Change mirror address configuration to project-local JSON

Environment variables are prone to shell injection attacks, especially
on build servers that many people may have access to. Changing address in
a file requires an explicit command that is supposedly under the control
of a trusted developer.

docs/markdown/Using-the-WrapDB.md

@@ -45,15 +45,3 @@ The contents of the Wrap database are tracked in git repos of the
 [Mesonbuild project](https://github.com/mesonbuild). The actual
 process is simple and described in [submission
 documentation](Adding-new-projects-to-wrapdb.md).
-
-## Self-hosted Wrap database
-
-If for whatever reason you want to use self-hosted or proxied Wrap database *(since 1.X.X)* you may override server address with the `MESON_WRAPDB_MIRROR` environment variable:
-
-```console
-$ export MESON_WRAPDB_MIRROR=user:[email protected]:8080
-$ meson wrap update-db
-$ meson wrap install zlib
-```
-
-You will be limited to the wraps available on the mirror.

docs/markdown/Using-wraptool.md

@@ -96,3 +96,16 @@ but available in WrapDB will automatically be downloaded.
 
 Automatic fetch of WrapDB subprojects can be disabled by removing the file
 `subprojects/wrapdb.json`, or by using `--wrap-mode=nodownload`.
+
+## Self-hosted Wrap database
+
+If for whatever reason you want to use self-hosted or proxied Wrap database *(since 1.X.X)* you may set mirror address to be used for the workspace:
+
+```console
+$ meson wrap set-db-mirror user:[email protected]:8080
+$ meson wrap update-db
+$ meson wrap install zlib
+```
+
+You will be limited to the wraps available on the mirror, only one source is used at a time.
+The address is stored in `subprojects/wrapdb-mirrors.json`, remove the file to use upstream address.

mesonbuild/wrap/wrap.py

@@ -25,7 +25,7 @@
 from base64 import b64encode
 from netrc import netrc
 from pathlib import Path, PurePath
-from functools import lru_cache
+from functools import cache, lru_cache
 
 from . import WrapMode
 from .. import coredata
@@ -49,18 +49,29 @@
     has_ssl = False
 
 REQ_TIMEOUT = 30.0
-
 WRAPDB_UPSTREAM_HOSTNAME = 'wrapdb.mesonbuild.com'
-WRAPDB_NETLOC = os.environ.get('MESON_WRAPDB_MIRROR', WRAPDB_UPSTREAM_HOSTNAME)
 
 ALL_TYPES = ['file', 'git', 'hg', 'svn', 'redirect']
 
 PATCH = shutil.which('patch')
 
+@cache
+def wrapdb_netloc() -> str:
+    try:
+        with Path('subprojects/wrapdb-mirrors.json').open('r', encoding='utf-8') as f:
+            mirrorlist = json.load(f)
+            version = mirrorlist['version']
+            if version > 1:
+                m = f'WrapDB mirrors file (v{version}) was created with the newer version of meson'
+                raise WrapException(m)
+            return mirrorlist['mirrors'][0]
+    except FileNotFoundError:
+        return WRAPDB_UPSTREAM_HOSTNAME
+
 def is_trusted_subdomain(hostname: str) -> bool:
     trusted_subdomains = {
         WRAPDB_UPSTREAM_HOSTNAME,
-        urllib.parse.urlparse(f'//{WRAPDB_NETLOC}').hostname,
+        urllib.parse.urlparse(f'//{wrapdb_netloc()}').hostname,
     }
     for entry in trusted_subdomains:
         if hostname.endswith(entry):
@@ -74,7 +85,7 @@ def expand_wrapdburl(urlstr: str) -> urllib.parse.ParseResult:
     if url.scheme == 'wrapdb':
         if url.netloc:
             raise WrapException(f'{urlstr} with wrapdb: scheme should not have a netloc')
-        url = url._replace(scheme='https', netloc=WRAPDB_NETLOC)
+        url = url._replace(scheme='https', netloc=wrapdb_netloc())
     if not url.hostname:
         raise WrapException(f'{urlstr} is not a valid URL')
     if not is_trusted_subdomain(url.hostname):

mesonbuild/wrap/wraptool.py

@@ -7,6 +7,7 @@
 import configparser
 import shutil
 import typing as T
+import json
 
 from glob import glob
 from .wrap import (open_wrapdburl, WrapException, get_releases, get_releases_data,
@@ -59,6 +60,10 @@ def add_arguments(parser: 'argparse.ArgumentParser') -> None:
     p.add_argument('project_path')
     p.set_defaults(wrap_func=promote)
 
+    p = subparsers.add_parser('set-db-mirror', help='Set WrapDB mirror address (RFC 3986 authority) to use')
+    p.add_argument('authority')
+    p.set_defaults(wrap_func=set_db_mirror)
+
     p = subparsers.add_parser('update-db', help='Update list of projects available in WrapDB (Since 0.61.0)')
     p.add_argument('--allow-insecure', default=False, action='store_true',
                    help='Allow insecure server connections.')
@@ -187,6 +192,14 @@ def status(options: 'argparse.Namespace') -> None:
         else:
             print('', name, f'not up to date. Have {current_branch} {current_revision}, but {latest_branch} {latest_revision} is available.')
 
+def set_db_mirror(options: 'argparse.Namespace') -> None:
+    Path('subprojects').mkdir(exist_ok=True)
+    with Path('subprojects/wrapdb-mirrors.json').open('w') as f:
+        json.dump(dict(
+            version=1, # If the stored format changes, don't want to guess how to preserve forward compatibility
+            mirrors=[options.authority]
+        ), f)
+
 def update_db(options: 'argparse.Namespace') -> None:
     data = get_releases_data(options.allow_insecure)
     Path('subprojects').mkdir(exist_ok=True)