opentofu/terraform/graph_builder_eval.go
James Bardin 35714e61e6 audit graph builder to make them more similar
Auditing the graph builder to remove unused transformers (planning does
not need to close provisioners for example), and re-order them. While
many of the transformations are commutative, using the same order
ensures the same behavior between operations when the commutative
property is lost or changed.
2020-10-06 17:39:53 -04:00

106 lines
3.4 KiB
Go

package terraform
import (
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs"
"github.com/hashicorp/terraform/dag"
"github.com/hashicorp/terraform/states"
"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 *states.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{
Config: b.Config,
},
// Add dynamic values
&RootVariableTransformer{Config: b.Config},
&ModuleVariableTransformer{Config: b.Config},
&LocalTransformer{Config: b.Config},
&OutputTransformer{Config: b.Config},
// Attach the configuration to any resources
&AttachResourceConfigTransformer{Config: b.Config},
// Attach the state
&AttachStateTransformer{State: b.State},
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, Config: b.Config},
// Create expansion nodes for all of the module calls. This must
// come after all other transformers that create nodes representing
// objects that can belong to modules.
&ModuleExpansionTransformer{Config: b.Config},
// 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{},
// Close root module
&CloseRootModuleTransformer{},
// Remove redundant edges to simplify the graph.
&TransitiveReductionTransformer{},
}
return steps
}