Skip to content

prefect.settings.sources

EnvFilterSettingsSource

Bases: EnvSettingsSource

Custom pydantic settings source to filter out specific environment variables.

All validation aliases are loaded from environment variables by default. We use AliasPath to maintain the ability set fields via model initialization, but those shouldn't be loaded from environment variables. This loader allows use to say which environment variables should be ignored.

Source code in src/prefect/settings/sources.py 
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
class EnvFilterSettingsSource(EnvSettingsSource):
    """
    Custom pydantic settings source to filter out specific environment variables.

    All validation aliases are loaded from environment variables by default. We use
    `AliasPath` to maintain the ability set fields via model initialization, but those
    shouldn't be loaded from environment variables. This loader allows use to say which
    environment variables should be ignored.
    """

    def __init__(
        self,
        settings_cls: type[BaseSettings],
        case_sensitive: Optional[bool] = None,
        env_prefix: Optional[str] = None,
        env_nested_delimiter: Optional[str] = None,
        env_ignore_empty: Optional[bool] = None,
        env_parse_none_str: Optional[str] = None,
        env_parse_enums: Optional[bool] = None,
        env_filter: Optional[List[str]] = None,
    ) -> None:
        super().__init__(
            settings_cls,
            case_sensitive,
            env_prefix,
            env_nested_delimiter,
            env_ignore_empty,
            env_parse_none_str,
            env_parse_enums,
        )
        if env_filter:
            if isinstance(self.env_vars, dict):
                for key in env_filter:
                    self.env_vars.pop(key, None)
            else:
                self.env_vars = {
                    key: value
                    for key, value in self.env_vars.items()  # type: ignore
                    if key.lower() not in env_filter
                }

PrefectTomlConfigSettingsSource

Bases: TomlConfigSettingsSourceBase

Custom pydantic settings source to load settings from a prefect.toml file

Source code in src/prefect/settings/sources.py 
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
class PrefectTomlConfigSettingsSource(TomlConfigSettingsSourceBase):
    """Custom pydantic settings source to load settings from a prefect.toml file"""

    def __init__(
        self,
        settings_cls: Type[BaseSettings],
    ):
        super().__init__(settings_cls)
        self.toml_file_path = settings_cls.model_config.get(
            "toml_file", DEFAULT_PREFECT_TOML_PATH
        )
        self.toml_data = self._read_files(self.toml_file_path)
        self.toml_table_header = settings_cls.model_config.get(
            "prefect_toml_table_header", tuple()
        )
        for key in self.toml_table_header:
            self.toml_data = self.toml_data.get(key, {})

ProfileSettingsTomlLoader

Bases: PydanticBaseSettingsSource

Custom pydantic settings source to load profile settings from a toml file.

See https://docs.pydantic.dev/latest/concepts/pydantic_settings/#customise-settings-sources

Source code in src/prefect/settings/sources.py 
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
class ProfileSettingsTomlLoader(PydanticBaseSettingsSource):
    """
    Custom pydantic settings source to load profile settings from a toml file.

    See https://docs.pydantic.dev/latest/concepts/pydantic_settings/#customise-settings-sources
    """

    def __init__(self, settings_cls: Type[BaseSettings]):
        super().__init__(settings_cls)
        self.settings_cls = settings_cls
        self.profiles_path = _get_profiles_path()
        self.profile_settings = self._load_profile_settings()

    def _load_profile_settings(self) -> Dict[str, Any]:
        """Helper method to load the profile settings from the profiles.toml file"""

        if not self.profiles_path.exists():
            return {}

        try:
            all_profile_data = toml.load(self.profiles_path)
        except toml.TomlDecodeError:
            warnings.warn(
                f"Failed to load profiles from {self.profiles_path}. Please ensure the file is valid TOML."
            )
            return {}

        if (
            sys.argv[0].endswith("/prefect")
            and len(sys.argv) >= 3
            and sys.argv[1] == "--profile"
        ):
            active_profile = sys.argv[2]

        else:
            active_profile = os.environ.get("PREFECT_PROFILE") or all_profile_data.get(
                "active"
            )

        profiles_data = all_profile_data.get("profiles", {})

        if not active_profile or active_profile not in profiles_data:
            return {}
        return profiles_data[active_profile]

    def get_field_value(
        self, field: FieldInfo, field_name: str
    ) -> Tuple[Any, str, bool]:
        """Concrete implementation to get the field value from the profile settings"""
        if field.validation_alias:
            if isinstance(field.validation_alias, str):
                value = self.profile_settings.get(field.validation_alias.upper())
                if value is not None:
                    return value, field_name, self.field_is_complex(field)
            elif isinstance(field.validation_alias, AliasChoices):
                for alias in field.validation_alias.choices:
                    if not isinstance(alias, str):
                        continue
                    value = self.profile_settings.get(alias.upper())
                    if value is not None:
                        return value, field_name, self.field_is_complex(field)

        value = self.profile_settings.get(
            f"{self.config.get('env_prefix','')}{field_name.upper()}"
        )
        return value, field_name, self.field_is_complex(field)

    def __call__(self) -> Dict[str, Any]:
        """Called by pydantic to get the settings from our custom source"""
        if _is_test_mode():
            return {}
        profile_settings: Dict[str, Any] = {}
        for field_name, field in self.settings_cls.model_fields.items():
            value, key, is_complex = self.get_field_value(field, field_name)
            if value is not None:
                prepared_value = self.prepare_field_value(
                    field_name, field, value, is_complex
                )
                profile_settings[key] = prepared_value
        return profile_settings

__call__()

Called by pydantic to get the settings from our custom source

Source code in src/prefect/settings/sources.py 
129
130
131
132
133
134
135
136
137
138
139
140
141
def __call__(self) -> Dict[str, Any]:
    """Called by pydantic to get the settings from our custom source"""
    if _is_test_mode():
        return {}
    profile_settings: Dict[str, Any] = {}
    for field_name, field in self.settings_cls.model_fields.items():
        value, key, is_complex = self.get_field_value(field, field_name)
        if value is not None:
            prepared_value = self.prepare_field_value(
                field_name, field, value, is_complex
            )
            profile_settings[key] = prepared_value
    return profile_settings

get_field_value(field, field_name)

Concrete implementation to get the field value from the profile settings

Source code in src/prefect/settings/sources.py 
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
def get_field_value(
    self, field: FieldInfo, field_name: str
) -> Tuple[Any, str, bool]:
    """Concrete implementation to get the field value from the profile settings"""
    if field.validation_alias:
        if isinstance(field.validation_alias, str):
            value = self.profile_settings.get(field.validation_alias.upper())
            if value is not None:
                return value, field_name, self.field_is_complex(field)
        elif isinstance(field.validation_alias, AliasChoices):
            for alias in field.validation_alias.choices:
                if not isinstance(alias, str):
                    continue
                value = self.profile_settings.get(alias.upper())
                if value is not None:
                    return value, field_name, self.field_is_complex(field)

    value = self.profile_settings.get(
        f"{self.config.get('env_prefix','')}{field_name.upper()}"
    )
    return value, field_name, self.field_is_complex(field)

PyprojectTomlConfigSettingsSource

Bases: TomlConfigSettingsSourceBase

Custom pydantic settings source to load settings from a pyproject.toml file

Source code in src/prefect/settings/sources.py 
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
class PyprojectTomlConfigSettingsSource(TomlConfigSettingsSourceBase):
    """Custom pydantic settings source to load settings from a pyproject.toml file"""

    def __init__(
        self,
        settings_cls: Type[BaseSettings],
    ):
        super().__init__(settings_cls)
        self.toml_file_path = Path("pyproject.toml")
        self.toml_data = self._read_files(self.toml_file_path)
        self.toml_table_header = settings_cls.model_config.get(
            "pyproject_toml_table_header", ("tool", "prefect")
        )
        for key in self.toml_table_header:
            self.toml_data = self.toml_data.get(key, {})

TomlConfigSettingsSourceBase

Bases: PydanticBaseSettingsSource, ConfigFileSourceMixin

Source code in src/prefect/settings/sources.py 
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
class TomlConfigSettingsSourceBase(PydanticBaseSettingsSource, ConfigFileSourceMixin):
    def __init__(self, settings_cls: Type[BaseSettings]):
        super().__init__(settings_cls)
        self.settings_cls = settings_cls
        self.toml_data = {}

    def _read_file(self, path: Path) -> Dict[str, Any]:
        return toml.load(path)

    def get_field_value(
        self, field: FieldInfo, field_name: str
    ) -> Tuple[Any, str, bool]:
        """Concrete implementation to get the field value from toml data"""
        value = self.toml_data.get(field_name)
        if isinstance(value, dict):
            # if the value is a dict, it is likely a nested settings object and a nested
            # source will handle it
            value = None
        return value, field_name, self.field_is_complex(field)

    def __call__(self) -> Dict[str, Any]:
        """Called by pydantic to get the settings from our custom source"""
        toml_setings: Dict[str, Any] = {}
        for field_name, field in self.settings_cls.model_fields.items():
            value, key, is_complex = self.get_field_value(field, field_name)
            if value is not None:
                prepared_value = self.prepare_field_value(
                    field_name, field, value, is_complex
                )
                toml_setings[key] = prepared_value
        return toml_setings

__call__()

Called by pydantic to get the settings from our custom source

Source code in src/prefect/settings/sources.py 
167
168
169
170
171
172
173
174
175
176
177
def __call__(self) -> Dict[str, Any]:
    """Called by pydantic to get the settings from our custom source"""
    toml_setings: Dict[str, Any] = {}
    for field_name, field in self.settings_cls.model_fields.items():
        value, key, is_complex = self.get_field_value(field, field_name)
        if value is not None:
            prepared_value = self.prepare_field_value(
                field_name, field, value, is_complex
            )
            toml_setings[key] = prepared_value
    return toml_setings

get_field_value(field, field_name)

Concrete implementation to get the field value from toml data

Source code in src/prefect/settings/sources.py 
156
157
158
159
160
161
162
163
164
165
def get_field_value(
    self, field: FieldInfo, field_name: str
) -> Tuple[Any, str, bool]:
    """Concrete implementation to get the field value from toml data"""
    value = self.toml_data.get(field_name)
    if isinstance(value, dict):
        # if the value is a dict, it is likely a nested settings object and a nested
        # source will handle it
        value = None
    return value, field_name, self.field_is_complex(field)