Jira (FACT-2054) Facter::Core::Execution.execute incorrectly expands shell builtins

[Charlie Sharpsteen (JIRA)]

Title: Message Title

Charlie Sharpsteen created an issue   Facter / FACT-2054 Facter::Core::Execution.execute incorrectly expands shell builtins Issue Type: Bug Assignee: Unassigned Created: 2019/10/03 7:03 AM Priority: Normal Reporter: Charlie Sharpsteen When executing commands, Facter will expand the first word in the command string to be a fully qualified path. I.e. ls -l will become /usr/bin/ls -l. If the command string is a compound command that contains a pipeline or looping construct, then Facter will wrap the executing in /bin/sh -c. However, the first word of the compound is still expanded to an absolute path. This breaks shell builtins like cd as they are expanded to external commands like /usr/bin/cd or fail to be found on the PATH. Reproduction Case Install the latest version of puppet-agent on CentOS 7, along with strace: yum install -y http://yum.puppetlabs.com/puppet-release-el-7.noarch.rpm yum install -y puppet-agent strace Create a test script that loads Facter, and uses it to execute a compound command that begins with cd: cat <<EOF > test.rb #!/opt/puppetlabs/puppet/bin/ruby require 'facter'   puts Facter::Core::Execution.execute('cd /opt/puppetlabs && ls') EOF chmod +x test.rb Execute the test scrip. Outcome The script prints the contents of the current working directory instead of /opt/puppetlabs: # ./test.rb 1 anaconda-ks.cfg linux.iso test.rb Running the script under strrace reveals that cd is being expanded to /usr/bin/cd before being passed to sh -c: # strace -f -e trace=execve ./test.rb execve("./test.rb", ["./test.rb"], [/* 23 vars */]) = 0 strace: Process 20373 attached strace: Process 20374 attached [pid 20374] execve("/usr/bin/sh", ["sh", "-c", "/usr/bin/cd /opt/puppetlabs && l"...], [/* 24 vars */]) = 0 strace: Process 20375 attached [pid 20375] execve("/usr/bin/cd", ["/usr/bin/cd", "/opt/puppetlabs"], [/* 24 vars */]) = 0 [pid 20375] +++ exited with 0 +++ [pid 20374] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=20375, si_uid=0, si_status=0, si_utime=0, si_stime=0} --- strace: Process 20376 attached [pid 20376] execve("/usr/bin/ls", ["ls"], [/* 24 vars */]) = 0 [pid 20376] +++ exited with 0 +++ [pid 20374] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=20376, si_uid=0, si_status=0, si_utime=0, si_stime=0} --- [pid 20374] +++ exited with 0 +++ [pid 20372] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=20374, si_uid=0, si_status=0, si_utime=0, si_stime=0} --- 1 anaconda-ks.cfg linux.iso test.rb [pid 20373] +++ exited with 0 +++ +++ exited with 0 +++ Expected Outcome The script prints the content of /opt/puppetlabs: # ./test.rb bin facter puppet pxp-agent Suggested Workaround The expansion only affects the first word in the command line, so adding an extra true && to the compound command acts as a sacrificial noop that takes the hit instead. Add Comment   This message was sent by Atlassian JIRA (v7.7.1#77002-sha1:e75ca93) -- You received this message because you are subscribed to the Google Groups "Puppet Bugs" group. To unsubscribe from this group and stop receiving emails from it, send an email to puppet-bugs+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/puppet-bugs/JIRA.327886.1570111406000.127518.1570111440329%40Atlassian.JIRA.