feat: add ListMysqlDatabases endpoint

pkg/api/README.md

@@ -54,6 +54,7 @@ Lazy creation means a connection failure to one database doesn't block startup o
 | GET | `/api/status` | `handleStatus` | All active schema changes |
 | GET | `/api/history/{database}` | `handleDatabaseHistory` | Apply history for a database |
 | GET | `/api/databases/{database}/environments` | `handleDatabaseEnvironments` | List environments |
+| GET | `/api/mysql/databases` | `handleListMysqlDatabases` | List configured MySQL databases |
 | GET | `/api/logs/{database}` | `handleLogs` | Apply logs for a database |
 | GET | `/api/logs` | `handleLogsWithoutDatabase` | Logs by apply ID |
 
@@ -106,6 +107,7 @@ See the top-level [README](../../README.md) for configuration examples.
 | `plan_handlers.go` | Plan and Apply HTTP handlers |
 | `control_handlers.go` | Cutover, Stop, Start, Volume, Revert handlers |
 | `progress_handlers.go` | Progress, Status, History handlers |
+| `mysql_handlers.go` | MySQL inventory handlers |
 | `health_handlers.go` | Health checks and JSON helpers |
 | `lock_handlers.go` | Lock acquire/release/list handlers |
 | `log_handlers.go` | Apply log handlers |

pkg/api/mysql_handlers.go

@@ -0,0 +1,68 @@
+package api
+
+import (
+	"net/http"
+	"sort"
+
+	"github.com/block/schemabot/pkg/apitypes"
+	"github.com/block/schemabot/pkg/storage"
+)
+
+// HandleListMysqlDatabases is the HTTP handler for GET /api/mysql/databases.
+func (s *Service) HandleListMysqlDatabases(w http.ResponseWriter, r *http.Request) {
+	s.handleListMysqlDatabases(w, r)
+}
+
+func (s *Service) handleListMysqlDatabases(w http.ResponseWriter, r *http.Request) {
+	environment := r.URL.Query().Get("environment")
+	resp := s.ListMysqlDatabases(environment)
+	s.writeJSON(w, http.StatusOK, resp)
+}
+
+// ListMysqlDatabases returns MySQL databases from the local SchemaBot catalog.
+func (s *Service) ListMysqlDatabases(environmentFilter string) *apitypes.ListMysqlDatabasesResponse {
+	databases := make([]*apitypes.MysqlDatabaseResponse, 0, len(s.config.Databases))
+	for name, dbConfig := range s.config.Databases {
+		if dbConfig.Type != storage.DatabaseTypeMySQL {
+			s.logger.Debug("skipping non-MySQL database in inventory list",
+				"database", name,
+				"database_type", dbConfig.Type)
+			continue
+		}
+
+		environments := matchingEnvironments(dbConfig.Environments, environmentFilter)
+		if len(environments) == 0 {
+			s.logger.Debug("skipping MySQL database with no matching environments",
+				"database", name,
+				"environment_filter", environmentFilter)
+			continue
+		}
+
+		databases = append(databases, &apitypes.MysqlDatabaseResponse{
+			Database:     name,
+			DatabaseType: dbConfig.Type,
+			Deployment:   name,
+			Environments: environments,
+		})
+	}
+
+	sort.Slice(databases, func(i, j int) bool {
+		return databases[i].Database < databases[j].Database
+	})
+
+	return &apitypes.ListMysqlDatabasesResponse{
+		Databases: databases,
+		Count:     len(databases),
+	}
+}
+
+func matchingEnvironments(configs map[string]EnvironmentConfig, environmentFilter string) []string {
+	environments := make([]string, 0, len(configs))
+	for environment := range configs {
+		if environmentFilter == "" || environment == environmentFilter {
+			environments = append(environments, environment)
+		}
+	}
+	sort.Strings(environments)
+	return environments
+}

pkg/api/mysql_handlers_test.go

@@ -0,0 +1,132 @@
+package api
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/block/schemabot/pkg/apitypes"
+	"github.com/block/schemabot/pkg/storage"
+)
+
+func TestListMysqlDatabases(t *testing.T) {
+	svc := newMysqlInventoryTestService(&ServerConfig{
+		Databases: map[string]DatabaseConfig{
+			"app_vitess": {
+				Type: storage.DatabaseTypeVitess,
+				Environments: map[string]EnvironmentConfig{
+					"staging": {DSN: "vitess-dsn"},
+				},
+			},
+			"orders": {
+				Type: storage.DatabaseTypeMySQL,
+				Environments: map[string]EnvironmentConfig{
+					"production": {DSN: "prod-dsn"},
+					"staging":    {DSN: "staging-dsn"},
+				},
+			},
+			"payments": {
+				Type: storage.DatabaseTypeMySQL,
+				Environments: map[string]EnvironmentConfig{
+					"staging": {DSN: "payments-dsn"},
+				},
+			},
+		},
+	})
+	mux := http.NewServeMux()
+	svc.ConfigureRoutes(mux)
+
+	req := httptest.NewRequestWithContext(t.Context(), "GET", "/api/mysql/databases", nil)
+	w := httptest.NewRecorder()
+	mux.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.NotContains(t, w.Body.String(), "prod-dsn")
+	assert.NotContains(t, w.Body.String(), "staging-dsn")
+
+	var resp apitypes.ListMysqlDatabasesResponse
+	err := json.NewDecoder(w.Body).Decode(&resp)
+	require.NoError(t, err, "failed to decode response")
+
+	require.Len(t, resp.Databases, 2)
+	assert.Equal(t, 2, resp.Count)
+	assert.Equal(t, "orders", resp.Databases[0].Database)
+	assert.Equal(t, storage.DatabaseTypeMySQL, resp.Databases[0].DatabaseType)
+	assert.Equal(t, "orders", resp.Databases[0].Deployment)
+	assert.Equal(t, []string{"production", "staging"}, resp.Databases[0].Environments)
+	assert.Equal(t, "payments", resp.Databases[1].Database)
+	assert.Equal(t, []string{"staging"}, resp.Databases[1].Environments)
+}
+
+func TestListMysqlDatabasesEnvironmentFilter(t *testing.T) {
+	svc := newMysqlInventoryTestService(&ServerConfig{
+		Databases: map[string]DatabaseConfig{
+			"orders": {
+				Type: storage.DatabaseTypeMySQL,
+				Environments: map[string]EnvironmentConfig{
+					"production": {DSN: "prod-dsn"},
+					"staging":    {DSN: "staging-dsn"},
+				},
+			},
+			"payments": {
+				Type: storage.DatabaseTypeMySQL,
+				Environments: map[string]EnvironmentConfig{
+					"staging": {DSN: "payments-dsn"},
+				},
+			},
+		},
+	})
+	mux := http.NewServeMux()
+	svc.ConfigureRoutes(mux)
+
+	req := httptest.NewRequestWithContext(t.Context(), "GET", "/api/mysql/databases?environment=production", nil)
+	w := httptest.NewRecorder()
+	mux.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var resp apitypes.ListMysqlDatabasesResponse
+	err := json.NewDecoder(w.Body).Decode(&resp)
+	require.NoError(t, err, "failed to decode response")
+
+	require.Len(t, resp.Databases, 1)
+	assert.Equal(t, 1, resp.Count)
+	assert.Equal(t, "orders", resp.Databases[0].Database)
+	assert.Equal(t, []string{"production"}, resp.Databases[0].Environments)
+}
+
+func TestListMysqlDatabasesWithoutConfiguredDatabases(t *testing.T) {
+	svc := newMysqlInventoryTestService(&ServerConfig{
+		TernDeployments: TernConfig{
+			"default": TernEndpoints{
+				"staging": "localhost:9090",
+			},
+		},
+	})
+	mux := http.NewServeMux()
+	svc.ConfigureRoutes(mux)
+
+	req := httptest.NewRequestWithContext(t.Context(), "GET", "/api/mysql/databases", nil)
+	w := httptest.NewRecorder()
+	mux.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var resp apitypes.ListMysqlDatabasesResponse
+	err := json.NewDecoder(w.Body).Decode(&resp)
+	require.NoError(t, err, "failed to decode response")
+
+	assert.Empty(t, resp.Databases)
+	assert.Zero(t, resp.Count)
+}
+
+func newMysqlInventoryTestService(config *ServerConfig) *Service {
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelError}))
+	return New(&mockStorage{}, config, nil, logger)
+}

pkg/api/service.go

@@ -398,6 +398,7 @@ func (s *Service) ConfigureRoutes(mux *http.ServeMux) {
 
 	// Config API (for CLI to discover environments)
 	mux.HandleFunc("GET /api/databases/{database}/environments", s.handleDatabaseEnvironments)
+	mux.HandleFunc("GET /api/mysql/databases", s.handleListMysqlDatabases)
 
 	// Orchestration API
 	mux.HandleFunc("POST /api/plan", s.handlePlan)

pkg/apitypes/apitypes.go

@@ -210,6 +210,20 @@ type TableChangeResponse struct {
 // GetTableName implements ddl.TableWithName for filtering Spirit internal tables.
 func (t *TableChangeResponse) GetTableName() string { return t.TableName }
 
+// MysqlDatabaseResponse represents a MySQL database known to SchemaBot.
+type MysqlDatabaseResponse struct {
+	Database     string   `json:"database"`
+	DatabaseType string   `json:"database_type"`
+	Deployment   string   `json:"deployment,omitempty"`
+	Environments []string `json:"environments"`
+}
+
+// ListMysqlDatabasesResponse is the response for GET /api/mysql/databases.
+type ListMysqlDatabasesResponse struct {
+	Databases []*MysqlDatabaseResponse `json:"databases"`
+	Count     int                      `json:"count"`
+}
+
 // LintViolationResponse represents a lint violation in the HTTP response.
 type LintViolationResponse struct {
 	Message  string `json:"message"`