SVG node shapes with ports

I'm creating a Graphviz graph using an SVG document as the node shape. I'd like to assign port identifiers to parts of that shape and then define edges that start or end at a port. Is this possible?

So far, I've got this SVG document:

$ cat node.svg
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   width="80.073914mm"
   height="50.37672mm"
   viewBox="0 0 80.073914 50.37672"
   version="1.1"
   id="svg1069"
   inkscape:version="1.0.2 (1.0.2+r75+1)"
   sodipodi:docname="node.svg">
 <g
     inkscape:label="Layer 1"
     inkscape:groupmode="layer"
     id="layer1"
     transform="translate(-44.44631,-39.799372)">
    <rect
       style="fill:#ffffff;stroke:#000000;stroke-width:0.2;stroke-linecap:round;stroke-dasharray:1.2, 0.2"
       id="rect1071"
       width="79.873917"
       height="50.17672"
       x="44.54631"
       y="39.899372" />
    <rect
       style="fill:#ffffff;stroke:#000000;stroke-width:0.2;stroke-linecap:round;stroke-dasharray:1.2, 0.2"
       id="rect1073"
       width="14.489976"
       height="13.654758"
       x="54.928062"
       y="50.225788"
       PORT="port1" />
    <rect
       style="fill:#ffffff;stroke:#000000;stroke-width:0.2;stroke-linecap:round;stroke-dasharray:1.2, 0.2"
       id="rect1075"
       width="17.208607"
       height="13.1411"
       x="98.100449"
       y="68.813545"
       PORT="port2" />
  </g>
</svg>

And this graph:

$ cat test.dot
digraph test {
    node [image="node.svg", shape=none]
    h1
    h2

    h1:port1 -> h2:port1
}

dot produces this output:

$ dot test.dot -Tsvg -o test.svg
Warning: node h1, port port1 unrecognized
Warning: node h2, port port1 unrecognized

The SVG image is correctly used as the node shape, but the edge is just between the outlines of the two nodes, not to a port on the node. I've also tried using port instead of PORT as the attribute name.

Solution

Simple answer: no. Graphviz does not allow custom nodes via SVG (but a nice idea)
Alternatives:

add this function to the codebase (just saying)
use your SVG nodes, but draw custom edges yourself. Straight edges are pretty easy. Maybe this can be automated if you need to repeat.
your node is quite simple. recreate it as two rectangles inside a cluster. define ports and dot will do the rest.
recreate your node as a single HTML-like node. again define your ports and let dot take over.

Here is more on custom node shapes: https://www.graphviz.org/faq/#FaqCustShape