Merge pull request #1304 from flux-iac/print-plan

Print plan before apply

docs/use-tf-controller/with-tf-runner-logging.md

@@ -19,3 +19,8 @@ the `DISABLE_TF_LOGS` variable must also be set to "1".
 
 For more information on configuring the Terraform Runner and its environment variables,
 please consult the documentation on [customizing runners](provision-resources-with-customized-runner-pods.md) within the Weave TF-controller.
+
+## Logging human-readable plan
+
+The plan can be logged in a human-readable format just before the applying it in the `tf-runner`.
+To enable this, set the environment variable `LOG_HUMAN_READABLE_PLAN` to "1" on the runner.

runner/server.go

@@ -382,6 +382,11 @@ func (r *TerraformRunnerServer) Apply(ctx context.Context, req *ApplyRequest) (*
 		applyOpt = append(applyOpt, tfexec.Parallelism(int(req.Parallelism)))
 	}
 
+	if err := printHumanReadablePlanIfEnabled(ctx, req.DirOrPlan, r.tfShowPlanFileRaw); err != nil {
+		log.Error(err, "unable to print plan")
+		return nil, err
+	}
+
 	if err := r.tf.Apply(ctx, applyOpt...); err != nil {
 		st := status.New(codes.Internal, err.Error())
 		var stateErr *tfexec.ErrStateLocked
@@ -401,6 +406,23 @@ func (r *TerraformRunnerServer) Apply(ctx context.Context, req *ApplyRequest) (*
 	return &ApplyReply{Message: "ok"}, nil
 }
 
+func printHumanReadablePlanIfEnabled(ctx context.Context, planName string, tfShowPlanFileRaw func(ctx context.Context, planPath string, opts ...tfexec.ShowOption) (string, error)) error {
+	if os.Getenv("LOG_HUMAN_READABLE_PLAN") == "1" {
+		if planName == "" {
+			planName = TFPlanName
+		}
+
+		rawOutput, err := tfShowPlanFileRaw(ctx, planName)
+		if err != nil {
+			return err
+		}
+
+		fmt.Println(rawOutput)
+	}
+
+	return nil
+}
+
 func getInventoryFromTerraformModule(m *tfjson.StateModule) []*Inventory {
 	var result []*Inventory
 	for _, r := range m.Resources {

runner/server_test.go

@@ -0,0 +1,52 @@
+package runner
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/hashicorp/terraform-exec/tfexec"
+	. "github.com/onsi/gomega"
+)
+
+func Test_printHumanReadablePlanIfEnabled(t *testing.T) {
+	g := NewGomegaWithT(t)
+	ctx := context.Background()
+
+	defer func() {
+		g.Expect(os.Unsetenv("LOG_HUMAN_READABLE_PLAN")).Should(Succeed())
+	}()
+
+	var tfShowPlanFileRawCalled int
+	expectedPlan := TFPlanName
+	tfShowPlanFileRaw := func(ctx context.Context, planPath string, opts ...tfexec.ShowOption) (string, error) {
+		g.Expect(planPath).To(Equal(expectedPlan))
+		tfShowPlanFileRawCalled++
+		return "", nil
+	}
+
+	// When plan is enabled, then it should be called once
+	g.Expect(os.Setenv("LOG_HUMAN_READABLE_PLAN", "1")).Should(Succeed())
+	g.Expect(printHumanReadablePlanIfEnabled(ctx, "", tfShowPlanFileRaw)).Should(Succeed())
+	g.Expect(tfShowPlanFileRawCalled).To(Equal(1))
+
+	// When the planName is non-empty, then it should use the planName
+	expectedPlan = "foo"
+	g.Expect(printHumanReadablePlanIfEnabled(ctx, expectedPlan, tfShowPlanFileRaw)).Should(Succeed())
+	g.Expect(tfShowPlanFileRawCalled).To(Equal(2))
+
+	// When it is disabled, then it should not be called
+	expectedPlan = TFPlanName
+	g.Expect(os.Setenv("LOG_HUMAN_READABLE_PLAN", "0")).Should(Succeed())
+	g.Expect(printHumanReadablePlanIfEnabled(ctx, "", tfShowPlanFileRaw)).Should(Succeed())
+	g.Expect(tfShowPlanFileRawCalled).To(Equal(2))
+
+	// When tfShowPlanFileRaw fails, then it should return an error
+	g.Expect(os.Setenv("LOG_HUMAN_READABLE_PLAN", "1")).Should(Succeed())
+	tfShowPlanFileRaw = func(ctx context.Context, planPath string, opts ...tfexec.ShowOption) (string, error) {
+		return "", fmt.Errorf("error")
+	}
+
+	g.Expect(printHumanReadablePlanIfEnabled(ctx, "", tfShowPlanFileRaw)).ShouldNot(Succeed())
+}