How to work around vcsrepo "duplicate declaration" evaluation error? - puppet

Question

I am installing from github using puppet-vcsrepo. The code looks something like this:
class demo_class(
$my_repo = undef,
$my_tag = undef,
){
vcsrepo { "$my_repo",
path => "/home/user/$my_repo",
source => 'git#github.com:7yl4r/$my_repo.git',
ensure => latest,
provider => git,
}
# then declare resources specific to my_tag
}
This works just fine when called only once, but I am iterating over a list and installing dependencies so this resource sometimes gets declared twice. I think this is roughly equivalent to the code below.
class {"demo_class":
my_repo => test_repo,
my_tag => test_tag1,
}
class {"demo_class":
my_repo => test_repo,
my_tag => test_tag2,
}
Doing this yields a server-side "Duplicate declaration" error because vcsrepo is trying to map the the same path twice. However, this is exactly the behavior I want: for both resources declared by demo_class to require the same repo in the same location. This is so that I can declare one or more resources using demo_class and be sure the repo given by my_repo (which may be common to multiple my_tags) is there.
How can I modify this class so that I can call it twice without hitting an error?

Answer 1

I see the problem.
I reproduced the issue using this code:
define my_vcs_repo ($myRepo, $myTag) {
vcsrepo { "$myRepo-$myTag":
path => "/home/user/$myRepo",
source => "git#github.com:7yl4r/$myRepo.git",
revision => $myTag,
ensure => latest,
provider => git,
}
}
$data = [
{
myRepo => testRepo,
myTag => testTag1,
},
{
myRepo => testRepo,
myTag => testTag2,
},
]
$data.each |$i, $ref| {
$myRepo = $ref['myRepo']
$myTag = $ref['myTag']
my_vcs_repo { "$myRepo-$i":
myRepo => $myRepo,
myTag => $myTag,
}
}
That then results in:
Puppet::PreformattedError:
Evaluation Error: Error while evaluating a Resource Statement, Evaluation Error: Error while evaluating a Resource Statement, Cannot alias Vcsrepo[testRepo-testTag2] to ["/home/user/testRepo"] at /
Users/alexharvey/git/modules/foo/spec/fixtures/modules/foo/manifests/init.pp:3; resource ["Vcsrepo", "/home/user/testRepo"] already declared at /Users/alexharvey/git/modules/foo/spec/fixtures/modules/foo/
manifests/init.pp:3 at /Users/alexharvey/git/modules/foo/spec/fixtures/modules/foo/manifests/init.pp:3:5 at /Users/alexharvey/git/modules/foo/spec/fixtures/modules/foo/manifests/init.pp:26 on node alexs-macbook-pro.local
The problem is that you are asking Puppet to clone the same Git module to a directory but with two different tags checked out. That does not make sense.
The fix is that you need to specify a unique path in the vcsrepo path attribute, e.g.:
vcsrepo { "$myRepo-$myTag":
path => "/home/user/$myRepo-$myTag",
source => "git#github.com:7yl4r/$myRepo.git",
revision => 'production',
ensure => latest,
provider => git,
}
By the way, I notice you are using camelCase for your variables. Don't do that. Aside from the fact that it is not idiomatic for Puppet, there are things that will break in some versions of Puppet/Rspec puppet that I have seen.
Use snake_case for your variable names and class parameter names.
Update
The question has been edited, and it is now a question about how to declare the same vcsrepo in more than one class.
In general, try to refactor so that you do not need to do this in the first place. In other words, just move it out of this class and put it somewhere that is only expected to be declared once.
If you cannot do this for some reason, then you can also use virtual resources, which will allow you to declare it in multiple classes that will be declared on the same node.
To do that, you just have to rewrite what you have there as:
#vcsrepo { $my_repo:
path => "/home/user/$my_repo",
source => "git#github.com:7yl4r/$my_repo.git",
ensure => latest,
provider => git,
}
realize Vcsrepo[$my_repo]
Keep in mind that you will not be able to declare the class demo_class twice on the same node either. You would need to turn it into a defined type, as I did above.
It is mentioned in the comments below that you can also use ensure_resource and ensure_resources; see docs in stdlib.