1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
PPoossttffiixx MMoonnggooDDBB HHoowwttoo
-------------------------------------------------------------------------------
MMoonnggooDDBB SSuuppppoorrtt iinn PPoossttffiixx
Postfix can use MongoDB as a source for any of its lookups: aliases(5), virtual
(5), canonical(5), etc. This allows you to keep information for your mail
service in a replicated noSQL database with fine-grained access controls. By
not storing it locally on the mail server, the administrators can maintain it
from anywhere, and the users can control whatever bits of it you think
appropriate. You can have multiple mail servers using the same information,
without the hassle and delay of having to copy it to each.
Topics covered in this document:
* Building Postfix with MongoDB support
* Configuring MongoDB lookups
* Example: virtual alias maps
* Example: Mailing lists
* Example: MongoDB projections
* Feedback
* Credits
BBuuiillddiinngg PPoossttffiixx wwiitthh MMoonnggooDDBB ssuuppppoorrtt
These instructions assume that you build Postfix from source code as described
in the INSTALL document. Some modification may be required if you build Postfix
from a vendor-specific source package.
The Postfix MongoDB client requires the mmoonnggoo--cc--ddrriivveerr library. This can be
built from source code from the mongod-c project, or this can be installed as a
binary package from your OS distribution, typically named mmoonnggoo--cc--ddrriivveerr,
mmoonnggoo--cc--ddrriivveerr--ddeevveell or lliibbmmoonnggoocc--ddeevv. Installing the mongo-c-driver library
may also install lliibbbbssoonn as a dependency.
To build Postfix with mongodb map support, add to the CCARGS environment
variable the options -DHAS_MONGODB and -I for the directory containing the
mongodb headers, and specify the AUXLIBS_MONGODB with the libmongoc and libbson
libraries, for example:
% make tidy
% make -f Makefile.init makefiles \
CCARGS="$CCARGS -DHAS_MONGODB -I/usr/include/libmongoc-1.0 \
-I/usr/include/libbson-1.0" \
AUXLIBS_MONGODB="-lmongoc-1.0 -lbson-1.0"
The 'make tidy' command is needed only if you have previously built Postfix
without MongoDB support.
If your MongoDB shared library is in a directory that the RUN-TIME linker does
not know about, add a "-Wl,-R,/path/to/directory" option after "-lbson-1.0".
Then, just run 'make'.
CCoonnffiigguurriinngg MMoonnggooDDBB llooookkuuppss
In order to use MongoDB lookups, define a MongoDB source as a table lookup in
main.cf, for example:
alias_maps = hash:/etc/aliases, proxy:mongodb:/etc/postfix/mongo-aliases.cf
The file /etc/postfix/mongo-aliases.cf can specify a number of parameters. For
a complete description, see the mongodb_table(5) manual page.
EExxaammppllee:: vviirrttuuaall((55)) aalliiaass mmaappss
Here's a basic example for using MongoDB to look up virtual(5) aliases. Assume
that in main.cf, you have:
virtual_alias_maps = hash:/etc/postfix/virtual_aliases,
proxy:mongodb:/etc/postfix/mongo-virtual-aliases.cf
and in mongodb:/etc/postfix/mongo-virtual-aliases.cf you have:
uri = mongodb+srv://user_name:password@some_server
dbname = mail
collection = mailbox
query_filter = {"$or": [{"username":"%s"}, {"alias.address": "%s"}],
"active": 1}
result_attribute = username
This example assumes mailbox names are stored in a MongoDB backend, in a format
like:
{ "username": "user@example.com",
"alias": [
{"address": "admin@example.com"},
{"address": "abuse@example.com"}
],
"active": 1
}
Upon receiving mail for "admin@example.com" that isn't found in the /etc/
postfix/virtual_aliases database, Postfix will search the MongoDB server/
cluster listening at port 27017 on some_server. It will connect using the
provided credentials, and search for any entries whose username is, or alias
field has "admin@example.com". It will return the username attribute of those
found, and build a list of their email addresses.
Notes:
* As with pprroojjeeccttiioonn (see below), the Postfix mongodb client automatically
removes the top-level '_id' field from a result_attribute result.
* The Postfix mongodb client will only parse result fields with data types
UTF8, INT32, INT64 and ARRAY. Other fields will be ignored, with a warning
in the logs.
EExxaammppllee:: MMaaiilliinngg lliissttss
When it comes to mailing lists, one way of implementing one would be as below:
{ "name": "dev@example.com", "active": 1, "address":
[ "hamid@example.com", "wietse@example.com", "viktor@example.com" ] }
using the filter below, will result in a comma separated string with all email
addresses in this list.
query_filter = {"name": "%s", "active": 1}
result_attribute = address
Notes:
* As with pprroojjeeccttiioonn (see below), the Postfix mongodb client automatically
removes the top-level '_id' field from a result_attribute result.
* The Postfix mongodb client will only parse result fields with data types
UTF8, INT32, INT64 and ARRAY. Other fields will be ignored, with a warning
in the logs.
EExxaammppllee:: aaddvvaanncceedd pprroojjeeccttiioonnss
This module also supports the use of more complex MongoDB projections. There
may be some use cases where operations such as concatenation are necessary to
be performed on the data retrieved from the database. Although it is encouraged
to keep the database design simple enough so this is not necessary, postfix
supports the use of MongoDB projections to achieve the goal.
Consider the example below:
{ "username": "user@example.com",
"local_part": "user",
"domain": "example.com",
"alias": [
{"address": "admin@example.com"},
{"address": "abuse@example.com"}
],
"active": 1
}
virtual_mailbox_maps can be created using below parameters in a mongodb:/etc/
postfix/mongo-virtual-mailboxes.cf file:
uri = mongodb+srv://user_name:password@some_server
dbname = mail
collection = mailbox
query_filter = {"$or": [{"username":"%s"}, {"alias.address": "%s"}],
"active": 1}
projection = { "mail_path": {"$concat": ["$domain", "/", "$local_part"]} }
This will return 'example.com/user' path built from the database fields.
A couple of considerations when using projections:
* As with rreessuulltt__aattttrriibbuuttee, the Postfix mongodb client automatically removes
the top-level '_id' field from a projection result.
* The Postfix mongodb client will only parse fields with data types UTF8,
INT32, INT64 and ARRAY. Other fields will be ignored, with a warning in the
logs. It is suggested to exclude any unnecessary fields when using a
projection.
FFeeeeddbbaacckk
If you have questions, send them to postfix-users@postfix.org. Please include
relevant information about your Postfix setup: MongoDB-related output from
postconf, which libraries you built with, and such. If your question involves
your database contents, please include the applicable bits of some database
entries.
CCrreeddiittss
* Stephan Ferraro (Aionda GmbH) implemented an early version of the Postfix
MongoDB client.
* Hamid Maadani (Dextrous Technologies, LLC) added support for projections
and %letter interpolation, and added documentation.
* Wietse Venema adopted and restructured the code and documentation.
|
