diff --git a/dockerimg/local_sshimmer_test.go b/dockerimg/local_sshimmer_test.go
new file mode 100644
index 0000000..d3deb1e
--- /dev/null
+++ b/dockerimg/local_sshimmer_test.go
@@ -0,0 +1,735 @@
+package dockerimg
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/ed25519"
+	"crypto/rand"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// MockFileSystem implements the FileSystem interface for testing
+type MockFileSystem struct {
+	Files          map[string][]byte
+	CreatedDirs    map[string]bool
+	OpenedFiles    map[string]*MockFile
+	StatCalledWith []string
+	TempFiles      []string
+	FailOn         map[string]error // Map of function name to error to simulate failures
+}
+
+func NewMockFileSystem() *MockFileSystem {
+	return &MockFileSystem{
+		Files:       make(map[string][]byte),
+		CreatedDirs: make(map[string]bool),
+		OpenedFiles: make(map[string]*MockFile),
+		TempFiles:   []string{},
+		FailOn:      make(map[string]error),
+	}
+}
+
+func (m *MockFileSystem) Stat(name string) (fs.FileInfo, error) {
+	m.StatCalledWith = append(m.StatCalledWith, name)
+	if err, ok := m.FailOn["Stat"]; ok {
+		return nil, err
+	}
+
+	_, exists := m.Files[name]
+	if exists {
+		return nil, nil // File exists
+	}
+	_, exists = m.CreatedDirs[name]
+	if exists {
+		return nil, nil // Directory exists
+	}
+	return nil, os.ErrNotExist
+}
+
+func (m *MockFileSystem) Mkdir(name string, perm fs.FileMode) error {
+	if err, ok := m.FailOn["Mkdir"]; ok {
+		return err
+	}
+	m.CreatedDirs[name] = true
+	return nil
+}
+
+func (m *MockFileSystem) MkdirAll(name string, perm fs.FileMode) error {
+	if err, ok := m.FailOn["MkdirAll"]; ok {
+		return err
+	}
+	m.CreatedDirs[name] = true
+	return nil
+}
+
+func (m *MockFileSystem) ReadFile(name string) ([]byte, error) {
+	if err, ok := m.FailOn["ReadFile"]; ok {
+		return nil, err
+	}
+
+	data, exists := m.Files[name]
+	if !exists {
+		return nil, fmt.Errorf("file not found: %s", name)
+	}
+	return data, nil
+}
+
+func (m *MockFileSystem) WriteFile(name string, data []byte, perm fs.FileMode) error {
+	if err, ok := m.FailOn["WriteFile"]; ok {
+		return err
+	}
+	m.Files[name] = data
+	return nil
+}
+
+// MockFile implements a simple in-memory file for testing
+type MockFile struct {
+	name     string
+	buffer   *bytes.Buffer
+	fs       *MockFileSystem
+	position int64
+}
+
+// MockFileContents represents in-memory file contents for testing
+type MockFileContents struct {
+	name     string
+	contents string
+}
+
+func (m *MockFileSystem) OpenFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
+	if err, ok := m.FailOn["OpenFile"]; ok {
+		return nil, err
+	}
+
+	// Initialize the file content if it doesn't exist and we're not in read-only mode
+	if _, exists := m.Files[name]; !exists && (flag&os.O_CREATE != 0) {
+		m.Files[name] = []byte{}
+	}
+
+	data, exists := m.Files[name]
+	if !exists {
+		return nil, fmt.Errorf("file not found: %s", name)
+	}
+
+	// For OpenFile, we'll just use WriteFile to simulate file operations
+	// The actual file handle isn't used for much in the localsshimmer code
+	// but we still need to return a valid file handle
+	tmpFile, err := os.CreateTemp("", "mockfile-*")
+	if err != nil {
+		return nil, err
+	}
+	if _, err := tmpFile.Write(data); err != nil {
+		tmpFile.Close()
+		return nil, err
+	}
+	if _, err := tmpFile.Seek(0, 0); err != nil {
+		tmpFile.Close()
+		return nil, err
+	}
+
+	return tmpFile, nil
+}
+
+func (m *MockFileSystem) TempFile(dir, pattern string) (*os.File, error) {
+	if err, ok := m.FailOn["TempFile"]; ok {
+		return nil, err
+	}
+
+	// Create an actual temporary file for testing purposes
+	tmpFile, err := os.CreateTemp(dir, pattern)
+	if err != nil {
+		return nil, err
+	}
+
+	// Record the temp file path
+	m.TempFiles = append(m.TempFiles, tmpFile.Name())
+
+	return tmpFile, nil
+}
+
+func (m *MockFileSystem) Rename(oldpath, newpath string) error {
+	if err, ok := m.FailOn["Rename"]; ok {
+		return err
+	}
+
+	// If the old path exists in our mock file system, move its contents
+	if data, exists := m.Files[oldpath]; exists {
+		m.Files[newpath] = data
+		delete(m.Files, oldpath)
+	}
+
+	return nil
+}
+
+func (m *MockFileSystem) SafeWriteFile(name string, data []byte, perm fs.FileMode) error {
+	if err, ok := m.FailOn["SafeWriteFile"]; ok {
+		return err
+	}
+
+	// For the mock, we'll create a backup if the file exists
+	if existingData, exists := m.Files[name]; exists {
+		backupName := name + ".bak"
+		m.Files[backupName] = existingData
+	}
+
+	// Write the new data
+	m.Files[name] = data
+
+	return nil
+}
+
+// MockKeyGenerator implements KeyGenerator interface for testing
+type MockKeyGenerator struct {
+	privateKey   ed25519.PrivateKey
+	publicKey    ed25519.PublicKey
+	sshPublicKey ssh.PublicKey
+	caSigner     ssh.Signer
+	FailOn       map[string]error
+}
+
+func NewMockKeyGenerator(privateKey ed25519.PrivateKey, publicKey ed25519.PublicKey, sshPublicKey ssh.PublicKey, caSigner ssh.Signer) *MockKeyGenerator {
+	return &MockKeyGenerator{
+		privateKey:   privateKey,
+		publicKey:    publicKey,
+		sshPublicKey: sshPublicKey,
+		caSigner:     caSigner,
+		FailOn:       make(map[string]error),
+	}
+}
+
+func (m *MockKeyGenerator) GenerateKeyPair() (ed25519.PrivateKey, ed25519.PublicKey, error) {
+	if err, ok := m.FailOn["GenerateKeyPair"]; ok {
+		return nil, nil, err
+	}
+	return m.privateKey, m.publicKey, nil
+}
+
+func (m *MockKeyGenerator) ConvertToSSHPublicKey(publicKey ed25519.PublicKey) (ssh.PublicKey, error) {
+	if err, ok := m.FailOn["ConvertToSSHPublicKey"]; ok {
+		return nil, err
+	}
+	// If we're generating the CA public key, return the caSigner's public key
+	if m.caSigner != nil && bytes.Equal(publicKey, m.publicKey) {
+		return m.caSigner.PublicKey(), nil
+	}
+	return m.sshPublicKey, nil
+}
+
+// setupMocks sets up common mocks for testing
+func setupMocks(t *testing.T) (*MockFileSystem, *MockKeyGenerator, ed25519.PrivateKey) {
+	// Generate a real Ed25519 key pair
+	publicKey, privateKey, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("Failed to generate test key pair: %v", err)
+	}
+
+	// Generate a test SSH public key
+	sshPublicKey, err := ssh.NewPublicKey(publicKey)
+	if err != nil {
+		t.Fatalf("Failed to generate test SSH public key: %v", err)
+	}
+
+	// Create CA key pair
+	_, caPrivKey, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("Failed to generate CA key pair: %v", err)
+	}
+
+	// Create CA signer
+	caSigner, err := ssh.NewSignerFromKey(caPrivKey)
+	if err != nil {
+		t.Fatalf("Failed to create CA signer: %v", err)
+	}
+
+	// Create mocks
+	mockFS := NewMockFileSystem()
+	mockKG := NewMockKeyGenerator(privateKey, publicKey, sshPublicKey, caSigner)
+
+	// Add some files needed for tests
+	mockFS.Files["/home/testuser/.config/sketch/host_cert"] = []byte("test-certificate")
+	caPubKeyBytes := ssh.MarshalAuthorizedKey(ssh.PublicKey(caSigner.PublicKey()))
+	mockFS.Files["/home/testuser/.config/sketch/container_ca.pub"] = caPubKeyBytes
+
+	return mockFS, mockKG, privateKey
+}
+
+// Helper function to setup a basic LocalSSHimmer for testing
+func setupTestLocalSSHimmer(t *testing.T) (*LocalSSHimmer, *MockFileSystem, *MockKeyGenerator) {
+	mockFS, mockKG, _ := setupMocks(t)
+
+	// Setup home dir in mock filesystem
+	homePath := "/home/testuser"
+	sketchDir := filepath.Join(homePath, ".config/sketch")
+	mockFS.CreatedDirs[sketchDir] = true
+
+	// Create empty files so the tests don't fail
+	sketchConfigPath := filepath.Join(sketchDir, "ssh_config")
+	mockFS.Files[sketchConfigPath] = []byte("")
+	knownHostsPath := filepath.Join(sketchDir, "known_hosts")
+	mockFS.Files[knownHostsPath] = []byte("")
+
+	// Set HOME environment variable for the test
+	oldHome := os.Getenv("HOME")
+	os.Setenv("HOME", homePath)
+	t.Cleanup(func() { os.Setenv("HOME", oldHome) })
+
+	// Create LocalSSHimmer with mocks
+	ssh, err := newLocalSSHimmerWithDeps("test-container", "localhost", "2222", mockFS, mockKG)
+	if err != nil {
+		t.Fatalf("Failed to create LocalSSHimmer: %v", err)
+	}
+
+	return ssh, mockFS, mockKG
+}
+
+func TestNewLocalSSHimmerCreatesRequiredDirectories(t *testing.T) {
+	mockFS, mockKG, _ := setupMocks(t)
+
+	// Set HOME environment variable for the test
+	oldHome := os.Getenv("HOME")
+	os.Setenv("HOME", "/home/testuser")
+	defer func() { os.Setenv("HOME", oldHome) }()
+
+	// Create empty files so the test doesn't fail
+	sketchDir := "/home/testuser/.config/sketch"
+	sketchConfigPath := filepath.Join(sketchDir, "ssh_config")
+	mockFS.Files[sketchConfigPath] = []byte("")
+	knownHostsPath := filepath.Join(sketchDir, "known_hosts")
+	mockFS.Files[knownHostsPath] = []byte("")
+
+	// Create sshimmer
+	_, err := newLocalSSHimmerWithDeps("test-container", "localhost", "2222", mockFS, mockKG)
+	if err != nil {
+		t.Fatalf("Failed to create LocalSSHimmer: %v", err)
+	}
+
+	// Check if the .config/sketch directory was created
+	expectedDir := "/home/testuser/.config/sketch"
+	if !mockFS.CreatedDirs[expectedDir] {
+		t.Errorf("Expected directory %s to be created", expectedDir)
+	}
+}
+
+func TestCreateKeyPairIfMissing(t *testing.T) {
+	ssh, mockFS, _ := setupTestLocalSSHimmer(t)
+
+	// Test key pair creation
+	keyPath := "/home/testuser/.config/sketch/test_key"
+	_, err := ssh.createKeyPairIfMissing(keyPath)
+	if err != nil {
+		t.Fatalf("Failed to create key pair: %v", err)
+	}
+
+	// Verify private key file was created
+	if _, exists := mockFS.Files[keyPath]; !exists {
+		t.Errorf("Private key file not created at %s", keyPath)
+	}
+
+	// Verify public key file was created
+	pubKeyPath := keyPath + ".pub"
+	if _, exists := mockFS.Files[pubKeyPath]; !exists {
+		t.Errorf("Public key file not created at %s", pubKeyPath)
+	}
+
+	// Verify public key content format
+	pubKeyContent, _ := mockFS.ReadFile(pubKeyPath)
+	if !bytes.HasPrefix(pubKeyContent, []byte("ssh-ed25519 ")) {
+		t.Errorf("Public key does not have expected format, got: %s", pubKeyContent)
+	}
+}
+
+// TestAddContainerToSSHConfig tests that the container gets added to the SSH config
+// This test uses a direct approach since the OpenFile mocking is complex
+func TestAddContainerToSSHConfig(t *testing.T) {
+	// Create a temporary directory for test files
+	tempDir, err := os.MkdirTemp("", "localsshimmer-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Create real files in temp directory
+	configPath := filepath.Join(tempDir, "ssh_config")
+	initialConfig := `# SSH Config
+Host existing-host
+  HostName example.com
+  User testuser
+`
+	if err := os.WriteFile(configPath, []byte(initialConfig), 0o644); err != nil {
+		t.Fatalf("Failed to write initial config: %v", err)
+	}
+
+	// Create a sshimmer with the real filesystem but custom paths
+	ssh := &LocalSSHimmer{
+		cntrName:         "test-container",
+		sshHost:          "localhost",
+		sshPort:          "2222",
+		sshConfigPath:    configPath,
+		userIdentityPath: filepath.Join(tempDir, "user_identity"),
+		fs:               &RealFileSystem{},
+		kg:               &RealKeyGenerator{},
+	}
+
+	// Add container to SSH config
+	err = ssh.addContainerToSSHConfig()
+	if err != nil {
+		t.Fatalf("Failed to add container to SSH config: %v", err)
+	}
+
+	// Read the updated file
+	configData, err := os.ReadFile(configPath)
+	if err != nil {
+		t.Fatalf("Failed to read updated config: %v", err)
+	}
+	configStr := string(configData)
+
+	// Check for expected values
+	if !strings.Contains(configStr, "Host test-container") {
+		t.Errorf("Container host entry not found in config")
+	}
+
+	if !strings.Contains(configStr, "HostName localhost") {
+		t.Errorf("HostName not correctly added to SSH config")
+	}
+
+	if !strings.Contains(configStr, "Port 2222") {
+		t.Errorf("Port not correctly added to SSH config")
+	}
+
+	if !strings.Contains(configStr, "User root") {
+		t.Errorf("User not correctly set to root in SSH config")
+	}
+
+	// Check if identity file path is correct
+	identityLine := "IdentityFile " + ssh.userIdentityPath
+	if !strings.Contains(configStr, identityLine) {
+		t.Errorf("Identity file path not correctly added to SSH config")
+	}
+}
+
+func TestAddContainerToKnownHosts(t *testing.T) {
+	// Skip this test as it requires more complex setup
+	// The TestLocalSSHimmerCleanup test covers the addContainerToKnownHosts
+	// functionality in a more integrated way
+	t.Skip("This test requires more complex setup, integrated test coverage exists in TestLocalSSHimmerCleanup")
+}
+
+func TestRemoveContainerFromSSHConfig(t *testing.T) {
+	// Create a temporary directory for test files
+	tempDir, err := os.MkdirTemp("", "localsshimmer-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Create paths for test files
+	sshConfigPath := filepath.Join(tempDir, "ssh_config")
+	userIdentityPath := filepath.Join(tempDir, "user_identity")
+	knownHostsPath := filepath.Join(tempDir, "known_hosts")
+
+	// Create initial SSH config with container entry
+	cntrName := "test-container"
+	sshHost := "localhost"
+	sshPort := "2222"
+
+	initialConfig := fmt.Sprintf(
+		`Host existing-host
+  HostName example.com
+  User testuser
+
+Host %s
+  HostName %s
+  User root
+  Port %s
+  IdentityFile %s
+  UserKnownHostsFile %s
+`,
+		cntrName, sshHost, sshPort, userIdentityPath, knownHostsPath,
+	)
+
+	if err := os.WriteFile(sshConfigPath, []byte(initialConfig), 0o644); err != nil {
+		t.Fatalf("Failed to write initial SSH config: %v", err)
+	}
+
+	// Create a sshimmer with the real filesystem but custom paths
+	ssh := &LocalSSHimmer{
+		cntrName:         cntrName,
+		sshHost:          sshHost,
+		sshPort:          sshPort,
+		sshConfigPath:    sshConfigPath,
+		userIdentityPath: userIdentityPath,
+		knownHostsPath:   knownHostsPath,
+		fs:               &RealFileSystem{},
+	}
+
+	// Remove container from SSH config
+	err = ssh.removeContainerFromSSHConfig()
+	if err != nil {
+		t.Fatalf("Failed to remove container from SSH config: %v", err)
+	}
+
+	// Read the updated file
+	configData, err := os.ReadFile(sshConfigPath)
+	if err != nil {
+		t.Fatalf("Failed to read updated config: %v", err)
+	}
+	configStr := string(configData)
+
+	// Check if the container host entry was removed
+	if strings.Contains(configStr, "Host "+cntrName) {
+		t.Errorf("Container host not removed from SSH config")
+	}
+
+	// Check if existing host remains
+	if !strings.Contains(configStr, "Host existing-host") {
+		t.Errorf("Existing host entry affected by container removal")
+	}
+}
+
+func TestRemoveContainerFromKnownHosts(t *testing.T) {
+	ssh, mockFS, _ := setupTestLocalSSHimmer(t)
+
+	// Setup server public key
+	_, publicKey, _ := ssh.kg.GenerateKeyPair()
+	sshPublicKey, _ := ssh.kg.ConvertToSSHPublicKey(publicKey)
+	ssh.serverPublicKey = sshPublicKey
+
+	// Create host line to be removed
+	hostLine := "[localhost]:2222 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQ..."
+	otherLine := "otherhost ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQ..."
+
+	// Set initial content with the line to be removed
+	initialContent := otherLine + "\n" + hostLine
+	mockFS.Files[ssh.knownHostsPath] = []byte(initialContent)
+
+	// Add the host to test remove function
+	err := ssh.addContainerToKnownHosts()
+	if err != nil {
+		t.Fatalf("Failed to add container to known_hosts for removal test: %v", err)
+	}
+
+	// Now remove it
+	err = ssh.removeContainerFromKnownHosts()
+	if err != nil {
+		t.Fatalf("Failed to remove container from known_hosts: %v", err)
+	}
+
+	// Verify content
+	updatedContent, _ := mockFS.ReadFile(ssh.knownHostsPath)
+	content := string(updatedContent)
+
+	hostPattern := ssh.sshHost + ":" + ssh.sshPort
+	if strings.Contains(content, hostPattern) {
+		t.Errorf("Container entry not removed from known_hosts")
+	}
+
+	// Verify other content remains
+	if !strings.Contains(content, otherLine) {
+		t.Errorf("Other known_hosts entries improperly removed")
+	}
+}
+
+func TestLocalSSHimmerCleanup(t *testing.T) {
+	// Create a temporary directory for test files
+	tempDir, err := os.MkdirTemp("", "localsshimmer-test-*")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Create paths for test files
+	sshConfigPath := filepath.Join(tempDir, "ssh_config")
+	userIdentityPath := filepath.Join(tempDir, "user_identity")
+	knownHostsPath := filepath.Join(tempDir, "known_hosts")
+	serverIdentityPath := filepath.Join(tempDir, "server_identity")
+
+	// Create keys for server key
+	publicKey, _, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatalf("Failed to generate key pair: %v", err)
+	}
+	sshPublicKey, err := ssh.NewPublicKey(publicKey)
+	if err != nil {
+		t.Fatalf("Failed to generate SSH public key: %v", err)
+	}
+
+	// Initialize files
+	os.WriteFile(sshConfigPath, []byte("initial ssh_config content"), 0o644)
+	os.WriteFile(knownHostsPath, []byte("initial known_hosts content"), 0o644)
+
+	// Create a sshimmer with the real filesystem but custom paths
+	cntrName := "test-container"
+	sshHost := "localhost"
+	sshPort := "2222"
+
+	ssh := &LocalSSHimmer{
+		cntrName:           cntrName,
+		sshHost:            sshHost,
+		sshPort:            sshPort,
+		sshConfigPath:      sshConfigPath,
+		userIdentityPath:   userIdentityPath,
+		knownHostsPath:     knownHostsPath,
+		serverIdentityPath: serverIdentityPath,
+		serverPublicKey:    sshPublicKey,
+		fs:                 &RealFileSystem{},
+		kg:                 &RealKeyGenerator{},
+	}
+
+	// Add container to configs
+	err = ssh.addContainerToSSHConfig()
+	if err != nil {
+		t.Fatalf("Failed to set up SSH config for cleanup test: %v", err)
+	}
+
+	err = ssh.addContainerToKnownHosts()
+	if err != nil {
+		t.Fatalf("Failed to set up known_hosts for cleanup test: %v", err)
+	}
+
+	// Execute cleanup
+	err = ssh.Cleanup()
+	if err != nil {
+		t.Fatalf("Cleanup failed: %v", err)
+	}
+
+	// Read updated files
+	configData, err := os.ReadFile(sshConfigPath)
+	if err != nil {
+		t.Fatalf("Failed to read updated SSH config: %v", err)
+	}
+	configStr := string(configData)
+
+	// Check container was removed from SSH config
+	hostEntry := "Host " + ssh.cntrName
+	if strings.Contains(configStr, hostEntry) {
+		t.Errorf("Container not removed from SSH config during cleanup")
+	}
+
+	// Verify known hosts was updated
+	knownHostsContent, err := os.ReadFile(knownHostsPath)
+	if err != nil {
+		t.Fatalf("Failed to read updated known_hosts: %v", err)
+	}
+
+	expectedHostPattern := ssh.sshHost + ":" + ssh.sshPort
+	if strings.Contains(string(knownHostsContent), expectedHostPattern) {
+		t.Errorf("Container not removed from known_hosts during cleanup")
+	}
+}
+
+func TestCheckForInclude_userAccepts(t *testing.T) {
+	mockFS := NewMockFileSystem()
+
+	// Set HOME environment variable for the test
+	oldHome := os.Getenv("HOME")
+	os.Setenv("HOME", "/home/testuser")
+	defer func() { os.Setenv("HOME", oldHome) }()
+
+	// Create a mock ssh config with the expected include
+	includeLine := "Include /home/testuser/.config/sketch/ssh_config"
+	initialConfig := fmt.Sprintf("%s\nHost example\n  HostName example.com\n", includeLine)
+
+	// Add the config to the mock filesystem
+	sshConfigPath := "/home/testuser/.ssh/config"
+	mockFS.Files[sshConfigPath] = []byte(initialConfig)
+	stdinReader := bufio.NewReader(strings.NewReader("y\n"))
+	// Test the function with our mock
+	err := CheckForIncludeWithFS(mockFS, *stdinReader)
+	if err != nil {
+		t.Fatalf("CheckForInclude failed with proper include: %v", err)
+	}
+
+	// Now test with config missing the include
+	mockFS.Files[sshConfigPath] = []byte("Host example\n  HostName example.com\n")
+
+	stdinReader = bufio.NewReader(strings.NewReader("y\n"))
+	err = CheckForIncludeWithFS(mockFS, *stdinReader)
+	if err != nil {
+		t.Fatalf("CheckForInclude should have created the Include line without an error")
+	}
+}
+
+func TestCheckForInclude_userDeclines(t *testing.T) {
+	mockFS := NewMockFileSystem()
+
+	// Set HOME environment variable for the test
+	oldHome := os.Getenv("HOME")
+	os.Setenv("HOME", "/home/testuser")
+	defer func() { os.Setenv("HOME", oldHome) }()
+
+	// Create a mock ssh config with the expected include
+	includeLine := "Include /home/testuser/.config/sketch/ssh_config"
+	initialConfig := fmt.Sprintf("%s\nHost example\n  HostName example.com\n", includeLine)
+
+	// Add the config to the mock filesystem
+	sshConfigPath := "/home/testuser/.ssh/config"
+	mockFS.Files[sshConfigPath] = []byte(initialConfig)
+	stdinReader := bufio.NewReader(strings.NewReader("n\n"))
+	// Test the function with our mock
+	err := CheckForIncludeWithFS(mockFS, *stdinReader)
+	if err != nil {
+		t.Fatalf("CheckForInclude failed with proper include: %v", err)
+	}
+
+	// Now test with config missing the include
+	missingInclude := []byte("Host example\n  HostName example.com\n")
+	mockFS.Files[sshConfigPath] = missingInclude
+
+	stdinReader = bufio.NewReader(strings.NewReader("n\n"))
+	err = CheckForIncludeWithFS(mockFS, *stdinReader)
+	if err == nil {
+		t.Errorf("CheckForInclude should have returned an error")
+	}
+	if !bytes.Equal(mockFS.Files[sshConfigPath], missingInclude) {
+		t.Errorf("ssh config should not have been edited")
+	}
+}
+
+func TestLocalSSHimmerWithErrors(t *testing.T) {
+	// Test directory creation failure
+	mockFS := NewMockFileSystem()
+	mockFS.FailOn["MkdirAll"] = fmt.Errorf("mock mkdir error")
+	mockKG := NewMockKeyGenerator(nil, nil, nil, nil)
+
+	// Set HOME environment variable for the test
+	oldHome := os.Getenv("HOME")
+	os.Setenv("HOME", "/home/testuser")
+	defer func() { os.Setenv("HOME", oldHome) }()
+
+	// Try to create sshimmer with failing FS
+	_, err := newLocalSSHimmerWithDeps("test-container", "localhost", "2222", mockFS, mockKG)
+	if err == nil || !strings.Contains(err.Error(), "mock mkdir error") {
+		t.Errorf("Should have failed with mkdir error, got: %v", err)
+	}
+
+	// Test key generation failure
+	mockFS = NewMockFileSystem()
+	mockKG = NewMockKeyGenerator(nil, nil, nil, nil)
+	mockKG.FailOn["GenerateKeyPair"] = fmt.Errorf("mock key generation error")
+
+	_, err = newLocalSSHimmerWithDeps("test-container", "localhost", "2222", mockFS, mockKG)
+	if err == nil || !strings.Contains(err.Error(), "key generation error") {
+		t.Errorf("Should have failed with key generation error, got: %v", err)
+	}
+}
+
+func TestRealSSHTheatherInit(t *testing.T) {
+	// Skip this test as it requires real files for the CA which we don't want to create
+	// in a real integration test
+	t.Skip("Skipping test that requires real file system access for the CA")
+}
+
+// Methods to help with the mocking interface
+func (m *MockKeyGenerator) GetCASigner() ssh.Signer {
+	return m.caSigner
+}
+
+func (m *MockKeyGenerator) IsMock() bool {
+	return true
+}