merge apt commands. pin mkdoc version

Signed-off-by: Manabu McCloskey <[email protected]>

Dockerfile

@@ -64,7 +64,8 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     apt-get update && \
     apt-get install -y --no-install-recommends libsqlite3-dev
 
-# Add kubectl.
+# Add kubectl for the kube apply plugin.
+# Add mkdocs for the TechDocs plugin.
 RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
     apt-get update && \
@@ -76,7 +77,13 @@ RUN curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.29/deb/Release.key | gpg --d
 RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
     apt-get update && \
-    apt-get install -y --no-install-recommends kubectl
+    apt-get install -y --no-install-recommends kubectl python3-pip python3-venv
+
+ENV VIRTUAL_ENV=/opt/venv
+RUN python3 -m venv $VIRTUAL_ENV
+ENV PATH="$VIRTUAL_ENV/bin:$PATH"
+
+RUN pip3 install 'mkdocs-techdocs-core==1.6.1'
 
 # Add cnoe cli.
 RUN curl -L -O https://github.com/cnoe-io/cnoe-cli/releases/download/v0.1.0/cnoe_Linux_x86_64.tar.gz && \
@@ -89,14 +96,6 @@ RUN curl -L -O https://github.com/cnoe-io/cnoe-cli/releases/download/v0.1.0/cnoe
 COPY ./cnoe-wrapper.sh /usr/bin/cnoe
 RUN chmod +x /usr/bin/cnoe
 
-RUN apt-get update && apt-get install -y python3 python3-pip python3-venv
-
-ENV VIRTUAL_ENV=/opt/venv
-RUN python3 -m venv $VIRTUAL_ENV
-ENV PATH="$VIRTUAL_ENV/bin:$PATH"
-
-RUN pip3 install mkdocs-techdocs-core
-
 # From here on we use the least-privileged `node` user to run the backend.
 USER node