feat: add flag to allow enable/disable project autodiscovery

cmd/server.go

@@ -54,6 +54,7 @@ const (
 	AllowForkPRsFlag                 = "allow-fork-prs"
 	AllowRepoConfigFlag              = "allow-repo-config"
 	AtlantisURLFlag                  = "atlantis-url"
+	AutoDiscover                     = "autodiscover"
 	AutomergeFlag                    = "automerge"
 	ParallelPlanFlag                 = "parallel-plan"
 	ParallelApplyFlag                = "parallel-apply"

runatlantis.io/docs/autodiscover.md

@@ -0,0 +1,92 @@
+# Autodiscover
+Atlantis can be configured to automatically discover Terraform projects in a repository.
+
+
+## How To Enable
+By default the autodiscover is enabled, but you can "enforce it":
+1. Server Side:
+    ```yaml
+    repo:
+        ...
+        autodiscover:
+          enabled: true
+        ...
+    ```
+1. Repo side `atlantis.yaml` file:
+    ```yaml
+    version: 3
+    autodiscover:
+        enabled: true
+    projects:
+    - dir: .
+    ```
+    :::tip NOTE
+    You need allow override in the server side configuration if you would like to disable it for a specific repo in the repo side configuration:
+    ```yaml
+    repo:
+        ...
+        allowed_overrides: [autodiscover]
+        ...
+    ```
+    ::::
+
+## How to Disable
+You can disable it globally for each repo in the server side.
+1. Server Side:
+    ```yaml
+    repo:
+        ...
+        autodiscover:
+          enabled: false
+        ...
+    ```
+or for a specific repo in the repo side `atlantis.yaml` file:
+1. Repo side `atlantis.yaml` file:
+    ```yaml
+    version: 3
+    autodiscover:
+        enabled: false
+    projects:
+    - dir: .
+    ```
+    :::tip NOTE
+    You need allow override in the server side configuration if you would like to disable it for a specific repo in the repo side configuration:
+    ```yaml
+    repo:
+        ...
+        allowed_overrides: [autodiscover]
+        ...
+    ```
+    ::::
+## Cases
+### Multiple Projects
+Atlantis will discover all Terraform projects in a repository. For example, if you have a repository with the following structure:
+```
+|── prod
+│   └── project1
+│          └── main.tf
+|   └── project2
+│          └── main.tf
+```
+Atlantis will discover both `project1` and `project2` and create a plan for each one.
+
+### Multi Server
+Image that you have a mono repository with multiples stages, and for each stage you have a different Atlantis server. You can configure each server to discover only the projects that are related to it. For example, if you have a repository with the following structure:
+```
+|── prod
+│   └── project1
+│   └── main.tf
+|── stage
+|── test
+└── project1
+└── main.tf
+```
+You can create the atlantis.yaml dynamically in each server to discover only the projects that are related to it. For example, the `prod` server side configuration will have the:
+```yaml
+repos:
+    - id: /.*/
+    apply_requirements: [approved, mergeable]
+    repo_config_file: atlantis-prod.yaml
+``` 
+
+and you can use a [pre_workflow_hooks](./pre-workflow-hooks.md) to create the `atlantis-prod.yaml` file dynamically.

runatlantis.io/docs/repo-level-atlantis-yaml.md

@@ -47,6 +47,8 @@ need to be defined.
 ```yaml
 version: 3
 automerge: true
+autodiscover:
+  enabled: true
 delete_source_branch_on_merge: true
 parallel_plan: true
 parallel_apply: true
@@ -148,6 +150,15 @@ projects:
 This will stop Atlantis automatically running plan when `project1/` is updated
 in a pull request.
 
+### Disabling Autodiscover
+```
+version: 3
+autodiscover:
+  enabled: false
+```
+
+This will stop Atlantis automatically discovering projects in a repo.
+
 ### Run plans and applies in parallel
 
 ```yaml

runatlantis.io/docs/server-side-repo-config.md

@@ -54,7 +54,7 @@ repos:
 
   # allowed_overrides specifies which keys can be overridden by this repo in
   # its atlantis.yaml file.
-  allowed_overrides: [apply_requirements, workflow, delete_source_branch_on_merge, repo_locking, custom_policy_check]
+  allowed_overrides: [apply_requirements, workflow, delete_source_branch_on_merge, repo_locking, custom_policy_check, autodiscover]
 
   # allowed_workflows specifies which workflows the repos that match 
   # are allowed to select.
@@ -88,6 +88,10 @@ repos:
   # policy_check defines if policy checking should be enable on this repository.
   policy_check: false
 
+  # autodiscover defines if atlantis should automatically discover projects in this repository.
+  autodiscover:
+    enabled: true
+
   # id can also be an exact match.
 - id: github.com/myorg/specific-repo
 
@@ -496,6 +500,7 @@ If you set a workflow with the key `default`, it will override this.
 | repo_locking                  | bool     | false   | no       | Whether or not to get a lock.                                                                                                                                                                                                                                                                             |
 | policy_check                  | bool     | false   | no       | Whether or not to run policy checks on this repository.                                                                                                                                                                                                                                                   |
 | custom_policy_check                  | bool     | false   | no       | Whether or not to enable custom policy check tools outside of Conftest on this repository.                                                                                                                                                                                                       |
+| autodiscover                  | Autodiscover     | true   | no       | Whether or not to enable autodiscover on this repository.                                                                                                                                                                                                                                                   |
 
 
 :::tip Notes

server/controllers/events/events_controller_e2e_test.go

@@ -1345,6 +1345,7 @@ func setupE2E(t *testing.T, repoDir string, opt setupOption) (events_controllers
 		false,
 		false,
 		false,
+		valid.Autodiscover{Enabled: true},
 		false,
 		false,
 		"",