ci: Don't assume that all runners have the same homedir

Part-of: <https://gitlab.freedesktop.org/gstreamer/cerbero/-/merge_requests/1635>

1 files changed, 26 insertions, 28 deletions

diff --git a/cerbero/commands/cache.py b/cerbero/commands/cache.py
index 579dc129..7b04f695 100644
--- a/cerbero/commands/cache.py
+++ b/cerbero/commands/cache.py
@@ -56,20 +56,27 @@ class BaseCache(Command):
         ]
         Command.__init__(self, args)
 
-    def get_ci_builds_dir(self, config):
-        if 'CI_BUILDS_DIR' in os.environ:
-            return os.environ['CI_BUILDS_DIR'].replace('\\', '/')
-        # For the convenience of people downloading the cache by hand
-        if config.platform == Platform.DARWIN:
-            return '/private/tmp/builds'
-        elif config.platform == Platform.WINDOWS:
-            return 'C:/Users/Administrator/runner/builds'
-        return '/builds'
-
-    def get_cache_home_dir(self, config, namespace):
-        ci_builds_dir = self.get_ci_builds_dir(config)
-        ci_home_dir = os.environ.get('CERBERO_HOME', 'cerbero-build')
-        return f'{ci_builds_dir}/{namespace}/cerbero/{ci_home_dir}'
+    def get_cache_home_dir(self, config):
+        """
+        Use the python virtual env config file in the build-tools dir to fetch
+        cerbero's home_dir. If it doesn't exist, we will error out loudly,
+        since it indicates a corrupted cache.
+        """
+        cache_file = os.path.join(config.build_tools_prefix, 'pyvenv.cfg')
+        with open(cache_file, 'r', encoding='utf-8') as f:
+            for line in f:
+                if not line.startswith('command = '):
+                    continue
+                _, cmd = line.split(' = ')
+                cache_build_tools_prefix = cmd.split(' -m venv ')[1].strip()
+                return os.path.dirname(cache_build_tools_prefix)
+        cache_file = os.path.join(config.build_tools_prefix, 'bin', 'meson')
+        with open(cache_file, 'r', encoding='utf-8') as f:
+            line = f.readline()
+            if line.startswith('#!'):
+                split_idx = line.rfind('/build-tools/bin/python')
+                return line[2:split_idx]
+        raise FatalError('Failed to relocate prefix: could not deduce cache homedir')
 
     def get_gnu_sed(self, config):
         if config.platform == Platform.DARWIN:
@@ -164,14 +171,6 @@ class FetchCache(BaseCache):
     doc = N_('Fetch a cached build from external storage based on cerbero git ' 'revision.')
     name = 'fetch-cache'
 
-    def __init__(self, args=[]):
-        args.append(
-            ArgparseArgument(
-                '--namespace', action='store', type=str, default='gstreamer', help='GitLab namespace to relocate from'
-            )
-        )
-        BaseCache.__init__(self, args)
-
     def find_dep(self, deps, sha, allow_old=False):
         for dep in deps:
             if dep['commit'] == sha:
@@ -252,13 +251,13 @@ class FetchCache(BaseCache):
             f.truncate(0)
             pickle.dump(p, f)
 
-    def relocate_prefix(self, config, namespace):
+    def relocate_prefix(self, config):
         """
         We need to relocate pc files that weren't generated by meson and
         python programs installed with pip because the shebang set by the
         virtualenv python uses an absolute path.
         """
-        origin = self.get_cache_home_dir(config, namespace)
+        origin = self.get_cache_home_dir(config)
         dest = config.home_dir
         if origin == dest:
             return
@@ -272,7 +271,7 @@ class FetchCache(BaseCache):
         elif config.platform == Platform.WINDOWS:
             self.mark_windows_build_tools_dirty(config)
 
-    async def fetch_dep(self, config, dep, namespace):
+    async def fetch_dep(self, config, dep):
         is_ci = 'CI' in os.environ
         try:
             dep_path = os.path.join(config.home_dir, os.path.basename(dep['url']))
@@ -287,10 +286,9 @@ class FetchCache(BaseCache):
             if is_ci:
                 m.action('Unpack complete, deleting artifact')
                 os.remove(dep_path)
-
-            self.relocate_prefix(config, namespace)
         except FatalError as e:
             m.warning('Could not retrieve dependencies for commit %s: %s' % (dep['commit'], e.msg))
+        self.relocate_prefix(config)
 
     def run(self, config, args):
         BaseCache.run(self, config, args)
@@ -299,7 +297,7 @@ class FetchCache(BaseCache):
         deps = self.get_deps(config, args)
         dep = self.find_dep(deps, sha, allow_old=True)
         if dep:
-            run_until_complete(self.fetch_dep(config, dep, args.namespace))
+            run_until_complete(self.fetch_dep(config, dep))
         m.message('All done!')