Optimize Dockerfiles

[ruffsl]

I was looking at the source Dockerfile for the ghcr.io/foxglove/rolling-ros2-bridge image, and noticed some optimizations that could be made. See commit history for details.

The only major change is swapping the base image for the ros2 bridge from ros-core over to ros-base:

REPOSITORY                TAG                SIZE
foxglove_bridge_rolling   base (after)       1.03GB
foxglove_bridge_rolling   core (before)      945MB
ros                       rolling-ros-base   752MB
ros                       rolling-ros-core   474MB
ubuntu                    jammy              77.8MB

I did this as most of the large dependencies being manually installed should already be provided by the base tag. While the resulting image is a little larger (1.03GB-945MB)=85MB, the resulting size of the added layers to be regularly pushed over the network and saved to disk with every update to the bridge image is reduced from (945MB-474MB)=471MB to just (1.03GB-752MB)=278MB. Given 1) most robots using docker are more likely to have at least the image layers for the ros-base tag cached locally already for other running ROS containers, 2) the lower cadence of changed layers in the ros-base image, this should help reduce the bandwidth and storage requirements for deploying these bridge images.

[CLAassistant]

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[achim-k]

Looks good, thank you!

[jhurliman]

I don't see where $ROS_DISTRO is being set

EDIT: I'm told $ROS_DISTRO is set in the base image