This change adds a `RegisterInputType` function (similar to the existing `RegisterOutputType`) that is used to register an input interface's type and its associated input type, and adds registrations for the built-in input types.
This will be used when copying inputs to an args struct for multi-lang components. When a field is typed as the input interface (e.g. `StringMapInput`) and doesn't need to be an `Output`, we can use this to lookup the non-Output type that implements the interface (e.g. `StringMap`) so it can be instantiated.
A subsequent change will update the Go SDK codegen to produce input type registrations for a provider's input types.
The Pulumi Go SDK does not currently await all outstanding asynchronous
work associated with a Pulumi program. Because all relevant asynchronous
work is created via the Pulumi SDK, we can track this asynchronous work
and ensure that it has all completed prior to returning from
`Context.Run`.
This is complicated by the fact that many of the existing APIs that are
able to create `Output`s--`NewOutput`, `ToOutput`, `Any`, `ToSecret`,
and `All`--do not have a `*Context` parameter, and so have no
straightforward way to associate themselves with a `*Context`. To address
this, these changes add new versions of each of these APIs as methods on
`*Context`.
Despite these new methods, most Pulumi programs should work without
changes: the bulk of `Output`s are created by the SDK itself as part of
resource registration, and for `Any` and `All`, we can pick up the
context from any `Output`s present in the arguments. The only programs
that should require changes are those that create outputs from whole
cloth using `NewOutput`, `ToOutput`, or `ToSecret` and create unawaited
async work rooted at those outputs.
On an implementation level, these changes track asynchronous work using
a `sync.WaitGroup` associated with each `*Context`. This `WaitGroup` is
passed to each output associated with the context. The SDK increments
this `WaitGroup`'s count prior to starting any asynchronous work and
decrements it once the work (including any callbacks triggered by the
work) is complete.
This fixes the Go portion of #3991.
These methods were getting promoted onto every struct that implemented
the Output interface, and are not necessary.
On a real world program, this saves 4% in binary size overall, and
15% of remaining binary size if `Apply<TypeName>` functions are
removed (https://github.com/pulumi/pulumi/issues/6592).
In preparation for publishing a separate module of the Go SDK for Pulumi
on which providers can depend, we should reduce the dependency footprint
so as to cause end users as few issues as possible with transitive
dependency versioning.
This commit removes all use of `github.com/pkg/errors` from the Go SDK
to that end, replacing it with the standard `errors` package and `fmt`
for error formatting where appropriate. We use the new (as of Go 1.13)
"%w" syntax for wrapping errors, so this code is no longer compatible
with Go 1.12.
The redesign is focused around providing better static typings and
improved ease-of-use for the Go SDK. Most of the redesign revolves
around three pivots:
- Strongly-typed inputs, especially for nested types
- Struct-based resource and invoke APIs
- Ease-of-use of Apply
1. Strongly-typed inputs
Input is the type of a generic input value for a Pulumi resource.
This type is used in conjunction with Output to provide polymorphism
over strongly-typed input values.
The intended pattern for nested Pulumi value types is to define an
input interface and a plain, input, and output variant of the value
type that implement the input interface.
For example, given a nested Pulumi value type with the following shape:
```
type Nested struct {
Foo int
Bar string
}
```
We would define the following:
```
var nestedType = reflect.TypeOf((*Nested)(nil)).Elem()
type NestedInput interface {
pulumi.Input
ToNestedOutput() NestedOutput
ToNestedOutputWithContext(context.Context) NestedOutput
}
type Nested struct {
Foo int `pulumi:"foo"`
Bar string `pulumi:"bar"`
}
type NestedInputValue struct {
Foo pulumi.IntInput `pulumi:"foo"`
Bar pulumi.StringInput `pulumi:"bar"`
}
func (NestedInputValue) ElementType() reflect.Type {
return nestedType
}
func (v NestedInputValue) ToNestedOutput() NestedOutput {
return pulumi.ToOutput(v).(NestedOutput)
}
func (v NestedInputValue) ToNestedOutputWithContext(ctx context.Context) NestedOutput {
return pulumi.ToOutputWithContext(ctx, v).(NestedOutput)
}
type NestedOutput struct { *pulumi.OutputState }
func (NestedOutput) ElementType() reflect.Type {
return nestedType
}
func (o NestedOutput) ToNestedOutput() NestedOutput {
return o
}
func (o NestedOutput) ToNestedOutputWithContext(ctx context.Context) NestedOutput {
return o
}
func (o NestedOutput) Foo() pulumi.IntOutput {
return o.Apply(func (v Nested) int {
return v.Foo
}).(pulumi.IntOutput)
}
func (o NestedOutput) Bar() pulumi.StringOutput {
return o.Apply(func (v Nested) string {
return v.Bar
}).(pulumi.StringOutput)
}
```
The SDK provides input and output types for primitives, arrays, and
maps.
2. Struct-based APIs
Instead of providing expected output properties in the input map passed
to {Read,Register}Resource and returning the outputs as a map, the user
now passes a pointer to a struct that implements one of the Resource
interfaces and has appropriately typed and tagged fields that represent
its output properties.
For example, given a custom resource with an int-typed output "foo" and
a string-typed output "bar", we would define the following
CustomResource type:
```
type MyResource struct {
pulumi.CustomResourceState
Foo pulumi.IntOutput `pulumi:"foo"`
Bar pulumi.StringOutput `pulumi:"bar"`
}
```
And invoke RegisterResource like so:
```
var resource MyResource
err := ctx.RegisterResource(tok, name, props, &resource, opts...)
```
Invoke arguments and results are also provided via structs, but use
plain-old Go types for their fields:
```
type MyInvokeArgs struct {
Foo int `pulumi:"foo"`
}
type MyInvokeResult struct {
Bar string `pulumi:"bar"`
}
var result MyInvokeResult
err := ctx.Invoke(tok, MyInvokeArgs{Foo: 42}, &result, opts...)
```
3. Ease-of-use of Apply
All `Apply` methods now accept an interface{} as the callback type.
The provided callback value must have one of the following signatures:
func (v T) U
func (v T) (U, error)
func (ctx context.Context, v T) U
func (ctx context.Context, v T) (U, error)
T must be assignable from the ElementType of the Output. If U is a type
that has a registered Output type, the result of the Apply will be the
corresponding Output type. Otherwise, the result of the Apply will be
AnyOutput.
Fixes https://github.com/pulumi/pulumi/issues/2149.
Fixes https://github.com/pulumi/pulumi/issues/3488.
Fixes https://github.com/pulumi/pulumi/issues/3487.
Fixes https://github.com/pulumi/pulumi-aws/issues/248.
Fixes https://github.com/pulumi/pulumi/issues/3492.
Fixes https://github.com/pulumi/pulumi/issues/3491.
Fixes https://github.com/pulumi/pulumi/issues/3562.
