app.py: setup remotes during startup

app.py

@@ -54,13 +54,17 @@ def set_remotes(remotes):
         global REMOTES
         REMOTES = remotes
 
+def fetch_remote(remote_name):
+    app.logger.info("Fetching remote %s" % remote_name)
+    run_git(['git', 'fetch', remote_name], sourcedir)
+
 def get_git_hash(remote, commit_reference, fetch=False):
     if remote is None or commit_reference  is None:
         return ''
 
     # fetch remote
     if fetch:
-        run_git(['git', 'fetch', remote], cwd=sourcedir)
+        fetch_remote(remote)
 
     app.logger.info("Running git rev-parse on %s remote for %s branch in %s" % (remote, commit_reference, sourcedir))
     # this returns git hash if commit_reference is a branch on given remote
@@ -119,7 +123,7 @@ def do_checkout(remote, commit_reference, s_dir, force_fetch=False, temp_branch_
     '''checkout to given commit/branch/tag and return the git hash'''
     # Note: remember to acquire head_lock before calling this method
     if force_fetch:
-        run_git(['git', 'fetch', remote], cwd=s_dir)
+        fetch_remote(remote)
 
     git_hash_target = get_git_hash(remote, commit_reference)
 
@@ -199,6 +203,30 @@ def get_build_options_from_ardupilot_tree(s_dir):
     }
 })
 
+def setup_remotes():
+    added_remotes = 0
+    for remote in REMOTES:
+        # add new remote
+        result = subprocess.run(['git', 'remote', 'add', remote['name'], remote['url']], cwd=sourcedir, encoding='utf-8', capture_output=True, shell=False)
+
+        # non-zero returncode? the remote already exists probably
+        # To-do
+        # change this condition to be specific for returncode 3
+        # which is returned when remote already exists, this change came after git version 2.30
+        if result.returncode != 0:
+            app.logger.info("Remote %s already exists, updating url" % remote['name'])
+            result = subprocess.run(['git', 'remote', 'set-url', remote['name'], remote['url']], cwd=sourcedir, encoding='utf-8', capture_output=True, shell=False)
+
+        # did we succeed?
+        if result.returncode != 0:
+            app.logger.error("Failed to add/update remote %s %s %s" % (remote['name'], remote['url'], result.stderr.rstrip()))
+        else:
+            app.logger.info("Initial fetch")
+            fetch_remote(remote['name'])
+            added_remotes += 1
+
+    app.logger.info("%d/%d remotes added" % (added_remotes, len(REMOTES)))
+
 def remove_directory_recursive(dirname):
     '''remove a directory recursively'''
     app.logger.info('Removing directory ' + dirname)
@@ -505,10 +533,7 @@ def update_submodules(s_dir):
     app.logger.info("No queue lock")
 
 load_remotes()
-app.logger.info('Initial fetch')
-# checkout to default branch, fetch remote, update submodules
-do_checkout("upstream", "master", s_dir=sourcedir, force_fetch=True)
-update_submodules(s_dir=sourcedir)
+setup_remotes()
 
 app.logger.info('Python version is: %s' % sys.version)