Rely on path for CLI calls when possible

We currently hard-code /usr/sbin/{pcs,crm_simulate,crm_resource} in a
few places. This is undesirable as it makes things difficult to
override, especially in the case where in a container you want to bind
mount those utils from the host in a specific-path.

Let's just call the utilities without the full path when the PATH
environment variable is set. It is the polite thing to do in case
an operator wants to use different versions of the tools in a different
path.

Tested by deploying tripleo with containers where pcs was both
bind-mounted in a specific location and with the standard /usr/sbin/pcs.

Related-Bug: #1771612

Change-Id: I933f101c82b9abad330fab622733e40cf15ef49b

lib/puppet/provider/pcmk_common.rb

@@ -9,6 +9,23 @@ PCMK_CHANGENEEDED   = 2
 # Base temporary CIB backup folder
 PCMK_TMP_BASE = "/var/lib/pacemaker/cib"
 
+# Let's use pcs from PATH when it is set:
+# Useful to run pcs from a different path when using
+# containers
+if ENV.has_key?('PATH')
+  PCS_BIN = 'pcs'
+  CRMDIFF_BIN = 'crm_diff'
+  CRMSIMULATE_BIN = 'crm_simulate'
+  CRMRESOURCE_BIN = 'crm_resource'
+  TIMEOUT_BIN = 'timeout'
+else
+  PCS_BIN = '/usr/sbin/pcs'
+  CRMDIFF_BIN = '/usr/sbin/crm_diff'
+  CRMSIMULATE_BIN = '/usr/sbin/crm_simulate'
+  CRMRESOURCE_BIN = '/usr/sbin/crm_resource'
+  TIMEOUT_BIN = '/usr/bin/timeout'
+end
+
 # Ruby 2.5 has dropped Dir::Tmpname.make_tmpname
 # https://github.com/ruby/ruby/commit/25d56ea7b7b52dc81af30c92a9a0e2d2dab6ff27
 def pcmk_tmpname((prefix, suffix), n)
@@ -35,7 +52,7 @@ end
 def backup_cib()
   # We use the pacemaker CIB folder because of its restricted access permissions
   cib = pcmk_tmpname("#{PCMK_TMP_BASE}/puppet-cib-backup", nil)
-  cmd = "/usr/sbin/pcs cluster cib #{cib}"
+  cmd = "#{PCS_BIN} cluster cib #{cib}"
   output = `#{cmd}`
   ret = $?
   if not ret.success?
@@ -62,8 +79,8 @@ def push_cib(cib)
     delete_cib(cib)
     return 0
   end
-  has_diffagainst = `/usr/sbin/pcs cluster cib-push --help`.include? 'diff-against'
-  cmd = "/usr/sbin/pcs cluster cib-push #{cib}"
+  has_diffagainst = `#{PCS_BIN} cluster cib-push --help`.include? 'diff-against'
+  cmd = "#{PCS_BIN} cluster cib-push #{cib}"
   if has_diffagainst
     cmd += " diff-against=#{cib}.orig"
   end
@@ -88,8 +105,8 @@ def pcs(name, resource_name, cmd, tries=1, try_sleep=0,
   max_tries.times do |try|
     cib = backup_cib()
     try_text = max_tries > 1 ? "try #{try+1}/#{max_tries}: " : ''
-    Puppet.debug("#{try_text}/usr/sbin/pcs -f #{cib} #{cmd}")
-    pcs_out = `/usr/sbin/pcs -f #{cib} #{cmd} 2>&1`
+    Puppet.debug("#{try_text}#{PCS_BIN} -f #{cib} #{cmd}")
+    pcs_out = `#{PCS_BIN} -f #{cib} #{cmd} 2>&1`
     if name.include?('show')
       delete_cib(cib)
       # return output for good exit or false for failure.
@@ -119,11 +136,11 @@ def pcs_create_with_verify(name, resource_name, cmd, tries=1, try_sleep=0)
   max_tries = tries
   max_tries.times do |try|
     try_text = max_tries > 1 ? "try #{try+1}/#{max_tries}: " : ''
-    Puppet.debug("#{try_text}/usr/sbin/pcs #{cmd}")
-    pcs_out = `/usr/sbin/pcs #{cmd} 2>&1`
+    Puppet.debug("#{try_text}#{PCS_BIN} #{cmd}")
+    pcs_out = `#{PCS_BIN} #{cmd} 2>&1`
     if $?.exitstatus == 0
       sleep try_sleep
-      cmd_show = "/usr/sbin/pcs resource show " + resource_name
+      cmd_show = "#{PCS_BIN} resource show " + resource_name
       Puppet.debug("Verifying with: "+cmd_show)
       `#{cmd_show}`
       if $?.exitstatus == 0
@@ -185,8 +202,8 @@ end
 # Much simpler logic compared to pcs()
 # return output for good exit or false for failure.
 def pcs_offline(cmd, cib)
-    pcs_out = `/usr/sbin/pcs -f #{cib} #{cmd}`
-    Puppet.debug("pcs_offline: /usr/sbin/pcs -f #{cib} #{cmd}. Output: #{pcs_out}")
+    pcs_out = `#{PCS_BIN} -f #{cib} #{cmd}`
+    Puppet.debug("pcs_offline: #{PCS_BIN} -f #{cib} #{cmd}. Output: #{pcs_out}")
     return $?.exitstatus == 0 ? pcs_out : false
 end
 
@@ -273,7 +290,7 @@ def is_crm_diff_buggy?
   </configuration>
 </cib>
 '''
-  cmd = "/usr/sbin/crm_diff --cib --original-string='#{xml1}' --new-string='#{xml2}'"
+  cmd = "#{CRMDIFF_BIN} --cib --original-string='#{xml1}' --new-string='#{xml2}'"
   cmd_out = `#{cmd}`
   ret = $?.exitstatus
   return false if ret == 0
@@ -283,7 +300,7 @@ end
 
 # same as pcmk_restart_resource? but using crm_diff
 def pcmk_restart_resource_ng?(resource_name, cib)
-  cmd = "/usr/sbin/crm_diff --cib -o #{cib}.orig -n #{cib}"
+  cmd = "#{CRMDIFF_BIN} --cib -o #{cib}.orig -n #{cib}"
   cmd_out = `#{cmd}`
   ret = $?.exitstatus
   # crm_diff returns 0 for no differences, 1 for differences, other return codes
@@ -313,7 +330,7 @@ end
 # https://bugzilla.redhat.com/show_bug.cgi?id=1561617
 def pcmk_restart_resource?(resource_name, cib, is_bundle=false)
   tmpfile = pcmk_tmpname("#{PCMK_TMP_BASE}/puppet-cib-simulate", nil)
-  cmd = "/usr/sbin/crm_simulate -x #{cib} -s -G#{tmpfile}"
+  cmd = "#{CRMSIMULATE_BIN} -x #{cib} -s -G#{tmpfile}"
   crm_out = `#{cmd}`
   if $?.exitstatus != 0
     FileUtils.rm(tmpfile, :force => true)
@@ -383,7 +400,7 @@ def pcmk_update_resource(resource, cmd_create, settle_timeout_secs=600)
     end
   end
   push_cib_offline(cib, resource[:tries], resource[:try_sleep], resource[:post_success_sleep])
-  cmd = "/usr/bin/timeout #{settle_timeout_secs} /usr/sbin/crm_resource --wait"
+  cmd = "#{TIMEOUT_BIN} #{settle_timeout_secs} #{CRMRESOURCE_BIN} --wait"
   cmd_out = `#{cmd}`
   ret = $?.exitstatus
   Puppet.debug("pcmk_update_resource: #{cmd} returned (#{ret}): #{cmd_out}")