opentofu/terraform/graph.go
Martin Atkins 05caff2ca3 Move tfdiags/ to internal/tfdiags/
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.

If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
2021-05-17 14:09:07 -07:00

97 lines
2.7 KiB
Go

package terraform
import (
"log"
"strings"
"github.com/hashicorp/terraform/internal/tfdiags"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/internal/dag"
)
// Graph represents the graph that Terraform uses to represent resources
// and their dependencies.
type Graph struct {
// Graph is the actual DAG. This is embedded so you can call the DAG
// methods directly.
dag.AcyclicGraph
// Path is the path in the module tree that this Graph represents.
Path addrs.ModuleInstance
}
func (g *Graph) DirectedGraph() dag.Grapher {
return &g.AcyclicGraph
}
// Walk walks the graph with the given walker for callbacks. The graph
// will be walked with full parallelism, so the walker should expect
// to be called in concurrently.
func (g *Graph) Walk(walker GraphWalker) tfdiags.Diagnostics {
return g.walk(walker)
}
func (g *Graph) walk(walker GraphWalker) tfdiags.Diagnostics {
// The callbacks for enter/exiting a graph
ctx := walker.EvalContext()
// Walk the graph.
walkFn := func(v dag.Vertex) (diags tfdiags.Diagnostics) {
log.Printf("[TRACE] vertex %q: starting visit (%T)", dag.VertexName(v), v)
defer func() {
log.Printf("[TRACE] vertex %q: visit complete", dag.VertexName(v))
}()
// vertexCtx is the context that we use when evaluating. This
// is normally the context of our graph but can be overridden
// with a GraphNodeModuleInstance impl.
vertexCtx := ctx
if pn, ok := v.(GraphNodeModuleInstance); ok {
vertexCtx = walker.EnterPath(pn.Path())
defer walker.ExitPath(pn.Path())
}
// If the node is exec-able, then execute it.
if ev, ok := v.(GraphNodeExecutable); ok {
diags = diags.Append(walker.Execute(vertexCtx, ev))
if diags.HasErrors() {
return
}
}
// If the node is dynamically expanded, then expand it
if ev, ok := v.(GraphNodeDynamicExpandable); ok {
log.Printf("[TRACE] vertex %q: expanding dynamic subgraph", dag.VertexName(v))
g, err := ev.DynamicExpand(vertexCtx)
if err != nil {
diags = diags.Append(err)
return
}
if g != nil {
// Walk the subgraph
log.Printf("[TRACE] vertex %q: entering dynamic subgraph", dag.VertexName(v))
subDiags := g.walk(walker)
diags = diags.Append(subDiags)
if subDiags.HasErrors() {
var errs []string
for _, d := range subDiags {
errs = append(errs, d.Description().Summary)
}
log.Printf("[TRACE] vertex %q: dynamic subgraph encountered errors: %s", dag.VertexName(v), strings.Join(errs, ","))
return
}
log.Printf("[TRACE] vertex %q: dynamic subgraph completed successfully", dag.VertexName(v))
} else {
log.Printf("[TRACE] vertex %q: produced no dynamic subgraph", dag.VertexName(v))
}
}
return
}
return g.AcyclicGraph.Walk(walkFn)
}