Switch NoFlo runner to noflo-nodejs

[bergie]

Currently imgflo-server is executing NoFlo graphs via the noflo command, which will be removed in 0.6: noflo/noflo#297

https://github.com/jonnor/imgflo-server/blob/970f519a19c6f5fded08154045a9a0cd4d8c197b/src/noflo.coffee#L39

Should use noflo-nodejs instead. This also has the additional benefit of adding component loader cache support needed for #55

[jonnor]

Branch noflo-cache, should have everything needed on imgflo-server side.
Fixed some things in noflo-nodejs, released as 0.6.1. But it needs some --port=auto feature also for concurrency to work.

But even with a single request, the network never stops. Tested with TESTS=1977 make check.

By my reckoning these component all have broken behavior. But I don't know right fixes, either network ended prematurely or never stopped. CC/ @bergie

• canvas/CreateCanvas and canvas/CreateCanvas-node - missing disconnect() ?
• canvas/Draw- missing connect handling/forwarding?
• noflo-helper-arrayable (basecomponent for bunch of canvas components) - missing disconnect() ?
• * image/CreateImage and image/CreateImage-node - possibly missing connect/disconnect unless AsyncComponent takes care of it

[jonnor]

Probably best way forward is to make some tests in noflo-image, with simple graphs ran with noflo-nodejs. For instance one which just loads file and saves it again, then one that does some simple processing. And just verify that the process exits as expected.

[jonnor]

Not fixed, just wanted to reference the issue in the commit.

[bergie]

Likely related to noflo/noflo#221

[jonnor]

Existing solution is OK