digraph {
    graph [nojustify=true] [labeljust=l]

    invisiblestart [label = ""] [color=white] [group=lifecycle];
    node [color=black] [fillcolor=white] [style=filled] [shape=box] [nojustify=true];
    uncommitted [label = "container request:\l   state=Uncommitted\l"] [fillcolor=lightgrey] [group=lifecycle];
    {
        rank=same;
        committed [label = "container request:\l   state=Committed\l   priority>0\l"] [group=lifecycle];
        reused [label = "container request:\l   state=Final\lcontainer:\l   state=Complete\l(reused existing container)\l"] [fillcolor=lightblue] [group=endstate];
    }
    invisiblestart -> uncommitted [label = "   user creates container request\l"] [color=navy] [fontcolor=navy];
    uncommitted -> committed [label = "   user updates to\l      state=Committed, priority>0\l"] [color=navy] [fontcolor=navy];
    queued [label = "container request:\l   state=Committed\l   priority>0\lcontainer:\l   state=Queued\l"] [group=lifecycle];
    committed -> queued [label = "   Arvados creates a new container\l"];
    {
        rank=same;
        locked [label = "container request:\l   state=Committed\l   priority>0\lcontainer:\l   state=Locked\l"] [group=lifecycle];
        latecancelled [label = "container request:\l   state=Final\lcontainer:\l   state=Cancelled\l"] [fillcolor=lightblue] [group=endstate];
    }
    queued -> locked [label = "   Arvados is ready to dispatch the container\l"];
    running [label = "container request:\l   state=Committed\l   priority>0\lcontainer:\l   state=Running\l"] [group=lifecycle];
    locked -> running [label = "   Arvados starts the container process\l"];

    node [color=black] [fillcolor=lightblue] [style=filled] [shape=box];
    {
        rank=same;
        containerfinished [label = "container request:\l   state=Final\lcontainer:\l   state=Complete\l   exit_code=0\l"] [group=lifecycle];
        containerfailed [label = "container request:\l   state=Final\lcontainer:\l   state=Complete\l   exit_code≠0\l"] [group=endstate];
    }

    committed -> reused [label = "Arvados selects an existing container"] [constraint=false];
    queued -> latecancelled [label = "user updates to priority=0"] [color=navy] [fontcolor=navy];
    locked -> latecancelled [label = "user updates to priority=0"] [color=navy] [fontcolor=navy] [constraint=false];
    running -> latecancelled [label = "user updates to priority=0"] [color=navy] [fontcolor=navy] [constraint=false];
    running -> containerfailed [label = "container process fails"];
    running -> containerfinished [label = "   container process succeeds\l"];

    # layout hacks
    // committed -> containerfinished [style=invis];
    // uncommitted -> latecancelled [style=invis];
    reused -> latecancelled [style=invis];
    latecancelled -> containerfailed [style=invis];
}