This is an initial implementation of the mgmt language. It is a
declarative (immutable) functional, reactive, domain specific
programming language. It is intended to be a language that is:
* safe
* powerful
* easy to reason about
With these properties, we hope this language, and the mgmt engine will
allow you to model the real-time systems that you'd like to automate.
This also includes a number of other associated changes. Sorry for the
large size of this patch.
Builds started failing due to go-libvirt-xml 6d97448. In that patch,
the DomainChannelTarget struct was changed from having a single type
field, to having an individual field for each virtualization type.
This patch updates the connection check in Init to reflect the changes
to go-libvirt-xml, so that builds no longer fail.
I previously broke the pkg auto edges because the package list wasn't
available by the time it was called. This fixes the pkg resource so that
it gets the necessary list of packages when needed. Since this means
that a possible failure could happen, we also update the AutoEdges API
to support errors. Errors can only be generated at AutoEdge struct
creation, once the struct has been returned (right before modification
of the graph structure) there is no possibility to return any errors.
It's important to remember that the AutoEdges stuff gets called because
the Init of each resource, so make sure it doesn't depend on anything
that happens there or that gets cached as a result of Init.
This is all much nicer now and has a test too :)
This is required if we're going to have out of package resources. In
particular for third party packages, and also for if we decide to split
out each resource into a separate sub package.
Avoid use of the reflect package, and use an extensible list of registred
resource kinds. This also has the benefit of removing the empty VirtRes and
AugeasRes struct types when compiling without libvirt and libaugeas.
I don't think this early exit is necessary any more, since the main
CheckApply function really just spawns out to the different sub workers
which all individually check the apply variable.
If I'm wrong, we can revert this. It was @roidelapluie that noticed the
check here to begin with.
This prevents us blocking an exit if we close when a callback was about
to run. This is because the callbacks are called from the
EventRunDefaultImpl method, which waits for their return to exit and
release the WaitGroup.
I think we should probably get rid of the obj.wg since the engine is
supposed to guarantee that Close doesn't happen before Watch finishes.
I'm still working on reducing the size of the monster patches that I
land, but I'm exercising the priviledge as the initial author. In any
case, this refactors worker into two, and cleans up the passing around
of the processChan. This puts common code into Init and Close.
This allows hot (un)plugging of CPU's! It also includes some general
cleanups which were necessary to support this as well as some other
features to the virt resource. Hotunplug requires Fedora 25.
It also comes with a mini shell script to help demo this capability.
Many thanks to pkrempa for his help with the libvirt API!
When creating new resources, we didn't specify the defaults, which for
the limit metaparam caused invalid resources by default. It would be
nice to change the limit param to have the 1/X (reciprocal) as the
default, although the problem with that is that (1) it is illogical, and
(2) it's not clear if the precision for the common cases is enough.
If someone wants to investigate this further, please do! Zero value
structs are definitely more useful! In any case, we can now specify the
default. It's not entirely obvious to me if this is the best way to do
it, or if there is a superior method.
Remove the New constructors since calling Init should be done by the
engine, and not by the user even when using mgmt as a lib. This is also
the case in tests! It used to be the case that a user might want to call
Init manually, but that is no longer the case!
This makes examples slightly nicer to commit, since you don't have to
have a hardcoded ~/james/ in their source value. It's also probably a
useful feature for the resource.
This patch makes a number of changes in the engine surrounding the
resource API. In particular:
* Cleanup of send/read event.
* Cleanup of DoSend (now Event) in the Watch method.
* Events are now more consistently pointers.
* Exiting within Watch is now done in a single place.
* Multiple incoming events will be combined into a single action.
* Events in flight during an action are played back after CheckApply.
* Addition of Close method to API
This gets things ready for rate limiting and semaphore metaparams!
This removes some boilerplate from the Watch methods which can be baked
into the engine instead.
This code should be checked for races and locks to make sure we only
start resources when it makes sense to.
This takes the Converged initialization and Startup patterns that are
common in all resources, and bakes it into the core engine. This way
resource writing is much more concise and there is less boilerplate!
This is a monster patch that splits out the yaml and puppet based graph
generation and pushes them behind a common API. In addition alternate
pluggable GAPI's can be easily added! The important side benefit is that
you can now write a custom GAPI for embedding mgmt!
This also includes some slight clean ups that I didn't find it worth
splitting into separate patches.
Remove the implicit emulator path from the domain definition. Libvirt is
already configured to use the correct emulator for kvm or qemu and
specifying it creates distro dependence.
Fixes#85
This adds an initial implementation of a virt resource based on libvirt.
It is not complete and requires more testing. The initial skeleton was
written by nseps but was not merged. It was later cleaned up and merged
in its current form by purpleidea. Many thanks to nseps for getting this
going, and hopefully we'll get you contributing more in the future!
