From dbf5e54307d734c14673f524739bf6fa9501bfcb Mon Sep 17 00:00:00 2001
From: Josh Durgin <josh.durgin@dreamhost.com>
Date: Tue, 5 Jul 2011 17:16:08 -0700
Subject: [PATCH] Add simple lock server HTTP interface.

---
 teuthology/locker/api.py    | 103 ++++++++++++++++++++++++++++++++++++
 teuthology/locker/config.py |  23 ++++++++
 teuthology/locker/locker.py |  15 ++++++
 3 files changed, 141 insertions(+)
 create mode 100644 teuthology/locker/api.py
 create mode 100644 teuthology/locker/config.py
 create mode 100755 teuthology/locker/locker.py

diff --git a/teuthology/locker/api.py b/teuthology/locker/api.py
new file mode 100644
index 0000000000..5266b1a759
--- /dev/null
+++ b/teuthology/locker/api.py
@@ -0,0 +1,103 @@
+import json
+import web
+
+from config import DB
+
+def load_machine(name):
+    results = list(DB.select('machine', what='*',
+                             where='name = $name',
+                             vars=dict(name=name)))
+    if not results:
+        raise web.NotFound()
+    return results[0]
+
+class MachineLock:
+    def GET(self, name):
+        row = load_machine(name)
+        row.locked_since = row.locked_since.isoformat()
+        web.header('Content-type', 'text/json')
+        return json.dumps(row)
+
+    def DELETE(self, name):
+        user = web.input('user')['user']
+        machine = load_machine(name)
+        if not machine.locked:
+            raise web.BadRequest()
+        if machine.locked_by != user:
+            raise web.Forbidden()
+
+        res = DB.update('machine',
+                        where='locked = true AND name = $name AND locked_by = $user',
+                        vars=dict(name=name, user=user),
+                        locked=False, locked_by=None)
+        assert res == 1, 'Failed to unlock machine {name}'.format(name=name)
+
+    def POST(self, name):
+        user = web.input('user')['user']
+        machine = load_machine(name)
+        if machine.locked:
+            raise web.Forbidden()
+        res = DB.update('machine', where='name = $name AND locked = false',
+                        vars=dict(name=name),
+                        locked=True,
+                        locked_by=user,
+                        locked_since=web.db.SQLLiteral('NOW()'))
+        assert res == 1, 'Failed to lock machine {name}'.format(name=name)
+
+    def PUT(self, name):
+        desc = web.input(desc=None)['desc']
+        status = web.input(status=None)['status']
+
+        updated = {}
+        if desc is not None:
+            updated['description'] = desc
+        if status is not None:
+            updated['up'] = (status == 'up')
+
+        if not updated:
+            raise web.BadRequest()
+        DB.update('machine', where='name = $name',
+                  vars=dict(name=name), **updated)
+
+class Lock:
+    def GET(self):
+        rows = list(DB.select('machine', what='*'))
+        if not rows:
+            raise web.NotFound()
+        for row in rows:
+            row.locked_since = row.locked_since.isoformat()
+        web.header('Content-type', 'text/json')
+        return json.dumps(rows)
+
+    def POST(self):
+        user = web.input('user')['user']
+        num = int(web.input('num')['num'])
+
+        if num < 1:
+            raise web.BadRequest()
+
+        tries = 0
+        while True:
+            try:
+                with DB.transaction():
+                    results = list(DB.select('machine', what='name',
+                                             where='locked = false and up = true',
+                                             limit=num))
+                    if len(results) < num:
+                        raise web.HTTPError(status='503 Service Unavailable')
+                    names = [row.name for row in results]
+                    num_locked = DB.update('machine', where=web.db.sqlors('name = ', names),
+                                           locked=True,
+                                           locked_by=user,
+                                           locked_since=web.db.SQLLiteral('NOW()'))
+                    assert num_locked == num, 'Failed to lock machines'
+            except:
+                tries += 1
+                if tries < 10:
+                    continue
+                raise
+            else:
+                break
+
+        web.header('Content-type', 'text/json')
+        return json.dumps(names)
diff --git a/teuthology/locker/config.py b/teuthology/locker/config.py
new file mode 100644
index 0000000000..f2bbe1b251
--- /dev/null
+++ b/teuthology/locker/config.py
@@ -0,0 +1,23 @@
+"""
+This file contains database configuration.
+
+The schema can be created with::
+
+    CREATE TABLE machine (
+        name varchar(255),
+        up boolean NOT NULL,
+        locked boolean NOT NULL,
+        locked_since timestamp NOT NULL DEFAULT '0000-00-00T00:00:00',
+        locked_by varchar(32),
+        description TEXT,
+        PRIMARY KEY (name),
+        INDEX (locked),
+        INDEX (up));
+
+If using MySQL, be sure to use an engine that supports
+transactions, like InnoDB.
+"""
+import web
+
+# Change these values to the connection info for your database.
+DB = web.database(dbn='dbms', db='db', user='user', pw='password', host='host')
diff --git a/teuthology/locker/locker.py b/teuthology/locker/locker.py
new file mode 100755
index 0000000000..93067cf84e
--- /dev/null
+++ b/teuthology/locker/locker.py
@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+
+import web
+
+from api import Lock, MachineLock
+
+urls = (
+    '/lock', 'Lock',
+    '/lock/(.*)', 'MachineLock',
+    )
+
+app = web.application(urls, globals())
+
+if __name__ == "__main__":
+    app.run()
-- 
2.39.5