Prepare Python SDK for CLI 1.0 workspace settings

.dagger/modules/e2e/main.dang

@@ -225,4 +225,34 @@ type E2e {
 
     null
   }
+
+  """
+  Workspace-scoped SDK settings (the PythonSdk constructor args, surfaced by
+  `dagger settings python-sdk`) should act as init defaults: when an init flag
+  is omitted, initModule inherits the constructor value, and an explicit
+  per-init flag still wins.
+  """
+  pub initSettingsDefaultCheck(ws: Workspace!): Void @check {
+    let configuredSdk = pythonSdk(defaultPythonVersion: "3.13", defaultUseUv: false, defaultBaseImage: "python:3.13-slim")
+
+    # Flags omitted: the constructor (workspace) defaults flow into pyproject.toml.
+    let inheritedPath = outputRoot + "/init-settings-inherited"
+    let inherited = configuredSdk.initModule(ws, name: "init-settings-inherited", path: inheritedPath)
+    let inheritedPyproj = inheritedPath + "/pyproject.toml"
+    assertAdded(inherited, inheritedPyproj)
+    assertContains(inherited.layer.file(inheritedPyproj).contents, ">=3.13", "default-python-version setting not applied at init")
+    assertContains(inherited.layer.file(inheritedPyproj).contents, "use-uv = false", "default-use-uv setting not applied at init")
+    assertContains(inherited.layer.file(inheritedPyproj).contents, "python:3.13-slim", "default-base-image setting not applied at init")
+    assertContains(inherited.layer.file(inheritedPyproj).contents, "dagger-io", "settings-default init dropped template data")
+
+    # Explicit per-init flags override the workspace defaults.
+    let overridePath = outputRoot + "/init-settings-override"
+    let override = configuredSdk.initModule(ws, name: "init-settings-override", path: overridePath, pythonVersion: "3.12", useUv: true, baseImage: "python:3.12-slim")
+    let overridePyproj = overridePath + "/pyproject.toml"
+    assertContains(override.layer.file(overridePyproj).contents, ">=3.12", "per-init python version did not override default-python-version")
+    assertContains(override.layer.file(overridePyproj).contents, "python:3.12-slim", "per-init base image did not override default-base-image")
+    assertNotContains(override.layer.file(overridePyproj).contents, "use-uv = false", "per-init use-uv=true did not override default-use-uv=false")
+
+    null
+  }
 }

README.md

@@ -60,6 +60,36 @@ engine supplies it in the dispatched path):
 dagger call python-sdk init-module --name my-module --path .dagger/modules/my-module
 ```
 
+## Configure workspace defaults
+
+Set SDK defaults once per workspace and have them apply to the modules you
+create. List the settings this SDK exposes:
+
+```sh
+dagger settings python-sdk
+```
+
+Set a default (the SDK's constructor arguments are the settings; camelCase maps
+to kebab-case on the CLI):
+
+```sh
+dagger settings python-sdk default-python-version 3.13
+dagger settings python-sdk default-use-uv false
+dagger settings python-sdk default-base-image python:3.13-slim
+```
+
+These act as fallbacks for `initModule`: when you create a module without the
+matching `dagger module init python` flag (`--python-version`, `--use-uv`,
+`--base-image`), the workspace default is applied. An explicit per-init flag
+always wins.
+
+> [!NOTE]
+> Settings are stored under `[modules.python-sdk.settings]` in `dagger.toml`,
+> are discoverable and typed today, and populate the SDK constructor on the
+> `dagger call python-sdk …` path. Inheriting them through the privileged
+> `dagger module init python` dispatch additionally requires the engine to
+> thread `[modules.python-sdk.settings]` into the SDK at init time.
+
 ## Configure an existing module
 
 Read the current configuration. Settings that are not explicitly written to

python-sdk.dang

@@ -12,6 +12,48 @@ type PythonSdk {
   """
   pub targetRuntime: String! = "python"
 
+  """
+  Workspace default Python version applied to modules this SDK creates.
+
+  Surfaced as the `default-python-version` setting of
+  `dagger settings python-sdk`. Empty leaves the template's Python version
+  untouched. `initModule` falls back to this when `--python-version` is omitted.
+  """
+  pub defaultPythonVersion: String!
+
+  """
+  Workspace default for building modules with uv (true) instead of pip.
+
+  Surfaced as the `default-use-uv` setting of `dagger settings python-sdk`.
+  `initModule` falls back to this when `--use-uv` is omitted.
+  """
+  pub defaultUseUv: Boolean!
+
+  """
+  Workspace default base container image for modules this SDK creates.
+
+  Surfaced as the `default-base-image` setting of `dagger settings python-sdk`.
+  Empty writes no base image override. `initModule` falls back to this when
+  `--base-image` is omitted.
+  """
+  pub defaultBaseImage: String!
+
+  """
+  Construct the SDK with its workspace-scoped settings.
+
+  The engine populates these constructor arguments from
+  `[modules.python-sdk.settings]`, and `dagger settings python-sdk` surfaces
+  them as typed settings (camelCase maps to kebab-case on the CLI:
+  default-python-version, default-use-uv, default-base-image). They act as
+  defaults that `initModule` applies when the matching per-init flag is omitted.
+  """
+  new(defaultPythonVersion: String! = "", defaultUseUv: Boolean! = true, defaultBaseImage: String! = "") {
+    self.defaultPythonVersion = defaultPythonVersion
+    self.defaultUseUv = defaultUseUv
+    self.defaultBaseImage = defaultBaseImage
+    self
+  }
+
   """
   Return every legacy dagger.json Dagger module whose sdk.source is "python".
 
@@ -118,10 +160,12 @@ type PythonSdk {
   default uses this module's minimal template.
 
   Pass `pythonVersion`, `useUv`, or `baseImage` to customize the generated
-  pyproject.toml. Defaults leave the template untouched: the template's Python
+  pyproject.toml. When one is omitted, the matching workspace setting
+  (`default-python-version`, `default-use-uv`, `default-base-image`) applies. If
+  that is also unset the template is left untouched: the template's Python
   version is used, uv is enabled, and no base image override is written.
   """
-  pub initModule(ws: Workspace!, name: String!, path: String!, template: String! = "", pythonVersion: String! = "", useUv: Boolean! = true, baseImage: String! = ""): Changeset! {
+  pub initModule(ws: Workspace!, name: String!, path: String!, template: String! = "", pythonVersion: String! = "", useUv: Boolean = null, baseImage: String! = ""): Changeset! {
     let rawPath = path.trimPrefix("./").trimPrefix("/")
 
     let modPath = if (rawPath == "" or rawPath == ".") {
@@ -137,7 +181,12 @@ type PythonSdk {
     if (currentModule.source.exists("templates/" + selectedTemplate) == false) {
       raise "unknown init template: " + template
     } else {
-      let templateSource = configuredTemplate(renderedTemplate(name, selectedTemplate), pythonVersion, useUv, baseImage)
+      # Per-init flags win; otherwise fall back to the workspace-scoped defaults.
+      let effectivePythonVersion = if (pythonVersion == "") { defaultPythonVersion } else { pythonVersion }
+      let effectiveUseUv = if (useUv != null) { useUv } else { defaultUseUv }
+      let effectiveBaseImage = if (baseImage == "") { defaultBaseImage } else { baseImage }
+
+      let templateSource = configuredTemplate(renderedTemplate(name, selectedTemplate), effectivePythonVersion, effectiveUseUv, effectiveBaseImage)
 
       polyfill.workspace(ws).fork
         .withDirectory(modPath, templateSource)