Files
opentf/terraform/graph_builder_eval.go
Martin Atkins 71cedf19a4 core: Don't create indirect provider dependencies for references
The prior commit changed the schema-access model so that all schemas are
fetched up front during context creation and are then readily available
for use throughout graph building and evaluation.

As a result, we no longer need to create dependency edges to a provider
when one of its resources is referenced by another node, and so the
ProviderTransformer needs only to worry about direct ownership
dependencies.

This also avoids the need for us to run AttachSchemaTransformer twice,
since ProviderTransformer no longer needs schema and we can therefore
defer attaching until just before ReferenceTransformer, when all of the
referencable and referencing nodes are already present in the graph.
2018-10-16 18:49:20 -07:00

108 lines
3.2 KiB
Go

package terraform
import (
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/tfdiags"
)
// EvalGraphBuilder implements GraphBuilder and constructs a graph suitable
// for evaluating in-memory values (input variables, local values, output
// values) in the state without any other side-effects.
//
// This graph is used only in weird cases, such as the "terraform console"
// CLI command, where we need to evaluate expressions against the state
// without taking any other actions.
//
// The generated graph will include nodes for providers, resources, etc
// just to allow indirect dependencies to be resolved, but these nodes will
// not take any actions themselves since we assume that their parts of the
// state, if any, are already complete.
//
// Although the providers are never configured, they must still be available
// in order to obtain schema information used for type checking, etc.
type EvalGraphBuilder struct {
// Config is the configuration tree.
Config *configs.Config
// State is the current state
State *State
// Components is a factory for the plug-in components (providers and
// provisioners) available for use.
Components contextComponentFactory
// Schemas is the repository of schemas we will draw from to analyse
// the configuration.
Schemas *Schemas
}
// See GraphBuilder
func (b *EvalGraphBuilder) Build(path addrs.ModuleInstance) (*Graph, tfdiags.Diagnostics) {
return (&BasicGraphBuilder{
Steps: b.Steps(),
Validate: true,
Name: "EvalGraphBuilder",
}).Build(path)
}
// See GraphBuilder
func (b *EvalGraphBuilder) Steps() []GraphTransformer {
concreteProvider := func(a *NodeAbstractProvider) dag.Vertex {
return &NodeEvalableProvider{
NodeAbstractProvider: a,
}
}
steps := []GraphTransformer{
// Creates all the data resources that aren't in the state. This will also
// add any orphans from scaling in as destroy nodes.
&ConfigTransformer{
Concrete: nil, // just use the abstract type
Config: b.Config,
Unique: true,
},
// Attach the state
&AttachStateTransformer{State: b.State},
// Attach the configuration to any resources
&AttachResourceConfigTransformer{Config: b.Config},
// Add root variables
&RootVariableTransformer{Config: b.Config},
// Add the local values
&LocalTransformer{Config: b.Config},
// Add the outputs
&OutputTransformer{Config: b.Config},
// Add module variables
&ModuleVariableTransformer{Config: b.Config},
TransformProviders(b.Components.ResourceProviders(), concreteProvider, b.Config),
// Must attach schemas before ReferenceTransformer so that we can
// analyze the configuration to find references.
&AttachSchemaTransformer{Schemas: b.Schemas},
// Connect so that the references are ready for targeting. We'll
// have to connect again later for providers and so on.
&ReferenceTransformer{},
// Although we don't configure providers, we do still start them up
// to get their schemas, and so we must shut them down again here.
&CloseProviderTransformer{},
// Single root
&RootTransformer{},
// Remove redundant edges to simplify the graph.
&TransitiveReductionTransformer{},
}
return steps
}