stages: add org.osbuild.nm.conf

New stage to create NetworkManager configuration files. Currently
only a subset of settings are supported. Include a simple stage
test case for it.

stages/org.osbuild.nm.conf

@@ -0,0 +1,204 @@
+#!/usr/bin/python3
+"""
+Create NetworkManager configuration files.
+
+This stages allows to create NetworkManager configuration files in the
+location specified via `path` with the `settings` provided. Only a
+subset of the all options are currently supported.
+
+The stage will use `true` and `false` for boolean values and `,` as
+list separator.
+
+NetworkManger looks in the following locations for configuration files:
+    - /etc/NetworkManager/NetworkManager.conf
+    - /etc/NetworkManager/conf.d/name.conf
+    - /usr/lib/NetworkManager/conf.d/name.conf,
+
+ and also in the following locations that very likely should not be used:
+    - /run/NetworkManager/conf.d/name.conf
+    -/var/lib/NetworkManager/NetworkManager-intern.conf
+"""
+
+import configparser
+import os
+import sys
+
+import osbuild.api
+
+
+SCHEMA = r"""
+"definitions": {
+  "device-list": {
+    "type": "array",
+    "minItems": 1,
+    "items": {
+      "type": "string"
+    }
+  },
+  "str-array": {
+    "type": "array",
+    "minItems": 1,
+    "items": {
+      "type": "string"
+    }
+  },
+  "device": {
+    "type": "object",
+    "additionalProperties": false,
+    "properties": {
+      "managed": {
+        "type": "boolean"
+      },
+      "wifi.scan-rand-mac-address": {
+        "type": "boolean"
+      }
+    }
+  },
+  "global-dns-domain": {
+    "type": "object",
+    "additionalProperties": false,
+    "required": ["servers"],
+    "properties": {
+      "servers": {
+        "type": "array",
+        "minItems": 1,
+        "items": {
+          "type": "string"
+        }
+      }
+    }
+  }
+},
+"additionalProperties": false,
+"required": ["path", "settings"],
+"properties": {
+  "path": {
+    "type": "string"
+  },
+  "settings": {
+    "type": "object",
+    "additionalProperties": false,
+    "properties": {
+      "main": {
+        "type": "object",
+        "additionalProperties": false,
+        "properties": {
+          "no-auto-default": {
+            "$ref": "#/definitions/device-list"
+          },
+          "plugins": {
+            "$ref": "#/definitions/str-array"
+          }
+        }
+      },
+      "device": {
+        "type": "array",
+        "minItems": 1,
+        "items": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": ["config"],
+          "properties": {
+            "name": {
+              "type": "string"
+            },
+            "config": {
+              "$ref": "#/definitions/device"
+            }
+          }
+        }
+      },
+      "global-dns-domain": {
+        "type": "array",
+        "minItems": 1,
+        "items": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": ["name", "config"],
+          "properties": {
+            "name": {
+              "type": "string"
+            },
+            "config": {
+              "$ref": "#/definitions/global-dns-domain"
+            }
+          }
+        }
+      },
+      "keyfile": {
+        "type": "object",
+        "additionalProperties": false,
+        "properties": {
+          "unmanaged-devices": {
+            "$ref": "#/definitions/device-list"
+          }
+        }
+      }
+    }
+  }
+}
+"""
+
+
+def make_value(value):
+    if isinstance(value, list):
+        val = ",".join(value)
+    elif isinstance(value, bool):
+        val = "true" if value else "false"
+    else:
+        val = str(value)
+    return val
+
+
+def make_section(cfg, name, settings):
+    if not cfg.has_section(name):
+        cfg.add_section(name)
+
+    for key, value in settings.items():
+        val = make_value(value)
+        cfg.set(name, key, val)
+
+
+def make_named_section(cfg, name: str, section):
+
+    config = section["config"]
+    suffix = section.get("name")
+    if suffix:
+        name = f"{name}-{suffix}"
+
+    make_section(cfg, name, config)
+
+
+def main(tree, options):
+    path = options["path"]
+    settings = options["settings"]
+
+    cfgfile = os.path.join(tree, path.lstrip("/"))
+
+    cfgpath = os.path.dirname(cfgfile)
+    os.makedirs(cfgpath, exist_ok=True)
+
+    cfg = configparser.ConfigParser()
+    cfg.optionxform = lambda o: o
+
+    for name, items in settings.items():
+
+        if isinstance(items, dict):
+            make_section(cfg, name, items)
+        elif isinstance(items, list):
+            for item in items:
+                make_named_section(cfg, name, item)
+        else:
+            raise ValueError(f"Invalid section type: {type(items)}")
+
+    with open(cfgfile, "w") as f:
+        os.fchmod(f.fileno(), 0o600)
+        cfg.write(f, space_around_delimiters=False)
+
+    return 0
+
+
+if __name__ == '__main__':
+    args = osbuild.api.arguments()
+    r = main(args["tree"], args["options"])
+    sys.exit(r)