Merge pull request #44 from Pix4D/move-before

add new command move-before

Author: marco-m-pix4d

CHANGELOG.md

@@ -5,13 +5,34 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
-### Fixes
-### Breaking changes
-### Changes
+## [v0.7.0] - (Unreleased)
+
 ### New
 
-## [v0.6.2] - (Unreleased)
+- New command `move-before`, to move resources to a root environment upstream in the dependency chain (see README for details):
+  ```
+  $ terravalet move-before -h
+  Usage: terravalet move-before --script SCRIPT --before BEFORE --after AFTER
+  Options:
+  --script SCRIPT    the migration scripts; will generate SCRIPT_up.sh and SCRIPT_down.sh
+  --before BEFORE    the before root directory; will look for BEFORE.tfplan and BEFORE.tfstate
+  --after AFTER      the after root directory; will look for AFTER.tfstate
+  ```
+
+- Simplify workflow for state move (see README for details).
+
+### Breaking changes
+
+- Rename command `move` to `move-after` (to be uniform with the new command `move-before`).
+- Command `move-after` now takes 3 (different) CLI options instead of the previous 6:
+  ```
+  $ terravalet move-after -h
+  Usage: terravalet move-after --script SCRIPT --before BEFORE --after AFTER
+  Options:
+  --script SCRIPT    the migration scripts; will generate SCRIPT_up.sh and SCRIPT_down.sh
+  --before BEFORE    the before root directory; will look for BEFORE.tfplan and BEFORE.tfstate
+  --after AFTER      the after root directory; will look for BEFORE.tfstate and AFTER.tfstate
+  ```
 
 ### Changes
 
@@ -54,8 +75,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [v0.4.0] - (2021-01-25)
 
-### Fixes
-
 ### Breaking changes
 
 - Due to the introduction of subcommands, the CLI API has changed; now it must be invoked by specifying a subcommand. See section New for details.
@@ -133,3 +152,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [v0.4.0]: https://github.com/Pix4D/terravalet/releases/tag/v0.4.0
 [v0.5.0]: https://github.com/Pix4D/terravalet/releases/tag/v0.5.0
 [v0.6.0]: https://github.com/Pix4D/terravalet/releases/tag/v0.6.0
+[v0.6.1]: https://github.com/Pix4D/terravalet/releases/tag/v0.6.1
+[v0.7.0]: https://github.com/Pix4D/terravalet/releases/tag/v0.7.0
+

cmdmoverename.go

@@ -141,6 +141,58 @@ func doMoveAfter(script, before, after string) error {
 	return nil
 }
 
+func doMoveBefore(script, before, after string) error {
+	beforePlanPath := before + ".tfplan"
+	beforePlanFile, err := os.Open(beforePlanPath)
+	if err != nil {
+		return fmt.Errorf("opening the terraform BEFORE plan file: %v", err)
+	}
+	defer beforePlanFile.Close()
+
+	upPath := script + "_up.sh"
+	upFile, err := os.Create(upPath)
+	if err != nil {
+		return fmt.Errorf("creating the up file: %v", err)
+	}
+	defer upFile.Close()
+
+	downPath := script + "_down.sh"
+	downFile, err := os.Create(downPath)
+	if err != nil {
+		return fmt.Errorf("creating the down file: %v", err)
+	}
+	defer downFile.Close()
+
+	beforeCreate, beforeDestroy, err := parse(beforePlanFile)
+	if err != nil {
+		return fmt.Errorf("parse BEFORE plan: %v", err)
+	}
+	if beforeCreate.Size() == 0 {
+		return fmt.Errorf("BEFORE plan does not contain resources to create")
+	}
+	if beforeDestroy.Size() > 0 {
+		return fmt.Errorf("BEFORE plan contains resources to destroy: %s",
+			sorted(beforeDestroy.List()))
+	}
+
+	upMatches, downMatches := matchExact(beforeCreate, beforeCreate)
+
+	beforeStatePath := before + ".tfstate"
+	afterStatePath := after + ".tfstate"
+
+	upStateFlags := fmt.Sprintf("-state=%s -state-out=%s", afterStatePath, beforeStatePath)
+	downStateFlags := fmt.Sprintf("-state=%s -state-out=%s", beforeStatePath, afterStatePath)
+
+	if err := upDownScript(upMatches, upStateFlags, upFile); err != nil {
+		return fmt.Errorf("writing the up script: %v", err)
+	}
+	if err := upDownScript(downMatches, downStateFlags, downFile); err != nil {
+		return fmt.Errorf("writing the down script: %v", err)
+	}
+
+	return nil
+}
+
 func collectErrors(create *strset.Set, destroy *strset.Set) string {
 	msg := ""
 	if create.Size() != 0 {

main.go

@@ -23,10 +23,11 @@ func main() {
 }
 
 type args struct {
-	Rename    *RenameCmd    `arg:"subcommand:rename" help:"rename resources in the same root environment"`
-	MoveAfter *MoveAfterCmd `arg:"subcommand:move-after" help:"move resources from one root environment to AFTER another"`
-	Import    *ImportCmd    `arg:"subcommand:import" help:"import resources generated out-of-band of Terraform"`
-	Version   *struct{}     `arg:"subcommand:version" help:"show version"`
+	Rename     *RenameCmd     `arg:"subcommand:rename" help:"rename resources in the same root environment"`
+	MoveAfter  *MoveAfterCmd  `arg:"subcommand:move-after" help:"move resources from one root environment to AFTER another"`
+	MoveBefore *MoveBeforeCmd `arg:"subcommand:move-before" help:"move resources from one root environment to BEFORE another"`
+	Import     *ImportCmd     `arg:"subcommand:import" help:"import resources generated out-of-band of Terraform"`
+	Version    *struct{}      `arg:"subcommand:version" help:"show version"`
 }
 
 func (args) Description() string {
@@ -51,6 +52,12 @@ type MoveAfterCmd struct {
 	After  string `arg:"required" help:"the after root directory; will look for AFTER.tfplan and AFTER.tfstate"`
 }
 
+type MoveBeforeCmd struct {
+	Script string `arg:"required" help:"the migration scripts; will generate SCRIPT_up.sh and SCRIPT_down.sh"`
+	Before string `arg:"required" help:"the before root directory; will look for BEFORE.tfplan and BEFORE.tfstate"`
+	After  string `arg:"required" help:"the after root directory; will look for AFTER.tfstate"`
+}
+
 type ImportCmd struct {
 	UpDown
 	ResourceDefs string `arg:"--res-defs,required" help:"path to resource definitions"`
@@ -72,6 +79,9 @@ func run() error {
 	case args.MoveAfter != nil:
 		cmd := args.MoveAfter
 		return doMoveAfter(cmd.Script, cmd.Before, cmd.After)
+	case args.MoveBefore != nil:
+		cmd := args.MoveBefore
+		return doMoveBefore(cmd.Script, cmd.Before, cmd.After)
 	case args.Import != nil:
 		return doImport(args.Import.Up, args.Import.Down,
 			args.Import.SrcPlanPath, args.Import.ResourceDefs)

main_test.go

@@ -175,11 +175,60 @@ func TestRunMoveAfterFailure(t *testing.T) {
 }
 
 func TestRunMoveBeforeSuccess(t *testing.T) {
+	testCases := []struct {
+		name       string
+		before     string
+		after      string // special prefix: dummy
+		wantScript string
+	}{
+		{
+			name:       "happy path simple",
+			before:     "testdata/move-before/01-before",
+			after:      "dummy-01-after",
+			wantScript: "testdata/move-before/01-want",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			args := []string{"terravalet", "move-before"}
+
+			runMoveSuccess(t, args, tc.before, tc.after, tc.wantScript)
+		})
+	}
 }
 
 func TestRunMoveBeforeFailure(t *testing.T) {
+	testCases := []struct {
+		name    string
+		before  string // special value: "non-existing"
+		wantErr string
+	}{
+		{
+			name:    "non existing BEFORE plan",
+			before:  "non-existing",
+			wantErr: "opening the terraform BEFORE plan file: open non-existing.tfplan: no such file or directory",
+		},
+		{
+			name:    "BEFORE plan must not contain resources to destroy",
+			before:  "testdata/move-before/02-before",
+			wantErr: "BEFORE plan contains resources to destroy: [aws_batch_compute_environment.foo_batch]",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			args := []string{"terravalet", "move-before",
+				"--before=" + tc.before, "--after=testdata/move-before/dummy-after",
+			}
+
+			runMoveFailure(t, args, tc.before, "non-existing", tc.wantErr)
+		})
+	}
 }
 
+// If after has special prefix "dummy", it will not attempt to copy the
+// corresponding tfplan files, to accomodate for move-before.
 func runMoveSuccess(t *testing.T, args []string, before, after, wantScript string) {
 	wantUpPath := wantScript + "_up.sh"
 	wantUp, err := os.ReadFile(wantUpPath)
@@ -204,9 +253,11 @@ func runMoveSuccess(t *testing.T, args []string, before, after, wantScript strin
 		filepath.Join(tmpDir, path.Base(before)+".tfplan")); err != nil {
 		t.Fatal(err)
 	}
-	if err := copyfile(after+".tfplan",
-		filepath.Join(tmpDir, path.Base(after)+".tfplan")); err != nil {
-		t.Fatal(err)
+	if !strings.HasPrefix(after, "dummy") {
+		if err := copyfile(after+".tfplan",
+			filepath.Join(tmpDir, path.Base(after)+".tfplan")); err != nil {
+			t.Fatal(err)
+		}
 	}
 
 	// Change directory to the tmpdir.

testdata/move-before/01-before.tfplan

@@ -0,0 +1,22 @@
+random_pet.prepend: Refreshing state... [id=brave-mole]
+
+Terraform used the selected providers to generate the following execution
+plan. Resource actions are indicated with the following symbols:
+  + create
+
+Terraform will perform the following actions:
+
+  # null_resource.res1 will be created
+  + resource "null_resource" "res1" {
+      + id = (known after apply)
+    }
+
+Plan: 1 to add, 0 to change, 0 to destroy.
+
+Changes to Outputs:
+  + res1_id = (known after apply)
+
+─────────────────────────────────────────────────────────────────────────────
+
+Note: You didn't use the -out option to save this plan, so Terraform can't
+guarantee to take exactly these actions if you run "terraform apply" now.

testdata/move-before/01-want_down.sh

@@ -0,0 +1,12 @@
+#! /bin/sh
+# DO NOT EDIT. Generated by terravalet.
+# terravalet_output_format=2
+#
+# This script will move 1 items.
+
+set -e
+
+terraform state mv -lock=false -state=01-before.tfstate -state-out=dummy-01-after.tfstate \
+    'null_resource.res1' \
+    'null_resource.res1'
+

testdata/move-before/01-want_up.sh

@@ -0,0 +1,12 @@
+#! /bin/sh
+# DO NOT EDIT. Generated by terravalet.
+# terravalet_output_format=2
+#
+# This script will move 1 items.
+
+set -e
+
+terraform state mv -lock=false -state=dummy-01-after.tfstate -state-out=01-before.tfstate \
+    'null_resource.res1' \
+    'null_resource.res1'
+

testdata/move-before/02-before.tfplan

@@ -0,0 +1,14 @@
+random_pet.prepend: Refreshing state... [id=brave-mole]
+
+Terraform used the selected providers to generate the following execution
+plan. Resource actions are indicated with the following symbols:
+  + create
+
+Terraform will perform the following actions:
+
+  # null_resource.res1 will be created
+  + resource "null_resource" "res1" {
+      + id = (known after apply)
+    }
+
+  # aws_batch_compute_environment.foo_batch will be destroyed