Add backup attribute to file resource (close #124)

[hico-horiuchi]

Add backup attribute to file (also remote_file, template and http_request).
This is the number of backups to be kept in /var/itamae/backup (default is 5.)
backup method is based on chef/lib/chef/deprecation/provider/file.rb.
(This attribute is same as file of Chef.)

For example:

file `/tmp/file` do
  content 'Hello New World'
  backup 5
end

(In this case, file is backed up to /var/itamae/backup/tmp/file.itamae-20160114001759.)

[hico-horiuchi]

/var/itamae/backup/tmp/file.itamae-20160114001759 is better ?
Sorry, I fixed backup path to "/var/itamae/backup/#{attributes.path}" according to Chef.

[hico-horiuchi]

@ryotarai Following error occured in Werker at start vm step.
Could you confirm the error ?

There was an error when attemping to rsync a share folder.
Please inspect the error message below for more info.

Host path: /pipeline/build/spec/integration/
Guest path: /vagrant
Error: ssh: connect to host 104.131.69.157 port 22: Connection timed out
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: unexplained error (code 255) at io.c(605) [sender=3.0.9]

[ryotarai]

I think the following is simpler

return if !attributes.backup || attributes.backup <= 0

[hico-horiuchi]

Thank you! I'll fix it.

[hico-horiuchi]

Should I use run_command("ls -1 #{::File.join(BACKUP_PATH, attributes.path + '.itamae-*')}") ?
(When I use ['ls', '-1', ::File.join(BACKUP_PATH, attributes.path + '.itamae-*'] , * is escaped to \* and can't execute.)

[ryotarai]

Current implementation is good.

[hico-horiuchi]

OK, thank you!

[hico-horiuchi]

@ryotarai I apologize for my late reply.
I fixed following codes. Could you confirm?
(I also rebased commits.)

• Baked-up files have same permission of source files.
  • run_command(['cp', '-p', attributes.path, backup_path])
• Directories under /var/lib/itamae are 777 .
  • run_command(['install', '-d', '-m=777', backup_directory])

[ryotarai]

Okay. It is better that run_command is replaced with run_specinfra.

[hico-horiuchi]

@ryotarai run_specinfra(:copy_file) doesn't seem to preserve the permission.
So, I use run_command(['cp', '-p', attributes.path, backup_path]) .

• mizzy/specinfra/lib/specinfra/command/base/file.rb#L157#L159

And run_specinfra(:change_mode) dosen't include -R option.
So, I use run_command(['install', '-d', '-m=777', backup_directory]) .
(run_specinfra(:create_file_as_directory, backup_directory) + run_command(['chmod', '-R', BACKUP_PATH]) is better?)

• mizzy/specinfra/lib/specinfra/command/base/file.rb#L140#L142

[ryotarai]

As you said, Specinfra doesn't have sufficient commands for this PR but you can send a PR to https://github.com/mizzy/specinfra
Would you do it?

[hico-horiuchi]

@ryotarai OK! I try to send PR to Specinfra.

[hico-horiuchi]

@ryotarai I fixed by using Specinfra v2.54.0!