1 files changed, 51 insertions, 0 deletions
diff --git a/puppet/modules/try/manifests/file.pp b/puppet/modules/try/manifests/file.pp
new file mode 100644
index 00000000..406c0b7a
--- /dev/null
+++ b/puppet/modules/try/manifests/file.pp
@@ -0,0 +1,51 @@
+#
+# like built-in type "file", but gets gracefully ignored if the target does not exist or is undefined.
+#
+# /bin/true and /usr/bin/test are hardcoded to their paths in debian.
+#
+
+define try::file (
+  $ensure = undef,
+  $target = undef,
+  $restore = true) {
+
+  if $target != undef {
+    exec { "check_${name}":
+      command => "/bin/true",
+      onlyif => "/usr/bin/test -e '${target}'",
+      loglevel => info;
+    }
+    file { "$name":
+      ensure => $ensure,
+      target => $target,
+      require => Exec["check_${name}"],
+      loglevel => info;
+    }
+  }
+
+  #
+  # if the target does not exist (or is undef), and the file happens to be in a git repo,
+  # then restore the file to its original state.
+  #
+  if $target == undef or $restore {
+    $file_basename = basename($name)
+    $file_dirname  = dirname($name)
+    $command = "git rev-parse && unlink '${name}'; git checkout -- '${file_basename}' && chown --reference='${file_dirname}' '${name}'; true"
+    debug($command)
+
+    if $target == undef {
+      exec { "restore_${name}":
+        command => $command,
+        cwd => $file_dirname,
+        loglevel => info;
+      }
+    } else {
+      exec { "restore_${name}":
+        unless => "/usr/bin/test -e '${target}'",
+        command => $command,
+        cwd => $file_dirname,
+        loglevel => info;
+      }
+    }
+  }
+}