feat: allow running otel log collector and fluent bit side by side

deploy/docs/opentelemetry_collector.md

@@ -67,7 +67,7 @@ fluent-bit:
   enabled: false
 ```
 
-> **NOTE** Fluent Bit must be disabled for OpenTelemetry Collector to be enabled, they are mutually exclusive.
+> **NOTE** Normally, Fluent Bit must be disabled for OpenTelemetry Collector to be enabled. This restriction can be lifted, see [here](#running-otelcol-and-fluent-bit-side-by-side).
 
 For metadata enrichment, it can be enabled by setting:
 
@@ -145,6 +145,28 @@ sumologic:
         - docker.service
 ```
 
+### Running otelcol and Fluent Bit side by side
+
+Normally, enabling both Otelcol and Fluent-Bit for log collection will fail with an error. The reason for this is that doing so naively results
+in each log line being delivered twice to Sumo Logic, incurring twice the cost without any benefit. However, there are reasons to do this; for example
+it makes for a smoother and less risky migration. Advanced users may also want to pin the different collectors to different Node groups.
+
+Because of this, we've included a way to allow running otelcol and Fluent Bit side by side. The minimal configuration enabling this is:
+
+```yaml
+sumologic:
+  logs:
+    collector:
+      otelcol:
+        enabled: true
+      allowSideBySide: true
+  
+fluent-bit:
+  enabled: true
+```
+
+> **WARNING** This will cause each log line to be ingested twice, with all the associated costs.
+
 ## Persistence
 
 The persistence for OpenTelemetry Collector can be configured in [`values.yaml`][values] by making changes under the `metadata.persistence`:

deploy/helm/sumologic/templates/_helpers.tpl

@@ -1384,7 +1384,8 @@ Example Usage:
 {{- if kindIs "invalid" $fluentBitEnabled -}}
 {{- $fluentBitEnabled = true -}}
 {{- end -}}
-{{- if and $enabled $fluentBitEnabled -}}
+{{- $sideBySideAllowed := .Values.sumologic.logs.collector.allowSideBySide -}}
+{{- if and $enabled $fluentBitEnabled (not $sideBySideAllowed) -}}
 {{- fail "Fluent-Bit and Otel log collector can't be enabled at the same time. Set either `fluent-bit.enabled` or `sumologic.logs.collector.otelcol.enabled` to false" -}}
 {{- end -}}
 {{ $enabled }}

deploy/helm/sumologic/values.yaml

@@ -222,6 +222,10 @@ sumologic:
       otelcol:
         enabled: false
 
+      ## Allow running otel and Fluent-Bit side by side. This will result in duplicated
+      ## logs being ingested. Only enabled this if you're **certain** it's what you want.
+      allowSideBySide: false
+
     multiline:
       enabled: true
       first_line_regex: "^\\[?\\d{4}-\\d{1,2}-\\d{1,2}.\\d{2}:\\d{2}:\\d{2}"

tests/integration/values/values_helm_otelcol_logs.yaml

@@ -3,14 +3,16 @@ sumologic:
     metadata:
       provider: otelcol
     collector:
-      enabled: true
+      otelcol:
+        enabled: true
+      allowSideBySide: true
 
   metrics:
     enabled: false
 
 # We're using otelcol instead
 fluent-bit:
-  enabled: false
+  enabled: true
 
 fluentd:
   events: