Minimal apt dependency (for Docker)

[lkm1321]

Hi there,

I'm trying to run moos inside a docker container derived from Ubuntu 18.04. I want to install only the bare minimum of apt packages to reduce the image size. I'm doing so by passing --no-install-recommends to apt install which prevents installing recommended/suggested packages.

However, I found out that if I pass --no-install-recommends to apt install, then MOOSDB and most other ivp binaries compile but don't run correctly and throw XPCException. This is being thrown somewhere in libMOOS/Comms.

Meanwhile, all is well if I don't pass --no-install-recommends and install all recommended/suggested packages, but obviously this makes the image size pretty big.

This makes me think there's an implicit runtime dependency for XPC communication. I'm trying to figure out what exactly it is, and was wondering if you have a pointer.

For your reference, here's a list of apt packages. The exception happens in both runtime and compile time images.

Runtime image:

• libboost-all-dev
• libfltk1.3
• libjpeg8
• libpcl-dev
• libtiff5
• libtiffxx5
• libvulkan1
• libxft2
• libxi6
• libxinerama1
• python3-empy
• python3-matplotlib
• python3-numpy
• python3-pip
• python3-tk
• python3-toml
• python3-yaml
• python-argparse
• python-empy
• python-future
• python-matplotlib
• python-numpy
• python-pip
• python-tk
• python-toml
• python-yaml
• ros-melodic-ros-base
• xterm
• xxd
• zip
• zlib1g

Compile time image:

• build-essential
• cmake
• curl
• exiftool
• fluid
• freeglut3-dev
• g++
• genromfs
• git
• libboost-all-dev
• libfltk1.3-dev
• libglu1-mesa-dev
• libjpeg-dev
• libopenexr-dev
• libpcl-dev
• libtiff5-dev
• libvulkan-dev
• libxft-dev
• libxi-dev
• libxinerama-dev
• openssh-server
• ninja-build
• nvidia-cg-dev
• python3-dev
• python3-empy
• python3-matplotlib
• python3-numpy
• python3-pip
• python3-tk
• python3-toml
• python3-yaml
• python-argparse
• python-dev
• python-empy
• python-future
• python-matplotlib
• python-numpy
• python-pip
• python-tk
• python-toml
• python-yaml
• subversion
• wget
• xorg-dev
• xterm
• xxd
• zip
• unzip
• zlib1g-dev

[chrissconyers]

Try apt install netbase in the runtime image. This solved the XPCException in my 16.04 container.

I don't remember why this fixed things. I had to do some gymnastics to rethrow the XPCException and see exactly what the original socket error was. But, I just ran across this problem in a new image and it was netbase that fixed it again.

The real issue here is the obfuscation of information by MOOS. This would be easier to diagnose if XPCException handling was more robust.

[lkm1321]

thanks @chrissconyers, that was spot-on! :)

should this be added to README.md as a dependency?