{"id":241,"date":"2021-07-02T09:28:53","date_gmt":"2021-07-02T13:28:53","guid":{"rendered":"https:\/\/blog.voipxswitch.com\/?p=241"},"modified":"2021-07-13T07:30:08","modified_gmt":"2021-07-13T11:30:08","slug":"kamailio-nats-module","status":"publish","type":"post","link":"https:\/\/blog.voipxswitch.com\/?p=241","title":{"rendered":"kamailio: nats module"},"content":{"rendered":"\n

I recently published a new module for kamailio<\/code> which allows it to connect to NATS and consume messages using queue groups<\/a><\/p>\n\n\n\n

NATS is a very cool distributed messaging system. One of my favorite things about NATS is, there are no brokers and it’s extremely easy to setup. You can setup a nats-server<\/a> cluster in about 2 minutes, connect kamailio<\/code> to it and start receiving messages inside your kamailio<\/code> routing configuration. Once kamailio<\/code> connects to the cluster, any of the nats-servers<\/code> (as long as one nats-server<\/code> remains up) can be taken down without any impact to the publishers or consumers. <\/p>\n\n\n\n

In this post, I will show an example of a simple NATS cluster with two nodes and sample kamailio<\/code> configuration to connect to the cluster. <\/p>\n\n\n\n

NATS Cluster<\/p>\n\n\n\n

In this example, node1<\/code> will have an IP Address of 10.10.10.11<\/code>, and node2<\/code> will be 10.10.10.12<\/code>.<\/p>\n\n\n\n

After you have downloaded and installed nats-server<\/a> to your system. Setup node1<\/code> with the configuration file (server.conf<\/code>):<\/p>\n\n\n\n

listen: 0.0.0.0:4222\nhttp: 0.0.0.0:8222\n\ncluster {\n  listen: 10.10.10.11:4248\n  routes = [\n    nats-route:\/\/10.10.10.12:4248\n  ]\n}<\/code><\/pre>\n\n\n\n
Setup node2<\/code> with the configuration file (server.conf<\/code>):<\/p>\n\n\n\n
listen: 0.0.0.0:4222\nhttp: 0.0.0.0:8222\n\ncluster {\n  listen: 10.10.10.12:4248\n  routes = [\n    nats-route:\/\/10.10.10.11:4248\n  ]\n}<\/code><\/pre>\n\n\n\n
Start nats-server<\/code> with the following command on each node:
.\/nats-server -c .\/server.conf<\/code><\/p>\n\n\n\n
Kamailio Setup<\/p>\n\n\n\n
You will need to compile the NATS module since nats.c<\/a> is not shipped with Debian. Once it’s compiled, you can load the module with a configuration like:<\/p>\n\n\n\n
loadmodule \"nats.so\"\nmodparam(\"nats\", \"nats_url\", \"nats:\/\/10.10.10.11:4222\")\nmodparam(\"nats\", \"nats_url\", \"nats:\/\/10.10.10.12:4222\")\nmodparam(\"nats\", \"subject_queue_group\", \"voxcom:kamailio\")\n\nevent_route[nats:connected] {\n    xlog(\"L_INFO\", \"nats connected!\");\n}\n\nevent_route[nats:disconnected] {\n    xlog(\"L_INFO\", \"nats disconnected!\");\n}\n\nevent_route[nats:voxcom] {\n    xlog(\"L_INFO\", \"nats payload received [$natsData]\\n\");\n}<\/code><\/pre>\n\n\n\n
Sample NATS Publisher<\/p>\n\n\n\n
Below is a simple go application which will publish a message on the voxcom subject. <\/p>\n\n\n\n
package main\n\nimport (\n\t\"log\"\n\n\t\"github.com\/nats-io\/nats.go\"\n)\n\nfunc main() {\n\tnc, err := nats.Connect(\"10.10.10.12:4222\", nats.Name(\"example\"))\n\tif err != nil {\n\t\tlog.Fatal(err)\n\t}\n\tdefer nc.Close()\n\n\tif err := nc.Publish(\"voxcom\", []byte(\"hello kamailio\")); err != nil {\n\t\tlog.Fatal(err)\n\t}\n}<\/code><\/pre>\n\n\n\n
Run the application with go run main.go<\/strong><\/span><\/code>
You should see the “hello kamailio” text in your kamailio log.<\/p>\n\n\n\n
Stop the nats-server<\/code> on node1<\/code><\/p>\n\n\n\n
If you are running nats-server<\/code> in foreground, hit CTRL+C to stop it on node1<\/code>.<\/p>\n\n\n\n
Kamailio should indicate disconnect from node1<\/code> but stay connected to node2<\/code>. You should be able to run the go app and still publish messages. Even if both nodes go down, the nats module will automatically reconnect and begin consuming messages again.<\/p>\n\n\n\n
Documentation on the NATS module can be found here: https:\/\/www.kamailio.org\/docs\/modules\/devel\/modules\/nats<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
I recently published a new module for kamailio which allows it to connect to NATS and consume messages using queue groups NATS is a very cool distributed messaging system. One of my favorite things about NATS is, there are no brokers and it’s extremely easy to setup. You can setup a nats-server cluster in about […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21,10,15],"tags":[],"class_list":["post-241","post","type-post","status-publish","format-standard","hentry","category-kamailio","category-nats","category-voip"],"_links":{"self":[{"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/posts\/241","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=241"}],"version-history":[{"count":3,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/posts\/241\/revisions"}],"predecessor-version":[{"id":245,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=\/wp\/v2\/posts\/241\/revisions\/245"}],"wp:attachment":[{"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=241"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=241"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.voipxswitch.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=241"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}