OMS Agent custom log wildcard issue fix (#517)

Author: shpimpal

Makefile

@@ -425,7 +425,7 @@ nxOMSCustomLog:
 
 nxOMSSudoCustomLog:
 	rm -rf output/staging; \
-	VERSION="2.1"; \
+	VERSION="2.2"; \
 	PROVIDERS="nxOMSSudoCustomLog"; \
 	STAGINGDIR="output/staging/$@/DSCResources"; \
 	cat Providers/Modules/$@.psd1 | sed "s@<MODULE_VERSION>@$${VERSION}@" > intermediate/Modules/$@.psd1; \

Providers/Modules/CustomLog/Plugin/in_sudo_tail.rb

@@ -13,7 +13,6 @@ class SudoTail < Input
     def initialize
       super
       @command = nil
-      @paths = []
     end
 
     attr_accessor :command
@@ -99,30 +98,8 @@ def receive_log(line)
       $log.info "#{line}" if line.start_with?('INFO')
     end
 
-    def readable_path(path)
-      if system("sudo test -r #{path}")
-        OMS::Log.info_once("Following tail of #{path}")
-        return path
-      else
-        OMS::Log.warn_once("#{path} is not readable. Cannot tail the file.")
-      end
-    end
-
     def set_system_command
-      @paths = @path.split(',').map {|path| path.strip }
-      date = Time.now
-      paths = ""
-      @paths.each { |path|
-        path = date.strftime(path)
-        if path.include?('*')
-          Dir.glob(path).select { |p|
-            paths += readable_path(p) + " "
-          }
-        else
-          paths += readable_path(path) + " "
-        end
-      }
-      @command = "sudo " << RUBY_DIR << TAILSCRIPT << paths <<  " -p #{@pos_file}"
+      @command = "sudo " << RUBY_DIR << TAILSCRIPT << @path <<  " -p #{@pos_file}"
     end
 
     def run_periodic
@@ -139,7 +116,6 @@ def run_periodic
       end
       until @finished
         begin
-          sleep @run_interval
           Open3.popen3(@command) {|writeio, readio, errio, wait_thread|
             writeio.close
             while line = readio.gets
@@ -152,6 +128,7 @@ def run_periodic
 
             wait_thread.value #wait until child process terminates
           }
+          sleep @run_interval
         rescue
           $log.error "sudo_tail failed to run or shutdown child proces", error => $!.to_s, :error_class => $!.class.to_s
           $log.warn_backtrace $!.backtrace

Providers/Modules/CustomLog/Plugin/tailfilereader.rb

@@ -20,8 +20,38 @@ def initialize(paths)
 
     attr_reader :paths
 
+    def file_exists(path)
+      if system("sudo test -f #{path}")
+        @log.info "Following tail of #{path}"
+        return path
+      else
+        @log.warn "#{path} does not exist. Cannot tail the file."
+        return nil
+      end
+    end
+
+    def expand_paths()
+      arr_paths = @paths.split(',').map {|path| path.strip }
+      date = Time.now
+      expanded_paths = []
+      arr_paths.each { |path|
+        path = date.strftime(path)
+        if path.include?('*')
+          Dir.glob(path).select { |p|
+            @log.info "Following tail of #{p}"
+            expanded_paths << p
+          }
+        else
+          file = file_exists(path)
+          expanded_paths << file unless file.nil?
+        end
+      }
+      return expanded_paths
+    end
+
     def start
-      start_watchers(@paths) unless @paths.empty?
+      paths = expand_paths()
+      start_watchers(paths) unless paths.empty?
     end
 
     def shutdown
@@ -365,7 +395,7 @@ def read_inode
     end
   end.parse!
 
-  a = Tailscript::NewTail.new(ARGV)
+  a = Tailscript::NewTail.new(ARGV[0])
   a.start
   a.shutdown
 end