Puppet Class: eventgate

Defined in:
puppet/modules/eventgate/manifests/init.pp

Overview

Class eventgate

Installs an EventGate service listening on internally port 8192. If $output == 'kafka', Kafka will be installed and EventGate will be configured to produce to Kafka. Otherwise, the default is to log events to $output as a file path.

EventGate is made available to POST events publicly at

http://eventgate.local.wmftest.net:8080/v1/events

You can reference this URL in other puppet configs via the $::eventgate::url variable.

This class does not set up any stream configs to enforce schemas in topics.

Parameters:

  • port (Any) (defaults to: 8192)
  • log_level (Any) (defaults to: undef)
  • output (Any) (defaults to: '/vagrant/logs/eventgate-events.json') 


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
 
# File 'puppet/modules/eventgate/manifests/init.pp', line 17

class eventgate(
    $port      = 8192,
    $log_level = undef,
    $output    = '/vagrant/logs/eventgate-events.json'
) {
    $node_version = lookup('npm::node_version')
    if $node_version < 16 {
        warning('EventGate requires NodeJS version 16. To use it, run `vagrant hiera npm::node_version 16 && vagrant provision`.')
    }

    require ::eventschemas
    include ::mwv # to get $::mwv::tld


    $base_config = {
        'user_agent' => 'eventgate-vagrant',

        # This field in each event will be used to extract a
        # (possibly relative) schema uri.  The default is $schema.
        # An array of field names will cause EventGate to search for
        # fields by these names in each event, using the first match.
        'schema_uri_field' => '$schema',

        # If set, this URI will be prepended to any relative schema URI
        # extracted from each event's schema_field./
        'schema_base_uris' =>  [
            "${::eventschemas::path}/primary/jsonschema/",
            "${::eventschemas::path}/secondary/jsonschema/",
        ],

        # This field in each event will be used to extract a destination 'stream' name.
        # This will equal the destination Kafka topic, unless a topic prefix
        # is also configured.
        'stream_field' => 'meta.stream',
        'topic_prefix' => 'datacenter1.',

        # This field will be used in log messages to uniquely ID each event.
        'id_field' => 'meta.id',

        # If a validation error is encountered, a validation error event
        # will be produced to this stream.
        'error_stream' =>  'eventgate-vagrant.error.validation',

        # If test_events is set, a GET /v1/_test/events route will be added.
        # When this route is requested, these test_events will be processed through EventGate
        # as if it they were directly POSTed to /v1/events.
        # This is useful for readiness probes that want to make sure the service
        # is alive and ready to produce events end to end.
        'test_events' => {
            '$schema' => '/test/event/1.0.0',
            'meta' => {
              'stream' => 'eventgate-vagrant.test.event',
            },
            'test' => 'eventgate-vagrant test event',
        },

        # If this is set and an event does not have schema_uri_field, the value of
        # event[schema_uri_field] will be set to the value of this HTTP query paramater
        'schema_uri_query_param' => 'schema_uri',

        # If this is set and an event does not have stream_field, the value of
        # event[stream_field] will be set to the value of this HTTP query paramater.
        'stream_query_param' => 'stream',
    }

    if $output == 'kafka' {
        require ::kafka
        $extra_config = {
            # eventgate-wikimedia.js factory uses Kafka
            'eventgate_factory_module' => 'eventgate-wikimedia.js',
            'kafka' => {
                'conf' => {
                    'metadata.broker.list' => 'localhost:9092',
                },
            },
        }
    } else {
        # eventgate-wikimedia-dev.js outputs to stdout, or a log file.
        $eventgate_factory_module = 'eventgate-wikimedia-dev.js'
        $extra_config = {
            'eventgate_factory_module' => 'eventgate-wikimedia-dev.js',
            'output_path' => $output,
        }
    }

    $config = merge($base_config, $extra_config)


    # eventgate-wikimedia has the WMF specific implementation of EventGate.
    # It specifies the eventgate (service-runner) package as a dependency
    # and runs the eventgate from it.
    service::node { 'eventgate-wikimedia':
        git_remote => 'https://gerrit.wikimedia.org/r/eventgate-wikimedia',
        port       => $port,
        log_level  => $log_level,
        module     => 'eventgate',
        entrypoint => 'app',
        script     => 'node_modules/eventgate/server.js',
        config     => $config,
    }

    # Add a reverse proxy from eventgate.local.wmftest.net to the
    # eventgate-wikimedia service.
    apache::reverse_proxy { 'eventgate':
        port => $port,
    }
    # The reverse_proxy will make this URL publicly addressable.
    # This is used by event clients (EventBus, EventLogging, etc.) to POST event data.
    $url = "http://eventgate${::mwv::tld}${::port_fragment}/v1/events"

    # make a symlink from srv/eventgate -> eventgate-wikimedia/node_modules/eventgate for
    # easier access to the EventGate package code for development purposes.
    file { '/vagrant/srv/eventgate':
        ensure  => 'link',
        target  => 'eventgate-wikimedia/node_modules/eventgate',
        require => Service::Node['eventgate-wikimedia'],
    }
}