In my carelessness, I was re-using pointers when a fact was used twice!
This could cause disastrous consequences like a double close panic on a
datetime.now() fact for example.
In other news, we should consider if it's possible to get more clever
about graph shape optimization so that we don't need more than once
instance of certain functions like datetime.now() in our graph.
Most of the time, we don't need to have a dynamic call sub graph, since
the actual function call could be represented statically as it
originally was before lambda functions were implemented. Simplifying the
graph shape has important performance benefits in terms of both keep the
graph smaller (memory, etc) and in avoiding the need to run transactions
at runtime (speed) to reshape the graph.
Co-authored-by: Samuel Gélineau <gelisam@gmail.com>
This commit implements a range function that mimicks python's range
built-in by having a start, stop, and range argument. There's also
a few examples and tests to mimick Python's examples to guarantee
we're consistent with their behaviour.
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!
/ Test (basic) on ubuntu-latest with golang 1.23 (push) Has been cancelled
/ Test (race) on ubuntu-latest with golang 1.23 (push) Has been cancelled
/ Test (shell) on ubuntu-latest with golang 1.23 (push) Has been cancelled
This lets us look at the available resource data for collection, and to
filter it so we can decide what we want to collect on our machine.
Other types of collect functions could be added in the future.
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.
This is a basic implementation of a detection method for whether mgmt is
running in a virtualized environment. We achieve this by doing two types
of checks: on one hand, we check if the CPU flags can confirm the
presence of a virtualized env; on the other, we check if the presence
of known files related with DMI (and their contents) can confirm whether
we're inside a virt env. Either of these situations will cause the
function to return true, with the default case being false. All of these
checks are relatively naive and can be improved by looking at the main
inspiration for this implementation, which was systemd's own check for
the presence of virtualization.
This provides a new kind of "world" backend, one that runs etcd over an
SSH connection. This is useful for situations where you want to run an
etcd cluster somewhere for clients across the net, but where you don't
want to expose the ports publicly.
If SSH authentication is setup correctly (using public keys) this will
tunnel over SSH for etcd to connect.
This patch does not yet support deploys over SSH, but that should be
fixed in the future as the world code gets cleaned up 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.
