[chart/grafana-agent][BUG]

[anwarchk]

Describe the bug

Using the latest chart causes the deployment to fail with the following error:

2022-04-18 19:08:22.868271 I | error loading config file /etc/agent/agent.yml: yaml: line 13: did not find expected alphabetic or numeric character

To Reproduce Steps to reproduce the behavior:

1. Follow the README and try to install the chart to a K8s cluster using Helm

Expected behavior The DaemonSet is deployed and working

Additional context

Helm generated ConfigMap where the error is originating from:

apiVersion: v1
metadata:
  name: grafana-agent
data:
  agent.yml: |
    server:
      log_level: info
    prometheus:
      global:
        scrape_interval: 15s
      wal_directory: /var/lib/agent/data
      configs:
        - name: agent
          remote_write:
            - url: http://<REDACTED>:8080/api/v1/push
              basic_auth:
                  password: <REDACTED>
                  username: *
              headers:
                X-Scope-OrgID: fake
          scrape_configs:
            - job_name: local_scrape
              static_configs:
                - targets: ['127.0.0.1:12345']
                  labels:
                    cluster: 'docker_compose'
                    container: 'agent'
                    pod: 'grafana-agent-local'

    tempo:
      configs:
        - name: default
          receivers:
            jaeger:
              protocols:
                thrift_http:
          attributes:
            actions:
            - action: upsert
              key: env
              value: prod
          remote_write:
            - endpoint: tempo:55680
              insecure: true
          batch:
            timeout: 5s
            send_batch_size: 100
          automatic_logging:
            backend: loki
            loki_name: default
            spans: true
            processes: true
            roots: true

    loki:
      positions_directory: /tmp/loki-positions
      configs:
      - name: default
        clients:
          - url: http://localhost:3100/loki/api/v1/push
        scrape_configs:
        - job_name: system
          static_configs:
          - targets: ['localhost']
            labels:
              job: varlogs
              __path__: /var/log/*log

[anwarchk]

Turns out having the value of "*" instead of "" caused this issue (see https://github.com/helm/helm/issues/9917). Sorry for the trouble.