fix: config via environment (testcontainers#2725)

Fix the ability to set the configuration of testcontainers using an
environment variable set by a caller before the use of testcontainers.

This removes the warning about disabling the reaper which is actually
safe when done correctly.

Optimise verbose check.

Improve Config struct and field documentation.

Fixes: testcontainers#2701 testcontainers#2636

internal/config/config.go

@@ -20,18 +20,71 @@ var (
 
 // testcontainersConfig {
 
-// Config represents the configuration for Testcontainers
+// Config represents the configuration for Testcontainers.
+// User values are read from ~/.testcontainers.properties file which can be overridden
+// using the specified environment variables. For more information, see [Custom Configuration].
+//
+// The Ryuk prefixed fields controls the [Garbage Collector] feature, which ensures that
+// resources are cleaned up after the test execution.
+//
+// [Garbage Collector]: https://golang.testcontainers.org/features/garbage_collector/
+// [Custom Configuration]: https://golang.testcontainers.org/features/configuration/
 type Config struct {
-	Host                    string        `properties:"docker.host,default="`
-	TLSVerify               int           `properties:"docker.tls.verify,default=0"`
-	CertPath                string        `properties:"docker.cert.path,default="`
-	HubImageNamePrefix      string        `properties:"hub.image.name.prefix,default="`
-	RyukDisabled            bool          `properties:"ryuk.disabled,default=false"`
-	RyukPrivileged          bool          `properties:"ryuk.container.privileged,default=false"`
+	// Host is the address of the Docker daemon.
+	//
+	// Environment variable: DOCKER_HOST
+	Host string `properties:"docker.host,default="`
+
+	// TLSVerify is a flag to enable or disable TLS verification when connecting to a Docker daemon.
+	//
+	// Environment variable: DOCKER_TLS_VERIFY
+	TLSVerify int `properties:"docker.tls.verify,default=0"`
+
+	// CertPath is the path to the directory containing the Docker certificates.
+	// This is used when connecting to a Docker daemon over TLS.
+	//
+	// Environment variable: DOCKER_CERT_PATH
+	CertPath string `properties:"docker.cert.path,default="`
+
+	// HubImageNamePrefix is the prefix used for the images pulled from the Docker Hub.
+	// This is useful when running tests in environments with restricted internet access.
+	//
+	// Environment variable: TESTCONTAINERS_HUB_IMAGE_NAME_PREFIX
+	HubImageNamePrefix string `properties:"hub.image.name.prefix,default="`
+
+	// RyukDisabled is a flag to enable or disable the Garbage Collector.
+	// Setting this to true will prevent testcontainers from automatically cleaning up
+	// resources, which is particularly important in tests which timeout as they
+	// don't run test clean up.
+	//
+	// Environment variable: TESTCONTAINERS_RYUK_DISABLED
+	RyukDisabled bool `properties:"ryuk.disabled,default=false"`
+
+	// RyukPrivileged is a flag to enable or disable the privileged mode for the Garbage Collector container.
+	// Setting this to true will run the Garbage Collector container in privileged mode.
+	//
+	// Environment variable: TESTCONTAINERS_RYUK_CONTAINER_PRIVILEGED
+	RyukPrivileged bool `properties:"ryuk.container.privileged,default=false"`
+
+	// RyukReconnectionTimeout is the time to wait before attempting to reconnect to the Garbage Collector container.
+	//
+	// Environment variable: TESTCONTAINERS_RYUK_RECONNECTION_TIMEOUT
 	RyukReconnectionTimeout time.Duration `properties:"ryuk.reconnection.timeout,default=10s"`
-	RyukConnectionTimeout   time.Duration `properties:"ryuk.connection.timeout,default=1m"`
-	RyukVerbose             bool          `properties:"ryuk.verbose,default=false"`
-	TestcontainersHost      string        `properties:"tc.host,default="`
+
+	// RyukConnectionTimeout is the time to wait before timing out when connecting to the Garbage Collector container.
+	//
+	// Environment variable: TESTCONTAINERS_RYUK_CONNECTION_TIMEOUT
+	RyukConnectionTimeout time.Duration `properties:"ryuk.connection.timeout,default=1m"`
+
+	// RyukVerbose is a flag to enable or disable verbose logging for the Garbage Collector.
+	//
+	// Environment variable: TESTCONTAINERS_RYUK_VERBOSE
+	RyukVerbose bool `properties:"ryuk.verbose,default=false"`
+
+	// TestcontainersHost is the address of the Testcontainers host.
+	//
+	// Environment variable: TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE
+	TestcontainersHost string `properties:"tc.host,default="`
 }
 
 // }

logger.go

@@ -8,34 +8,20 @@ import (
 	"testing"
 
 	"github.com/docker/docker/client"
-
-	"github.com/testcontainers/testcontainers-go/internal/config"
 )
 
 // Logger is the default log instance
 var Logger Logging = log.New(os.Stderr, "", log.LstdFlags)
 
 func init() {
-	verbose := false
 	for _, arg := range os.Args {
 		if strings.EqualFold(arg, "-test.v=true") || strings.EqualFold(arg, "-v") {
-			verbose = true
-			break
+			return
 		}
 	}
 
-	if !verbose {
-		Logger = &noopLogger{}
-	}
-
-	if config.Read().RyukDisabled {
-		ryukDisabledMessage := `
-**********************************************************************************************
-Ryuk has been disabled for the current execution. This can cause unexpected behavior in your environment.
-More on this: https://golang.testcontainers.org/features/garbage_collector/
-**********************************************************************************************`
-		Logger.Printf(ryukDisabledMessage)
-	}
+	// If we are not running in verbose mode, we configure a noop logger by default.
+	Logger = &noopLogger{}
 }
 
 // Validate our types implement the required interfaces.