first path segment in URL cannot contain colon

[rdxmb]

Bug report

Relevant telegraf.conf:

[[outputs.influxdb]]
  urls = ["$INFLUXDB_HOST_FULL_ADDRESS"] # required
  ## The target database for metrics (telegraf will create it if not exists).
  database = "$INFLUXDB_DB"
  username = "$INFLUXDB_WRITE_USER"
  password = "$INFLUXDB_WRITE_USER_PASSWORD"

System info:

telegraf 1.5.2

Steps to reproduce:

1. define telegraf in docker with

services:
  telegraf-servicechecker:
    image: telegraf
    hostname: telegraf-servicechecker
    env_file: 
      - .monitoring-env

2. .monitoring-env is

INFLUXDB_HOST_FULL_ADDRESS="http://yoururl.com:8086"
INFLUXDB_DB=monitoring
INFLUXDB_WRITE_USER=writetoinflux
INFLUXDB_WRITE_USER_PASSWORD=veeeeerysecret

Expected behavior:

• works ;)

If not works, the error output should be something like:
"do not use double quotes ..."

Actual behavior:

E! Failed to connect to output influxdb, retrying in 15s, error was 'Error creating HTTP Client ["http://yoururl.com:8086"]: error parsing config.URL: parse "http://yoururl.com:8086": first path segment in URL cannot contain colon'

Aditional info

edit the line to
INFLUXDB_HOST_FULL_ADDRESS=http://yoururl.com:8086
fixes the problem

[danielnelson]

I feel like this is a quirk of docker-compose, when you set an environment variable in your shell script these outer quotes are not part of the variable:

$ export INFLUX_URL="http://localhost:8086"
$ env | grep INFLUX
INFLUX_URL=http://localhost:8086

I see in the docker-compose docs that they warn about this, I'm sure many others have ran into this:

There is no special handling of quotation marks. This means that they are part of the VAL.

I don't want to strip outer quotes automatically because I think it will cause more bugs and confusion.

[rdxmb]

I don't want to strip outer quotes automatically because I think it will cause more bugs and confusion.

Of course. Anyway: Is there a way to edit the error message? "do not use double quotes ..." is not that significant.

Anyway, the problem was really yaml-specific, as
key=value interprets all values as strings already.

[danielnelson]

It looks like this part of the error message, parse "http://yoururl.com:8086": first path segment in URL cannot contain colon', comes directly from the Go standard library. Unfortunately you can't easily see if the quotes are extra or not from a message like this, but we probably wouldn't want to get in the business of trying to special case the error.

We are free to switch up the prefix though: Error creating HTTP Client ["http://yoururl.com:8086"]: error parsing config.URL: , perhaps we can use a %q format for the url, so that it would appear like "\"http://yoururl.com:8086\"" if there are extra quotes. Do you think that would help?

[rdxmb]

Yes, absolutely! If it is possible, I would even prefer single quotes for the outer quotes. That would give the same output as running
declare
in a telegraf container.

environment-file in yaml:

INFLUXDB_HOST_FULL_ADDRESS_DOUBLE_QUOTES="http://yourdomain.com:8086"
INFLUXDB_HOST_FULL_ADDRESS_SINGLE_QUOTES='http://yourdomain.com:8086'
INFLUXDB_HOST_FULL_ADDRESS=http://yourdomain.com:8086

running declare in the container:

root@telegraf-servicechecker:/# declare | grep HOST_FULL
INFLUXDB_HOST_FULL_ADDRESS=http://yourdomain.com:8086
INFLUXDB_HOST_FULL_ADDRESS_DOUBLE_QUOTES='"http://yourdomain.com:8086"'
INFLUXDB_HOST_FULL_ADDRESS_SINGLE_QUOTES=''\''http://yourdomain.com:8086'\'''

(if there is a better tool like declare, that could be the reference though)