terraform/terraform/graph_builder_apply.go

129 lines
3.3 KiB
Go

package terraform
import (
"github.com/hashicorp/terraform/config/module"
"github.com/hashicorp/terraform/dag"
)
// ApplyGraphBuilder implements GraphBuilder and is responsible for building
// a graph for applying a Terraform diff.
//
// Because the graph is built from the diff (vs. the config or state),
// this helps ensure that the apply-time graph doesn't modify any resources
// that aren't explicitly in the diff. There are other scenarios where the
// diff can be deviated, so this is just one layer of protection.
type ApplyGraphBuilder struct {
// Module is the root module for the graph to build.
Module *module.Tree
// Diff is the diff to apply.
Diff *Diff
// State is the current state
State *State
// Providers is the list of providers supported.
Providers []string
// Provisioners is the list of provisioners supported.
Provisioners []string
// DisableReduce, if true, will not reduce the graph. Great for testing.
DisableReduce bool
// Destroy, if true, represents a pure destroy operation
Destroy bool
// Validate will do structural validation of the graph.
Validate bool
}
// See GraphBuilder
func (b *ApplyGraphBuilder) Build(path []string) (*Graph, error) {
return (&BasicGraphBuilder{
Steps: b.Steps(),
Validate: b.Validate,
Name: "ApplyGraphBuilder",
}).Build(path)
}
// See GraphBuilder
func (b *ApplyGraphBuilder) Steps() []GraphTransformer {
// Custom factory for creating providers.
concreteProvider := func(a *NodeAbstractProvider) dag.Vertex {
return &NodeApplyableProvider{
NodeAbstractProvider: a,
}
}
concreteResource := func(a *NodeAbstractResource) dag.Vertex {
return &NodeApplyableResource{
NodeAbstractResource: a,
}
}
steps := []GraphTransformer{
// Creates all the nodes represented in the diff.
&DiffTransformer{
Concrete: concreteResource,
Diff: b.Diff,
Module: b.Module,
State: b.State,
},
// Create orphan output nodes
&OrphanOutputTransformer{Module: b.Module, State: b.State},
// Attach the configuration to any resources
&AttachResourceConfigTransformer{Module: b.Module},
// Attach the state
&AttachStateTransformer{State: b.State},
// Create all the providers
&MissingProviderTransformer{Providers: b.Providers, Concrete: concreteProvider},
&ProviderTransformer{},
&DisableProviderTransformer{},
&ParentProviderTransformer{},
&AttachProviderConfigTransformer{Module: b.Module},
// Destruction ordering
&DestroyEdgeTransformer{Module: b.Module, State: b.State},
GraphTransformIf(
func() bool { return !b.Destroy },
&CBDEdgeTransformer{Module: b.Module, State: b.State},
),
// Provisioner-related transformations
&MissingProvisionerTransformer{Provisioners: b.Provisioners},
&ProvisionerTransformer{},
// Add root variables
&RootVariableTransformer{Module: b.Module},
// Add the outputs
&OutputTransformer{Module: b.Module},
// Add module variables
&ModuleVariableTransformer{Module: b.Module},
// Connect references so ordering is correct
&ReferenceTransformer{},
// Add the node to fix the state count boundaries
&CountBoundaryTransformer{},
// Single root
&RootTransformer{},
}
if !b.DisableReduce {
// Perform the transitive reduction to make our graph a bit
// more sane if possible (it usually is possible).
steps = append(steps, &TransitiveReductionTransformer{})
}
return steps
}