Tagpass with multiple output

[2solt]

Bug report

Only the first first tagpass being used when using multiply outputs from the same type

Relevant telegraf.conf:

[agent]
  interval            = "1m"
  round_interval      = true
  metric_batch_size   = 1000
  metric_buffer_limit = 10000
  collection_jitter   = "0s"
  flush_interval      = "1m"
  flush_jitter        = "0s"
  precision           = ""
  debug               = true
  quiet               = false
  logfile             = ""
  omit_hostname       = true

[[inputs.http_listener]]
  service_address = "127.0.0.1:8187"

[[outputs.prometheus_client]]
  listen = ":9273"
  path = "/m"
  expiration_interval = "1m"
  [outputs.prometheus_client.tagpass]
   tag1 = ["1"]

[[outputs.prometheus_client]]
  listen = ":9274"
  path = "/m"
  expiration_interval = "1m"
  [outputs.prometheus_client.tagpass]
    tag1 = ["2"]

System info:

Telegraf v1.5.0~rc2 (git: release-1.5 fd964bd)
linux_amd64

Steps to reproduce:

1. curl -i -XPOST http://127.0.0.1:8187/write?db=test --data-binary "test,tag1=1 value=1 $(date +%s)"
2. curl -i -XPOST http://127.0.0.1:8187/write?db=test --data-binary "test,tag1=2 value=2 $(date +%s)"
3. curl -s 127.0.0.1:9273/m |grep test
4. curl -s 127.0.0.1:9274/m |grep test

Expected behavior:

curl -s 127.0.0.1:9273/m |grep test
# HELP test Telegraf collected metric
# TYPE test untyped
test{tag1="1"} 1

curl -s 127.0.0.1:9274/m |grep test
# HELP test Telegraf collected metric
# TYPE test untyped
test{tag1="2"} 2

Actual behavior:

curl -s 127.0.0.1:9273/m |grep test
# HELP test Telegraf collected metric
# TYPE test untyped
test{tag1="1"} 1

curl -s 127.0.0.1:9274/m |grep test
# HELP test Telegraf collected metric
# TYPE test untyped
test{tag1="1"} 1

Use case:

Routing metrics

[danielnelson]

I think this is a bug in the prometheus_client output, we must be using some global state. I tested with the file output and did not have the same issue. I also tested with Telegraf 1.4.5 which has the same issue.

[2solt]

Thanks for the quick response, and fix!
Tested master, all good now