rosmsg not working with Github Action

edit

I have a (private) repo where I am now just trying to save the list of ros msgs on a file. I have the following main.yml file in .github/workflows/:

name: ROS kinetic CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-16.04
    container: ros:kinetic
    services: 
      ros: 
        image: ros
    steps:
      - name: Check out repository code
        uses: actions/checkout@v2
      - name: Save all ros msgs into a file
        run: rosmsg list > ros_msg_list.txt

When the job runs, it fails on that job that calls rosmsg with the error:

Run rosmsg list > ros_msg_list.txt
  rosmsg list > ros_msg_list.txt
  shell: sh -e {0}
/__w/_temp/a3af4a58-e885-4af2-ab31-016bd46cd1d5.sh: 1: /__w/_temp/a3af4a58-e885-4af2-ab31-016bd46cd1d5.sh: rosmsg: not found
Error: Process completed with exit code 127.

What am I missing here? I run locally docker run -it ros:kinetic bash and inside the container I can directly run rosmsg show without any issues. Thanks for the help.