feat: allow autodiscover workspace override

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

@@ -57,6 +57,7 @@ version: 3 # Available since v0.1.0
 automerge: true # Available since v0.15.0
 autodiscover: # Available since v0.18.0
   mode: auto
+  workspace: default
   ignore_paths:
   - some/path
 delete_source_branch_on_merge: true # Available since v0.15.0
@@ -418,6 +419,16 @@ autodiscover:
 
 Autodiscover can also be configured to skip over directories that match a path glob (as defined [here](https://pkg.go.dev/github.com/bmatcuk/doublestar/v4))
 
+```yaml
+autodiscover:
+   mode: "enabled"
+   workspace: qa
+   ignore_paths:
+      - terraform/aws-test/**
+```
+
+Use `workspace` to set the Terraform workspace for all autodiscovered projects. This is useful when running separate Atlantis instances per workspace on a shared repository. The configured workspace takes precedence over any workspace detected from `terraform { cloud { workspaces { name = "..." } } }` blocks in Terraform code.
+
 ### Custom Backend Config
 
 See [Custom Workflow Use Cases: Custom Backend Config](custom-workflows.md#custom-backend-config)

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

@@ -100,6 +100,8 @@ repos:
   # If any part of this setting is set here, it overrides the entire setting in the repo config.
   autodiscover:
     mode: auto
+    # Optionally set a workspace for all autodiscovered projects
+    workspace: ""
     # Optionally ignore some paths for autodiscovery by a glob path
     ignore_paths:
       - foo/*
@@ -546,7 +548,7 @@ If you set a workflow with the key `default`, it will override this.
 | repo_locks                    | [RepoLocks](#repolocks) | `mode: on_plan` | no       | Whether or not repository locks are enabled for this project on plan or apply. See [RepoLocks](#repolocks) for more details.                                                                                                                                                                              |
 | 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            | none            | no       | Auto discover settings for this repo                                                                                                                                                                                                                                                                      |
+| autodiscover                  | [AutoDiscover](#autodiscover) | none     | no       | Auto discover settings for this repo. See [AutoDiscover](#autodiscover) for more details.                                                                                                                                                                                                                 |
 | silence_pr_comments           | []string                | none            | no       | Silence PR comments from defined stages while preserving PR status checks. Useful in large environments with many Atlantis instances and/or projects, when the comments are too big and too many, therefore it is preferable to rely solely on PR status checks. Supported values are: `plan`, `apply`.   |
 
 :::tip Notes
@@ -584,6 +586,21 @@ If you set a workflow with the key `default`, it will override this.
     by the `id: github.com/owner/repo` config because it didn't define that key.
 :::
 
+### AutoDiscover
+
+```yaml
+mode: auto
+workspace: ""
+ignore_paths:
+  - some/path/**
+```
+
+| Key          | Type            | Default  | Required | Description                                                                                                                                                                                                           |
+|--------------|-----------------|----------|----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| mode         | string          | `"auto"` | no       | When `auto`, projects are discovered only if the repo has no `projects` configured. When `enabled`, discovery always runs. When `disabled`, discovery never runs.                                                     |
+| workspace    | string          | `""`     | no       | Workspace to use for all autodiscovered projects. When set, this overrides workspace detection from `terraform { cloud { workspaces { name = "..." } } }` blocks. Useful when running one Atlantis instance per workspace. |
+| ignore_paths | array\[string\] | `[]`     | no       | List of path globs (as defined [here](https://pkg.go.dev/github.com/bmatcuk/doublestar/v4)) to exclude from autodiscovery.                                                                                            |
+
 ### RepoLocks
 
 ```yaml

server/core/config/raw/autodiscover.go

@@ -18,6 +18,7 @@ var DefaultAutoDiscoverMode = valid.AutoDiscoverAutoMode
 type AutoDiscover struct {
 	Mode        *valid.AutoDiscoverMode `yaml:"mode,omitempty"`
 	IgnorePaths []string                `yaml:"ignore_paths,omitempty"`
+	Workspace   string                  `yaml:"workspace,omitempty"`
 }
 
 func (a AutoDiscover) ToValid() *valid.AutoDiscover {
@@ -30,6 +31,7 @@ func (a AutoDiscover) ToValid() *valid.AutoDiscover {
 	}
 
 	v.IgnorePaths = a.IgnorePaths
+	v.Workspace = a.Workspace
 
 	return &v
 }

server/core/config/raw/autodiscover_test.go

@@ -38,6 +38,16 @@ ignore_paths:
 				IgnorePaths: []string{"foobar"},
 			},
 		},
+		{
+			description: "workspace set",
+			input: `
+workspace: qa
+`,
+			exp: raw.AutoDiscover{
+				Mode:      nil,
+				Workspace: "qa",
+			},
+		},
 	}
 
 	for _, c := range cases {
@@ -198,6 +208,17 @@ func TestAutoDiscover_ToValid(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "workspace set",
+			input: raw.AutoDiscover{
+				Mode:      &autoDiscoverEnabled,
+				Workspace: "qa",
+			},
+			exp: &valid.AutoDiscover{
+				Mode:      valid.AutoDiscoverEnabledMode,
+				Workspace: "qa",
+			},
+		},
 	}
 	for _, c := range cases {
 		t.Run(c.description, func(t *testing.T) {

server/core/config/valid/autodiscover.go

@@ -17,6 +17,7 @@ const (
 type AutoDiscover struct {
 	Mode        AutoDiscoverMode
 	IgnorePaths []string
+	Workspace   string
 }
 
 func (a AutoDiscover) IsPathIgnored(path string) bool {

server/events/project_command_builder.go

@@ -384,13 +384,13 @@ func (p *DefaultProjectCommandBuilder) autoDiscoverModeEnabled(ctx *command.Cont
 // isAutoDiscoverPathIgnored determines whether this particular path is ignored for the purposes of auto discovery
 func (p *DefaultProjectCommandBuilder) isAutoDiscoverPathIgnored(ctx *command.Context, repoCfg valid.RepoCfg, path string) bool {
 	fromGlobalAutoDiscover := p.GlobalCfg.RepoAutoDiscoverCfg(ctx.Pull.BaseRepo.ID())
-	if fromGlobalAutoDiscover != nil {
+	// Only use global config's IgnorePaths if they are explicitly set; otherwise fall through to repo-level.
+	if fromGlobalAutoDiscover != nil && fromGlobalAutoDiscover.IgnorePaths != nil {
 		return fromGlobalAutoDiscover.IsPathIgnored(path)
 	}
 	if repoCfg.AutoDiscover != nil {
 		return repoCfg.AutoDiscover.IsPathIgnored(path)
 	}
-
 	return false
 }
 
@@ -447,12 +447,26 @@ func (p *DefaultProjectCommandBuilder) getMergedProjectCfgs(ctx *command.Context
 		}
 		ctx.Log.Info("automatically determined that there were %d additional projects modified in this pull request: %s",
 			len(modifiedProjects), modifiedProjects)
+		// Determine the workspace to use for autodiscovered projects. Global config takes precedence
+		// over repo-level config; both are only consulted when explicitly set (non-empty).
+		configuredWorkspace := ""
+		fromGlobalAutoDiscover := p.GlobalCfg.RepoAutoDiscoverCfg(ctx.Pull.BaseRepo.ID())
+		if fromGlobalAutoDiscover != nil && fromGlobalAutoDiscover.Workspace != "" {
+			configuredWorkspace = fromGlobalAutoDiscover.Workspace
+		} else if repoCfg.AutoDiscover != nil && repoCfg.AutoDiscover.Workspace != "" {
+			configuredWorkspace = repoCfg.AutoDiscover.Workspace
+		}
 		for _, mp := range modifiedProjects {
 			ctx.Log.Debug("determining config for project at dir: '%s'", mp.Path)
 			absProjectDir := filepath.Join(repoDir, mp.Path)
-			pWorkspace, err := p.ProjectFinder.DetermineWorkspaceFromHCL(ctx.Log, absProjectDir)
-			if err != nil {
-				return nil, fmt.Errorf("looking for Terraform Cloud workspace from configuration in '%s': %w", absProjectDir, err)
+			var pWorkspace string
+			if configuredWorkspace != "" {
+				pWorkspace = configuredWorkspace
+			} else {
+				pWorkspace, err = p.ProjectFinder.DetermineWorkspaceFromHCL(ctx.Log, absProjectDir)
+				if err != nil {
+					return nil, fmt.Errorf("looking for Terraform Cloud workspace from configuration in '%s': %w", absProjectDir, err)
+				}
 			}
 
 			pCfg := p.GlobalCfg.DefaultProjCfg(ctx.Log, ctx.Pull.BaseRepo.ID(), mp.Path, pWorkspace)

server/events/project_command_builder_test.go

@@ -1117,6 +1117,30 @@ projects:
 				},
 			},
 		},
+		"autodiscover workspace set in autodiscover config": {
+			DirStructure: map[string]any{
+				"project1": map[string]any{
+					"main.tf": nil,
+				},
+				"project2": map[string]any{
+					"main.tf": nil,
+				},
+			},
+			AtlantisYAML: `version: 3
+autodiscover:
+  mode: enabled
+  workspace: qa
+  ignore_paths:
+  - project2`,
+			ModifiedFiles: []string{"project1/main.tf", "project2/main.tf"},
+			Exp: []expCtxFields{
+				{
+					ProjectName: "",
+					RepoRelDir:  "project1",
+					Workspace:   "qa",
+				},
+			},
+		},
 		"autodiscover enabled but project excluded by empty when_modified": {
 			DirStructure: map[string]any{
 				"project1": map[string]any{