build: Containerfile for the main PCP container using supported builds

[natoscott]

No description provided.

[kurik]

container-entrypoint script is missing in the built container. We need to copy it into the container.

COPY build/containers/pcp/root /

[natoscott]

@kurik I'm not following this - the COPY line is there but later in the file (under comment ## Setup). What was the nature of the failure there?

[kurik]

gettext package, which is used by the container-entrypoint script is missing in the centos:stream10-minimal image. We need to install it:

RUN microdnf install -y --setopt=install_weak_deps=0 --setopt=tsflags=nodocs \                              
    pcp-zeroconf gettext

[natoscott]

Should this be gettext-envsubst?

[kurik]

Yes, gettext-envsubst is sufficient to pull, we do not need the whole gettext.

[kurik]

UID/GID of the pcp user may vary with every build of the container image. This might lead to the situation that archives created by an older container will not be readable/writeable by a newer container build. To avoid this, the solution used in the Dockerfile was to have fixed UID/GID specified directly in the Dockefile/Containerfile. I would recommend to use the same approach here as well:

RUN groupadd -g 1001 -r pcp                                                                                 
RUN useradd  -u 1001 -g pcp -r -d /var/lib/pcp -s /sbin/nologin -c "Performance Co-Pilot" pcp               

This might lead to split of the microdnf install to two parts as we need to have groupadd and useradd installed (package shadow-utils) before these are used in the Dockerfile/Containerfile , while pcp-zeroconf needs to have the UID/GID already created.

The final code might looks like this:

RUN microdnf install -y --setopt=install_weak_deps=0 --setopt=tsflags=nodocs \                              
    shadow-utils                                                                                    
RUN groupadd -g 1001 -r pcp                                                                                 
RUN useradd  -u 1001 -g pcp -r -d /var/lib/pcp -s /sbin/nologin -c "Performance Co-Pilot" pcp               
RUN microdnf install -y --setopt=install_weak_deps=0 --setopt=tsflags=nodocs \                              
    pcp-zeroconf 

[natoscott]

Its a shame this isn't handled by our systemd sysusers.d configuration, and I worry that that newer mechanism conflicts with this use of user/group-add commands (whoever goes first wins?). A potential splitting up of rpm installation makes a bad situation worse IMO. AIUI, in OpenShift and k8s it would seem none of this matters anyway since the base UIDs are assigned dynamically. Ugh, we need more experimentation here I think.

[kurik]

Currently the centos-stream-9 as well as centos-stream-10 contain PCPv6, so I expect this is a preparation for the upcoming PCPv7 release.

[natoscott]

Yep.