Overriding role attributes in chef-client with pac

问题:

I have a chef role:

{
  "name": "my-role",
  "description": "Defines a role",
  "override_attributes": {
    "cookbook_one" {
      "key": "value"
    }
  }
  "run_list": [
    recipe["cookbook_one"],
    recipe["cookbook_two"]
  ]
}

Which I call with Packer in the provisioner block:

{
  "variables": {
    "my-variable": ""
  },
  "provisioners": [
    {
      "type": "chef-client",
      "server_url": "https://mychefserver.com/",
      "run_list": "role[my-role]",
      ...
    }

I need to be able to add some attributes to recipe_two from within Packer. I read I can use the json block of the chef-client provisioner to add some attributes to the runlist. I tried

  "type": "chef-client",
  "server_url": "https://mychefserver.com/",
  "run_list": "role[my-role]",
  "json": {
    "override_attributes": {
      "cookbook_two": {
        "some_key": "value"
      }
    }
  }

and when I run packer I can see in /tmp/packer-chef-client/first-boot.json

   {
     "override_attributes": {
       "cookbook_two": {
         "some_key": "{{ user `my-variable` }}"
       }
     },
     "run_list": [
       "role[my-role]"
     ]
   }

But the override_attributes for recipe_two are not exposed to the cookbook. I cannot find any examples of how to get it to work in this way nor the correct format of the "json": {} block to pass through.

Any direction to exposing overridden attributes to my cookbook through the role called from Packer would be greatly appreciated

回答1:

your issue has nothing to do with packer itself, but rather how to execute chef-client and provide custom attribute to the chef-client run.

you can provide custom attributes by including --json-attributes (i strongly advise you to visit the documentation, since it holds examples) in chef-client

-j PATH, --json-attributes PATH

The path to a file that contains JSON data. Used to setup the first client run. For all the future runs with option -i the attributes are expected to be persisted in the chef-server.

so back to your question with packer... create a json file with the attributes which you would like to override and make sure that you invoke chef-client from packer with the --json-attributes and point it to the json file you created.