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
|
# Copyright (C) 2017 MongoDB, Inc.
#
# Licensed under the Apache License, Version 2.0 (the 'License');
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an 'AS IS' BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require 'resolv'
module Mongo
class URI
# Parser for a URI using the mongodb+srv protocol, which specifies a DNS to query for SRV records.
# The driver will query the DNS server for SRV records on {hostname}.{domainname},
# prefixed with _mongodb._tcp
# The SRV records can then be used as the seedlist for a Mongo::Client.
# The driver also queries for a TXT record providing default connection string options.
# Only one TXT record is allowed, and only a subset of Mongo::Client options is allowed.
#
# Please refer to the Initial DNS Seedlist Discovery spec for details.
#
# https://github.com/mongodb/specifications/blob/master/source/initial-dns-seedlist-discovery
#
# @example Use the uri string to make a client connection.
# client = Mongo::Client.new('mongodb+srv://test6.test.build.10gen.cc/')
#
# @since 2.5.0
class SRVProtocol < URI
# Gets the options hash that needs to be passed to a Mongo::Client on instantiation, so we
# don't have to merge the txt record options, credentials, and database in at that point -
# we only have a single point here.
#
# @example Get the client options.
# uri.client_options
#
# @return [ Hash ] The options passed to the Mongo::Client
#
# @since 2.5.0
def client_options
opts = @txt_options.merge(ssl: true)
opts = opts.merge(uri_options).merge(:database => database)
@user ? opts.merge(credentials) : opts
end
private
RECORD_PREFIX = '_mongodb._tcp.'.freeze
DOT_PARTITION = '.'.freeze
VALID_TXT_OPTIONS = ['replicaset', 'authsource'].freeze
INVALID_HOST = "One and only one host is required in a connection string with the " +
"'#{MONGODB_SRV_SCHEME}' protocol.".freeze
INVALID_PORT = "It is not allowed to specify a port in a connection string with the " +
"'#{MONGODB_SRV_SCHEME}' protocol.".freeze
INVALID_DOMAIN = "The domain name must consist of at least two parts: the domain name, " +
"and a TLD.".freeze
NO_SRV_RECORDS = "The DNS query returned no SRV records at hostname (%s)".freeze
MORE_THAN_ONE_TXT_RECORD_FOUND = "Only one TXT record is allowed. Querying hostname (%s) " +
"returned more than one result.".freeze
INVALID_TXT_RECORD_OPTION = "TXT records can only specify the options " +
"[#{VALID_TXT_OPTIONS.join(', ')}].".freeze
MISMATCHED_DOMAINNAME = "Parent domain name in SRV record result (%s) does not match " +
"that of the hostname (%s)".freeze
FORMAT = 'mongodb+srv://[username:password@]host[/[database][?options]]'.freeze
def scheme
MONGODB_SRV_SCHEME
end
def raise_invalid_error!(details)
raise Error::InvalidURI.new(@string, details, FORMAT)
end
def resolver
@resolver ||= Resolv::DNS.new
end
def parse_creds_hosts!(string)
hostname, creds = split_creds_hosts(string)
validate_hostname!(hostname)
records = get_records(hostname)
@txt_options = get_txt_opts(hostname) || {}
@servers = parse_servers!(records.join(','))
@user = parse_user!(creds)
@password = parse_password!(creds)
end
def validate_hostname!(hostname)
raise_invalid_error!(INVALID_HOST) if hostname.empty?
raise_invalid_error!(INVALID_HOST) if hostname.include?(HOST_DELIM)
raise_invalid_error!(INVALID_PORT) if hostname.include?(HOST_PORT_DELIM)
_, _, domain = hostname.partition(DOT_PARTITION)
raise_invalid_error!(INVALID_DOMAIN) unless domain.include?(DOT_PARTITION)
end
def get_records(hostname)
query_name = RECORD_PREFIX + hostname
records = resolver.getresources(query_name, Resolv::DNS::Resource::IN::SRV).collect do |record|
record_host = record.target.to_s
port = record.port
validate_record!(record_host, hostname)
"#{record_host}#{HOST_PORT_DELIM}#{port}"
end
raise Error::NoSRVRecords.new(NO_SRV_RECORDS % hostname) if records.empty?
records
end
def validate_record!(record_host, hostname)
domainname = hostname.split(DOT_PARTITION)[1..-1]
host_parts = record_host.split(DOT_PARTITION)
unless (host_parts.size > domainname.size) && (domainname == host_parts[-domainname.length..-1])
raise Error::MismatchedDomain.new(MISMATCHED_DOMAINNAME % [record_host, domainname])
end
end
def get_txt_opts(host)
records = resolver.getresources(host, Resolv::DNS::Resource::IN::TXT)
unless records.empty?
if records.size > 1
raise Error::InvalidTXTRecord.new(MORE_THAN_ONE_TXT_RECORD_FOUND % host)
end
options_string = records[0].strings.join
parse_txt_options!(options_string)
end
end
def parse_txt_options!(string)
return {} unless string
string.split(INDIV_URI_OPTS_DELIM).reduce({}) do |txt_options, opt|
raise Error::InvalidTXTRecord.new(INVALID_OPTS_VALUE_DELIM) unless opt.index(URI_OPTS_VALUE_DELIM)
key, value = opt.split(URI_OPTS_VALUE_DELIM)
raise Error::InvalidTXTRecord.new(INVALID_TXT_RECORD_OPTION) unless VALID_TXT_OPTIONS.include?(key.downcase)
strategy = URI_OPTION_MAP[key.downcase]
add_uri_option(strategy, value, txt_options)
txt_options
end
end
end
end
end
|
