OTel manager failed: failed to generate otel config: error translating config for output: ... source data must be an array or slice, got string #11352
Description
To reproduce in 9.2.1 use the following configuration and run the agent with the command:
ELASTIC_ENDPOINT="myESHost:9200" ./elastic-agent run -e --develop outputs:
default:
type: elasticsearch
hosts: ${ELASTIC_ENDPOINT}
api_key: "example-key"
preset: balanced
agent.monitoring:
enabled: true
metrics: true
logs: true
use_output: default
inputs:
- id: unique-system-metrics-id
type: system/metrics
streams:
- metricset: load
data_stream.dataset: system.cpuThe agent will become unhealthy with the following error:
message: |-
OTel manager failed: failed to generate otel config: error translating config for output: monitoring, unit: prometheus/metrics-monitoring, error: failed decoding config. decoding failed due to the following error(s):
'hosts' source data must be an array or slice, got stringLooking at how Filebeat (or Metricbeat) want the hosts format to be they want it to be a list: https://www.elastic.co/docs/reference/beats/filebeat/elasticsearch-output#hosts-option so at first glance this error seems correct:
output.elasticsearch:
hosts: ["https://myEShost:9200"]However Beats will happily start if you use a string instead, so we have become more strict than before. The following config will run for a standalone beat where as it fails with a 9.2.1 agent if it is used in the monitoring output.
filebeat.inputs:
- type: filestream
id: my-filestream-id
enabled: true
paths:
- /var/log/*.log
output.elasticsearch:
hosts: "myESHost:9200"The workaround is to fix the format of hosts to be a list the way it is expected to be. Since there is only one host the config change below will fix it immediately (hosts: ["${ELASTICSEARCH_HOST}"] also works):
outputs:
default:
hosts:
- ${ELASTICSEARCH_HOST}