Post a NIFI template via REST?

Question

I have multiple nifi servers that I would like to be able to POST templates to via the REST interface from a script

The "/controller/templates" endpoint appears to be the proper REST endpoint to support POSTing an arbitrary template to my Nifi installation. The "snippetId" field is what is confusing me, how do I determine "The id of the snippet whose contents will comprise the template"? Does anyone have an example of how I can upload a template "test.xml" to my server without having to use the UI?

Answer 1

The provided documentation is somewhat confusing, and the solution I worked out was derived from the nifi api deploy groovy script at https://github.com/aperepel/nifi-api-deploy

Ultimately, to POST a template directly, you can use the following in Python requests

requests.post("%s/nifi-api/controller/templates"%(url,), files={"template":open(filename, 'rb')})

Where filename is the filename of your template and url is the path to your nifi instance. I haven't figured it out in curl directly but this should hopefully get folks with a similar question started!

Edit: Note that you also can't upload a template with the same name as an existing template. Make sure to delete your existing template before attempting to re-upload. Using the untangle library to parse the XML of the template, the following script works just fine:

import untangle, sys, requests

def deploy_template(filename, url):
    p = untangle.parse(filename)
    new_template_name=p.template.name.cdata
    r=requests.get("%s/nifi-api/controller/templates"%(url,), headers={"Accept":"application/json"})

    for each in r.json()["templates"]:
        if each["name"]==new_template_name:
            requests.delete(each["uri"])
    requests.post("%s/nifi-api/controller/templates"%(url,), files={"template":open(filename, 'rb')})

if __name__=="__main__":
    deploy_template(sys.argv[1], sys.argv[2])