patch-notes.txt

Change netifaces dependency to 0.10.4

Currently versions Ubuntu <=20.10 use netifaces 0.10.4 By requiring
netifaces 0.10.9, the VMware datasource omitted itself from cloud-init
on Ubuntu <=20.10.

This patch changes the netifaces dependency to 0.10.4. While it is true
there are patches to netifaces post 0.10.4 that are desirable, testing
against the most common network configuration was performed to verify
the VMware datasource will still function with netifaces 0.10.4.

To verify this patch, two Dockerfiles were created based on Ubuntu
20.04:

    netifaces 0.10.4

        FROM ubuntu:20.04
        
        RUN apt-get -y update && \
            apt-get -y --no-install-recommends install \
              ca-certificates \
              curl \
              git \
              python3 \
              python3-configobj \
              python3-distutils \
              python3-requests \
              python3-yaml
        
        RUN mkdir -p /usr/local/src && \
            git clone https://github.com/canonical/cloud-init.git /usr/local/src/cloud-init
        
        RUN apt-get -y --no-install-recommends install python3-netifaces
        
        WORKDIR /usr/local/src/cloud-init
        
        ENV PYTHONPATH=/usr/local/src/cloud-init
        
        CMD [ "/usr/local/src/cloud-init/cloudinit/sources/DataSourceVMware.py" ]
        ENTRYPOINT [ "/usr/bin/python3" ]


   netifaces 0.10.9

        FROM ubuntu:20.04
        
        RUN apt-get -y update && \
            apt-get -y --no-install-recommends install \
              ca-certificates \
              curl \
              git \
              python3 \
              python3-configobj \
              python3-distutils \
              python3-requests \
              python3-yaml
        
        RUN mkdir -p /usr/local/src && \
            git clone https://github.com/canonical/cloud-init.git /usr/local/src/cloud-init
        
        RUN apt-get -y install python3-pip && pip3 install 'netifaces == 0.10.9'
        
        WORKDIR /usr/local/src/cloud-init
        
        ENV PYTHONPATH=/usr/local/src/cloud-init
        
        CMD [ "/usr/local/src/cloud-init/cloudinit/sources/DataSourceVMware.py" ]
        ENTRYPOINT [ "/usr/bin/python3" ]

The two Dockerfiles were built with the following commands:

    docker build -t cloud-init-netifaces-0.10.4 \
                 -f Dockerfile.Ubuntu-20.04-Netifaces-0.10.4 . && \
    docker build -t cloud-init-netifaces-0.10.9 \
                 -f Dockerfile.Ubuntu-20.04-Netifaces-0.10.9 .

The following command was used to prove there is no distinguishable
difference in the output for the datasource using the different versions of
netifaces against a single IPv4 address on a single device:

    diff -I '"local-ipv4":' \
         -I '"addr":' \
         -I '"[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}":' \
      <(docker run --rm \
                   --hostname netifaces \
                   --mac-address 12:34:56:78:9a:bc \
                   docker.io/library/cloud-init-netifaces-0.10.4 2>/dev/null) \
      <(docker run --rm \
                   --hostname netifaces \
                   --mac-address 12:34:56:78:9a:bc \
                   docker.io/library/cloud-init-netifaces-0.10.9 2>/dev/null)

Finally, the following series of commands validates netifaces 0.10.4 against
a container with multiple network interfaces:

    docker network create --subnet=172.19.0.0/16 netifaces

    docker create \
      --hostname netifaces \
      --network bridge \
      --name netifaces-0.10.4 \
      docker.io/library/cloud-init-netifaces-0.10.4 && \
    docker network connect netifaces netifaces-0.10.4

    docker create \
      --hostname netifaces \
      --network bridge \
      --name netifaces-0.10.9 \
      docker.io/library/cloud-init-netifaces-0.10.9 && \
    docker network connect netifaces netifaces-0.10.9

    diff -I '"local-ipv4":' \
         -I '"addr":' \
         -I '"mac":' \
         -I '"[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}.[[:digit:]]\{1,3\}":' \
         -I '"[[:alnum:]]\{2\}:[[:alnum:]]\{2\}:[[:alnum:]]\{2\}:[[:alnum:]]\{2\}:[[:alnum:]]\{2\}:[[:alnum:]]\{2\}":' \
      <(docker start -a netifaces-0.10.4 2>/dev/null) \
      <(docker start -a netifaces-0.10.9 2>/dev/null)

    docker stop netifaces-0.10.4 netifaces-0.10.9 && \
    docker rm netifaces-0.10.4 netifaces-0.10.9

While this is not all of the possible network configurations, they are
the most common, and it is better to have the VMware datasource on
Ubuntu 20.04 with netifaces 0.10.4 than not have the datasource at all.