feat: support reading Docker host from the current Docker context

docker_test.go

@@ -440,7 +440,7 @@ func TestContainerCreationWithName(t *testing.T) {
 			Name:       creationName,
 			// no network means it will be connected to the default bridge network
 			// of any given container runtime
-			Networks: []string{},
+			// Networks: []string{},
 		},
 		Started: true,
 	})
@@ -456,7 +456,7 @@ func TestContainerCreationWithName(t *testing.T) {
 	require.NoError(t, err)
 	require.Lenf(t, networks, 1, "Expected networks 1. Got '%d'.", len(networks))
 	network := networks[0]
-	assert.Equalf(t, Bridge, network, "Expected network name '%s'. Got '%s'.", Bridge, network)
+	require.Equal(t, Bridge, network)
 
 	endpoint, err := nginxC.PortEndpoint(ctx, nginxDefaultPort, "http")
 	require.NoError(t, err)
@@ -671,7 +671,7 @@ func Test_BuildContainerFromDockerfileWithBuildLog(t *testing.T) {
 
 	temp := strings.Split(string(out), "\n")
 	require.NotEmpty(t, temp)
-	assert.Regexpf(t, `^(?i:Step)\s*1/\d+\s*:\s*FROM alpine$`, temp[0], "Expected stdout first line to be %s. Got '%s'.", "Step 1/* : FROM alpine", temp[0])
+	require.Regexp(t, `^(?i:Step)\s*1/\d+\s*:\s*FROM alpine$`, temp[0])
 }
 
 func TestContainerCreationWaitsForLogAndPortContextTimeout(t *testing.T) {

docs/system_requirements/docker.md

@@ -45,10 +45,10 @@ docker context use orbstack
 
 ### Podman
 
-Podman does not create its own Docker context when it is installed so, after starting a `podman-machine`, please create it with the following command:
+Podman does not create its own Docker context when it is installed so, after starting a `podman-machine` in **rootful mode**, please create the context with the following command:
 
 ```sh
-docker context create podman --description "podman context" --docker "host=unix:///var/folders/_j/nhbgdck523n3008dd3zlsm5m0000gn/T/podman/podman-machine-default-api.sock"
+podman context create podman --description "podman context" --docker "host=unix:///var/folders/_j/nhbgdck523n3008dd3zlsm5m0000gn/T/podman/podman-machine-default-api.sock"
 ```
 
 !!! note
@@ -57,7 +57,7 @@ docker context create podman --description "podman context" --docker "host=unix:
 Then you can set this as the active context by running:
 
 ```sh
-docker context use podman
+podman context use podman
 ```
 
 ### Rancher Desktop

internal/config/config.go

@@ -11,7 +11,13 @@ import (
 	"github.com/magiconair/properties"
 )
 
-const ReaperDefaultImage = "testcontainers/ryuk:0.11.0"
+const (
+	// ReaperDefaultImage is the default image used for Ryuk, the resource reaper.
+	ReaperDefaultImage = "testcontainers/ryuk:0.11.0"
+
+	// TestcontainersProperties is the name of the properties file used to configure Testcontainers.
+	TestcontainersProperties = ".testcontainers.properties"
+)
 
 var (
 	tcConfig     Config
@@ -89,31 +95,6 @@ type Config struct {
 
 // }
 
-// defaultConfig
-func defaultConfig() Config {
-	config := Config{}
-
-	home, err := os.UserHomeDir()
-	if err != nil {
-		return applyEnvironmentConfiguration(config)
-	}
-
-	tcProp := filepath.Join(home, ".testcontainers.properties")
-	// Init from a file, ignore if it doesn't exist, which is the case for most users.
-	// The properties library will return the default values for the struct.
-	props, err := properties.LoadFiles([]string{tcProp}, properties.UTF8, true)
-	if err != nil {
-		return applyEnvironmentConfiguration(config)
-	}
-
-	if err := props.Decode(&config); err != nil {
-		fmt.Printf("invalid testcontainers properties file, returning an empty Testcontainers configuration: %v\n", err)
-		return applyEnvironmentConfiguration(config)
-	}
-
-	return config
-}
-
 func applyEnvironmentConfiguration(config Config) Config {
 	ryukDisabledEnv := os.Getenv("TESTCONTAINERS_RYUK_DISABLED")
 	if parseBool(ryukDisabledEnv) {
@@ -167,7 +148,25 @@ func Reset() {
 }
 
 func read() Config {
-	config := defaultConfig()
+	var config Config
+
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return applyEnvironmentConfiguration(config)
+	}
+
+	tcProp := filepath.Join(home, TestcontainersProperties)
+	// Init from a file, ignore if it doesn't exist, which is the case for most users.
+	// The properties library will return the default values for the struct.
+	props, err := properties.LoadFiles([]string{tcProp}, properties.UTF8, true)
+	if err != nil {
+		return applyEnvironmentConfiguration(config)
+	}
+
+	if err := props.Decode(&config); err != nil {
+		fmt.Printf("invalid testcontainers properties file, returning an empty Testcontainers configuration: %v\n", err)
+		return applyEnvironmentConfiguration(config)
+	}
 
 	return applyEnvironmentConfiguration(config)
 }

internal/config/config_test.go

@@ -102,7 +102,11 @@ func TestReadTCConfig(t *testing.T) {
 
 		config := read()
 
-		expected := defaultConfig()
+		// The time fields are set to the default values.
+		expected := Config{
+			RyukReconnectionTimeout: 10 * time.Second,
+			RyukConnectionTimeout:   time.Minute,
+		}
 
 		assert.Equal(t, expected, config)
 	})
@@ -114,7 +118,14 @@ func TestReadTCConfig(t *testing.T) {
 		t.Setenv("DOCKER_HOST", tcpDockerHost33293)
 
 		config := read()
-		expected := defaultConfig() // the config does not read DOCKER_HOST, that's why it's empty
+
+		// The time fields are set to the default values,
+		// and the config does not read DOCKER_HOST,
+		// that's why it's empty
+		expected := Config{
+			RyukReconnectionTimeout: 10 * time.Second,
+			RyukConnectionTimeout:   time.Minute,
+		}
 
 		assert.Equal(t, expected, config)
 	})

internal/core/docker_context.go

@@ -21,23 +21,27 @@ import (
 const (
 	// defaultContextName is the name reserved for the default context (config & env based)
 	defaultContextName = "default"
+
 	// envOverrideContext is the name of the environment variable that can be
 	// used to override the context to use. If set, it overrides the context
 	// that's set in the CLI's configuration file, but takes no effect if the
 	// "DOCKER_HOST" env-var is set (which takes precedence.
 	envOverrideContext = "DOCKER_CONTEXT"
+
 	// envOverrideConfigDir is the name of the environment variable that can be
 	// used to override the location of the client configuration files (~/.docker).
 	//
 	// It takes priority over the default.
 	envOverrideConfigDir = "DOCKER_CONFIG"
+
 	// configFileName is the name of the client configuration file inside the
 	// config-directory.
 	configFileName = "config.json"
 	configFileDir  = ".docker"
 	contextsDir    = "contexts"
 	metadataDir    = "meta"
 	metaFile       = "meta.json"
+
 	// DockerEndpoint is the name of the docker endpoint in a stored context
 	dockerEndpoint string = "docker"
 )
@@ -118,6 +122,7 @@ type untypedContextMetadata struct {
 	Name      string                     `json:"name,omitempty"`
 }
 
+// getByID returns the metadata for a context by its ID
 func (s *metadataStore) getByID(id contextdir) (metadata, error) {
 	fileName := filepath.Join(s.contextDir(id), metaFile)
 	bytes, err := os.ReadFile(fileName)
@@ -134,17 +139,17 @@ func (s *metadataStore) getByID(id contextdir) (metadata, error) {
 	}
 
 	if err := json.Unmarshal(bytes, &untyped); err != nil {
-		return metadata{}, fmt.Errorf("parsing %s: %w", fileName, err)
+		return metadata{}, fmt.Errorf("parsing %s (metadata): %w", fileName, err)
 	}
 
 	r.Name = untyped.Name
 	if r.Metadata, err = parseTypedOrMap(untyped.Metadata, s.config.contextType); err != nil {
-		return metadata{}, fmt.Errorf("parsing %s: %w", fileName, err)
+		return metadata{}, fmt.Errorf("parsing %s (context type): %w", fileName, err)
 	}
 
 	for k, v := range untyped.Endpoints {
 		if r.Endpoints[k], err = parseTypedOrMap(v, s.config.endpointTypes[k]); err != nil {
-			return metadata{}, fmt.Errorf("parsing %s: %w", fileName, err)
+			return metadata{}, fmt.Errorf("parsing %s (endpoint types): %w", fileName, err)
 		}
 	}
 
@@ -176,8 +181,11 @@ func (s *metadataStore) list() ([]metadata, error) {
 	return res, nil
 }
 
+// contextdir is a type used to represent a context directory
 type contextdir string
 
+// isContextDir checks if the given path is a context directory,
+// which means it contains a meta.json file.
 func isContextDir(path string) bool {
 	s, err := os.Stat(filepath.Join(path, metaFile))
 	if err != nil {
@@ -187,33 +195,35 @@ func isContextDir(path string) bool {
 	return !s.IsDir()
 }
 
+// listRecursivelyMetadataDirs lists all directories that contain a meta.json file
 func listRecursivelyMetadataDirs(root string) ([]string, error) {
-	fis, err := os.ReadDir(root)
+	fileEntries, err := os.ReadDir(root)
 	if err != nil {
 		return nil, err
 	}
 
 	var result []string
-	for _, fi := range fis {
-		if fi.IsDir() {
-			if isContextDir(filepath.Join(root, fi.Name())) {
-				result = append(result, fi.Name())
+	for _, fileEntry := range fileEntries {
+		if fileEntry.IsDir() {
+			if isContextDir(filepath.Join(root, fileEntry.Name())) {
+				result = append(result, fileEntry.Name())
 			}
 
-			subs, err := listRecursivelyMetadataDirs(filepath.Join(root, fi.Name()))
+			subs, err := listRecursivelyMetadataDirs(filepath.Join(root, fileEntry.Name()))
 			if err != nil {
 				return nil, err
 			}
 
 			for _, s := range subs {
-				result = append(result, filepath.Join(fi.Name(), s))
+				result = append(result, filepath.Join(fileEntry.Name(), s))
 			}
 		}
 	}
 
 	return result, nil
 }
 
+// parseTypedOrMap parses a JSON payload into a typed object or a map
 func parseTypedOrMap(payload []byte, getter typeGetter) (any, error) {
 	if len(payload) == 0 || string(payload) == "null" {
 		return nil, nil
@@ -298,7 +308,7 @@ func GetDockerHostFromCurrentContext() (string, error) {
 		}
 	}
 
-	return "", ErrDockerSocketNotSetInDockerContext
+	return "", errDockerSocketNotSetInDockerContext
 }
 
 // currentContext returns the current context name, based on

internal/core/docker_host.go

@@ -19,16 +19,16 @@
 var DockerHostContextKey = dockerHostContext("docker_host")
 
 var (
-	ErrDockerHostNotSet                  = errors.New("DOCKER_HOST is not set")
-	ErrDockerSocketOverrideNotSet        = errors.New("TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE is not set")
-	ErrDockerSocketNotSetInContext       = errors.New("socket not set in Go context")
-	ErrDockerSocketNotSetInDockerContext = errors.New("socket not set in Docker context")
-	ErrDockerSocketNotSetInProperties    = errors.New("socket not set in ~/.testcontainers.properties")
-	ErrNoUnixSchema                      = errors.New("URL schema is not unix")
-	ErrSocketNotFound                    = errors.New("socket not found")
-	ErrSocketNotFoundInPath              = errors.New("docker socket not found in " + DockerSocketPath)
-	// ErrTestcontainersHostNotSetInProperties this error is specific to Testcontainers
-	ErrTestcontainersHostNotSetInProperties = errors.New("tc.host not set in ~/.testcontainers.properties")
+	errDockerHostNotSet                  = errors.New("DOCKER_HOST is not set")
+	errDockerSocketOverrideNotSet        = errors.New("TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE is not set")
+	errDockerSocketNotSetInContext       = errors.New("socket not set in Go context")
+	errDockerSocketNotSetInDockerContext = errors.New("socket not set in Docker context")
+	errDockerSocketNotSetInProperties    = errors.New("socket not set in ~/.testcontainers.properties")
+	errNoUnixSchema                      = errors.New("URL schema is not unix")
+	errSocketNotFound                    = errors.New("socket not found")
+	errSocketNotFoundInPath              = errors.New("docker socket not found in " + DockerSocketPath)
+	// errTestcontainersHostNotSetInProperties this error is specific to Testcontainers
+	errTestcontainersHostNotSetInProperties = errors.New("tc.host not set in ~/.testcontainers.properties")
 )
 
 var (
@@ -127,7 +127,9 @@
 		testcontainersHostFromProperties,
 		dockerHostFromEnv,
 		dockerHostFromContext,
-		dockerHostFromDockerContext,
+		func(_ context.Context) (string, error) {
+			return GetDockerHostFromCurrentContext()
+		},
 		dockerSocketPath,
 		dockerHostFromProperties,
 		rootlessDockerSocketPath,
@@ -155,7 +157,7 @@
 		return "", errors.Join(errs...)
 	}
 
-	return "", ErrSocketNotFound
+	return "", errSocketNotFound
 }
 
 // extractDockerSocket Extracts the docker socket from the different alternatives, without caching the result.
@@ -232,11 +234,11 @@
 // not being set, false otherwise.
 func isHostNotSet(err error) bool {
 	switch {
-	case errors.Is(err, ErrTestcontainersHostNotSetInProperties),
-		errors.Is(err, ErrDockerHostNotSet),
-		errors.Is(err, ErrDockerSocketNotSetInContext),
-		errors.Is(err, ErrDockerSocketNotSetInProperties),
-		errors.Is(err, ErrSocketNotFoundInPath),
+	case errors.Is(err, errTestcontainersHostNotSetInProperties),
+		errors.Is(err, errDockerHostNotSet),
+		errors.Is(err, errDockerSocketNotSetInContext),
+		errors.Is(err, errDockerSocketNotSetInProperties),
+		errors.Is(err, errSocketNotFoundInPath),
 		errors.Is(err, ErrXDGRuntimeDirNotSet),
 		errors.Is(err, ErrRootlessDockerNotFoundHomeRunDir),
 		errors.Is(err, ErrRootlessDockerNotFoundHomeDesktopDir),
@@ -253,7 +255,7 @@
 		return dockerHostPath, nil
 	}
 
-	return "", ErrDockerHostNotSet
+	return "", errDockerHostNotSet
 }
 
 // dockerHostFromContext returns the docker host from the Go context, if it's not empty
@@ -267,11 +269,11 @@
 		return parsed, nil
 	}
 
-	return "", ErrDockerSocketNotSetInContext
+	return "", errDockerSocketNotSetInContext
 }
 
 // dockerHostFromContext returns the docker host from the Go context, if it's not empty
 func dockerHostFromDockerContext(ctx context.Context) (string, error) {
 	dockerHost, err := GetDockerHostFromCurrentContext()
 	if err == nil {
 		return dockerHost, nil
@@ -288,7 +290,7 @@
 		return socketPath, nil
 	}
 
-	return "", ErrDockerSocketNotSetInProperties
+	return "", errDockerSocketNotSetInProperties
 }
 
 // dockerSocketOverridePath returns the docker socket from the TESTCONTAINERS_DOCKER_SOCKET_OVERRIDE environment variable,
@@ -298,7 +300,7 @@
 		return dockerHostPath, nil
 	}
 
-	return "", ErrDockerSocketOverrideNotSet
+	return "", errDockerSocketOverrideNotSet
 }
 
 // dockerSocketPath returns the docker socket from the default docker socket path, if it's not empty
@@ -308,7 +310,7 @@
 		return DockerSocketPathWithSchema, nil
 	}
 
-	return "", ErrSocketNotFoundInPath
+	return "", errSocketNotFoundInPath
 }
 
 // testcontainersHostFromProperties returns the testcontainers host from the ~/.testcontainers.properties file, if it's not empty
@@ -324,7 +326,7 @@
 		return parsed, nil
 	}
 
-	return "", ErrTestcontainersHostNotSetInProperties
+	return "", errTestcontainersHostNotSetInProperties
 }
 
 // InAContainer returns true if the code is running inside a container