feat: proxy (#10)

.github/workflows/integration_test.yaml

@@ -16,3 +16,4 @@ jobs:
         ./tests/integration/pre_run_script.sh"
       self-hosted-runner: true
       self-hosted-runner-label: "edge"
+      modules: '["test_charm", "test_proxy"]'

requirements.txt

@@ -1,2 +1,3 @@
 ops>=2,<3
 jinja2>=3,<4
+pydantic>=2,<3

src-docs/state.py.md

@@ -10,6 +10,37 @@ tmate-ssh-server states.
 - **DEBUG_SSH_INTEGRATION_NAME**
 
 
+---
+
+## <kbd>class</kbd> `CharmConfigInvalidError`
+Exception raised when a charm configuration is found to be invalid. 
+
+
+
+**Attributes:**
+
+ - <b>`msg`</b>:  Explanation of the error. 
+
+<a href="../src/state.py#L42"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+
+### <kbd>function</kbd> `__init__`
+
+```python
+__init__(msg: str)
+```
+
+Initialize a new instance of the CharmConfigInvalidError exception. 
+
+
+
+**Args:**
+
+ - <b>`msg`</b>:  Explanation of the error. 
+
+
+
+
+
 ---
 
 ## <kbd>class</kbd> `CharmStateBaseError`
@@ -24,7 +55,7 @@ Represents an error with charm state.
 ## <kbd>class</kbd> `InvalidCharmStateError`
 Represents an invalid charm state. 
 
-<a href="../src/state.py#L21"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/state.py#L26"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ### <kbd>function</kbd> `__init__`
 
@@ -44,6 +75,73 @@ Initialize the error.
 
 
 
+---
+
+## <kbd>class</kbd> `ProxyConfig`
+Configuration for accessing Jenkins through proxy. 
+
+
+
+**Attributes:**
+
+ - <b>`http_proxy`</b>:  The http proxy URL. 
+ - <b>`https_proxy`</b>:  The https proxy URL. 
+ - <b>`no_proxy`</b>:  Comma separated list of hostnames to bypass proxy. 
+
+
+---
+
+#### <kbd>property</kbd> model_computed_fields
+
+Get the computed fields of this model instance. 
+
+
+
+**Returns:**
+  A dictionary of computed field names and their corresponding `ComputedFieldInfo` objects. 
+
+---
+
+#### <kbd>property</kbd> model_extra
+
+Get extra fields set during validation. 
+
+
+
+**Returns:**
+  A dictionary of extra fields, or `None` if `config.extra` is not set to `"allow"`. 
+
+---
+
+#### <kbd>property</kbd> model_fields_set
+
+Returns the set of fields that have been explicitly set on this model instance. 
+
+
+
+**Returns:**
+  A set of strings representing the fields that have been set,  i.e. that were not filled from defaults. 
+
+
+
+---
+
+<a href="../src/state.py#L64"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+
+### <kbd>classmethod</kbd> `from_env`
+
+```python
+from_env() → Optional[ForwardRef('ProxyConfig')]
+```
+
+Instantiate ProxyConfig from juju charm environment. 
+
+
+
+**Returns:**
+  ProxyConfig if proxy configuration is provided, None otherwise. 
+
+
 ---
 
 ## <kbd>class</kbd> `State`
@@ -54,13 +152,14 @@ The tmate-ssh-server operator charm state.
 **Attributes:**
 
  - <b>`ip_addr`</b>:  The host IP address of the given tmate-ssh-server unit. 
+ - <b>`proxy_config`</b>:  The proxy configuration to apply to services used by tmate. 
 
 
 
 
 ---
 
-<a href="../src/state.py#L40"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/state.py#L94"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ### <kbd>classmethod</kbd> `from_charm`
 
@@ -86,5 +185,6 @@ Initialize the state from charm.
 **Raises:**
 
  - <b>`InvalidCharmStateError`</b>:  if the network bind address was not of IPv4/IPv6. 
+ - <b>`CharmConfigInvalidError`</b>:  if there was something wrong with charm configuration values. 
 
 

src-docs/tmate.py.md

@@ -9,32 +9,39 @@ Configurations and functions to operate tmate-ssh-server.
 ---------------
 - **APT_DEPENDENCIES**
 - **GIT_REPOSITORY_URL**
+- **TMATE_SERVICE_NAME**
 - **USER**
 - **GROUP**
 - **PORT**
 
 ---
 
-<a href="../src/tmate.py#L59"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/tmate.py#L99"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ## <kbd>function</kbd> `install_dependencies`
 
 ```python
-install_dependencies() → None
+install_dependencies(proxy_config: Optional[ProxyConfig] = None) → None
 ```
 
 Install dependenciese required to start tmate-ssh-server container. 
 
 
 
+**Args:**
+
+ - <b>`proxy_config`</b>:  The proxy configuration to enable for dockerd. 
+
+
+
 **Raises:**
 
  - <b>`DependencySetupError`</b>:  if there was something wrong installing the apt package  dependencies. 
 
 
 ---
 
-<a href="../src/tmate.py#L78"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/tmate.py#L116"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ## <kbd>function</kbd> `install_keys`
 
@@ -59,7 +66,7 @@ Install key creation script and generate keys.
 
 ---
 
-<a href="../src/tmate.py#L103"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/tmate.py#L141"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ## <kbd>function</kbd> `start_daemon`
 
@@ -84,7 +91,7 @@ Install unit files and start daemon.
 
 ---
 
-<a href="../src/tmate.py#L157"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/tmate.py#L192"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ## <kbd>function</kbd> `get_fingerprints`
 
@@ -108,7 +115,7 @@ Get fingerprint from generated keys.
 
 ---
 
-<a href="../src/tmate.py#L181"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
+<a href="../src/tmate.py#L216"><img align="right" style="float:right;" src="https://img.shields.io/badge/-source-cccccc?style=flat-square"></a>
 
 ## <kbd>function</kbd> `generate_tmate_conf`
 

src/charm.py

@@ -53,7 +53,7 @@ def _on_install(self, event: ops.InstallEvent) -> None:
 
         try:
             self.unit.status = ops.MaintenanceStatus("Installing packages.")
-            tmate.install_dependencies()
+            tmate.install_dependencies(self.state.proxy_config)
         except tmate.DependencySetupError as exc:
             logger.error("Failed to install docker package, %s.", exc)
             raise

src/state.py

@@ -4,9 +4,14 @@
 """tmate-ssh-server states."""
 import dataclasses
 import ipaddress
+import logging
+import os
 import typing
 
 import ops
+from pydantic import BaseModel, HttpUrl, ValidationError
+
+logger = logging.getLogger(__name__)
 
 DEBUG_SSH_INTEGRATION_NAME = "debug-ssh"
 
@@ -27,15 +32,64 @@ def __init__(self, reason: str):
         self.reason = reason
 
 
+class CharmConfigInvalidError(CharmStateBaseError):
+    """Exception raised when a charm configuration is found to be invalid.
+
+    Attributes:
+        msg: Explanation of the error.
+    """
+
+    def __init__(self, msg: str):
+        """Initialize a new instance of the CharmConfigInvalidError exception.
+
+        Args:
+            msg: Explanation of the error.
+        """
+        self.msg = msg
+
+
+class ProxyConfig(BaseModel):
+    """Configuration for accessing Jenkins through proxy.
+
+    Attributes:
+        http_proxy: The http proxy URL.
+        https_proxy: The https proxy URL.
+        no_proxy: Comma separated list of hostnames to bypass proxy.
+    """
+
+    http_proxy: typing.Optional[HttpUrl]
+    https_proxy: typing.Optional[HttpUrl]
+    no_proxy: typing.Optional[str]
+
+    @classmethod
+    def from_env(cls) -> typing.Optional["ProxyConfig"]:
+        """Instantiate ProxyConfig from juju charm environment.
+
+        Returns:
+            ProxyConfig if proxy configuration is provided, None otherwise.
+        """
+        http_proxy = os.environ.get("JUJU_CHARM_HTTP_PROXY")
+        https_proxy = os.environ.get("JUJU_CHARM_HTTPS_PROXY")
+        no_proxy = os.environ.get("JUJU_CHARM_NO_PROXY")
+        if not http_proxy and not https_proxy:
+            return None
+        # Mypy doesn't understand str is supposed to be converted to HttpUrl by Pydantic.
+        return cls(
+            http_proxy=http_proxy, https_proxy=https_proxy, no_proxy=no_proxy  # type: ignore
+        )
+
+
 @dataclasses.dataclass(frozen=True)
 class State:
     """The tmate-ssh-server operator charm state.
 
     Attributes:
         ip_addr: The host IP address of the given tmate-ssh-server unit.
+        proxy_config: The proxy configuration to apply to services used by tmate.
     """
 
-    ip_addr: typing.Union[ipaddress.IPv4Address, ipaddress.IPv6Address, str, None]
+    ip_addr: typing.Optional[typing.Union[ipaddress.IPv4Address, ipaddress.IPv6Address, str]]
+    proxy_config: typing.Optional[ProxyConfig]
 
     @classmethod
     def from_charm(cls, charm: ops.CharmBase) -> "State":
@@ -49,14 +103,24 @@ def from_charm(cls, charm: ops.CharmBase) -> "State":
 
         Raises:
             InvalidCharmStateError: if the network bind address was not of IPv4/IPv6.
+            CharmConfigInvalidError: if there was something wrong with charm configuration values.
         """
+        try:
+            proxy_config = ProxyConfig.from_env()
+        except ValidationError as exc:
+            logger.error("Invalid juju model proxy configuration, %s", exc)
+            raise CharmConfigInvalidError("Invalid model proxy configuration.") from exc
+
         binding = charm.model.get_binding("juju-info")
         if not binding:
-            return cls(ip_addr=None)
+            return cls(ip_addr=None, proxy_config=proxy_config)
         # If unable to get a casted IPvX address, it is not useful.
         # https://github.com/canonical/operator/blob/8a08e8e1b389fce4e7b54663863c4b2d06e72224/ops/model.py#L939-L947
         if isinstance(binding.network.bind_address, str):
             raise InvalidCharmStateError(
                 f"Invalid network bind address {binding.network.bind_address}."
             )
-        return cls(ip_addr=binding.network.bind_address if binding else None)
+
+        return cls(
+            ip_addr=binding.network.bind_address if binding else None, proxy_config=proxy_config
+        )