Reduce buildbox image size

[awly]

The current buildbox image is >1GB.
This hits our CI performance and cost.

We should trim the amount of data in the image and/or use multi-stage builds.

[webvictim]

I'm working on #6145 as a quick resolution to Docker-related slowdowns as well.

I've also just realised that Drone's sqlite database is 4GB in size and located on a standard GKE PV which uses spinning disks rather than SSDs.

[gliptak]

are the sources for https://quay.io/repository/gravitational/teleport-buildbox?tag=latest&tab=tags public?

the up-to-date release has a number of vulnerabilities identified https://quay.io/repository/gravitational/teleport-buildbox/manifest/sha256:0a493df70dbdc593b84df9de8eb740e178838afde3123c5c1b01a539186d1825?tab=vulnerabilities

[webvictim]

Yes - https://github.com/gravitational/teleport/blob/master/build.assets/Dockerfile

[tcsc]

Some candidates for easy wins:

• Delete the gcloud backup directory /opt/google-cloud-sdk/.install/.backup after installing gcloud sdk & firestore emulator (this is several hundred MB by itself)
• Make a shallow clone of the protobuf repo, e.g.

RUN (git clone https://github.com/gogo/protobuf.git --branch ${GOGO_PROTO_TAG} --depth 1 ${GOPATH}/src/github.com/gogo/protobuf && \
     cd ${GOPATH}/src/github.com/gogo/protobuf && \
     make install && \
     make clean)

• Delete the etcd tarball after it's unpacked
• Run make clean after make install for protobuf & libbpf

[tcsc]

The current buildbox image is >1GB.

This seems so quaint now, as our buildbox is currently > 6GB

[zmb3]

This seems so quaint now, as our buildbox is currently > 6GB

Hey, we're down to under 4.5GB now :-)