6 """This module provides functions to manage servers in server database
10     Create a server with given role, with status primary.
13     Delete a server from the database.
17     Modify a server's role, status, note, or attribute:
18     1. Add role to a server. If the server is in primary status, proper actions
20     2. Delete a role from a server. If the server is in primary status, proper
22     3. Change status of a server. If the server is changed from or to primary
24        or disable each role of the server.
25     4. Change note of a server. Note is a field you can add description about
26        the server.
27     5. Change/delete attribute of a server. Attribute can be used to store
28        information about a server. For example, the max_processes count for a
42 from autotest_lib.frontend.server import models as server_models
47 def _add_role(server, role, action):  argument
48     """Add a role to the server.
50     @param server: An object of server_models.Server.
51     @param role: Role to be added to the server.
58     if role in server.get_role_names():
60                 'Server %s already has role %s.' % (server.hostname, role))
62     # Verify server
63     if not server_manager_utils.check_server(server.hostname, role):
65                 'Server %s is not ready for role %s.' % (server.hostname, role))
68         server.status == server_models.Server.STATUS.PRIMARY):
69         servers = server_models.Server.objects.filter(
70                 roles__role=role, status=server_models.Server.STATUS.PRIMARY)
73                 'Role %s must be unique. Server %s already has role %s.' %
76     server_models.ServerRole.objects.create(server=server, role=role)
78     # If needed, apply actions to enable the role for the server.
79     server_manager_actions.try_execute(server, [role], enable=True,
82     print('Role %s is added to server %s.' % (role, server.hostname))
85 def _delete_role(server, role, action=False):  argument
86     """Delete a role from the server.
88     @param server: An object of server_models.Server.
89     @param role: Role to be deleted from the server.
96     if role not in server.get_role_names():
98                 'Server %s does not have role %s.' % (server.hostname, role))
100     if server.status == server_models.Server.STATUS.PRIMARY:
101         server_manager_utils.warn_missing_role(role, server)
103     # Apply actions to disable the role for the server before the role is
104     # removed from the server.
105     server_manager_actions.try_execute(server, [role], enable=False,
108     print('Deleting role %s from server %s...' % (role, server.hostname))
109     server.roles.get(role=role).delete()
111     # Apply actions to disable the role for the server after the role is
112     # removed from the server.
113     server_manager_actions.try_execute(server, [role], enable=False,
116     if (not server.get_role_names() and
117         server.status == server_models.Server.STATUS.PRIMARY):
118         print ('Server %s has no role.')
120     print('Role %s is deleted from server %s.' % (role, server.hostname))
123 def _change_status(server, status, action):  argument
124     """Change the status of the server.
126     @param server: An object of server_models.Server.
127     @param status: New status of the server.
134     if server.status == status:
136                 'Server %s already has status of %s.' %
137                 (server.hostname, status))
138     if (not server.roles.all() and
139         status == server_models.Server.STATUS.PRIMARY):
141                 'Server %s has no role associated. Server must have a role to '
142                 'be in status primary.' % server.hostname)
144     # Abort the action if the server's status will be changed to primary and
145     # the Autotest instance already has another server running an unique role.
146     # For example, a scheduler server is already running, and a repair_required
147     # server with role scheduler should not be changed to status primary.
148     unique_roles = server.roles.filter(
150     if unique_roles and status == server_models.Server.STATUS.PRIMARY:
152             servers = server_models.Server.objects.filter(
154                     status=server_models.Server.STATUS.PRIMARY)
157                         'Role %s must be unique. Server %s already has the '
160     # Post a warning if the server's status will be changed from primary to
161     # other value and the server is running a unique role across database, e.g.
163     if server.status == server_models.Server.STATUS.PRIMARY:
164         for role in server.get_role_names():
165             server_manager_utils.warn_missing_role(role, server)
167     enable = status == server_models.Server.STATUS.PRIMARY
168     server_manager_actions.try_execute(server, server.get_role_names(),
172     prev_status = server.status
173     server.status = status
174     server.save()
176     # Apply actions to enable/disable roles of the server after the status is
178     server_manager_actions.try_execute(server, server.get_role_names(),
183     print('Status of server %s is changed from %s to %s. Affected roles: %s' %
184           (server.hostname, prev_status, status,
185            ', '.join(server.get_role_names())))
190     """Create a new server.
192     The status of new server will always be primary.
194     @param hostname: hostname of the server.
195     @param role: role of the new server, default to None.
196     @param note: notes about the server, default to None.
198     @return: A Server object that contains the server information.
201     server = server_models.Server.objects.create(
202             hostname=hostname, status=server_models.Server.STATUS.PRIMARY,
204     server_models.ServerRole.objects.create(server=server, role=role)
205     return server
209 def delete(hostname, server=None):  argument
210     """Delete given server from server database.
212     @param hostname: hostname of the server to be deleted.
213     @param server: Server object from database query, this argument should be
216     @raise ServerActionError: If delete server action failed, e.g., server is
219     print('Deleting server %s from server database.' % hostname)
222         server.status == server_models.Server.STATUS.PRIMARY):
223         print('Server %s is in status primary, need to disable its '
225         for role in server.roles.all():
226             _delete_role(server, role.role)
228     server.delete()
229     print('Server %s is deleted from server database.' % hostname)
234            attribute=None, value=None, action=False, server=None):  argument
235     """Modify given server with specified actions.
237     @param hostname: hostname of the server to be modified.
238     @param role: Role to be added to the server.
239     @param status: Modify server status.
240     @param delete: True to delete given role from the server, default to False.
241     @param note: Note of the server.
242     @param attribute: Name of an attribute of the server.
243     @param value: Value of an attribute of the server.
246     @param server: Server object from database query, this argument should be
255             _add_role(server, role, action)
257             _delete_role(server, role, action)
260         _change_status(server, status, action)
263         server.note = note
264         server.save()
267         server_manager_utils.change_attribute(server, attribute, value)
269         server_manager_utils.delete_attribute(server, attribute)
271     return server