How do I use a json tag as a parameter in benthos - benthos

Question

input:
generate:
mapping: root = {"id":48554}
pipeline:
processors:
- http:
url: https://example.com/**use_id_here_from_root**
verb: GET
retries: 5
timeout: 10s
retry_period: 2s
I tried using {{.id}}, eq.${! json("id") } but both of these dont seem to be working.

Answer 1

The http processor url field supports interpolation functions. You should be on the right track with ${! json("id") }, but there might be something wrong with how your test setup.
This config worked for me:
input:
generate:
count: 1
interval: 0s
mapping: root = {"id":48554}
pipeline:
processors:
- http:
url: http://127.0.0.1:6666/${! json("id") }
verb: GET
retries: 5
timeout: 10s
retry_period: 2s
output:
stdout: {}
To test it, I ran nc in a loop:
> while true; do echo -e "HTTP/1.1 200 OK\r\n" | nc -l 127.0.0.1 6666; done
then I ran benthos:
> benthos -c test.yaml
and I got the following output from nc:
GET /48554 HTTP/1.1
Host: 127.0.0.1:6666
User-Agent: Go-http-client/1.1
Content-Length: 12
Content-Type: application/octet-stream
Accept-Encoding: gzip
{"id":48554}