Support incremental builds (#207)

Makefile

@@ -1,4 +1,4 @@
-VERSION=1.12.5
+VERSION=1.13.0
 PATH_BUILD=build/
 FILE_COMMAND=terragrunt-atlantis-config
 FILE_ARCH=darwin_amd64

README.md

@@ -48,7 +48,7 @@ Then, make sure `terragrunt-atlantis-config` is present on your Atlantis server.
 
 ```hcl
 variable "terragrunt_atlantis_config_version" {
-  default = "1.12.5"
+  default = "1.13.0"
 }
 
 build {
@@ -122,6 +122,7 @@ One way to customize the behavior of this module is through CLI flag values pass
 | `--create-workspace`         | Use different auto-generated workspace for each project. Default is use default workspace for everything                                                                        | false             |
 | `--create-project-name`      | Add different auto-generated name for each project                                                                                                                              | false             |
 | `--preserve-workflows`       | Preserves workflows from old output files. Useful if you want to define your workflow definitions on the client side                                                            | true              |
+| `--preserve-projects`        | Preserves projects from old output files. Useful for incremental builds using `--filter` | false              |
 | `--workflow`                 | Name of the workflow to be customized in the atlantis server. If empty, will be left out of output                                                                              | ""                |
 | `--apply-requirements`    | Requirements that must be satisfied before `atlantis apply` can be run. Currently the only supported requirements are `approved` and `mergeable`. Can be overridden by locals   | []                |
 | `--output`                   | Path of the file where configuration will be generated. Typically, you want a file named "atlantis.yaml". Default is to write to `stdout`.                                      | ""                |
@@ -189,7 +190,7 @@ You can install this tool locally to checkout what kinds of config it will gener
 Recommended: Install any version via go get:
 
 ```bash
-cd && GO111MODULE=on go get github.com/transcend-io/terragrunt-atlantis-config@v1.12.5 && cd -
+cd && GO111MODULE=on go get github.com/transcend-io/terragrunt-atlantis-config@v1.13.0 && cd -
 ```
 
 This module officially supports golang versions v1.13, v1.14, v1.15, and v1.16, tested on CircleCI with each build

cmd/generate.go

@@ -669,6 +669,9 @@ func main(cmd *cobra.Command, args []string) error {
 	if oldConfig != nil && preserveWorkflows {
 		config.Workflows = oldConfig.Workflows
 	}
+	if oldConfig != nil && preserveProjects {
+		config.Projects = oldConfig.Projects
+	}
 
 	lock := sync.Mutex{}
 	ctx := context.Background()

cmd/generate_test.go

@@ -34,6 +34,7 @@ func resetForRun() error {
 	createWorkspace = false
 	createProjectName = false
 	preserveWorkflows = true
+	preserveProjects = true
 	defaultWorkflow = ""
 	filterPath = ""
 	outputPath = ""
@@ -355,6 +356,53 @@ func TestPreservingOldWorkflows(t *testing.T) {
 	}
 }
 
+func TestPreservingOldProjects(t *testing.T) {
+	err := resetForRun()
+	if err != nil {
+		t.Error("Failed to reset default flags")
+		return
+	}
+
+	randomInt := rand.Int()
+	filename := filepath.Join("test_artifacts", fmt.Sprintf("%d.yaml", randomInt))
+	defer os.Remove(filename)
+
+	// Create an existing file to simulate an existing atlantis.yaml file
+	contents := []byte(`projects:
+- autoplan:
+    enabled: false
+    when_modified:
+    - '*.hcl'
+    - '*.tf*'
+  dir: someDir
+  name: projectFromPreviousRun 
+`)
+	ioutil.WriteFile(filename, contents, 0644)
+
+	content, err := RunWithFlags(filename, []string{
+		"generate",
+		"--preserve-projects",
+		"--output",
+		filename,
+		"--root",
+		filepath.Join("..", "test_examples", "basic_module"),
+	})
+	if err != nil {
+		t.Error("Failed to read file")
+		return
+	}
+
+	goldenContents, err := ioutil.ReadFile(filepath.Join("golden", "oldProjectsPreserved.yaml"))
+	if err != nil {
+		t.Error("Failed to read golden file")
+		return
+	}
+
+	if string(content) != string(goldenContents) {
+		t.Errorf("Content did not match golden file.\n\nExpected Content: %s\n\nContent: %s", string(goldenContents), string(content))
+	}
+}
+
 func TestEnablingAutomerge(t *testing.T) {
 	runTest(t, filepath.Join("golden", "withAutomerge.yaml"), []string{
 		"--root",

cmd/golden/oldProjectsPreserved.yaml

@@ -0,0 +1,18 @@
+automerge: false
+parallel_apply: true
+parallel_plan: true
+projects:
+- autoplan:
+    enabled: false
+    when_modified:
+    - '*.hcl'
+    - '*.tf*'
+  dir: .
+- autoplan:
+    enabled: false
+    when_modified:
+    - '*.hcl'
+    - '*.tf*'
+  dir: someDir
+  name: projectFromPreviousRun
+version: 3

main.go

@@ -5,7 +5,7 @@ import "github.com/transcend-io/terragrunt-atlantis-config/cmd"
 // This variable is set at build time using -ldflags parameters.
 // But we still set a default here for those using plain `go get` downloads
 // For more info, see: http://stackoverflow.com/a/11355611/483528
-var VERSION string = "1.12.5"
+var VERSION string = "1.13.0"
 
 func main() {
 	cmd.Execute(VERSION)