documentclass{article}

usepackage{color}

usepackage{listings}
usepackage[justification=centering]{caption}

lstdefinestyle{SC}{
    language=erlang,
    xleftmargin=.2textwidth,
    xrightmargin=.2textwidth
}

lstset{
    numbers=left,
    numberstyle=tiny,
    basicstyle=scriptsize,
    showstringspaces=false,
    showspaces=false,
    commentstyle=color{blue},
    keywordstyle=bfseriescolor{purple},
    captionpos=t,
    frame=lines
}

begin{document}

begin{lstlisting}[style=SC, caption={test}]
% Stop all containers
docker stop $(docker ps -a -q)
% Delete all containers
docker rm $(docker ps -a -q)
% Delete all images
docker rmi $(docker images -q)
end{lstlisting}

end{document}

documentclass{article}

usepackage{color}

usepackage{listings}


usepackage[justification=centering,singlelinecheck=false]{caption}
makeatletter

 deflst@MakeCaption#1{% #1 is `t' or `b'
    begingroup
      caption@setposition{#1}%
      caption@iftop{%
        ifdimhsize>linewidth
          hsizelinewidth
        fi
        @tempdimabelowcaptionskip
        belowcaptionskipabovecaptionskip
        abovecaptionskip@tempdima}
        {ifdimhsize>dimexpr linewidth + lst@xleftmargin + lst@xrightmarginrelax
          hsizedimexpr linewidth + lst@xleftmargin + lst@xrightmarginrelax
        fi}%
      caption@setup{rule=0}%
      caption@setoptions{lstlisting}%
      caption@setautoposition{#1}%
      caption@begin{lstlisting}%
        caption@ORI@lst@MakeCaption{#1}%
      caption@end
    endgroup}%
makeatother

lstdefinestyle{SC}{
    language=erlang,
    xleftmargin=.2textwidth,
    xrightmargin=.2textwidth
}

lstset{
    numbers=left,
    numberstyle=tiny,
    basicstyle=scriptsize,
    showstringspaces=false,
    showspaces=false,
    commentstyle=color{blue},
    keywordstyle=bfseriescolor{purple},
    captionpos=t,
    frame=lines
}

begin{document}

begin{lstlisting}[style=SC, caption={test},captionpos=t]
xxxxxxxxxxxxxxxxxxxxx\
xxxxxxxxxxxxxxxxxxxxxxxx
end{lstlisting}

begin{lstlisting}[style=SC, caption={test},captionpos=b]
% Stop all containers
docker stop $(docker ps -a -q)
% Delete all containers
docker rm $(docker ps -a -q)
% Delete all images
docker rmi $(docker images -q)
end{lstlisting}

end{document}

listfiles
documentclass{article}

usepackage{color}

usepackage{listings}

lstdefinestyle{SC}{
    language=erlang,
    xleftmargin=.2textwidth,
    xrightmargin=.2textwidth
}

lstset{
    numbers=left,
    numberstyle=tiny,
    basicstyle=scriptsize,
    showstringspaces=false,
    showspaces=false,
    commentstyle=color{blue},
    keywordstyle=bfseriescolor{purple},
    captionpos=b,
    frame=lines
}

begin{document}

begin{lstlisting}[style=SC, caption={test}]
% Stop all containers
docker stop $(docker ps -a -q)
% Delete all containers
docker rm $(docker ps -a -q)
% Delete all images
docker rmi $(docker images -q)
end{lstlisting}

end{document}

*File List*
 article.cls    2014/09/29 v1.4h Standard LaTeX document class
  size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option)
   color.sty    2016/07/10 v1.1e Standard LaTeX Color (DPC)
   color.cfg    2016/01/02 v1.6 sample color configuration
  pdftex.def    2018/01/08 v1.0l Graphics/color driver for pdftex
infwarerr.sty    2016/05/16 v1.4 Providing info/warning/error messages (HO)
 ltxcmds.sty    2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
listings.sty    2015/06/04 1.6 (Carsten Heinz)
  keyval.sty    2014/10/28 v1.15 key=value parser (DPC)
 lstmisc.sty    2015/06/04 1.6 (Carsten Heinz)
listings.cfg    2015/06/04 1.6 listings configuration
supp-pdf.mkii
lstlang1.sty    2015/06/04 1.6 listings language file
lstlang2.sty    2015/06/04 1.6 listings language file
lstlang3.sty    2015/06/04 1.6 listings language file
 ***********