YAML to JSON to string and output variable max length

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1

Hi,

I have a large configuration file in YAML format which is stored in source control (Git). I want to make all of the key-value pairs within the YAML file available to all steps within a deployment. I don’t want to store my configuration in variables in Octopus permanently since I need that same configuration elsewhere in our deployment pipeline. I want to have a single source of truth.

Using PowerShell I’m looking to import the YAML file using PowerYAML, convert the resulting hash table to a JSON object, and then convert this to a string. I can then pass that string to Octopus as an output variable. Any steps requiring a configuration parameter could read the variable and translate it back from a string to JSON again where I can easily find and access the key/value pairs.

Is there a max length restriction on output variables which could limit this approach or a better way out there to access YAML or JSON as a variable at deployment time (not a string).

Many thanks,
Blair.

2

I’ve just seen the Octostache Json Formatting post at https://octopus.com/blog/octostache-json-formatting so will try to use that first.

Many thanks,
Blair.

3

Hi Blair,

Hopefully it works out to be perfect timing! Keep in touch and let us know how you get on. :slight_smile:

Happy Deployments!
Mike

4

Hi Mike,

I’m pleased to report that I have a solution which works. I don’t appear to have hit a limitation on the output variable length yet. Unfortunately I wasn’t able to use the recent Octostache improvements due to the way PowerShell converts to JSON. My solution is:

  1. I obtain a YAML configuration file from Git which contains all configuration (key/value pairs) required for a deployment. This YAML file is read in as a hash table within a PowerShell deployment script step.

  2. Using the PowerShell ConvertTo-JSON cmdlet, I convert the hash table to a single JSON formatted string and then pass this to an Octopus output variable.

  3. In subsequent deployment scripts I can read the output variable back in use the ConvertFrom-JSON cmdlet. I can then access all my key/value items with a simple hash table key/value reference.

Cheers,
Blair.

5

Hi Blair,

Thanks for getting back to me. I have heard of some quirks with PowerShell’s conversion to JSON related to how deep it traverses the graph. You could try setting the -Depth argument to make it traverse deeper, or using the -Compress flag to omit formatting in the resulting string.

Either way it sounds like you’re really getting your hands dirty and making headway! :slight_smile:

Keep in touch!
Mike