Error when using blackbox exporter

[Nicholas Reid]

Hi Everyone, 

I'm new to this group so please let me know if I break any etiquette. 

I'm wondering if anyone can help with the below issue I am facing. 

I am using docker compose to startup prometheus and the blackbox exporter. 

I am seeing errors from my prometheus and blackbox docker containers that indicate I have used an incorrect yml syntax but I'm not clear where I am going wrong here. 

If anyone have any idea where I might be going wrong I greatly appreciate your input. 

Thank you in advance.

Nick

The errors are as follows:

From the prometheus container 

level=error ts=2020-05-01T08:45:35.540Z caller=main.go:747 err="error loading config from \"/etc/prometheus/prometheus.yml\": couldn't load configuration                                                                                (--config.file=\"/etc/prometheus/prometheus.yml\"): parsing YAML file /etc/prometheus/prometheus.yml: yaml: unmarshal errors:\n  line 39: cannot unmarshal !!str `smtp_st...` into []string"

From the blackbox container

blackbox  | level=error ts=2020-05-01T08:45:49.658Z caller=main.go:216 msg="Error loading config" err="error parsing config file: yaml: line 3: mapping values are not allowed in this context"

My blackbox.yml is:

modules:

  smtp_starttls:

      prober: tcp

      timeout: 5s

      tcp:

        query_response:

          - expect: "^220 ([^ ]+) ESMTP (.+)$"

          - send: "EHLO prober"

          - expect: "^250-STARTTLS"

          - send: "STARTTLS"

          - expect: "^220"

          - starttls: true

          - send: "EHLO prober"

          - expect: "^250-AUTH"

          - send: "QUIT"

My prometheus.yml is: 

global:

  scrape_interval: 30s

  evaluation_interval: 30s

scrape_configs:

  - job_name: blackbox

    metrics_path: /probe

    params:

      module: smtp_starttls

    static_configs:

      - targets:

        - hostname:26

    relabel_configs:

      - source_labels: [__address__]

        target_label: __param_target

      - source_labels: [__param_target]

        target_label: instance

      - target_label: __address__

        replacement: blackbox:9115  # The blackbox exporter's real hostname:port.

[Brian Candler]

It seems you've trimmed these files, because the error in prometheus.yml is in line 39, but you haven't shown 39 lines.

For prometheus.yml, the problem is that each parameter needs to be a list:

params:

  module: [smtp_starttls]

For blackbox.yml, if I copy-paste your config it works for me, with blackbox_exporter 0.16.0.  (Your indention is unconventional, I'd remove 2 spaces from "prober:" onwards, but not illegal).  Either there's a problem with some sort of non-printing space, or the erroneous section has been trimmed.

[Nicholas Reid]

Hi Brian,

Thank you for your very helpful reply. 

I am very new to editing these sorts of config so I didn't realise realise the issues with copying text from webpages. 

After having typed out the blackbox.yml this is now working. 

Nick