fix(plugins/container): use an unique ctx for fetcher.

Podman relies upon context to store its connection infos.
Using same ctx already used by the real Podman engine means that
we are going to tamper with its connection info stored in the main ctx.

Instead, fetcher should use its own context.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

Author: FedeDP

plugins/container/go-worker/pkg/container/fetcher.go

@@ -22,22 +22,28 @@ func GetFetcherChan() chan<- string {
 
 type fetcher struct {
 	getters []getter
+	ctx     context.Context
 }
 
 // NewFetcherEngine returns a fetcher engine.
 // The fetcher engine is responsible to allow us to get() single container
 // trying all container engines enabled.
-func NewFetcherEngine(ctx context.Context, containerEngines []Engine) Engine {
+func NewFetcherEngine(_ context.Context, containerEngines []Engine) Engine {
 	f := fetcher{
 		getters: make([]getter, len(containerEngines)),
+		// Since podman relies upon context to store
+		// connection-related info,
+		// we need a unique context for fetcher
+		// to avoid tampering with real podman engine context.
+		ctx: context.Background(),
 	}
 	for i, engine := range containerEngines {
 		copyEngine, ok := engine.(copier)
 		if !ok {
 			// We need all engines to implement the copier interface to be copied by fetcher.
 			panic("not a copier")
 		}
-		e, _ := copyEngine.copy(ctx)
+		e, _ := copyEngine.copy(f.ctx)
 		if e != nil {
 			// No type check since Engine interface extends getter.
 			f.getters[i] = e.(getter)
@@ -75,7 +81,7 @@ func (f *fetcher) Listen(ctx context.Context, wg *sync.WaitGroup) (<-chan event.
 				return
 			case containerId := <-fetcherChan:
 				for _, e := range f.getters {
-					evt, _ := e.get(ctx, containerId)
+					evt, _ := e.get(f.ctx, containerId)
 					if evt != nil {
 						outCh <- *evt
 						break