otel-agent: simplify Deployment mode to reuse otel-collector

When openTelemetry.agent.kind=Deployment, skip the otel-agent DaemonSet
and point OTEL_EXPORTER_OTLP_ENDPOINT directly at the existing
otel-collector Deployment (http://otel-collector:4317), which already has
the OTLP gRPC receiver enabled.

Removes the unnecessary otel-agent Deployment + ClusterIP Service that
were added in the previous commit.

https://claude.ai/code/session_01K2AnXLduzruntPtUsC7xiA

Author: claude

charts/sourcegraph/README.md

@@ -203,7 +203,7 @@ In addition to the documented values, all services also support the following va
 | openTelemetry.agent.containerSecurityContext.runAsGroup | int | `101` |  |
 | openTelemetry.agent.containerSecurityContext.runAsUser | int | `100` |  |
 | openTelemetry.agent.hostPorts | object | `{"grpcOtlp":4317,"httpOtlp":4318,"httpZpages":55679}` | Resource requests & limits for the `otel-agent` container, learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/) |
-| openTelemetry.agent.kind | string | `"DaemonSet"` | The workload kind for the otel-agent. Valid values are `DaemonSet` and `Deployment`. Use `Deployment` in environments where DaemonSets are restricted (e.g. some managed Kubernetes offerings). When set to `Deployment`, a ClusterIP Service is created for the agent and application pods send traces directly to that Service instead of using the node's host IP. |
+| openTelemetry.agent.kind | string | `"DaemonSet"` | The workload kind for the otel-agent. Valid values are `DaemonSet` and `Deployment`. Use `Deployment` in environments where DaemonSets are restricted (e.g. some managed Kubernetes offerings). When set to `Deployment`, the otel-agent DaemonSet is not created and application pods send traces directly to the existing otel-collector Deployment (otel-collector:4317) instead. |
 | openTelemetry.agent.name | string | `"otel-agent"` | Name used by resources. Does not affect service names or PVCs. |
 | openTelemetry.agent.resources.limits.cpu | string | `"500m"` |  |
 | openTelemetry.agent.resources.limits.memory | string | `"500Mi"` |  |

charts/sourcegraph/templates/_helpers.tpl

@@ -171,7 +171,7 @@ app.kubernetes.io/name: jaeger
 {{- if .Values.openTelemetry.enabled -}}
 {{- if eq (.Values.openTelemetry.agent.kind | default "DaemonSet") "Deployment" -}}
 - name: OTEL_EXPORTER_OTLP_ENDPOINT
-  value: http://otel-agent:4317
+  value: http://otel-collector:4317
 {{- else -}}
 # OTEL_AGENT_HOST must be defined before OTEL_EXPORTER_OTLP_ENDPOINT to substitute the node IP on which the DaemonSet pod instance runs in the latter variable
 - name: OTEL_AGENT_HOST

charts/sourcegraph/templates/otel-collector/otel-agent.Deployment.yaml

@@ -24,45 +24,7 @@ tests:
     asserts:
       - hasDocuments:
           count: 0
-  - it: should render a Deployment when kind is Deployment
-    template: otel-collector/otel-agent.Deployment.yaml
-    set:
-      openTelemetry:
-        agent:
-          kind: "Deployment"
-    asserts:
-      - isKind:
-          of: Deployment
-  - it: should not render a Deployment by default
-    template: otel-collector/otel-agent.Deployment.yaml
-    asserts:
-      - hasDocuments:
-          count: 0
-  - it: should render a Service when kind is Deployment
-    template: otel-collector/otel-agent.Service.yaml
-    set:
-      openTelemetry:
-        agent:
-          kind: "Deployment"
-    asserts:
-      - isKind:
-          of: Service
-      - equal:
-          path: metadata.name
-          value: otel-agent
-      - contains:
-          path: spec.ports
-          content:
-            name: grpc-otlp
-            port: 4317
-            protocol: TCP
-            targetPort: grpc-otlp
-  - it: should not render a Service by default (DaemonSet mode)
-    template: otel-collector/otel-agent.Service.yaml
-    asserts:
-      - hasDocuments:
-          count: 0
-  - it: should set OTEL_EXPORTER_OTLP_ENDPOINT to otel-agent service when kind is Deployment
+  - it: should set OTEL_EXPORTER_OTLP_ENDPOINT to otel-collector when kind is Deployment
     template: searcher/searcher.StatefulSet.yaml
     set:
       openTelemetry:
@@ -73,40 +35,8 @@ tests:
           path: spec.template.spec.containers[0].env
           content:
             name: OTEL_EXPORTER_OTLP_ENDPOINT
-            value: "http://otel-agent:4317"
+            value: "http://otel-collector:4317"
       - notContains:
           path: spec.template.spec.containers[0].env
           content:
             name: OTEL_AGENT_HOST
-  - it: should set default replica count of 1 for Deployment kind
-    template: otel-collector/otel-agent.Deployment.yaml
-    set:
-      openTelemetry:
-        agent:
-          kind: "Deployment"
-    asserts:
-      - equal:
-          path: spec.replicas
-          value: 1
-  - it: should allow configuring replicas for Deployment kind
-    template: otel-collector/otel-agent.Deployment.yaml
-    set:
-      openTelemetry:
-        agent:
-          kind: "Deployment"
-          replicas: 3
-    asserts:
-      - equal:
-          path: spec.replicas
-          value: 3
-  - it: should not have hostPorts in Deployment mode
-    template: otel-collector/otel-agent.Deployment.yaml
-    set:
-      openTelemetry:
-        agent:
-          kind: "Deployment"
-    asserts:
-      - notContains:
-          path: spec.template.spec.containers[0].ports
-          content:
-            hostPort: 4317

charts/sourcegraph/templates/otel-collector/otel-agent.Service.yaml

@@ -660,8 +660,8 @@ openTelemetry:
     name: "otel-agent"
     # -- The workload kind for the otel-agent. Valid values are `DaemonSet` and `Deployment`.
     # Use `Deployment` in environments where DaemonSets are restricted (e.g. some managed Kubernetes offerings).
-    # When set to `Deployment`, a ClusterIP Service is created for the agent and application pods send
-    # traces directly to that Service instead of using the node's host IP.
+    # When set to `Deployment`, the otel-agent DaemonSet is not created and application pods send
+    # traces directly to the existing otel-collector Deployment (otel-collector:4317) instead.
     kind: "DaemonSet"
     # -- Resource requests & limits for the `otel-agent` container,
     # learn more from the [Kubernetes documentation](https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/)