Class: AwsLogs::Tail
Constant Summary collapse
- @@end_loop_signal =
The stop_follow! results in a little waiting because it signals to break the polling loop. Since it’s in the middle of the loop process, the loop will finish the sleep 5 first. So it can pause from 0-5 seconds.
false
Class Method Summary collapse
Instance Method Summary collapse
- #check_follow_until! ⇒ Object
- #data(since = "1d", quiet_not_found = false) ⇒ Object
-
#display ⇒ Object
There can be duplicated events as events can be written to the exact same timestamp.
- #filter_log_events(start_time, end_time, next_token = nil) ⇒ Object
-
#initialize(options = {}) ⇒ Tail
constructor
A new instance of Tail.
- #output ⇒ Object
-
#refresh_events(start_time, end_time) ⇒ Object
TODO: lazy Enum or else its seems stuck for long –since.
- #reset ⇒ Object
-
#run ⇒ Object
The start and end time is useful to limit results and make the API fast.
- #say(text) ⇒ Object
- #set_trap ⇒ Object
Methods included from AwsServices
Constructor Details
#initialize(options = {}) ⇒ Tail
Returns a new instance of Tail.
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# File 'lib/aws_logs/tail.rb', line 5 def initialize(={}) super # Setting to ensure matches default CLI option @follow = @options[:follow].nil? ? true : @options[:follow] @refresh_rate = @options[:refresh_rate] || 5 @wait_exists = @options[:wait_exists] @wait_exists_retries = @options[:wait_exists_retries] @loop_count = 0 @output = [] # for specs reset set_trap end |
Class Method Details
.stop_follow! ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 156 def self.stop_follow! @@end_loop_signal = true end |
Instance Method Details
#check_follow_until! ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 129 def check_follow_until! follow_until = @options[:follow_until] return unless follow_until = @events.map(&:message) @@end_loop_signal = .detect { |m| m.include?(follow_until) } end |
#data(since = "1d", quiet_not_found = false) ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 19 def data(since="1d", quiet_not_found=false) since, now = Since.new(since).to_i, current_now resp = filter_log_events(since, now) resp.events rescue Aws::CloudWatchLogs::Errors::ResourceNotFoundException => e puts "WARN: #{e.class}: #{e.}" unless quiet_not_found [] end |
#display ⇒ Object
There can be duplicated events as events can be written to the exact same timestamp. So also track the last_shown_event_id and prevent duplicate log lines from re-appearing.
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# File 'lib/aws_logs/tail.rb', line 111 def display new_events = @events shown_index = new_events.find_index { |e| e.event_id == @last_shown_event_id } if shown_index new_events = @events[shown_index+1..-1] || [] end new_events.each do |e| time = Time.at(e./1000).utc line = [time.to_s.color(:green), e.] format = @options[:format] || "detailed" line.insert(1, e.log_stream_name.color(:purple)) if format == "detailed" say line.join(' ') unless @options[:silence] end @last_shown_event_id = @events.last&.event_id check_follow_until! end |
#filter_log_events(start_time, end_time, next_token = nil) ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 92 def filter_log_events(start_time, end_time, next_token=nil) = { log_group_name: @log_group_name, # required start_time: start_time, end_time: end_time, # limit: 1000, # interleaved: true, } [:log_stream_names] = @options[:log_stream_names] if @options[:log_stream_names] [:log_stream_name_prefix] = @options[:log_stream_name_prefix] if @options[:log_stream_name_prefix] [:filter_pattern] = @options[:filter_pattern] if @options[:filter_pattern] [:next_token] = next_token if next_token != :start && !next_token.nil? cloudwatchlogs.filter_log_events() end |
#output ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 141 def output @output.join("\n") + "\n" end |
#refresh_events(start_time, end_time) ⇒ Object
TODO: lazy Enum or else its seems stuck for long –since
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# File 'lib/aws_logs/tail.rb', line 78 def refresh_events(start_time, end_time) @events = [] next_token = :start # TODO: can hit throttle limit if there are lots of pages while next_token resp = filter_log_events(start_time, end_time, next_token) @events += resp.events next_token = resp.next_token end @events end |
#reset ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 28 def reset @events = [] # constantly replaced with recent events @last_shown_event_id = nil @completed = nil end |
#run ⇒ Object
The start and end time is useful to limit results and make the API fast. We’ll leverage it like so:
1. load all events from an initial since time
2. after that load events pass that first window
It’s a sliding window of time we’re using.
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# File 'lib/aws_logs/tail.rb', line 41 def run if ENV['AWS_LOGS_NOOP'] puts "Noop test" return end # We overlap the sliding window because CloudWatch logs can receive or send the logs out of order. # For example, a bunch of logs can all come in at the same second, but they haven't registered to CloudWatch logs # yet. If we don't overlap the sliding window then we'll miss the logs that were delayed in registering. overlap = 60*1000 # overlap the sliding window by a minute since, now = initial_since, current_now @wait_retries ||= 0 until end_loop? refresh_events(since, now) display since, now = now-overlap, current_now loop_count! sleep @refresh_rate if @follow && !ENV["AWS_LOGS_TEST"] end # Refresh and display a final time in case the end_loop gets interrupted by stop_follow! refresh_events(since, now) display rescue Aws::CloudWatchLogs::Errors::ResourceNotFoundException => e if @wait_exists seconds = 5 puts "Waiting for log group #{@log_group_name} to exist. Waiting #{seconds} seconds." sleep seconds @wait_retries += 1 if !@wait_exists_retries || @wait_retries < @wait_exists_retries retry end end puts "ERROR: #{e.class}: #{e.}".color(:red) puts "Log group #{@log_group_name} not found." end |
#say(text) ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 137 def say(text) ENV["AWS_LOGS_TEST"] ? @output << text : puts(text) end |
#set_trap ⇒ Object
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# File 'lib/aws_logs/tail.rb', line 145 def set_trap Signal.trap("INT") { puts "\nCtrl-C detected. Exiting..." exit # immediate exit } end |