Using REST in TCL to POST in JSON format? - json

Question

Essentially what I'm attempting to do is post to a REST API, but no matter what I do I end up with HTTP 400. Here is my extremely quick and extremely dirty code:
package require rest
package require json
::http::register https 443 ::tls::socket
set credentials {username admin password LabPass1}
set url1 [format "%s/%s" "https://127.0.0.1:8834" session]
set unformattedToken [dict get [::json::json2dict [::rest::post $url1 $credentials]] token]
set cookie [format "token=%s" $unformattedToken]
set header [list X-Cookie $cookie Content-type application/json]
set config [list method post format json headers $header]
set url [format "%s/%s" "https://127.0.0.1:8834" scans]
set uuid 7485-2345-566
set name "Testing TCL Network Scan"
set desc "Basic Network Scan using API"
set pid 872
set target 127.0.0.1
set data {{"uuid":"$uuid","settings": {"name":"$name","description":"$desc", "policy_id":"$pid","text_targets":"$target", "launch":"ONETIME","enabled":false,"launch_now":true}}}
set jsonData [json::json2dict $data]
set response [::rest::simple $url $jsonData $config]
I've tried using the above code and I've also tried removing the json::json2dict call and just sending the data. I believe, and I could be wrong, that my issue is the data is going as line-based text data:
POST /scans HTTP/1.1
Host: 127.0.0.1:8834
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 10.0) http/2.8.9 Tcl/8.6.4
Connection: close
X-Cookie: token=301b8dcdf855a29b5b902cf8d93c49750935c925a965445e
Content-type: application/json
Accept: */*
Accept-Encoding: gzip,deflate,compress
Content-Length: 270
uuid=7485-2345-566&settings=name%20%7BTesting%20TCL%20Network%20Scan%7D%20description%20%7BBasic%20Network%20Scan%20using%20API%7D%20policy_id%20872%20text_targets%20127.0.0.1%20launch%20ONETIME%20enabled%20false%20launch_now%20true
I've reviewed the JSON documentation, and the REST documentation but I'm having a hard time finding an example of posting using JSON format. Here is what this looks like in a curl command:
curl https://127.0.0.1:8834/scans -k -X POST -H 'Content-Type: application/json' -H 'X-Cookie: token= <token>' -d '{"uuid":"7485-2345-566","settings":{"name":"Testing TCL Network Scan","description":"Basic Network Scan using API", "policy_id":"872","text_targets":"127.0.0.1", "launch":"ONETIME","enabled":false,"launch_now":true}'

Answer 1

One problem you have is that the values in the query aren't evaluated. "uuid":"$uuid" becomes "uuid":"$uuid", for instance. This is because of the braces around the value that data is set to.
The best solution would seem to be to not create a json object and then convert it to a dict, but instead create the dict directly, like this:
set data [list uuid $uuid settings [list name $name description $desc policy_id $pid text_targets $target launch ONETIME enabled false launch_now true]]
or like this, for shorter lines:
dict set data uuid $uuid
dict set data settings name $name
dict set data settings description $desc
dict set data settings policy_id $pid
dict set data settings text_targets $target
dict set data settings launch ONETIME
dict set data settings enabled false
dict set data settings launch_now true
or by some other method.
Documentation: dict, list, set