Dockerfile: Include /sbin dir in PATH

[ricardo-larosa]

When trying to install additional tools in the Dockerfile of a custom image based on the Flux image.
Example:

FROM docker.io/fluxcd/flux:1.20.0
RUN apk add --no-cache jq && apk add --no-cache gettext

You get this:

/bin/sh: apk: not found

A workaround is to set the PATH before like this:

FROM docker.io/fluxcd/flux:1.20.0
ENV PATH=/bin:/sbin:/usr/bin:/usr/local/bin:/usr/lib/kubeyaml
RUN apk add --no-cache jq && apk add --no-cache gettext
RUN wget -q -O /usr/bin/yq $(wget -q -O - https://api.github.com/repos/mikefarah/yq/releases/latest | jq -r '.assets[] | select(.name == "yq_linux_amd64") | .browser_download_url') \
    && chmod +x /usr/bin/yq

With this change, I don't have to set the PATH in the Dockerfile

[stefanprodan]

LGTM

Thanks @ricardo-larosa