stages/org.osbuild.dnf.config: Edit /etc/dnf/dnf.conf

Fixes #906

stages/org.osbuild.dnf.config

@@ -6,8 +6,9 @@ The stage changes persistent DNF configuration on the filesystem. Currently,
 only DNF variables can be defined.
 """
 
-
+import os
 import sys
+import iniparse
 
 import osbuild.api
 
@@ -30,6 +31,13 @@ SCHEMA = r"""
         "description": "Value of the variable."
       }
     }
+  },
+  "config_main": {
+    "ip_resolve": {
+      "type": "string",
+      "enum": ["4", "IPv4", "6", "IPv6"],
+      "description": "Determines how DNF resolves host names."
+    }
   }
 },
 "additionalProperties": false,
@@ -41,6 +49,16 @@ SCHEMA = r"""
     "items": {
         "$ref": "#/definitions/variable"
     }
+  },
+  "config": {
+    "additionalProperties": false,
+    "type": "object",
+    "description": "DNF global configuration.",
+    "properties": {
+      "main": {
+        "$ref": "#/definitions/config_main"
+      }
+    }
   }
 }
 """
@@ -61,12 +79,53 @@ def configure_variable(tree, name, value):
         f.write(value + "\n")
 
 
+def make_value(value):
+    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_dnf_config(tree, config_options):
+    """
+    Merges the given config object into /etc/dnf/dnf.conf, overwriting existing
+    values.
+    """
+    dnf_config_path = f"{tree}/etc/dnf/dnf.conf"
+    dnf_config = iniparse.SafeConfigParser()
+
+    try:
+        with open(dnf_config_path, "r") as f:
+            dnf_config.readfp(f)
+    except FileNotFoundError:
+        print(f"Warning: DNF configuration file '{dnf_config_path}' does not exist, will create it.")
+        os.makedirs(f"{tree}/etc/dnf", exist_ok=True)
+
+    for section, items  in config_options.items():
+        make_section(dnf_config, section, items)
+
+    with open(dnf_config_path, "w") as f:
+        os.fchmod(f.fileno(), 0o644)
+        dnf_config.write(f)
+
+
 def main(tree, options):
     variables = options.get("variables", [])
 
     for variable in variables:
         configure_variable(tree, variable["name"], variable["value"])
 
+    config_options = options.get("config")
+    if config_options:
+        make_dnf_config(tree, config_options)
+
     return 0
 
 

test/data/stages/dnf.config/b.json

@@ -500,7 +500,12 @@
               "name": "releasever",
               "value": "8.4"
             }
-          ]
+          ],
+          "config": {
+            "main": {
+              "ip_resolve": "4"
+            }
+          }
         }
       }
     ]

test/data/stages/dnf.config/b.mpp.json

@@ -37,7 +37,12 @@
               "name": "releasever",
               "value": "8.4"
             }
-          ]
+          ],
+          "config": {
+            "main": {
+              "ip_resolve": "4"
+            }
+          }
         }
       }
     ]

test/data/stages/dnf.config/diff.json

@@ -3,5 +3,12 @@
     "/etc/dnf/vars/releasever"
   ],
   "deleted_files": [],
-  "differences": {}
+  "differences": {
+    "/etc/dnf/dnf.conf": {
+      "content": [
+        "sha256:c517559154f0de26716dd6464fbf524aeebf965cb8cf89ebde69e51355633878",
+        "sha256:86795d352e3107dfb5257a9a4466fdc93668ec0776def8f62e211560f6fabeac"
+      ]
+    }
+  }
 }