{"id":7754,"library":"sshconf","title":"sshconf: Lightweight SSH Config Library","description":"sshconf is a Python library designed for reading and modifying your `~/.ssh/config` file in a non-intrusive way. It aims to keep the file's structure largely intact after modifications, providing a simple interface to manage SSH client configurations. The current version is 0.2.7. It has an irregular release cadence, with the last release in June 2024.","status":"active","version":"0.2.7","language":"en","source_language":"en","source_url":"https://github.com/sorend/sshconf","tags":["ssh","config","configuration management","automation","sysadmin"],"install":[{"cmd":"pip install sshconf","lang":"bash","label":"Install with pip"}],"dependencies":[],"imports":[{"note":"Primary function to load an existing SSH configuration file.","symbol":"read","correct":"import sshconf\nconfig = sshconf.read('~/.ssh/config')"},{"note":"Function to create an empty SshConfig object for a new configuration.","symbol":"empty","correct":"import sshconf\nconfig = sshconf.empty()"}],"quickstart":{"code":"import sshconf\nimport os\n\n# Create a temporary config file for demonstration\ntemp_config_path = os.path.expanduser('~/.ssh/config_temp')\n\n# Ensure the .ssh directory exists\nos.makedirs(os.path.dirname(temp_config_path), exist_ok=True)\n\n# Start with an empty configuration\nconfig = sshconf.empty()\n\n# Add a new host entry\nconfig.add(\n    'devserver',\n    Hostname='192.168.1.100',\n    User='devuser',\n    IdentityFile=os.path.expanduser('~/.ssh/id_rsa_dev')\n)\n\n# Update an existing entry or add a new parameter\nconfig.set(\n    'devserver',\n    Port=2222,\n    ForwardAgent='yes'\n)\n\n# Add another host with minimal options\nconfig.add(\n    'testserver',\n    Hostname='test.example.com',\n    User='testuser'\n)\n\n# Remove a parameter from a host\nconfig.unset('devserver', 'ForwardAgent')\n\n# Get configuration for a host\nhost_config = config.host('devserver')\nprint(f\"Devserver config: {host_config.to_dict()}\")\n\n# Write the changes to a new file (or save() to overwrite original)\nconfig.write(temp_config_path)\n\nprint(f\"SSH config written to: {temp_config_path}\")\nprint(\"Contents of the temporary config file:\")\nwith open(temp_config_path, 'r') as f:\n    print(f.read())\n\n# Clean up the temporary file (optional)\n# os.remove(temp_config_path)","lang":"python","description":"This quickstart demonstrates how to create a new SSH configuration, add and modify host entries, and then write the configuration to a file. It uses `sshconf.empty()` to start a new configuration and `write()` to save it, avoiding modification of your actual `~/.ssh/config` file for safety. Remember that `save()` will overwrite the file it was read from."},"warnings":[{"fix":"Always use `config.write('/path/to/new_config')` unless you explicitly want to overwrite the source file. Consider backing up your `~/.ssh/config` before using `save()`.","message":"The `save()` method overwrites the SSH configuration file from which the `SshConfig` object was initially loaded. Use `write(filepath)` to save changes to a different file, or carefully use `save()` if overwriting is intended.","severity":"gotcha","affected_versions":"All versions"},{"fix":"Be aware that `Include` directives will be expanded. If you rely on separate include files for modularity, you may need to manage them manually or use `sshconf` only for specific sections.","message":"When `sshconf` reads a configuration file containing `Include` directives and then writes or saves it, the included files' contents are merged into the main output file. This flattens the configuration and removes the original `Include` structure.","severity":"gotcha","affected_versions":"All versions"},{"fix":"Arrange `Host` blocks in `~/.ssh/config` from most specific to least specific. For example, place `Host *` as the very last entry to ensure it only applies if no other host matches.","message":"OpenSSH clients process configuration options based on the first matching `Host` entry. If you have overlapping patterns (e.g., `Host *.example.com` and `Host specific.example.com`), the order matters. Less specific patterns appearing before more specific ones can lead to unexpected configurations being applied.","severity":"gotcha","affected_versions":"All versions (OpenSSH client behavior)"},{"fix":"Ensure `~/.ssh` directory has `chmod 700`, `~/.ssh/config` and private key files have `chmod 600`. Use `chmod 700 ~/.ssh` and `chmod 600 ~/.ssh/config` (and for private keys).","message":"SSH client configuration files (`~/.ssh/config`) and private key files (`~/.ssh/id_rsa`) require strict file permissions. Incorrect permissions (e.g., world-readable) will cause the SSH client to ignore them for security reasons, leading to authentication failures or ignored configurations.","severity":"gotcha","affected_versions":"All versions (OpenSSH client behavior)"}],"env_vars":null,"last_verified":"2026-04-16T00:00:00.000Z","next_check":"2026-07-15T00:00:00.000Z","problems":[{"fix":"Correct the spelling of the SSH directive. Refer to `man ssh_config` for a list of valid options and their correct syntax. For example, `HostNamee` should be `Hostname`.","cause":"A directive (keyword) in the SSH configuration file has a typo or is not recognized by the OpenSSH client.","error":"Bad configuration option: <incorrect_option_name>"},{"fix":"Verify that your `~/.ssh` directory has permissions `700`, `~/.ssh/config` has `600`, and your private key file (e.g., `~/.ssh/id_rsa`) has `600`. Use `chmod 700 ~/.ssh` and `chmod 600 ~/.ssh/config ~/.ssh/id_rsa`.","cause":"The SSH client cannot use your private key for authentication because its file permissions are too open, or the SSH config file itself has incorrect permissions and is being ignored.","error":"Permission denied (publickey)."},{"fix":"Reorder the `Host` entries in your `~/.ssh/config` file so that more specific host definitions (e.g., `Host myhost.example.com`) appear *before* more general ones (e.g., `Host *.example.com` or `Host *`). Use `ssh -vvv <hostname>` to debug which configurations are being applied.","cause":"Your `~/.ssh/config` file has conflicting `Host` patterns, and a more general pattern is matched first, preventing your specific host configuration from being applied.","error":"SSH client is not using the specific configuration options (e.g., wrong user, key, or port) I set for a host."}]}