blob: 29e60ff6a0d8720c757fa4c04bec4df396175915 [file] [log] [blame]
package terraform
import (
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/configs"
"github.com/hashicorp/terraform/internal/dag"
"github.com/hashicorp/terraform/internal/plans"
"github.com/hashicorp/terraform/internal/states"
"github.com/hashicorp/terraform/internal/tfdiags"
)
// 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 {
// Config is the configuration tree that the diff was built from.
Config *configs.Config
// Changes describes the changes that we need apply.
Changes *plans.Changes
// State is the current state
State *states.State
// RootVariableValues are the root module input variables captured as
// part of the plan object, which we must reproduce in the apply step
// to get a consistent result.
RootVariableValues InputValues
// Plugins is a library of the plug-in components (providers and
// provisioners) available for use.
Plugins *contextPlugins
// Targets are resources to target. This is only required to make sure
// unnecessary outputs aren't included in the apply graph. The plan
// builder successfully handles targeting resources. In the future,
// outputs should go into the diff so that this is unnecessary.
Targets []addrs.Targetable
// ForceReplace are the resource instance addresses that the user
// requested to force replacement for when creating the plan, if any.
// The apply step refers to these as part of verifying that the planned
// actions remain consistent between plan and apply.
ForceReplace []addrs.AbsResourceInstance
// Plan Operation this graph will be used for.
Operation walkOperation
}
// See GraphBuilder
func (b *ApplyGraphBuilder) Build(path addrs.ModuleInstance) (*Graph, tfdiags.Diagnostics) {
return (&BasicGraphBuilder{
Steps: b.Steps(),
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 &nodeExpandApplyableResource{
NodeAbstractResource: a,
}
}
concreteResourceInstance := func(a *NodeAbstractResourceInstance) dag.Vertex {
return &NodeApplyableResourceInstance{
NodeAbstractResourceInstance: a,
forceReplace: b.ForceReplace,
}
}
steps := []GraphTransformer{
// Creates all the resources represented in the config. During apply,
// we use this just to ensure that the whole-resource metadata is
// updated to reflect things such as whether the count argument is
// set in config, or which provider configuration manages each resource.
&ConfigTransformer{
Concrete: concreteResource,
Config: b.Config,
},
// Add dynamic values
&RootVariableTransformer{Config: b.Config, RawValues: b.RootVariableValues},
&ModuleVariableTransformer{Config: b.Config},
&LocalTransformer{Config: b.Config},
&OutputTransformer{
Config: b.Config,
ApplyDestroy: b.Operation == walkDestroy,
},
// Creates all the resource instances represented in the diff, along
// with dependency edges against the whole-resource nodes added by
// ConfigTransformer above.
&DiffTransformer{
Concrete: concreteResourceInstance,
State: b.State,
Changes: b.Changes,
Config: b.Config,
},
// Attach the state
&AttachStateTransformer{State: b.State},
// Create orphan output nodes
&OrphanOutputTransformer{Config: b.Config, State: b.State},
// Attach the configuration to any resources
&AttachResourceConfigTransformer{Config: b.Config},
// add providers
transformProviders(concreteProvider, b.Config),
// Remove modules no longer present in the config
&RemovedModuleTransformer{Config: b.Config, State: b.State},
// Must attach schemas before ReferenceTransformer so that we can
// analyze the configuration to find references.
&AttachSchemaTransformer{Plugins: b.Plugins, 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 references so ordering is correct
&ReferenceTransformer{},
&AttachDependenciesTransformer{},
// Detect when create_before_destroy must be forced on for a particular
// node due to dependency edges, to avoid graph cycles during apply.
&ForcedCBDTransformer{},
// Destruction ordering
&DestroyEdgeTransformer{
Changes: b.Changes,
Operation: b.Operation,
},
&CBDEdgeTransformer{
Config: b.Config,
State: b.State,
},
// We need to remove configuration nodes that are not used at all, as
// they may not be able to evaluate, especially during destroy.
// These include variables, locals, and instance expanders.
&pruneUnusedNodesTransformer{},
// Target
&TargetsTransformer{Targets: b.Targets},
// Close opened plugin connections
&CloseProviderTransformer{},
// close the root module
&CloseRootModuleTransformer{},
// Perform the transitive reduction to make our graph a bit
// more understandable if possible (it usually is possible).
&TransitiveReductionTransformer{},
}
return steps
}