Configure immutable component sources and process scoped Go transport

Why: Prepare ordinary component workspaces and real module downloads without changing global Git configuration or other feature branches. Evidence: SELF clean-cache module consumption and real temporary-Git transport tests are recorded by make evidence in the task card, including expected RED and passing GREEN runs. Impact: Add component identities/source locks and non-secret transport configuration. Existing submodule layout remains supported during migration. Refs: Versioned dependencies U1/U2; R15; feature/dependency-workspace
2026-10-13 15:25:37 +00:00
parent e0982c8428
commit f71058cb7e
6 changed files with 746 additions and 3 deletions
@@ -0,0 +1,49 @@
+"""Process-local module transport; configuration contains no credentials."""
+import json
+import os
+from pathlib import Path
+from urllib.parse import urlsplit
+
+
+def _url(value):
+    if not isinstance(value, str) or any(c.isspace() for c in value):
+        raise ValueError('invalid module transport URL')
+    parsed = urlsplit(value)
+    if parsed.scheme not in {'https', 'ssh', 'git+ssh', 'file'} or parsed.password:
+        raise ValueError('unsupported transport or credentials in URL')
+    if parsed.scheme == 'https' and parsed.username:
+        raise ValueError('transport URL must not contain credentials')
+    if parsed.scheme == 'file' and parsed.netloc not in {'', 'localhost'}:
+        raise ValueError('file transport must be local')
+    if parsed.query or parsed.fragment or not parsed.path:
+        raise ValueError('transport URL must identify a repository path')
+    return value
+
+
+def environment(root=None):
+    root = Path(root) if root is not None else Path(__file__).resolve().parents[2]
+    path = root / 'components.json'
+    config = json.loads(path.read_text()).get('transport', {}) if path.exists() else {}
+    env = os.environ.copy()
+    env.update(GOWORK='off', GOTOOLCHAIN='local')
+    private = config.get('go_private', [])
+    if not isinstance(private, list) or any(not isinstance(p, str) or not p or any(c.isspace() for c in p) for p in private):
+        raise ValueError('invalid private module prefixes')
+    if private:
+        env.update(GOPRIVATE=','.join(private), GONOPROXY=','.join(private), GONOSUMDB=','.join(private))
+    rewrites = config.get('git_rewrites', [])
+    if not isinstance(rewrites, list):
+        raise ValueError('invalid Git transport mappings')
+    if rewrites:
+        # Do not inherit temporary authentication configuration into candidate code.
+        for key in list(env):
+            if key == 'GIT_CONFIG_COUNT' or key.startswith(('GIT_CONFIG_KEY_', 'GIT_CONFIG_VALUE_')):
+                del env[key]
+        for i, rewrite in enumerate(rewrites):
+            if not isinstance(rewrite, dict) or set(rewrite) != {'from', 'to'}:
+                raise ValueError('invalid Git transport mapping')
+            source, target = _url(rewrite['from']), _url(rewrite['to'])
+            env[f'GIT_CONFIG_KEY_{i}'] = f'url.{target}.insteadOf'
+            env[f'GIT_CONFIG_VALUE_{i}'] = source
+        env['GIT_CONFIG_COUNT'] = str(len(rewrites))
+    return env