Is it possible to have a sidecar with collector running in Deployment mode?

[himamulch]

Component(s)

collector

Describe the issue you're reporting

Hi, I have an otel collector running as a deployment in EKS pod, using opentelemetry-operator. I have a requirement to have another container in the same collector pod. Is it possible to have this multi-container setup with the operator setup?
The docs show an example of the collector running in sidecar mode which is the opposite of what I am looking for.
Could you please advise.
Thanks

[fyuan1316]

opentelemetry-operator/internal/manifests/collector/deployment.go

Lines 59 to 76 in ea97b6a

	Spec: corev1.PodSpec{
	ServiceAccountName: ServiceAccountName(params.OtelCol),
	InitContainers: params.OtelCol.Spec.InitContainers,
	Containers: append(params.OtelCol.Spec.AdditionalContainers, Container(params.Config, params.Log, params.OtelCol, true)),
	Volumes: Volumes(params.Config, params.OtelCol),
	DNSPolicy: manifestutils.GetDNSPolicy(params.OtelCol.Spec.HostNetwork, params.OtelCol.Spec.PodDNSConfig),
	DNSConfig: &params.OtelCol.Spec.PodDNSConfig,
	HostNetwork: params.OtelCol.Spec.HostNetwork,
	ShareProcessNamespace: &params.OtelCol.Spec.ShareProcessNamespace,
	Tolerations: params.OtelCol.Spec.Tolerations,
	NodeSelector: params.OtelCol.Spec.NodeSelector,
	SecurityContext: params.OtelCol.Spec.PodSecurityContext,
	PriorityClassName: params.OtelCol.Spec.PriorityClassName,
	Affinity: params.OtelCol.Spec.Affinity,
	TerminationGracePeriodSeconds: params.OtelCol.Spec.TerminationGracePeriodSeconds,
	TopologySpreadConstraints: params.OtelCol.Spec.TopologySpreadConstraints,
	},
	},

Hi @himamulch
As you can see from the code, the native opentelemetry-operator does not support adding sidecar containers to the collector pod in deployment mode.

Perhaps you need to implement your own sidecar injection mechanism using the MutatingAdmissionWebhook. This is similar to how a typical istio service mesh creates sidecar container.

[jaronoff97]

Right now we don't support the sidecar container definition, however, a user should be able to specify AdditionalContainers which run as a sidecar to the deployment pod.

[jaronoff97]

I'm going to close this issue, please let me know if you have any issues setting additional containers