Discovery: Docker & regexp not working as documented

[das-peter]

Description

According to https://docs.newrelic.com/docs/infrastructure/host-integrations/installation/container-auto-discovery-host-integrations/#define-discover it should be possible to use regular expressions for the discovery:

Properties values will be matched with an exact string, unless the value to match is set between /.../. The contents within the slashes will be matched as regular expressions.

And there's also code to handle that in the agent:

infrastructure-agent/pkg/databind/internal/discovery/fields.go

Line 40 in 35aa46d

if metaRegexp.MatchString(str) {

However, I couldn't get regular expressions to work with discovery.

Maybe related - I can't remember: #1753

Steps to Reproduce

The attached debug.zip provides a docker setup which can be used to reproduce the issue.

The docker-compose.yaml defines two redis services:

  redis:
    container_name: debug-newrelic-redis
    image: redis:latest
    ports:
      - "6379"

  redis2:
    container_name: debug-newrelic-redis2
    image: redis:latest
    ports:
      - "6379"

There are two infra configs for redis:

1. Exact matching

integration_name: com.newrelic.redis
discovery:
  docker:
    match:
      image: redis:latest

2. Regexp

integration_name: com.newrelic.redis
discovery:
  docker:
    match:
      image: /redis.*/

If I understand the regexp matching correctly both configs should find both redis services from the docker-compose.yaml.
But only the exact matching one works - the other config throws an error.

Success - Exact:

----------
Integration Name: nri-redis
Integration Output: {"name":"com.newrelic.redis","protocol_version":"3","integration_version":"1.11.8",.........}
----------
----------
Integration Name: nri-redis
Integration Output: {"name":"com.newrelic.redis","protocol_version":"3","integration_version":"1.11.8",.........}
----------
time="2024-10-16T12:46:51Z" level=info msg="Integration health check finished with success" component=integrations.runner.Runner integration_name=nri-redis role="${discovery.name}" runner_uid=ae8cd154af

Error - Regexp:

time="2024-10-16T12:46:05Z" level=error msg="can't start integration" component=integrations.runner.Runner error="value not found: discovery.ip" integration_name=nri-redis role="${discovery.name}" runner_uid=ae8cd154af

How to use provided docker env:

NEWRELIC_KEY=REDACTED docker compose up -d --build

docker exec -ti debug-newrelic-agent newrelic-infra -dry_run -integration_config_path /etc/newrelic-infra/integrations.d/redis-exact-config.yml

docker exec -ti debug-newrelic-agent newrelic-infra -dry_run -integration_config_path /etc/newrelic-infra/integrations.d/redis-regexp-config.yml

For Maintainers Only or Hero Triaging this bug

Suggested Priority (P1,P2,P3,P4,P5):
Suggested T-Shirt size (S, M, L, XL, Unknown):

[workato-integration]

https://new-relic.atlassian.net/browse/NR-328696