How can I pass context params using talend api? - talend

Question

I'm trying to automate talend job executions using the Talend API but I'm getting an error when I try to pass the context params using the api.
The json I'm encoding to 64 is the following:
JSON='{ "actionName":"runTask", "authPass": "TalendPass", "authUser": "name#example.com", "jvmParams": [ "-Xmx256m" , "-Xms64m" ], "contextParams": ["host_mysql_db01": "failed", "database_analytics": "testing.it"],"mode": "synchronous", "taskId": 43}'
Error message:
{"error":"Expected a ',' or ']' at character 172","returnCode":2}
I found another stackoverflow issue Add context parameters to Talend job in Tac via API without actually running it but he doesn't say how he pass it and I cannot reply with a comment asking how he did it
The real talend api call is:
wget -O file http://localhost:8080/org.talend.administrator/metaServlet?$JSON_ENCODED
Can I get some help?

Answer 1

Actually, the json your are passing to the metaservlet is not valid json. You can check it with an online validator like http://jsonlint.com.
You are specifying the contextParams attribute as an array, but that syntax is not valid in json. An array can contain either a list of values (like jvmParams) or objects (which can themselves contain arrays). Here's an example.
Moreover, according to Talend reference, the attribute should be called "context" and must be an object instead of an array, like so:
"context":{"varname1": "varvalue", "varname2": "varvalue2"}