Allow `exec` `creates` to check for all files instead of at least one

[yakatz]

Describe the Bug

I tried to convert an exec resource from multiple invocations of test -f to use the built-in creates option, but it doesn't work as expected, it will not execute unless none of the files are present.

Original:

  exec {'generate snakeoil certificate':
    command => "/usr/bin/sscg -q \
     --cert-file     /etc/pki/tls/certs/localhost.crt   \
     --cert-key-file /etc/pki/tls/private/localhost.key \
     --ca-file       /etc/pki/tls/certs/localhost.crt   \
     --dhparams-file /tmp/dhparams.pem                  \
     --lifetime      3650                               \
     --hostname      ${facts['networking']['fqdn']}     \
     --email         root@${facts['networking']['fqdn']}",
    unless  => [
      '/usr/bin/test -f /etc/pki/tls/certs/localhost.crt',
      '/usr/bin/test -f /etc/pki/tls/private/localhost.key',
    ],
    notify  => Service['httpd'],
  }

Expected equivalent:

  exec {'generate snakeoil certificate':
    command => "/usr/bin/sscg -q \
     --cert-file     /etc/pki/tls/certs/localhost.crt   \
     --cert-key-file /etc/pki/tls/private/localhost.key \
     --ca-file       /etc/pki/tls/certs/localhost.crt   \
     --dhparams-file /tmp/dhparams.pem                  \
     --lifetime      3650                               \
     --hostname      ${facts['networking']['fqdn']}     \
     --email         root@${facts['networking']['fqdn']}",
    creates => [
      '/etc/pki/tls/certs/localhost.crt',
      '/etc/pki/tls/private/localhost.key',
    ],
    notify  => Service['httpd'],
  }

Debug output if both exist:

Info: Applying configuration version '1700663411'
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]/creates: Checking that 'creates' path '/etc/pki/tls/certs/localhost.crt' exists
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]: '/usr/libexec/httpd-ssl-gencerts' won't be executed because of failed check 'creates'
Debug: Finishing transaction 12600

Debug output if the first file is missing and the second one exists:

Info: Applying configuration version '1700663438'
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]/creates: Checking that 'creates' path '/etc/pki/tls/certs/localhost.crt' exists
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]/creates: Checking that 'creates' path '/etc/pki/tls/private/localhost.key' exists
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]: '/usr/libexec/httpd-ssl-gencerts' won't be executed because of failed check 'creates'
Debug: Finishing transaction 12600

Debug output if neither file exists (debug run without notify httpd):

Info: Applying configuration version '1700663608'
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]/creates: Checking that 'creates' path '/etc/pki/tls/certs/localhost.crt' exists
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]/creates: Checking that 'creates' path '/etc/pki/tls/private/localhost.key' exists
Debug: Exec[generate snakeoil certificate](provider=posix): Executing '/usr/libexec/httpd-ssl-gencerts'
Debug: Executing: '/usr/libexec/httpd-ssl-gencerts'
Notice: /Stage[main]/Main/Exec[generate snakeoil certificate]/returns: executed successfully
Debug: /Stage[main]/Main/Exec[generate snakeoil certificate]: The container Class[Main] will propagate my refresh event
Debug: Class[Main]: The container Stage[main] will propagate my refresh event
Debug: Finishing transaction 12600

Expected Behavior

I would expect the command to be executed if any of the files listed in creates are missing.

Environment

• Version 7.27.0
• Platform RHEL 9.2

[yakatz]

Discussing on Slack, another option that preserves backwards compatibility would be to take a multi-dimensional array:

[
  [all of these files, 2, 3, 4],
  [or all of these files, 5, 6, 7],
  [or even all of these],
]

[cthorn42]

@yakatz I think the best solution here is to take your #9167 PR and get that merged in there.

[github-actions]

Migrated issue to PUP-11989

[joshcooper]

@yakatz I'm confused. The unless docs say

puppet/lib/puppet/type/exec.rb

Lines 490 to 491 in 82ad86e

	This `exec` would only run if every command in the array has a
	non-zero exit code.

In your example, that means test -f <file> commands must return non-zero for the exec to run, which is the same as none of the files existing. And that's equivalent to how creates behaves:

puppet/lib/puppet/type/exec.rb

Line 445 in 82ad86e

will only run the command if both files don't exist.

In this example, note how both execs don't run if I just delete one of their related files:

❯ cat <<END > creates.pp 
exec { 'creates':
  command => '/usr/bin/touch /tmp/creates1 && /usr/bin/touch /tmp/creates2',
  creates => [
    '/tmp/creates1',
    '/tmp/creates2'
  ]
}

exec { 'unless':
  command => '/usr/bin/touch /tmp/unless1 && /usr/bin/touch /tmp/unless2',
  unless => [
    '/usr/bin/test -f /tmp/unless1',
    '/usr/bin/test -f /tmp/unless2'
  ]
}
END
❯ rm /tmp/creates* /tmp/unless*
❯ bundle exec puppet apply creates.pp
Notice: Compiled catalog for localhost in environment production in 0.05 seconds
Notice: /Stage[main]/Main/Exec[creates]/returns: executed successfully
Notice: /Stage[main]/Main/Exec[unless]/returns: executed successfully
Notice: Applied catalog in 0.03 seconds
❯ bundle exec puppet apply creates.pp
Notice: Compiled catalog for localhost in environment production in 0.05 seconds
Notice: Applied catalog in 0.02 seconds
❯ rm /tmp/creates1 /tmp/unless1
❯ bundle exec puppet apply creates.pp
Notice: Compiled catalog for localhost in environment production in 0.05 seconds
Notice: Applied catalog in 0.02 seconds
❯ ls /tmp/creates* /tmp/unless* 
/tmp/creates2  /tmp/unless2

It's only when I delete both files that the execs run:

❯ rm /tmp/creates* /tmp/unless*
❯ bundle exec puppet apply creates.pp
Notice: Compiled catalog for localhost in environment production in 0.05 seconds
Notice: /Stage[main]/Main/Exec[creates]/returns: executed successfully
Notice: /Stage[main]/Main/Exec[unless]/returns: executed successfully
Notice: Applied catalog in 0.04 seconds
❯ ls /tmp/creates* /tmp/unless*
/tmp/creates1  /tmp/creates2  /tmp/unless1  /tmp/unless2

[yakatz]

It might have been a copy/paste error - I don't have it in front of me now to check, but it is working as described in production: we have a condition that will have the exec run if either file is missing and it would be nice to natively support that.

[joshcooper]

we have a condition that will have the exec run if either file is missing and it would be nice to natively support that.

@yakatz could you provide steps to reproduce.

[yakatz]

@yakatz could you provide steps to reproduce.

You're right, it probably never worked that way. At some point we changed it to a single unless test for both files.

unless  => '/usr/bin/test -f /etc/pki/tls/certs/localhost.crt && /usr/bin/test -f /etc/pki/tls/private/localhost.key'

[joshcooper]

@yakatz ok thanks for letting us know. So IIUC we can close this? Please reopen if I'm confused.

[yakatz]

It would still be a useful feature to have, so consider it a feature request.

[joshcooper]

Given there's already a way to check that all files must exist using:

  unless => [
    '/usr/bin/test -f /tmp/unless1',
    '/usr/bin/test -f /tmp/unless2'
  ]

I'd be reluctant to add more complexity to the creates parameter. Trying to differentiate between creates => [ '/tmp/...'] behaves like OR while creates => [ [ '/tmp/...'] ] behaves like AND is magical and IMO should be avoided.