title: OCI runtime exec failed: exec failed: (...) executable file not found in $PATH": unknown
body: <p>I have dockerized an app which has ffmpeg installed in it via libav-tools. The app launches without problem, yet the problem occured when fluent-ffmpeg npm module tried to execute ffmpeg command, which was not found. When I wanted to check the version of the ffmpeg and the linux distro set up in the image, I used <code>sudo docker exec -it c44f29d30753 "lsb_release -a"</code> command, but it gave the following error: <code>OCI runtime exec failed: exec failed: container_linux.go:296: starting container process caused "exec: \"lsb_release -a\": executable file not found in $PATH": unknown</code></p>
  
  <p>Then I realized that it gives me the same error with all the commands that I try to run inside the image or the container.</p>
  
  <pre><code>OCI runtime exec failed: exec failed: container_linux.go:296: starting container process caused "exec: \"ffmpeg -a\": executable file not found in $PATH": unknown
  </code></pre>
  
  <p>This is my Dockerfile:</p>
  
  <pre><code>FROM ubuntu:xenial
  FROM node
  RUN apt-get -y update
  RUN apt-get --yes install libav-tools
  RUN mkdir -p /usr/src/app
  WORKDIR /usr/src/app
  COPY package.json /usr/src/app
  RUN npm install
  COPY . /usr/src/app
  RUN npm run build
  ENV NODE_ENV production
  EXPOSE 8000
  CMD ["npm", "run", "start:prod"]
  </code></pre>
  
  <p>I would kindly ask for your help. Thank you very much!</p>