Introduce open-iscsi module to manage targets on the initiator.

library/system/open_iscsi

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2013, Serge van Ginderachter <serge@vanginderachter.be>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+DOCUMENTATION = '''
+---
+module: open_iscsi
+author: Serge van Ginderachter
+version_added: "1.3"
+short_description: Manage iscsi targets with open-iscsi
+description:
+    - Discover targets on given portal, (dis)connect targets, mark targets to
+      manually or auto start, return device nodes of connected targets.
+requirements:
+    - open_iscsi library and tools (iscsiadm)
+options:
+    portal:
+        required: false
+        aliases: [ip]
+        description:
+        - the ip address of the iscsi target
+    port:
+        required: false
+        default: 3260
+        description:
+        - the port on which the iscsi target process listens
+    target:
+        required: false
+        aliases: [name, targetname]
+        description:
+        - the iscsi target name
+    login:
+        required: false
+        choices: [true, false]
+        description:
+        - whether the target node should be connected
+    node_auth:
+        required: false
+        default: CHAP
+        description:
+        - discovery.sendtargets.auth.authmethod
+    node_user:
+        required: false
+        description:
+        - discovery.sendtargets.auth.username
+    node_pass:
+        required: false
+        description:
+        - discovery.sendtargets.auth.password
+    auto_node_startup:
+        aliases: [automatic]
+        required: false
+        choices: [true, false]
+        description:
+        - whether the target node should be automatically connected at startup
+    discover:
+        required: false
+        choices: [true, false]
+        description:
+        - whether the list of target nodes on the portal should be
+          (re)discovered and added to the persistent iscsi database.
+          Keep in mind that iscsiadm discovery resets configurtion, like node.startup
+          to manual, hence combined with auto_node_startup=yes will allways return
+          a changed state.
+    show_nodes:
+        required: false
+        choices: [true, false]
+        description:
+        - whether the list of nodes in the persistent iscsi database should be
+          returned by the module
+
+examples:
+    - description: perform a discovery on 10.1.2.3 and show available target
+                   nodes
+      code: open_iscsi: show_nodes=yes discover=yes portal=10.1.2.3
+    - description: discover targets on portal and login to the one available
+                   (only works if exactly one target is exported to the initiator)
+      code: open_iscsi: portal={{iscsi_target}} login=yes discover=yes
+    - description: connect to the named target, after updating the local
+                   persistent database (cache)
+      code: login=yes target=iqn.1986-03.com.sun:02:f8c1f9e0-c3ec-ec84-c9c9-8bfb0cd5de3d
+    - description: discconnect from the cached named target
+      code: login=no target=iqn.1986-03.com.sun:02:f8c1f9e0-c3ec-ec84-c9c9-8bfb0cd5de3d"
+'''
+
+import glob
+import time
+
+ISCSIADM = 'iscsiadm'
+
+def compare_nodelists(l1, l2):
+
+    l1.sort()
+    l2.sort()
+    return l1 == l2
+
+
+def iscsi_get_cached_nodes(module, portal=None):
+
+    cmd = '%s --mode node' % iscsiadm_cmd
+    (rc, out, err) = module.run_command(cmd)
+
+    if rc == 0:
+        lines = out.splitlines()
+        nodes = []
+        for line in lines:
+            # line format is "ip:port,target_portal_group_tag targetname"
+            parts = line.split()
+            if len(parts) > 2:
+                module.fail_json(msg='error parsing output', cmd=cmd)
+            target = parts[1]
+            parts = parts[0].split(':')
+            target_portal = parts[0]
+
+            if portal is None or portal == target_portal:
+                nodes.append(target)
+
+    # older versions of scsiadm don't have nice return codes
+    # for newer versions see iscsiadm(8); also usr/iscsiadm.c for details
+                                  # err can contain [N|n]o records...
+    elif rc == 21 or (rc == 255 and err.find("o records found") != -1):
+        nodes = []
+    else:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+    return nodes
+
+
+def iscsi_discover(module, portal, port):
+
+    cmd = '%s --mode discovery --type sendtargets --portal %s:%s' % (iscsiadm_cmd, portal, port)
+    (rc, out, err) = module.run_command(cmd)
+
+    if rc > 0:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_loggedon(module, target):
+
+    cmd = '%s --mode session' % iscsiadm_cmd
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc == 0:
+        return target in out
+    else:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_login(module, target):
+
+    node_auth = module.params['node_auth']
+    node_user = module.params['node_user']
+    node_pass = module.params['node_pass']
+
+    if node_user:
+        params = [('node.session.auth.authmethod', node_auth),
+                  ('node.session.auth.username', node_user),
+                  ('node.session.auth.password', node_pass)]
+        for (name, value) in params:
+            cmd = '%s --mode node --targetname %s --op=update --name %s --value %s' % (iscsiadm_cmd, target, name, value)
+            (rc, out, err) = module.run_command(cmd)
+            if rc > 0:
+                module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+    cmd = '%s --mode node --targetname %s --login' % (iscsiadm_cmd, target)
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc > 0:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_logout(module, target):
+
+    cmd = '%s --mode node --targetname %s --logout' % (iscsiadm_cmd, target)
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc > 0:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_device_node(module, target):
+
+    # if anyone know a better way to find out which devicenodes get created for
+    # a given target...
+
+    devices = glob.glob('/dev/disk/by-path/*%s*' % target)
+    if len(devices) == 0:
+        return None
+    else:
+        devdisks = []
+        for dev in devices:
+            # exclude partitions
+            if "-part" not in dev:
+                devdisk = os.path.realpath(dev)
+                # only add once (multi-path?)
+                if devdisk not in devdisks:
+                    devdisks.append(devdisk)
+        return devdisks
+
+
+def target_isauto(module, target):
+
+    cmd = '%s --mode node --targetname %s' % (iscsiadm_cmd, target)
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc == 0:
+        lines = out.splitlines()
+        for line in lines:
+            if 'node.startup' in line:
+                return 'automatic' in line
+        return False
+    else:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_setauto(module, target):
+
+    cmd = '%s --mode node --targetname %s --op=update --name node.startup --value automatic' % (iscsiadm_cmd, target)
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc > 0:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def target_setmanual(module, target):
+
+    cmd = '%s --mode node --targetname %s --op=update --name node.startup --value manual' % (iscsiadm_cmd, target)
+    (rc, out, err) = module.run_command(cmd)
+    
+    if rc > 0:
+        module.fail_json(cmd=cmd, rc=rc, msg=err)
+
+
+def main():
+
+    # load ansible module object
+    module = AnsibleModule(
+        argument_spec = dict(
+
+            # target 
+            portal = dict(required=False, aliases=['ip']),
+            port = dict(required=False, default=3260),
+            target = dict(required=False, aliases=['name', 'targetname']),
+            node_auth = dict(required=False, default='CHAP'),
+            node_user = dict(required=False),
+            node_pass = dict(required=False),
+
+            # actions
+            login = dict(type='bool', aliases=['state']),
+            auto_node_startup = dict(type='bool', aliases=['automatic']),
+            discover = dict(type='bool', default=False),
+            show_nodes = dict(type='bool', default=False)
+        ),  
+
+        required_together=[['discover_user', 'discover_pass'],
+                           ['node_user', 'node_pass']],
+        supports_check_mode=True
+    )
+
+    global iscsiadm_cmd 
+    iscsiadm_cmd = module.get_bin_path('iscsiadm', required=True)
+
+    # parameters
+    portal = module.params['portal']
+    target = module.params['target']
+    port = module.params['port']
+    login = module.params['login']
+    automatic = module.params['auto_node_startup']
+    discover = module.params['discover']
+    show_nodes = module.params['show_nodes']
+
+    check = module.check_mode
+
+    cached = iscsi_get_cached_nodes(module, portal)
+
+    # return json dict 
+    result = {}
+    result['changed'] = False
+
+    if discover:
+        if portal is None:
+            module.fail_json(msg = "Need to specify at least the portal (ip) to discover")
+        elif check:
+            nodes = cached
+        else:
+            iscsi_discover(module, portal, port)
+            nodes = iscsi_get_cached_nodes(module, portal)
+        if not compare_nodelists(cached, nodes):
+            result['changed'] |= True
+            result['cache_updated'] = True
+    else:
+        nodes = cached
+
+    if login is not None or automatic is not None:
+        if target is None:
+            if len(nodes) > 1:
+                module.fail_json(msg = "Need to specify a target")
+            else:
+                target = nodes[0]
+        else:
+            # check given target is in cache
+            check_target = False
+            for node in nodes:
+                if node == target:
+                    check_target = True
+                    break
+            if not check_target:
+                module.fail_json(msg = "Specified target not found")
+
+    if show_nodes:
+        result['nodes'] = nodes
+
+    if login is not None:
+        loggedon = target_loggedon(module,target)
+        if (login and loggedon) or (not login and not loggedon):
+            result['changed'] |= False
+            if login:
+                result['devicenodes'] = target_device_node(module,target)
+        elif not check:
+            if login:
+                target_login(module, target)
+                # give udev some time
+                time.sleep(1)
+                result['devicenodes'] = target_device_node(module,target)
+            else:
+                target_logout(module, target)
+            result['changed'] |= True
+            result['connection_changed'] = True
+        else:
+            result['changed'] |= True
+            result['connection_changed'] = True
+
+    if automatic is not None:
+        isauto = target_isauto(module, target)
+        if (automatic and isauto) or (not automatic and not isauto):
+            result['changed'] |= False
+            result['automatic_changed'] = False
+        elif not check:
+            if automatic:
+                target_setauto(module, target)
+            else:
+                target_setmanual(module, target)
+            result['changed'] |= True
+            result['automatic_changed'] = True
+        else:
+            result['changed'] |= True
+            result['automatic_changed'] = True
+
+    module.exit_json(**result)
+
+
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+
+main()
+