feat(queueconfig): adding entity and basic interface for queue config

entity/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "batch_dependent.go",
         "build.go",
         "change_provider.go",
+        "queue_config.go",
         "request.go",
         "speculation_tree.go",
     ],
@@ -16,7 +17,10 @@ go_library(
 
 go_test(
     name = "entity_test",
-    srcs = ["request_test.go"],
+    srcs = [
+        "queue_config_test.go",
+        "request_test.go",
+    ],
     embed = [":entity"],
     deps = [
         "@com_github_stretchr_testify//assert",

entity/queue_config.go

@@ -0,0 +1,44 @@
+package entity
+
+// QueueConfig holds the configuration for a single submit queue.
+// Each queue maps a VCS repository + target to a processing pipeline.
+// A repository can have multiple queues, but each queue has exactly one target.
+// Immutable after creation.
+type QueueConfig struct {
+	// Name uniquely identifies this queue within the system.
+	// Referenced by Request.Queue.
+	Name string
+
+	// VCSType identifies the version control system (e.g., "git", "svn", "perforce").
+	// A queue operates on exactly one VCS.
+	VCSType string
+
+	// VCSAddress identifies the repository in the version control system.
+	// The format is VCS-specific:
+	//   - Git: remote URL (e.g., "git@github.com:uber/submitqueue.git")
+	//   - Perforce: depot path (e.g., "//depot/project")
+	//   - SVN: repository URL (e.g., "https://svn.example.com/repos/project")
+	VCSAddress string
+
+	// Target is the landing target where changes are merged.
+	// The format is VCS-specific:
+	//   - Git: branch ref (e.g., "main", "release/v2")
+	//   - Perforce: stream or depot path (e.g., "//depot/main/...")
+	//   - SVN: repository path (e.g., "trunk/")
+	Target string
+}
+
+// NewQueueConfig creates a new QueueConfig with the given parameters.
+func NewQueueConfig(
+	name string,
+	vcsType string,
+	vcsAddress string,
+	target string,
+) QueueConfig {
+	return QueueConfig{
+		Name:       name,
+		VCSType:    vcsType,
+		VCSAddress: vcsAddress,
+		Target:     target,
+	}
+}

entity/queue_config_test.go

@@ -0,0 +1,16 @@
+package entity
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewQueueConfig(t *testing.T) {
+	cfg := NewQueueConfig("uber/submitqueue/main", "git", "git@github.com:uber/submitqueue.git", "main")
+
+	assert.Equal(t, "uber/submitqueue/main", cfg.Name)
+	assert.Equal(t, "git", cfg.VCSType)
+	assert.Equal(t, "git@github.com:uber/submitqueue.git", cfg.VCSAddress)
+	assert.Equal(t, "main", cfg.Target)
+}

extension/queueconfig/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "queueconfig",
+    srcs = ["queueconfig.go"],
+    importpath = "github.com/uber/submitqueue/extension/queueconfig",
+    visibility = ["//visibility:public"],
+    deps = ["//entity"],
+)

extension/queueconfig/README.md

@@ -0,0 +1,22 @@
+# Queue Config Extension
+
+Vendor-agnostic interface for providing queue configurations.
+
+## Interfaces
+
+### Store
+
+Provides queue configurations by name.
+
+```go
+type Store interface {
+    Get(ctx context.Context, name string) (entity.QueueConfig, error)
+    List(ctx context.Context) ([]entity.QueueConfig, error)
+}
+```
+
+## Entities
+
+Queue configuration entity lives in `entity/queue_config.go`:
+
+- **QueueConfig** — configuration for a single submit queue (name, VCS type, VCS repo, target)

extension/queueconfig/queueconfig.go

@@ -0,0 +1,22 @@
+package queueconfig
+
+import (
+	"context"
+	"errors"
+
+	"github.com/uber/submitqueue/entity"
+)
+
+// ErrNotFound is returned when the requested queue configuration does not exist.
+var ErrNotFound = errors.New("queue config not found")
+
+// Store loads and provides queue configurations.
+// Implementations may read from YAML files, databases, remote services, etc.
+type Store interface {
+	// Get returns the configuration for a named queue.
+	// Returns ErrNotFound if no configuration exists for the given name.
+	Get(ctx context.Context, name string) (entity.QueueConfig, error)
+
+	// List returns all configured queues.
+	List(ctx context.Context) ([]entity.QueueConfig, error)
+}