This adds a "fragments" mode to the file resource. In addition to
"content" and "source", you can now alternatively build a file from the
file fragments of other files.
This will be done by refactoring the current method, to return an error
message instead of a boolean value. This will also update a typo on the
user res.
This might be slightly controversial, in that you must specify the state
if a file would need to be created to perform the action. We no longer
implicitly assume that just specifying content is enough. As it turns
out, I believe this is safer and more correct. The code to implement
this turns out to be much more logical and simplified, and does this
removes an ambiguous corner case from the reversed resource code.
Some discussion in: https://github.com/purpleidea/mgmt/issues/540
This patch also does a bit of related cleanup.
This adds the first reversible resource (file) and the necessary engine
API hooks to make it all work. This allows a special "reversed" resource
to be added to the subsequent graph in the stream when an earlier
version "disappears". This disappearance can happen if it was previously
in an if statement that then becomes false.
It might be wise to combine the use of this meta parameter with the use
of the `realize` meta parameter to ensure that your reversed resource
actually runs at least once, if there's a chance that it might be gone
for a while.
This patch also adds a new test harness for testing resources. It
doesn't test the "live" aspect of resources, as it doesn't run Watch,
but it was designed to ensure CheckApply works as intended, and it runs
very quickly with a simplified timeline of happenings.
This simple check should prevent some silly mistakes and make the logic
easier for other parts of the code that won't have to worry about this
pattern.
The default file state should be undefined. This is important because if
a reverse scenario that doesn't specify the state gets given this
default, it will be as if it was specified explicitly, which wouldn't
necessarily be what we want. Instead, an undefined state should
implicitly cause a file to get created if there's a reason to do so,
such as if content or another attribute is specified.
Hopefully this change doesn't introduce any bugs in the CheckApply code,
if it does, then it was due to a lack of implicit file creation.
The Reload method cannot just be invoked on the administrative DBus
object. Just like the method for reloading specific units, it needs
to be invoked on the proper DBus service, addressing the proper object
and using the right interface.
Added an additional constant for the systemd DBus service. Even though
it shares the same value as the interface base name, this is
happenstance and it's technically incorrect to open a connection to an
interface name. The connection needs a service name.
Fixes#509
If you ran some extremely absurd code, it turns out you can cause a
race. This was found by roiedelapluie experimenting! In this case, it
would panic with: fatal error: concurrent map read and map write. This
patch adds the mutex to avoid this rare race.
This is a giant cleanup of the etcd code. The earlier version was
written when I was less experienced with golang.
This is still not perfect, and does contain some races, but at least
it's a decent base to start from. The automatic elastic clustering
should be considered an experimental feature. If you need a more
battle-tested cluster, then you should manage etcd manually and point
mgmt at your existing cluster.
Named return params aren't a favourite feature of mine, and they're
rarely used in the resource writing. They keep popping up because I once
used them and we've been copying and pasting code ever since. Get rid of
them all to help prevent the unnecessary spread.
Part of this was rotten, and not fully functional. This fixes the rot,
adds some tests, and improves the type checking that occurs when sending
and receiving values. In addition, a significant portion of this happens
at compile time.
There is still more work to be done here, but this should get us a good
chunk of the way for now.
This new utility function makes verifying send/recv struct comparisons
consistent. Unfortunately it doesn't yet support coercing from *string
to string or from string to *string.
This replaces the static obj.path and obj.isDir with live variants. I
don't know why I ever cared about caching these before, and if we ever
care we can memoize properly in the future.
This caused a small bug to actually be masked in the gob code. It is now
fixed in the previous commit.
The fields that we might want to store with encoding/gob or any other
encoding package, need to be public. We currently don't use any of these
at the moment, but we might in the future.
Not sure how I let this in, but we should never do this. Hopefully the
Validate should catch this issue in advance, and if not, at least we'll
only error.
If the file res was defined with state => "exists" but no content
specified, it was not created. This patch fixes this bug and adds a test
and an example.
The exec resource was an early addition to the project, and it was due
for some fixes and integration into our automated tests. This patch
fixes a number of issues, and makes it ready for more general use.
Add option RefreshOnly (default to false) on print ressource, to print only when
notified by other resource. When a print is RefreshOnly, it can't be grouped anymore.
This adds the ability to wait with a timeout for CheckApply happenings
in a resource. This helps avoid unnecessary long sleeping and timing
guesses. This also adds a cleanup function to run at the end.
Some of the early code I wrote probably wouldn't pass my own reviews
today. Here's one example of a rare deadlock that could sometimes occur
when a Process/CheckApply caused a shutdown, but the bufio tried to send
on a channel that nobody was going to read any more. Now we properly
unblock that send with a context.
This adds back the retry loop around Process. This is done as a
separate commit so you can more easily see the logic of the retry magic
This commit is similar but different to the earlier commit adding retry
around Watch.
The engine core had some unfortunate bugs that were the result of some
early design errors when I wasn't as familiar with channels. I've
finally rewritten most of the bad parts, and I think it's much more
logical and stable now.
This also simplifies the resource API, since more of the work is done
completely in the engine, and hidden from view.
Lastly, this adds a few new metaparameters and associated code.
There are still some open problems left to solve, but hopefully this
brings us one step closer.
