contest: add trivial brancher

Add a very trivial brancher to start pushing fake branches
to test. For now those branches are just a copy of net-next.

Signed-off-by: Jakub Kicinski <[email protected]>

core/tree.py

@@ -56,6 +56,10 @@ def git_pull(self, pull_url):
         cmd += pull_url.split()
         return self.git(cmd)
 
+    def git_push(self, remote, spec):
+        cmd = ["push", remote, spec]
+        return self.git(cmd)
+
     def git_status(self, untracked=None, short=False):
         cmd = ["status"]
         if short:
@@ -104,6 +108,23 @@ def reset(self, fetch=None):
         finally:
             core.log_end_sec()
 
+    def remotes(self):
+        """
+        Returns a dict of dicts like {"origin": {"fetch": URL1, "push": URL2}}
+        """
+        cmd = ["remote", "-v"]
+        ret = self.git(cmd)
+        lines = ret.split('\n')
+        result = {}
+        for l in lines:
+            if not l:
+                continue
+            bits = l.split()
+            info = result.get(bits[0], {})
+            info[bits[2][1:-1]] = bits[1]
+            result[bits[0]] = info
+        return result
+
     def contains(self, commit):
         core.log_open_sec("Checking for commit " + commit)
         try:

trivial-net-brancher.py

@@ -0,0 +1,177 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+import configparser
+import datetime
+import json
+import os
+import time
+
+from core import NIPA_DIR
+from core import log, log_open_sec, log_end_sec, log_init
+from core import Tree
+
+"""
+Config:
+
+[trees]
+net-next=net-next, net-next, origin, origin/main
+[target]
+public_url=https://github.com/linux-netdev/testing.git
+[email protected]:linux-netdev/testing.git
+branch_pfx=net-next-
+[output]
+branches=branches.json
+"""
+
+
+def hour_timestamp(when=None) -> int:
+    if when is None:
+        when = datetime.datetime.now(datetime.UTC)
+    ts = when.timestamp()
+    return int(ts / (60 * 60))
+
+
+def dump_branches(config, state) -> None:
+    log_open_sec("Update branches manifest")
+    pub_url = config.get('target', 'public_url')
+
+    data = []
+    for name, val in state["branches"].items():
+        data.append({"branch": name, "date": val, "url": pub_url + " " + name})
+
+    branches = config.get("output", "branches")
+    with open(branches, 'w') as fp:
+        json.dump(data, fp)
+    log_end_sec()
+
+
+def create_new(config, state, tree, tgt_remote) -> None:
+    now = datetime.datetime.now(datetime.UTC)
+    pfx = config.get("target", "branch_pfx")
+    branch_name = pfx + datetime.datetime.now(datetime.UTC).strftime("%Y-%m-%d--%H-%M")
+
+    log_open_sec("Fetching latest net-next")
+    tree.git_fetch(tree.remote)
+    tree.git_reset(tree.branch, hard=True)
+    log_end_sec()
+
+    state["branches"][branch_name] = now.isoformat()
+
+    log_open_sec("Pushing out")
+    tree.git_push(tgt_remote, "HEAD:" + branch_name)
+    log_end_sec()
+
+
+def reap_old(config, state, tree, tgt_remote) -> None:
+    now = datetime.datetime.now(datetime.UTC)
+    pfx = config.get("target", "branch_pfx")
+
+    log_open_sec("Clean up old branches")
+    tree.git_fetch(tgt_remote)
+
+    branches = tree.git(['branch', '-a'])
+    branches = branches.split('\n')
+    r_tgt_pfx = 'remotes/' + tgt_remote + '/'
+
+    found = set()
+    for br in branches:
+        br = br.strip()
+        if not br.startswith(r_tgt_pfx + pfx):
+            continue
+        br = br[len(r_tgt_pfx):]
+        found.add(br)
+        if br not in state["branches"]:
+            tree.git_push(tgt_remote, ':' + br)
+            continue
+        when = datetime.datetime.fromisoformat(state["branches"][br])
+        if now - when > datetime.timedelta(days=5):
+            tree.git_push(tgt_remote, ':' + br)
+            del state["branches"][br]
+            continue
+    state_has = set(state["branches"].keys())
+    lost = state_has.difference(found)
+    for br in lost:
+        log_open_sec("Removing lost branch " + br + " from state")
+        del state["branches"][br]
+        log_end_sec()
+    log_end_sec()
+
+
+def main_loop(config, state, tree, tgt_remote) -> None:
+    now = datetime.datetime.now(datetime.UTC)
+    now_h = hour_timestamp(now)
+    if now_h - state["last"] < 3:
+        time.sleep(20)
+        return
+
+    reap_old(config, state, tree, tgt_remote)
+    create_new(config, state, tree, tgt_remote)
+
+    state["last"] = now_h
+
+    dump_branches(config, state)
+
+
+def prep_remote(config, tree) -> str:
+    tgt_tree = config.get('target', 'push_url')
+
+    log_open_sec("Prep remote")
+    remotes = tree.remotes()
+    for r in remotes:
+        if remotes[r]["push"] == tgt_tree:
+            log("Found remote, it is " + r)
+            return r
+
+    log("Remote not found, adding")
+
+    if "brancher" in remotes:
+        log("Remote 'brancher' already exists with different URL")
+        raise Exception("Remote exists with different URL")
+
+    tree.git(['remote', 'add', 'brancher', tgt_tree])
+    log_end_sec()
+
+
+def main() -> None:
+    config = configparser.ConfigParser()
+    config.read(['nipa.config', 'pw.config', 'brancher.config'])
+
+    log_init(config.get('log', 'type', fallback='stdout'),
+             config.get('log', 'file', fallback=None))
+
+    state = {}
+    if os.path.exists("brancher.state"):
+        with open("brancher.state") as fp:
+            state = json.load(fp)
+
+    if "last" not in state:
+        state["last"] = 0
+    if "branches" not in state:
+        state["branches"] = {}
+
+    tree_obj = None
+    tree_dir = config.get('dirs', 'trees', fallback=os.path.join(NIPA_DIR, "../"))
+    for tree in config['trees']:
+        opts = [x.strip() for x in config['trees'][tree].split(',')]
+        prefix = opts[0]
+        fspath = opts[1]
+        remote = opts[2]
+        branch = opts[3]
+        src = os.path.join(tree_dir, fspath)
+        # name, pfx, fspath, remote=None, branch=None
+        tree_obj = Tree(tree, prefix, src, remote=remote, branch=branch)
+    tree = tree_obj
+
+    tgt_remote = prep_remote(config, tree)
+
+    try:
+        while True:
+            main_loop(config, state, tree, tgt_remote)
+    finally:
+        with open('brancher.state', 'w') as f:
+            json.dump(state, f)
+
+
+if __name__ == "__main__":
+    main()