Class: Wrapbox::LogFetcher::Awslogs

Inherits:
Object
  • Object
show all
Defined in:
lib/wrapbox/log_fetcher/awslogs.rb

Constant Summary collapse

STOP_WAIT_TIMELIMIT = 
10
COLOR_ESCAPE_SEQUENCES = 
[33, 31, 32, 34, 35, 36]

Instance Method Summary collapse

Constructor Details

#initialize(log_group:, log_stream_prefix:, filter_pattern: nil, region: nil, access_key_id: nil, secret_access_key: nil, timestamp_format: "%Y-%m-%d %H:%M:%S.%3N", delay: 2, **options) ⇒ Awslogs

Returns a new instance of Awslogs.



6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
 
# File 'lib/wrapbox/log_fetcher/awslogs.rb', line 6

def initialize(log_group:, log_stream_prefix:, filter_pattern: nil, region: nil, access_key_id: nil, secret_access_key: nil, timestamp_format: "%Y-%m-%d %H:%M:%S.%3N", delay: 2, **options)
  begin
    require 'aws-sdk-cloudwatchlogs'
  rescue LoadError
    $stderr.puts "Require aws-sdk-cloudwatchlogs gem"
    exit 1
  end

  @log_group = log_group
  @log_stream_prefix = log_stream_prefix
  @filter_pattern = filter_pattern
  @region = region
  @access_key_id = access_key_id
  @secret_access_key = secret_access_key
  @timestamp_format = timestamp_format
  @delay = delay
  @options = options.reject { |_, v| v.nil? }
  @displayed_log_stream_names = {}
  @displayed_log_stream_number = 0
  @displayed_event_ids = {}
end

Instance Method Details

#display_message(ev, output: $stdout) ⇒ Object 



88
89
90
91
92
93
94
95
96
97
98
99
100
 
# File 'lib/wrapbox/log_fetcher/awslogs.rb', line 88

def display_message(ev, output: $stdout)
  num = @displayed_log_stream_names.fetch(ev.log_stream_name) do |key|
    current = @displayed_log_stream_number
    @displayed_log_stream_names[key] = current
    @displayed_log_stream_number += 1
    current
  end

  sequence_number = COLOR_ESCAPE_SEQUENCES[num % COLOR_ESCAPE_SEQUENCES.length]

  time = Time.at(ev.timestamp / 1000.0)
  output.puts("\e[#{sequence_number}m#{time.strftime(@timestamp_format)} #{ev.log_stream_name}\e[0m #{ev.message}")
end

#main_loop(task) ⇒ Object 



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
 
# File 'lib/wrapbox/log_fetcher/awslogs.rb', line 47

def main_loop(task)
  task_id = task.task_arn.split("/").last
  log_stream_names = task.containers.map do |container|
    [@log_stream_prefix, container.name, task_id].join("/")
  end
  filter_log_opts = {
    log_group_name: @log_group,
    log_stream_names: log_stream_names,
    filter_pattern: @filter_pattern,
  }.compact
  @max_timestamp = ((Time.now.to_f - 120) * 1000).round

  until @stop do
    filter_log_opts[:start_time] = @max_timestamp + 1
    begin
      client.filter_log_events(filter_log_opts).each do |r|
        r.events.each do |ev|
          next if @displayed_event_ids.member?(ev.event_id)
          display_message(ev)
          @displayed_event_ids[ev.event_id] = ev.timestamp
          @max_timestamp = ev.timestamp if @max_timestamp < ev.timestamp
        end
      end

      @displayed_event_ids.each do |event_id, ts|
        if ts < (Time.now.to_f - 600) * 1000
          @displayed_event_ids.delete(event_id)
        end
      end
    rescue Aws::CloudWatchLogs::Errors::ResourceNotFoundException
      # Ignore the error because it is an error like "The specified log stream does not exist.",
      # which occurs when the log stream hasn't been created yet, that is, the task hasn't started yet.
    rescue Aws::CloudWatchLogs::Errors::ThrottlingException
      Wrapbox.logger.warn("Failed to fetch logs due to Aws::CloudWatchLogs::Errors::ThrottlingException")
    end

    sleep @delay
  end
end

#run(task:) ⇒ Object 



28
29
30
31
32
33
34
35
36
37
38
39
40
 
# File 'lib/wrapbox/log_fetcher/awslogs.rb', line 28

def run(task:)
  @loop_thread = Thread.start do
    # It smees that task.contaienrs is empty
    # if capacity_provider_strategy is specified and there are no remaining capacity
    while task.containers.empty?
      Wrapbox.logger.warn("The task has no containers, so fetch it again")
      sleep 10
      task = ecs_client.describe_tasks(cluster: task.cluster_arn, tasks: [task.task_arn]).tasks.first
    end

    main_loop(task)
  end
end

#stop ⇒ Object 



42
43
44
45
 
# File 'lib/wrapbox/log_fetcher/awslogs.rb', line 42

def stop
  @stop = true
  @loop_thread&.join(STOP_WAIT_TIMELIMIT)
end