Cookbook error

[pguerin3]

As a newbie of stream processing, to get started I'm running some of the examples in the cookbook.

Then I came across this one:
https://www.benthos.dev/cookbooks/custom-metrics/

The example is listed as follows:

http:
  address: 0.0.0.0:4195

input:
  generate:
    interval: 60s
    mapping: root = ""

pipeline:
  processors:
    - http:
        url: https://formulae.brew.sh/api/formula/benthos.json
        verb: GET

    - metric:
        type: gauge 
        name: downloads
        labels:
          source: homebrew
        value: ${! json("analytics.install.30d.benthos") }

    - mapping: root = ""

    - http:
        url: https://hub.docker.com/v2/repositories/jeffail/benthos/
        verb: GET

    - metric:
        type: gauge
        name: downloads
        labels:
          source: dockerhub
        value: ${! json("pull_count") }

    - mapping: root = deleted()

metrics:
  mapping: if this != "downloads" { deleted() }
  prometheus: {}

However I get an error when I run it:

$ docker run -it --rm --name benthos-test -p 127.0.0.1:4195:4195 -v ~/benthos.yaml:/benthos.yaml jeffail/benthos
INFO Running main config from specified file       @service=benthos benthos_version=v4.24.0 path=/benthos.yaml
INFO Listening for HTTP requests at: http://0.0.0.0:4195  @service=benthos
INFO Launching a benthos instance, use CTRL+C to close  @service=benthos
ERRO HTTP request to 'https://hub.docker.com/v2/repositories/jeffail/benthos/' failed: https://hub.docker.com/v2/repositories/jeffail/benthos/: HTTP request returned unexpected response code (406): 406 Not Acceptable, Error: {"message":"406: Not Acceptable\n\nAvailable representations: "}  @service=benthos label="" path=root.pipeline.processors.3
ERRO Value interpolation error: target message part does not exist  @service=benthos label="" path=root.pipeline.processors.4

Seems like something is missing from the config.
So I'm wondering if anyone else has tried to run this example, and what I need to do to get it to work....

[mihaitodor]

Hey @pguerin3 👋 Sorry for the late reply! I had a look and I believe it's due to a change in the DockerHub REST API. I added the expected Content-Type: application/json header in #2459 and, hopefully, that fixes the issue.

[pguerin3]

ok - I'll wait until the change comes to benthosdev/benthos:latest