Fix “(InvalidMetadata) JSON::ParserError” and other JSON errors in Puppet Enterprise by installing a JSON linter

When selecting a task to run in the console, you might get an Internal Server Error: org.jruby.exceptions.RuntimeError: (InvalidMetadata) JSON::ParserError error at the top of the page.

Error messages and logs

Internal Server Error: org.jruby.exceptions.RuntimeError: (InvalidMetadata) JSON::ParserError` error
at opt.puppetlabs.puppet.lib.ruby.vendor_ruby.puppet.module.task.read_metadata(/opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/module/task.rb:240)
”

You get this error when there are JSON files in the module or module environment which cause services to fail when they are parsed.

Version and installation information

PE version: All supported

Solution

To resolve the error, use a linter to fix JSON metadata syntax issues associated with the affected module tasks. If you have a preferred JSON linting tool, you can use that. You can also use the following steps to install jsonlint, a gem-based JSON linting tool, using either Puppet Development Kit (PDK) or the version of Ruby included in Puppet Enterprise (PE). If you set up PDK, you can also test your code and avoid future issues with module code.

Note: We can’t provide support for third-party software.

Install and use jsonlint using PDK

Complete the following steps to install jsonlint in PDK on a Puppet Enterprise node that has internet access and a copy of the module’s code on it.

Before you begin:

• PDK must be installed.

• The module you want to lint must be converted to a standardized PDK module.

To install the jsonlint gem, run the following commands:

1. Add jsonlint to Gemfile.local by running echo 'gem "jsonlint"' >> Gemfile.local

2. Add dependencies for jsonlint by running pdk bundle install

3. Lint JSON files in the code development environment by running pdk bundle exec jsonlint **/*.json

4. Check the output and resolve any errors that you find. Learn how to fix some common JSON errors.

After you fix the issues, redeploy your code.

Install and use jsonlint using the Ruby included with PE

To install jsonlint using the Ruby included with PE, complete the following steps on a node with the module’s code on it, PE installed, and online access.

Before you begin, make sure that you have the RubyGems gem installed on the node.

1. Install the jsonlint gem by running gem install jsonlint

2. Add the gem to Ruby by running rehash

3. Lint JSON files in the Puppet Enterprise code development environment by running jsonlint/etc/puppetlabs/code/environments/dev/**/*.json

   Note: You can use a different path using jsonlint/<PATH YOU WANT TO LINT>/**/*.json

4. Check the output and resolve any JSON syntax issues that you find. Learn how to fix some common JSON errors.

After you fix the issues, redeploy your code.

Help with JSON errors

• Empty JSON files are not valid JSON - Puppet Enterprise (PE) 2021.7.0 uses stricter JSON parsing than older versions do, so you might experience this error after an upgrade. JSON parsing returns null when the JSON string is empty. To fix the error, remove empty JSON metadata files to fix the error.

• expected hash key, not a hash close - a { “key”: “value” } pair might be missing a colon.