slap/standalone: support setting multi-master in slapos.cfg

This allow to use standalone slapos with some requests being forwarded
to another slapos master. The intended use case is to make have frontend
requests forwarded to "real" slapos master when embedding slapos in
theia or slaprunner.

slapos/slap/standalone.py

@@ -34,6 +34,7 @@ import time
 import errno
 import socket
 import shutil
+import collections
 
 from six.moves import urllib
 from six.moves import http_client
@@ -43,6 +44,13 @@ try:
 except ImportError:
   import subprocess
 
+try:
+  from typing import TYPE_CHECKING, Optional, Iterable, Dict, Union
+  if TYPE_CHECKING:
+    import subprocess
+except ImportError: # XXX to be removed once we depend on typing
+  pass
+
 import xml_marshaller
 import zope.interface
 import psutil
@@ -151,10 +159,27 @@ class SupervisorConfigWriter(ConfigWriter):
 class SlapOSConfigWriter(ConfigWriter):
   """Write slapos configuration at etc/slapos.cfg
   """
+  def _getPartitionForwardConfiguration(self):
+    # type: () -> Iterable[str]
+    for pfc in self._standalone_slapos._partition_forward_configuration:
+      software_release_list = '\n  '.join(pfc.software_release_list)
+      config = '[multimaster/{pfc.master_url}]\n'.format(pfc=pfc)
+      if pfc.cert:
+        config += 'cert = {pfc.cert}\n'.format(pfc=pfc)
+      if pfc.key:
+        config += 'key = {pfc.key}\n'.format(pfc=pfc)
+      config += 'software_release_list =\n  {}\n'.format('\n  '.join(pfc.software_release_list))
+      if isinstance(pfc, PartitionForwardAsPartitionConfiguration):
+        config += "computer = {pfc.computer}\n".format(pfc=pfc)
+        config += "partition = {pfc.partition}\n".format(pfc=pfc)
+      yield config
+
   def writeConfig(self, path):
-    standalone_slapos = self._standalone_slapos  # type: StandaloneSlapOS
+    # type: (str) -> None
+    standalone_slapos = self._standalone_slapos
     read_only_shared_part_list = '\n  '.join( #  pylint: disable=unused-variable; used in format()
         standalone_slapos._shared_part_list)
+    partition_forward_configuration = '\n'.join(self._getPartitionForwardConfiguration())
     with open(path, 'w') as f:
       f.write(
           textwrap.dedent(
@@ -176,6 +201,8 @@ class SlapOSConfigWriter(ConfigWriter):
               host = {standalone_slapos._server_ip}
               port = {standalone_slapos._server_port}
               database_uri = {standalone_slapos._proxy_database}
+
+              {partition_forward_configuration}
               """).format(**locals()))
 
 
@@ -195,6 +222,46 @@ class SlapOSCommandWriter(ConfigWriter):
     os.chmod(path, 0o755)
 
 
+class PartitionForwardConfiguration(object):
+  """Specification of request forwarding to another master, requested as user.
+  """
+  def __init__(
+      self,
+      master_url,
+      cert=None,
+      key=None,
+      software_release_list=(),
+  ):
+    # type: (str, Optional[str], Optional[str], Iterable[str]) -> None
+    self.master_url = master_url
+    self.cert = cert
+    self.key = key
+    self.software_release_list = list(software_release_list)
+
+
+class PartitionForwardAsPartitionConfiguration(PartitionForwardConfiguration):
+  """Specification of request forwarding to another master, requested as partition.
+  """
+  def __init__(
+      self,
+      master_url,
+      computer,
+      partition,
+      cert=None,
+      key=None,
+      software_release_list=(),
+  ):
+    # type: (str, str, str, Optional[str], Optional[str], Iterable[str]) -> None
+    super(PartitionForwardAsPartitionConfiguration, self).__init__(
+        master_url,
+        cert,
+        key,
+        software_release_list,
+    )
+    self.computer = computer
+    self.partition = partition
+
+
 @zope.interface.implementer(ISupply, IRequester)
 class StandaloneSlapOS(object):
   """A SlapOS that can be embedded in other applications, also useful for testing.
@@ -215,7 +282,10 @@ class StandaloneSlapOS(object):
       shared_part_list=(),
       software_root=None,
       instance_root=None,
-      shared_part_root=None):
+      shared_part_root=None,
+      partition_forward_configuration=(),
+    ):
+    # type: (str, str, int, str, Iterable[str], Optional[str], Optional[str], Optional[str], Iterable[Union[PartitionForwardConfiguration, PartitionForwardAsPartitionConfiguration]]) -> None
     """Constructor, creates a standalone slapos in `base_directory`.
 
     Arguments:
@@ -226,6 +296,7 @@ class StandaloneSlapOS(object):
       * `software_root` -- directory to install software, default to "soft" in `base_directory`
       * `instance_root` -- directory to create instances, default to "inst" in `base_directory`
       * `shared_part_root` -- directory to hold shared parts software, default to "shared" in `base_directory`.
+      * `partition_forward_configuration` -- configuration of partition request forwarding to external SlapOS master.
 
     Error cases:
       * `PathTooDeepError` when `base_directory` is too deep. Because of limitation
@@ -241,6 +312,7 @@ class StandaloneSlapOS(object):
 
     self._base_directory = base_directory
     self._shared_part_list = list(shared_part_list)
+    self._partition_forward_configuration = list(partition_forward_configuration)
 
     self._slapos_commands = {
         'slapos-node-software': {

slapos/tests/test_standalone.py

@@ -37,11 +37,14 @@ import errno
 import time
 import multiprocessing
 from contextlib import closing
+from six.moves.configparser import ConfigParser
 
 import psutil
 
 from slapos.slap.standalone import StandaloneSlapOS
 from slapos.slap.standalone import SlapOSNodeCommandError
+from slapos.slap.standalone import PartitionForwardConfiguration
+from slapos.slap.standalone import PartitionForwardAsPartitionConfiguration
 
 SLAPOS_TEST_IPV4 = os.environ['SLAPOS_TEST_IPV4']
 SLAPOS_TEST_IPV6 = os.environ['SLAPOS_TEST_IPV6']
@@ -165,6 +168,89 @@ class TestSlapOSStandaloneSetup(unittest.TestCase):
     with self.assertRaises(BaseException):
       standalone1.stop()
 
+  def test_partition_forward(self):
+    # type: () -> None
+    working_dir = tempfile.mkdtemp(prefix=__name__)
+    self.addCleanup(shutil.rmtree, working_dir)
+    partition_forward_config = [
+        PartitionForwardConfiguration(
+            'https://slapos1.example.com',
+            'path/to/cert',
+            'path/to/key',
+            software_release_list=('https://example.com/software-1.cfg', ),
+        ),
+        PartitionForwardConfiguration(
+            'https://slapos2.example.com',
+            software_release_list=('https://example.com/software-2.cfg', ),
+        ),
+        PartitionForwardAsPartitionConfiguration(
+            'https://slapos3.example.com',
+            'computer',
+            'partition',
+            'path/to/cert',
+            'path/to/key',
+            software_release_list=('https://example.com/software-3.cfg', ),
+        ),
+        PartitionForwardAsPartitionConfiguration(
+            'https://slapos4.example.com',
+            'computer',
+            'partition',
+            software_release_list=('https://example.com/software-4.cfg', ),
+        ),
+    ]
+    standalone = StandaloneSlapOS(
+        working_dir,
+        SLAPOS_TEST_IPV4,
+        SLAPOS_TEST_PORT,
+        partition_forward_configuration=partition_forward_config,
+    )
+    self.addCleanup(standalone.stop)
+
+    config_parser = ConfigParser()
+    config_parser.read([os.path.join(working_dir, 'etc', 'slapos.cfg')])
+    self.assertTrue(
+        config_parser.has_section('multimaster/https://slapos1.example.com'))
+    self.assertEqual(
+        'path/to/cert',
+        config_parser.get('multimaster/https://slapos1.example.com', 'cert'))
+    self.assertEqual(
+        'path/to/key',
+        config_parser.get('multimaster/https://slapos1.example.com', 'key'))
+    self.assertEqual(
+        'https://example.com/software-1.cfg',
+        config_parser.get(
+            'multimaster/https://slapos1.example.com',
+            'software_release_list').strip())
+    self.assertFalse(
+        config_parser.has_option(
+            'multimaster/https://slapos2.example.com', 'computer'))
+    self.assertFalse(
+        config_parser.has_option(
+            'multimaster/https://slapos2.example.com', 'partition'))
+
+    self.assertTrue(
+        config_parser.has_section('multimaster/https://slapos2.example.com'))
+    self.assertFalse(
+        config_parser.has_option(
+            'multimaster/https://slapos2.example.com', 'cert'))
+    self.assertFalse(
+        config_parser.has_option(
+            'multimaster/https://slapos2.example.com', 'key'))
+
+    self.assertTrue(
+        config_parser.has_section('multimaster/https://slapos3.example.com'))
+    self.assertEqual(
+        'computer',
+        config_parser.get(
+            'multimaster/https://slapos3.example.com', 'computer'))
+    self.assertEqual(
+        'partition',
+        config_parser.get(
+            'multimaster/https://slapos3.example.com', 'partition'))
+
+    self.assertTrue(
+        config_parser.has_section('multimaster/https://slapos4.example.com'))
+
 
 class SlapOSStandaloneTestCase(unittest.TestCase):
   # This test case takes care of stopping the standalone instance