pkg/acquisition: remove/restore mock datasources after usage (#4190)

this allows us to override regular datasources as well during tests

Author: mmetc

pkg/acquisition/acquisition_test.go

@@ -76,15 +76,19 @@ func (*MockSourceCantRun) CanRun() error   { return errors.New("can't run bro")
 func (*MockSourceCantRun) GetName() string { return "mock_cant_run" }
 
 // appendMockSource is only used to add mock source for tests.
-func appendMockSource() {
-	registry.RegisterTestFactory("mock", func() types.DataSource { return &MockSource{} })
-	registry.RegisterTestFactory("mock_cant_run", func() types.DataSource { return &MockSourceCantRun{} })
+func appendMockSource(t *testing.T) {
+	t.Helper()
+
+	restore := registry.RegisterTestFactory("mock", func() types.DataSource { return &MockSource{} })
+	t.Cleanup(restore)
+	restore = registry.RegisterTestFactory("mock_cant_run", func() types.DataSource { return &MockSourceCantRun{} })
+	t.Cleanup(restore)
 }
 
 func TestDataSourceConfigure(t *testing.T) {
 	ctx := t.Context()
 
-	appendMockSource()
+	appendMockSource(t)
 
 	tests := []struct {
 		TestName      string
@@ -218,7 +222,7 @@ filename: foo.log
 }
 
 func TestLoadAcquisitionFromFiles(t *testing.T) {
-	appendMockSource()
+	appendMockSource(t)
 	t.Setenv("TEST_ENV", "test_value2")
 
 	ctx := t.Context()
@@ -554,7 +558,8 @@ func TestConfigureByDSN(t *testing.T) {
 		},
 	}
 
-	registry.RegisterTestFactory("mockdsn", func() types.DataSource { return &MockSourceByDSN{} })
+	restore := registry.RegisterTestFactory("mockdsn", func() types.DataSource { return &MockSourceByDSN{} })
+	t.Cleanup(restore)
 
 	for _, tc := range tests {
 		t.Run(tc.dsn, func(t *testing.T) {

pkg/acquisition/registry/registry.go

@@ -3,53 +3,82 @@ package registry
 import (
 	"errors"
 	"fmt"
+	"sync"
 
 	"github.com/crowdsecurity/crowdsec/pkg/acquisition/types"
 	"github.com/crowdsecurity/crowdsec/pkg/cwversion/component"
 )
 
 // factoriesByName is filled at init time so the application can report
 // if the datasources are unsupported, or simply excluded from the build.
-// We don't need to guard with a mutex if all writes to the map are done
-// inside init() functions, as they are guaranteed to run sequentially.
-var factoriesByName = map[string]func() types.DataSource{}
+var (
+	factoriesByName = map[string]types.DataSourceFactory{}
+	mu sync.RWMutex
+)
+
+func register(module string, factory types.DataSourceFactory) (restore func()) {
+	if module == "" {
+		panic("registry: datasource type is empty")
+	}
+
+	if factory == nil {
+		panic("registry: factory is nil for " + module)
+	}
+
+	mu.Lock()
+	prev, had := factoriesByName[module]
+	factoriesByName[module] = factory
+	mu.Unlock()
+
+	return func() {
+	        mu.Lock()
+	        if had {
+			factoriesByName[module] = prev
+		} else {
+			delete(factoriesByName, module)
+		}
+		mu.Unlock()
+	}
+}
 
 // RegisterFactory registers a datasource constructor in the factoriesByName map.
 // It must be called in the init() function of the datasource package.
 // In addition, the build component is registered so it will be reported
 // by the "cscli version / crowdsec --version" commands.
-func RegisterFactory(moduleName string, factory types.DataSourceFactory) {
-	component.Register("datasource_" + moduleName)
-	factoriesByName[moduleName] = factory
+func RegisterFactory(module string, factory types.DataSourceFactory) {
+	component.Register("datasource_" + module)
+	register(module, factory)
 }
 
 // RegisterTestFactory does not attempt to register it as a component,
 // production code should call RegisterFactory() instead and make the datasource
 // code optional using the appropriate build tag.
 // This function may be called outside init().
-func RegisterTestFactory(moduleName string, factory types.DataSourceFactory) {
-	factoriesByName[moduleName] = factory
+func RegisterTestFactory(module string, factory types.DataSourceFactory) (restore func()) {
+	return register(module, factory)
 }
 
-func LookupFactory(moduleName string) (types.DataSourceFactory, error) {
-	source, registered := factoriesByName[moduleName]
-	if registered {
-		return source, nil
+func LookupFactory(module string) (types.DataSourceFactory, error) {
+	if module == "" {
+		return nil, errors.New("data source type is empty")
 	}
 
-	built, known := component.Built["datasource_"+moduleName]
+	mu.RLock()
+	factory, registered := factoriesByName[module]
+	mu.RUnlock()
 
-	if moduleName == "" {
-		return nil, errors.New("data source type is empty")
+	if registered {
+		return factory, nil
 	}
 
+	built, known := component.Built["datasource_"+module]
 	if !known {
-		return nil, fmt.Errorf("unknown data source %s", moduleName)
+		return nil, fmt.Errorf("unknown data source %s", module)
 	}
 
 	if built {
-		panic("datasource " + moduleName + " is built but not registered")
+		panic("datasource " + module + " is built but not registered")
 	}
 
-	return nil, fmt.Errorf("data source %s is not built in this version of crowdsec", moduleName)
+	return nil, fmt.Errorf("data source %s is not built in this version of crowdsec", module)
 }