These changes enable tracing of Pulumi API calls.
The span with which to associate an API call is passed via a
`context.Context` parameter. This required plumbing a
`context.Context` parameter through a rather large number of APIs,
especially in the backend.
In general, all API calls are associated with a new root span that
exists for essentially the entire lifetime of an invocation of the
Pulumi CLI. There were a few places where the plumbing got a bit hairier
than I was willing to address with these changes; I've used
`context.Background()` in these instances. API calls that receive this
context will create new root spans, but will still be traced.
This changes the CLI interface in a few ways:
* `pulumi preview` is back! The alternative of saying
`pulumi update --preview` just felt awkward, and it's a common
operation to want to perform. Let's just make it work.
* There are two flags consistent across all update commands,
`update`, `refresh`, and `destroy`:
- `--skip-preview` will skip the preview step. Note that this
does *not* skip the prompt to confirm that you'd like to proceed.
Indeed, it will still prompt, with a little warning text about
the fact that the preview has been skipped.
* `--yes` will auto-approve the updates.
This lands us in a simpler and more intuitive spot for common scenarios.
I found the flag --force to be a strange name for skipping a preview,
since that name is usually reserved for operations that might be harmful
and yet you're coercing a tool to do it anyway, knowing there's a chance
you're going to shoot yourself in the foot.
I also found that what I almost always want in the situation where
--force was being used is to actually just run a preview and have the
confirmation auto-accepted. Going straight to --force isn't the right
thing in a CI scenario, where you actually want to run a preview first,
just to ensure there aren't any issues, before doing the update.
In a sense, there are four options here:
1. Run a preview, ask for confirmation, then do an update (the default).
2. Run a preview, auto-accept, and then do an update (the CI scenario).
3. Just run a preview with neither a confirmation nor an update (dry run).
4. Just do an update, without performing a preview beforehand (rare).
This change enables all four workflows in our CLI.
Rather than have an explosion of flags, we have a single flag,
--preview, which can specify the mode that we're operating in. The
following are the values which correlate to the above four modes:
1. "": default (no --preview specified)
2. "auto": auto-accept preview confirmation
3. "only": only run a preview, don't confirm or update
4. "skip": skip the preview altogether
As part of this change, I redid a bit of how the preview modes
were specified. Rather than booleans, which had some illegal
combinations, this change introduces a new enum type. Furthermore,
because the engine is wholly ignorant of these flags -- and only the
backend understands them -- it was confusing to me that
engine.UpdateOptions stored this flag, especially given that all
interesting engine options _also_ accepted a dryRun boolean. As of
this change, the backend.PreviewBehavior controls the preview options.
hese changes plumb basic support for cancellation through the engine.
Two types of cancellation are supported for all engine operations:
- Cancellation, which waits for the operation to drive itself to a safe
point before the operation returns, and
- Termination, which does not wait for the operation to drive itself
to a safe opint for the operation returns.
When updating local or managed stacks, a single ^C triggers cancellation
of any running operation; a second ^C will trigger termination.
Fixes#513, #1077.
This change implements a `pulumi refresh` command. It operates a bit
like `pulumi update`, and friends, in that it supports `--preview` and
`--diff`, along with the usual flags, and will update your checkpoint.
It works through substitution of the deploy.Source abstraction, which
generates a sequence of resource registration events. This new
deploy.RefreshSource takes in a prior checkpoint and will walk it,
refreshing the state via the associated resource providers by invoking
Read for each resource encountered, and merging the resulting state with
the prior checkpoint, to yield a new resource.Goal state. This state is
then fed through the engine in the usual ways with a few minor caveats:
namely, although the engine must generate steps for the logical
operations (permitting us to get nice summaries, progress, and diffs),
it mustn't actually carry them out because the state being imported
already reflects reality (a deleted resource has *already* been deleted,
so of course the engine need not perform the deletion). The diffing
logic also needs to know how to treat the case of refresh slightly
differently, because we are going to be diffing outputs and not inputs.
Note that support for managed stacks is not yet complete, since that
requires updates to the service to support a refresh endpoint. That
will be coming soon ...
