Appending to template toJson

[LecrisUT]

I have looked into the text/template and sprig documentation and tried a few options, but I can't find how to add additional variables to the toJson part. For example, I want to setup:

   	"principals": {{ append .Principals .Token.preferred_username | toJson }},

Also using toJson .Token.preferred_username fails because it's not an array, but is there a way to test/force it to be a Json array?

[maraino]

The line that you have should work if .Token.preferred_username is a string.

If you want to use just that you can use "principals": {{ list .Token.preferred_username | toJson }}

[LecrisUT]

That would resolve {{ toJson .Token.preferred_username }}, but would it work as {{ list .Principals .Token.preferred_username }}?

Edit: It doesn't work:

 error unmarshaling certificate: json: cannot unmarshal array into Go struct field Certificate.principals of type string

[maraino]

The example that you had was working for me without issues:

"principals": {{ append .Principals .Token.preferred_username | toJson }},

[maraino]

I've created a simple program to show this working https://github.com/maraino/ssh-template-test

It outputs a certificate with the foobar principal coming from the token:

{
  "Nonce": "TE4ke1ZETVxuWnAzKVNARzVzeH1uc25jPjsibmJKbzk=",
  "Key": "1RAl/m05whrOLQWml4Hb3mrmmsJWL7nduAoflgEQGMM=",
  "Serial": 17283346687152004381,
  "CertType": 1,
  "KeyId": "[email protected]",
  "ValidPrincipals": [
    "mariano",
    "foobar"
  ],
  "ValidAfter": 0,
  "ValidBefore": 0,
  "CriticalOptions": null,
  "Extensions": {
    "permit-X11-forwarding": "",
    "permit-agent-forwarding": "",
    "permit-port-forwarding": "",
    "permit-pty": "",
    "permit-user-rc": ""
  },
  "Reserved": null,
  "SignatureKey": "th+PJQE5AEblE9NacOZrsVMtsuK77l5oc3/X7Pcz3Z4=",
  "Signature": {
    "Format": "ssh-ed25519",
    "Blob": "oyeoD4v7GXZ7VuiViRJ/WtPvrXwLoNZ9YKFCbTTkg4CCXFRFy3LWryhOypy4/WSNfX3JxYcHC9bvSEDRFRSyAQ==",
    "Rest": null
  }
}

[LecrisUT]

You are right. I must have had another error in the template when I first tested this. Sorry for the confusion.