[capistrano] Add ability to use etc.getpwuid instead of `etc.getlog…

…in` to get the user name (#146)

* Do not use getlogin() function to obtain username

`getlogin()` obtains the logged-in username by looking up the current tty in `utmp` and reporting the login name found in that utmp record. If Capistrano is ran from Jenkins in the host it returns the user logged in to `pts/0`, which is not the same user as runs the Capistrano. Also Ruby docs recommends avoid using `getlogin()`:
>getlogin → String
>Returns the short user name of the currently logged in user. Unfortunately, it is often rather easy to fool ::getlogin.
>
>Avoid ::getlogin for security-related purposes.
>
>If ::getlogin fails, try ::getpwuid.
>
>See the unix manpage for getpwuid(3) for more detail.
http://ruby-doc.org/stdlib-2.2.0/libdoc/etc/rdoc/Etc.html#method-c-getlogin

* keep backward compat

* rubocop

* add doc

Co-authored-by: Hippolyte HENRY <zippolyte@users.noreply.github.com>

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2020-01-13 15:42:46 -0500 using RuboCop version 0.49.1.
+# on 2020-01-30 14:50:03 +0100 using RuboCop version 0.49.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -42,14 +42,17 @@ Layout/EmptyLineAfterMagicComment:
   Exclude:
     - 'dogapi.gemspec'
 
-# Offense count: 2
+# Offense count: 16
 # Cop supports --auto-correct.
 Layout/EmptyLines:
   Exclude:
+    - 'config/deploy.rb'
+    - 'config/deploy/production.rb'
+    - 'config/deploy/staging.rb'
     - 'lib/capistrano/datadog/v2.rb'
     - 'lib/dogapi/facade.rb'
 
-# Offense count: 89
+# Offense count: 92
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles.
 # SupportedStyles: empty_lines, empty_lines_except_namespace, empty_lines_special, no_empty_lines
@@ -129,7 +132,6 @@ Layout/SpaceAroundEqualsInParameterDefault:
     - 'lib/dogapi/common.rb'
     - 'lib/dogapi/event.rb'
     - 'lib/dogapi/facade.rb'
-    - 'lib/dogapi/v1/dash.rb'
     - 'lib/dogapi/v1/embed.rb'
     - 'lib/dogapi/v1/event.rb'
     - 'lib/dogapi/v1/metric.rb'
@@ -201,9 +203,9 @@ Lint/UselessAssignment:
 
 # Offense count: 12
 Metrics/AbcSize:
-  Max: 51
+  Max: 53
 
-# Offense count: 28
+# Offense count: 29
 # Configuration parameters: CountComments, ExcludedMethods.
 Metrics/BlockLength:
   Max: 123
@@ -215,23 +217,23 @@ Metrics/ClassLength:
 
 # Offense count: 3
 Metrics/CyclomaticComplexity:
-  Max: 8
+  Max: 9
 
 # Offense count: 16
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
   Max: 34
 
-# Offense count: 5
+# Offense count: 7
 # Configuration parameters: CountKeywordArgs.
 Metrics/ParameterLists:
   Max: 7
 
 # Offense count: 2
 Metrics/PerceivedComplexity:
-  Max: 9
+  Max: 10
 
-# Offense count: 13
+# Offense count: 19
 Style/AccessorMethodName:
   Exclude:
     - 'lib/dogapi/facade.rb'
@@ -240,8 +242,8 @@ Style/AccessorMethodName:
     - 'lib/dogapi/v1/dashboard.rb'
     - 'lib/dogapi/v1/embed.rb'
     - 'lib/dogapi/v1/screenboard.rb'
-    - 'lib/dogapi/v1/user.rb'
     - 'lib/dogapi/v1/synthetics.rb'
+    - 'lib/dogapi/v1/user.rb'
 
 # Offense count: 1
 # Cop supports --auto-correct.
@@ -279,7 +281,7 @@ Style/ClassCheck:
     - 'lib/dogapi/facade.rb'
     - 'lib/dogapi/v1/event.rb'
 
-# Offense count: 2
+# Offense count: 3
 # Cop supports --auto-correct.
 Style/ClassMethods:
   Exclude:
@@ -297,14 +299,6 @@ Style/ColonMethodCall:
     - 'lib/capistrano/datadog.rb'
     - 'lib/capistrano/datadog/v2.rb'
 
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, AllowInnerBackticks.
-# SupportedStyles: backticks, percent_x, mixed
-Style/CommandLiteral:
-  Exclude:
-    - 'lib/dogapi/common.rb'
-
 # Offense count: 1
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles, SingleLineConditionsOnly, IncludeTernaryExpressions.
@@ -313,7 +307,7 @@ Style/ConditionalAssignment:
   Exclude:
     - 'lib/capistrano/datadog.rb'
 
-# Offense count: 21
+# Offense count: 20
 # Cop supports --auto-correct.
 Style/DefWithParentheses:
   Exclude:
@@ -340,7 +334,7 @@ Style/GuardClause:
     - 'lib/capistrano/datadog.rb'
     - 'lib/dogapi/facade.rb'
 
-# Offense count: 86
+# Offense count: 88
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles, UseHashRocketsWithSymbolValues, PreferHashRocketsForNonAlnumEndingSymbols.
 # SupportedStyles: ruby19, hash_rockets, no_mixed_keys, ruby19_no_mixed_keys
@@ -361,7 +355,7 @@ Style/HashSyntax:
     - 'lib/dogapi/v1/snapshot.rb'
     - 'lib/dogapi/v1/tag.rb'
 
-# Offense count: 15
+# Offense count: 16
 # Cop supports --auto-correct.
 # Configuration parameters: MaxLineLength.
 Style/IfUnlessModifier:
@@ -381,7 +375,7 @@ Style/LineEndConcatenation:
   Exclude:
     - 'dogapi.gemspec'
 
-# Offense count: 18
+# Offense count: 21
 # Cop supports --auto-correct.
 Style/MethodCallWithoutArgsParentheses:
   Exclude:
@@ -396,7 +390,7 @@ Style/MultilineIfThen:
   Exclude:
     - 'lib/capistrano/datadog.rb'
 
-# Offense count: 33
+# Offense count: 37
 # Cop supports --auto-correct.
 Style/MutableConstant:
   Enabled: false
@@ -416,12 +410,11 @@ Style/Not:
   Exclude:
     - 'lib/dogapi/v1/metric.rb'
 
-# Offense count: 4
+# Offense count: 3
 # Cop supports --auto-correct.
 # Configuration parameters: PreferredDelimiters.
 Style/PercentLiteralDelimiters:
   Exclude:
-    - 'lib/dogapi/common.rb'
     - 'spec/integration/event_spec.rb'
     - 'spec/integration/monitor_spec.rb'
 
@@ -477,14 +470,17 @@ Style/SpecialGlobalVars:
   Exclude:
     - 'dogapi.gemspec'
 
-# Offense count: 25
+# Offense count: 35
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles, ConsistentQuotesInMultiline.
 # SupportedStyles: single_quotes, double_quotes
 Style/StringLiterals:
   Exclude:
+    - 'Capfile'
     - 'Gemfile'
     - 'Rakefile'
+    - 'config/deploy.rb'
+    - 'config/deploy/staging.rb'
     - 'dogapi.gemspec'
     - 'examples/Capfile'
     - 'examples/custom_event.rb'

lib/capistrano/README.md

@@ -18,7 +18,10 @@ To set up your Capfile:
     # for instance, only push the production event
     # set :datadog_event_filter, proc { |event, hosts| event.msg_title.include?('ran production') ? [event, hosts] : nil }
 
+    # (optional) use the `Etc.getlogin` method (default) or the `Etc.getpwuid` method to get the user name
+    # default: use `Etc.getlogin`
+    # set :use_getlogin, true
+
 You can find your Datadog API key [here](https://app.datadoghq.com/account/settings#api). If you don't have a Datadog account, you can sign up for one [here](http://www.datadoghq.com/).
 
 `capistrano/datadog` will capture each Capistrano task that that Capfile runs, including the roles that the task applies to and any logging output that it emits and submits them as events to Datadog at the end of the execution of all the tasks. If sending to Datadog fails for any reason, your scripts will still succeed.
-

lib/capistrano/datadog.rb

@@ -28,11 +28,11 @@ def self.cap_version()
       @cap_version
     end
 
-    def self.submit(api_key)
+    def self.submit(api_key, use_getlogin=true)
       begin
         if api_key
           dog = Dogapi::Client.new(api_key)
-          reporter.report.each do |event, hosts|
+          reporter.report(use_getlogin).each do |event, hosts|
             if hosts.size > 0
               hosts.each do |host|
                 dog.emit_event event, host: host
@@ -93,9 +93,9 @@ def record_hostname(hostname)
         end
       end
 
-      def report()
+      def report(use_getlogin=true)
         hostname = Dogapi.find_localhost
-        user = Etc.getlogin
+        user = use_getlogin ? Etc.getlogin : Etc.getpwuid.name
 
         # Lazy randomness
         aggregation_key = Digest::MD5.hexdigest "#{Time.new}|#{rand}"

lib/capistrano/datadog/v2.rb

@@ -62,7 +62,11 @@ def puts(message)
       namespace :datadog do
         desc 'Submit the tasks that have run to Datadog as events'
         task :submit do |ns|
-          Capistrano::Datadog.submit variables[:datadog_api_key]
+          if variables[:use_getlogin].nil?
+            Capistrano::Datadog.submit variables[:datadog_api_key]
+          else
+            Capistrano::Datadog.submit variables[:datadog_api_key], variables[:use_getlogin]
+          end
         end
       end
     end

lib/capistrano/datadog/v3.rb

@@ -80,5 +80,10 @@ def initialize(oio)
 
 at_exit do
   api_key = Capistrano::Configuration.env.fetch :datadog_api_key
-  Capistrano::Datadog.submit api_key
+  use_getlogin = Capistrano::Configuration.env.fetch :use_getlogin
+  if use_getlogin.nil?
+    Capistrano::Datadog.submit api_key
+  else
+    Capistrano::Datadog.submit api_key, use_getlogin
+  end
 end