Tikz Edge: Distance from other nodes?

There are probably various approaches to this. This example shows one that I frequently use.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}
\begin{document}

\begin{tikzpicture}
    \tikzstyle{bordered} = [draw,thick,inner sep=5,minimum size=10,minimum width=100,font=\sffamily]
    \tikzstyle{arrow} = [thick,-latex,font=\sffamily]

    \node [] (init) {};
    \node [bordered,below=of init] (image) {App Image};
    \node [bordered,below=of image] (running) {Running Container};
    \node [bordered,below=of running] (stopped) {Persisted Container};

    \draw [arrow] (init) -- (image) node [midway,right] {Install};
    \draw [arrow] (image) -- (running) node [midway,right] {Start};
    \draw [arrow] (running) -- (stopped) node [midway,right] {Terminate or Kill};


    \draw [arrow] ($(stopped.west)+(0,2pt)$)  -- 
                  ++(-1em,0)                  -- 
                  ($(running.west)+(-1em,0)$) 
                  node [midway,right] {Start} -- 
                  (running.west);

    \draw [arrow] ($(stopped.west)+(0,-2pt)$) -- 
                  ++(-2em,0)                  -- 
                  ($(image.west)+(-2em,0)$) 
                  node [midway,left] {Reset}  -- 
                  (image.west) ;
\end{tikzpicture}

\end{document}

Somewhat simpler variant using the perpendicular syntax (|- or -|):

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}
\begin{document}

\begin{tikzpicture}
    \tikzstyle{bordered} = [draw,thick,inner sep=5,minimum size=10,minimum width=100,font=\sffamily]
    \tikzstyle{arrow} = [thick,-latex,font=\sffamily]

    \node [] (init) {};
    \node [bordered,below=of init] (image) {App Image};
    \node [bordered,below=of image] (running) {Running Container};
    \node [bordered,below=of running] (stopped) {Persisted Container};

    \draw [arrow] (init) -- (image) node [midway,right] {Install};
    \draw [arrow] (image) -- (running) node [midway,right] {Start};
    \draw [arrow] (running) -- (stopped) node [midway,right] {Terminate or Kill};


    \draw [arrow] 
          (stopped.west) ++ (up:2pt) 
          -- ++(left:1em) 
          |- (running.west)
          node[pos=0.25,right]{Start} ;

    \draw [arrow] 
    (stopped.west) ++ (down:2pt)
          -- ++(left:2em) 
          |- (image.west)
          node[pos=0.25,left]{Reset};
\end{tikzpicture}

\end{document}

A PSTricks solution:

\documentclass{article}

\usepackage{pstricks}
\usepackage{xfp}

% parameters
\def\boxWidth{3.4}
\def\boxHeight{0.7}
\def\separation{1}
\def\arrow{0.4}

% simplifies notation
\def\constA#1#2{\fpeval{#1*\boxHeight+#2*\separation}}
\def\constB#1{\fpeval{1+#1*\arrow}}
\def\constC#1{\fpeval{\constB{2}+#1*\boxWidth}}


\begin{document}

\psset{arrows = ->}
\begin{pspicture}(\fpeval{1+2*\arrow+max(\boxWidth,\boxWidth/2+2.85)},
                  \fpeval{3*(\boxHeight+\separation)})
  \psline(\constC{0.5},\constA{3}{3})(\constC{0.5},\constA{3}{2})
  \uput[r](\constC{0.5},\constA{2.5}{3}){Install}
  \psframe(\constB{2},\constA{2}{2})(\constC{1},\constA{3}{2})
  \rput(\constC{0.5},\constA{2.5}{2}){App Image}
  \psline(\constC{0.5},\constA{2}{2})(\constC{0.5},\constA{2}{1})
  \uput[r](\constC{0.5},\constA{2}{1.5}){Start}
  \psframe(\constB{2},\constA{1}{1})(\constC{1},\constA{2}{1})
  \rput(\constC{0.5},\constA{1.5}{1}){Running Container}
  \uput[r](\constC{0.5},\constA{1}{0.5}){Terminate or Kill}
  \psline(\constC{0.5},\constA{1}{1})(\constC{0.5},\constA{1}{0})
  \psframe(\constB{2},0)(\constC{1},\constA{1}{0})
  \rput(\constC{0.5},\constA{0.5}{0}){Persisted Container}
  \psline(\constB{2},\fpeval{1/3*\boxHeight})%
         (1,\fpeval{1/3*\boxHeight})%
         (1,\constA{2.5}{2})%
         (\constB{2},\constA{2.5}{2})
  \uput[l](1,\constA{1.5}{1}){Reset}
  \psline(\constB{2},\fpeval{2/3*\boxHeight})%
         (\constB{1},\fpeval{2/3*\boxHeight})%
         (\constB{1},\constA{1.5}{1})%
         (\constB{2},\constA{1.5}{1})
  \uput[r](\constB{1},\constA{1}{0.5}){Start}
\end{pspicture}

\end{document}

All you have to do is change the values of the parameters and the drawing will be adjusted accordingly.