This commit will introduce the ability to load providers in `query`
mode.
Previously, `query` mode has been effectively a stand-alone execution
environment for language hosts, running without (e.g.) the
`StepExecutor` and similar engine facilities, but with some minimal
constructs hooked up, notably the ability to retrieve stack snapshots
from the backend for querying.
This commit extends this functionality somewhat by allowing `query` to
load Pulumi resource providers, and to run `Invoke` on them. This will
allow us, in the future, to "query" resource providers in the same way
we can query stack snapshots.
This avoids unnecessary blocking inside pre/post-step callbacks if the
reader on the other side of the event channel is slow.
We do not use a buffered channel in the event pipe because it is
empirically less likely that the goroutine reading from a buffered
channel will be scheduled when new data is placed in the channel. In the
case of our event system in which events will not be delivered to the
service and display until the copying goroutine is scheduled, this can
lead to unacceptable delay between the send of the original event and
its output.
* Fix some tracing issues.
- Add endpoints for `startUpdate` and `postEngineEventsBatch` so that
spans for these invocations have proper names
- Inject a tracing span when walking a plan so that resource operations
are properly parented
- When handling gRPC calls, inject a tracing span into the call's
metadata if no span is already present so that resource monitor and
engine spans are properly parented
- Do not trace client gRPC invocations of the empty method so that these
calls (which are used to determine server availability) do not muddy
the trace. Note that I tried parenting these spans appropriately, but
doing so broke the trace entirely.
With these changes, the only unparented span in a typical Pulumi
invocation is a single call to `getUser`. This span is unparented
because that call does not have a context available. Plumbing a context
into that particular call is surprisingly tricky, as it is often called
by other context-less functions.
* Make tracing support more flexible.
- Add support for writing trace data to a local file using Appdash
- Add support for viewing Appdash traces via the CLI
Previously, when the CLI wanted to install a plugin, it used a special
method, `DownloadPlugin` on the `httpstate` backend to actually fetch
the tarball that had the plugin. The reason for this is largely tied
to history, at one point during a closed beta, we required presenting
an API key to download plugins (as a way to enforce folks outside the
beta could not download them) and because of that it was natural to
bake that functionality into the part of the code that interfaced with
the rest of the API from the Pulumi Service.
The downside here is that it means we need to host all the plugins on
`api.pulumi.com` which prevents community folks from being able to
easily write resource providers, since they have to manually manage
the process of downloading a provider to a machine and getting it on
the `$PATH` or putting it in the plugin cache.
To make this easier, we add a `--server` argument you can pass to
`pulumi plugin install` to control the URL that it attempts to fetch
the tarball from. We still have perscriptive guidence on how the
tarball must be
named (`pulumi-[<type>]-[<provider-name>]-vX.Y.Z.tar.gz`) but the base
URL can now be configured.
Folks publishing packages can use install scripts to run `pulumi
plugin install` passing a custom `--server` argument, if needed.
There are two improvements we can make to provide a nicer end to end
story here:
- We can augment the GetRequiredPlugins method on the language
provider to also return information about an optional server to use
when downloading the provider.
- We can pass information about a server to download plugins from as
part of a resource registration or creation of a first class
provider.
These help out in cases where for one reason or another where `pulumi
plugin install` doesn't get run before an update takes place and would
allow us to either do the right thing ahead of time or provide better
error messages with the correct `--server` argument. But, for now,
this unblocks a majority of the cases we care about and provides a
path forward for folks that want to develop and host their own
resource providers.
This command exposes a new resource `Invoke` operation,
`pulumi:pulumi:readStackResourceOutputs` which retrieves all resource
outputs for some user-specified stack, not including those deleted.
Fixes#2600.
`pulumi query` is designed, essentially, as a souped-up `exec`. We
execute a query program, and add a few convenience constructs (e.g., the
default providers that give you access to things like `getStack`).
Early in the design process, we decided to not re-use the `up`/update
path, both to minimize risk to update operations, and to simplify the
implementation.
This commit will add this "parallel query universe" into the engine
package. In particular, this includes:
* `QuerySource`, which executes the language provider running the query
program, and providing it with some simple constructs, such as the
default provider, which provides access to `getStack`. This is much
like a very simplified `EvalSource`, though notably without any of the
planning/step execution machinery.
* `queryResmon`, which disallows all resource operations, except the
`Invoke` that retrieves the resource outputs of some stack's last
snapshot. This is much like a simplified `resmon`, but without any of
the provider resolution, and without and support for resource
operations generally.
* Various static functions that pull together miscellaneous things
needed to execute a query program. Notably, this includes gathering
language plugins.
