An OpenShift Dev Spaces container image for Ansible."
+LABEL org.opencontainers.image.source=https://github.com/ansible/ansible-workspace-env-reference-image
+LABEL org.opencontainers.image.authors="Ansible DevTools"
+LABEL org.opencontainers.image.vendor="Red Hat"
+LABEL org.opencontainers.image.licenses="GPL-3.0"
+LABEL org.opencontainers.image.description="An OpenShift Dev Spaces container image for Ansible."
 
 USER 0
 
-# install ansible-dev-tools specific packages
-RUN <<EOF
-    set -e
-    dnf -y makecache
-    dnf -y update
-    dnf install -y \
-        tar \
-        podman \
-        fuse-overlayfs \
-        openssh-clients \
-        zsh \
-        util-linux-user \
-        which \
-        git \
-        dumb-init \
-        gcc \
-        git-core \
-        libssh-devel \
-        python3-markupsafe \
-        ncurses \
-        python3-bcrypt \
-        python3-cffi \
-        python3-pip \
-        python3-pyyaml \
-        python3-ruamel-yaml \
-        python3-wheel \
-        --exclude container-selinux
-    dnf clean all
-EOF
-
-COPY ./requirements.txt requirements.txt
-COPY ./requirements.yml requirements.yml
-RUN \
-/usr/bin/python${PYV} -m pip install --no-cache-dir -r requirements.txt \
-&& ansible-galaxy collection install -r requirements.yml
-
-RUN chgrp -R 0 /home && chmod -R g=u /etc/passwd /etc/group /home
-
-# Configure the podman wrapper
-COPY --chown=0:0 podman.py /usr/bin/podman.wrapper
-RUN chmod +x /usr/bin/podman.wrapper
+WORKDIR /context
+# install ansible-dev-tools specific packages and dependencies while avoiding
+# adding multiple layers to the image.
+RUN --mount=type=bind,target=. --mount=type=cache,dst=/var/cache/dnf --mount=type=cache,dst=/root/.cache/pip ./setup.sh
 
 USER 10001

context/setup.sh

@@ -0,0 +1,40 @@
+#!/bin/bash -e
+set -eux pipefail
+
+set -e
+dnf -y makecache
+dnf -y update
+dnf install -y \
+    tar \
+    podman \
+    fuse-overlayfs \
+    openssh-clients \
+    zsh \
+    util-linux-user \
+    which \
+    git \
+    dumb-init \
+    gcc \
+    git-core \
+    libssh-devel \
+    python3-markupsafe \
+    ncurses \
+    python3-bcrypt \
+    python3-cffi \
+    python3-pip \
+    python3-pyyaml \
+    python3-ruamel-yaml \
+    python3-wheel \
+    --exclude container-selinux
+dnf clean all
+
+/usr/bin/python${PYV} -m pip install --no-cache-dir -r requirements.txt
+
+ansible-galaxy collection install -r requirements.yml
+
+ chgrp -R 0 /home && chmod -R g=u /etc/passwd /etc/group /home
+
+# Configure the podman wrapper
+cp podman.py /usr/bin/podman.wrapper
+chown 0:0 /usr/bin/podman.wrapper
+chmod +x /usr/bin/podman.wrapper