chore: proper messaging on disabling ryuk (#566)

* chore: add a banner qhen Ryuk is disabled

* docs: document unexpected behaviors when disabling Ryuk

* chore: link to docs in the message

* docs: improve message in docs

* chore: extract banner to a function

docker.go

@@ -951,6 +951,8 @@ func (p *DockerProvider) CreateContainer(ctx context.Context, req ContainerReque
 				req.Labels[k] = v
 			}
 		}
+	} else {
+		p.printReaperBanner("container")
 	}
 
 	if err = req.Validate(); err != nil {
@@ -1164,6 +1166,8 @@ func (p *DockerProvider) ReuseOrCreateContainer(ctx context.Context, req Contain
 		if err != nil {
 			return nil, fmt.Errorf("%w: connecting to reaper failed", err)
 		}
+	} else {
+		p.printReaperBanner("container")
 	}
 	dc := &DockerContainer{
 		ID:                c.ID,
@@ -1323,6 +1327,8 @@ func (p *DockerProvider) CreateNetwork(ctx context.Context, req NetworkRequest)
 				req.Labels[k] = v
 			}
 		}
+	} else {
+		p.printReaperBanner("network")
 	}
 
 	response, err := p.client.NetworkCreate(ctx, req.Name, nc)
@@ -1381,6 +1387,15 @@ func (p *DockerProvider) GetGatewayIP(ctx context.Context) (string, error) {
 	return ip, nil
 }
 
+func (p *DockerProvider) printReaperBanner(resource string) {
+	ryukDisabledMessage := `
+	**********************************************************************************************
+	Ryuk has been disabled for the ` + resource + `. This can cause unexpected behavior in your environment.
+	More on this: https://golang.testcontainers.org/features/garbage_collector/
+	**********************************************************************************************`
+	p.Logger.Printf(ryukDisabledMessage)
+}
+
 func inAContainer() bool {
 	// see https://github.com/testcontainers/testcontainers-java/blob/3ad8d80e2484864e554744a4800a81f6b7982168/core/src/main/java/org/testcontainers/dockerclient/DockerClientConfigUtils.java#L15
 	if _, err := os.Stat("/.dockerenv"); err == nil {

docs/features/garbage_collector.md

@@ -37,9 +37,13 @@ container labels to determine which resources were created by the package
 to determine the entities that are safe to remove. If a container is running
 for more than 10 seconds, it will be killed.
 
-!!!tip
+!!!warning
+
+    This feature can be disabled when creating a container or a network,
+    but it can cause **unexpected behavior** in your environment.
 
-    This feature can be disabled when creating a container.
+    We recommend using it only for Continuous Integration services that have their
+    own mechanism to clean up resources.
 
 Even if you do not call Terminate, Ryuk ensures that the environment will be
 kept clean and even cleans itself when there is nothing left to do.