This should ensure this sort order of longer thing first, when running
the algorithm. We want to autogroup two or more http:server:flag
resources together first, before the whole grouped resource gets pulled
into the http:server one.
Not sure why I was blocking this previously, perhaps there was no use
case, and I was trying to ensure there wasn't accidental, unwanted
grouping? Perhaps I wanted to improve performance? In any case, let's
turn this off for now, and check for bugs.
These can "break" silently and not autogroup if we change the resource
and it no longer fulfills the interface. Add this compile time check to
prevent that.
Resources that can be grouped into the http:server resource must have
that prefix. Grouping is basically hierarchical, and without that common
prefix, it means we'd have to special-case our grouping algorithm.
I inverted the logic for complex setups and forgot to handle the zero
cases. I also didn't notice my loop continue error. This cleans all this
up so that we can have proper exported resource matching.
I think this is what I want in most scenarios, is there a reason to do
otherwise? This is because we may wish to export incomplete resources,
where the remaining necessary fields for validation happens on collect.
Initially I wasn't 100% clear or decided on the send/recv semantics.
After some experimenting, I think this is much closer to what we want.
Nothing should break or regress here, this only enables more
possibilities.
Many years ago I built and demoed a prototype of a simple web ui with a
slider, and as you moved it left and right, it started up or shutdown
some number of virtual machines.
The webui was standalone code, but the rough idea of having events from
a high-level overview flow into mgmt, was what I wanted to test out. At
this stage, I didn't even have the language built yet. This prototype
helped convince me of the way a web ui would fit into everything.
Years later, I build an autogrouping prototype which looks quite similar
to what we have today. I recently picked it back up to polish it a bit
more. It's certainly not perfect, and might even be buggy, but it's
useful enough that it's worth sharing.
If I had more cycles, I'd probably consider removing the "store" mode,
and replace it with the normal "value" system, but we would need the
resource "mutate" API if we wanted this. This would allow us to directly
change the "value" field, without triggering a graph swap, which would
be a lot less clunky than the "store" situation.
Of course I'd love to see a GTK version of this concept, but I figured
it would be more practical to have a web ui over HTTP.
One notable missing feature, is that if the "web ui" changes (rather
than just a value changing) we need to offer to the user to reload it.
It currently doesn't get an event for that, and so don't confuse your
users. We also need to be better at validating "untrusted" input here.
There's also no major reason to use the "gin" framework, we should
probably redo this with the standard library alone, but it was easier
for me to push out something quick this way. We can optimize that later.
Lastly, this is all quite ugly since I'm not a very good web dev, so if
you want to make this polished, please do! The wasm code is also quite
terrible due to limitations in the compiler, and maybe one day when that
works better and doesn't constantly deadlock, we can improve it.
I think we were not benefitting from the cache and sending unnecessary
events. It would be great to have tests for this, but commit this fix
for now, and be embarrassed in the future if I got this code wrong.
This adds initial symlink support to the file resource, and while it is
hopefully correct, there are always sneaky edge cases around symlinks
and security, so review and tests are highly encouraged!
These two small bugs would allow thrashing to occur since we'd
constantly delete and re-add exports, and constantly think that a noop
etcd operation made a change.
I've been waiting to write this patch for a long time. I firmly believe
that the idea of "exported resources" was truly a brilliant one, but
which was never even properly understood by its original inventors! This
patch set aims to show how it should have been done.
The main differences are:
* Real-time modelling, since "once per run" makes no sense.
* Filter with code/functions not language syntax.
* Directed exporting to limit the intended recipients.
The next step is to add more "World" reading and filtering functions to
make it easy and expressive to make your selection of resources to
collect!
These were really just stubs so that I could prove out the reactive
model very early, and I don't think they're really used anywhere.
I'm also not really using the yamlgraph frontend. If someone wants any
of that code, step up, or it will rot even more.
A subtlety about the engine is that while it guarantees CheckApply
happens in the listed edge-based dependency order, it doesn't stop
Watch from starting up in whatever order it wants to. As a result, we
can prematurely error since the docker service isn't running yet. It may
in fact be in the process of getting installed and started by mgmt
before we then try and use this resource! As a result, let it error once
for free and wait for CheckApply to get going before we start again.
Keep in mind, Watch has to use the .Running() method once to tell
CheckApply to do its initial event. So this concurrency is complex!
It's unclear if this is a bug in mgmt or not, but I'm leaning towards
not, particularly since there isn't an obvious way to fix it.
