refactor: deprecate clickhouse.json feature gate in favor of per-exporter json config

Replace the deprecated --feature-gates=clickhouse.json CLI flag with the
per-exporter json: true config option, as recommended by the upstream
OpenTelemetry ClickHouse exporter (v0.149.0).

The old OTEL_AGENT_FEATURE_GATE_ARG env var is still supported for other
feature gates. When it contains clickhouse.json, the entrypoint strips
that specific gate, maps it to HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE=true,
and prints a deprecation warning. Any remaining feature gates are preserved
and passed through to the collector binary as before.

Changes:
- Add HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE env var as the new canonical config
- Add json field to ClickHouse exporter configs in opampController.ts
- Add json field to standalone config (config.standalone.yaml)
- Strip clickhouse.json from OTEL_AGENT_FEATURE_GATE_ARG with deprecation
  warning, preserving other feature gates

Ref: HDX-3994

Author: wrn14897

docker/otel-collector/config.standalone.yaml

@@ -33,6 +33,7 @@ exporters:
     logs_table_name: hyperdx_sessions
     timeout: 5s
     create_schema: ${env:HYPERDX_OTEL_EXPORTER_CREATE_LEGACY_SCHEMA:-false}
+    json: ${env:HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE:-false}
     retry_on_failure:
       enabled: true
       initial_interval: 5s
@@ -46,6 +47,7 @@ exporters:
     ttl: 720h
     timeout: 5s
     create_schema: ${env:HYPERDX_OTEL_EXPORTER_CREATE_LEGACY_SCHEMA:-false}
+    json: ${env:HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE:-false}
     retry_on_failure:
       enabled: true
       initial_interval: 5s

docker/otel-collector/entrypoint.sh

@@ -1,8 +1,26 @@
 #!/bin/sh
 set -e
 
-# Fall back to legacy schema when the ClickHouse JSON feature gate is enabled
+# DEPRECATED: The clickhouse.json feature gate has been removed upstream.
+# When OTEL_AGENT_FEATURE_GATE_ARG contains clickhouse.json, strip it and
+# map it to HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE instead. Other feature gates
+# are preserved and passed through to the collector.
 if echo "$OTEL_AGENT_FEATURE_GATE_ARG" | grep -q "clickhouse.json"; then
+  echo "WARNING: '--feature-gates=clickhouse.json' is deprecated and no longer supported by the collector."
+  echo "WARNING: Use HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE=true instead. This flag will be removed in a future release."
+  export HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE=true
+
+  # Strip clickhouse.json from the feature gates, keeping any other gates
+  REMAINING_GATES=$(echo "$OTEL_AGENT_FEATURE_GATE_ARG" | sed 's/--feature-gates=//' | tr ',' '\n' | grep -v 'clickhouse.json' | tr '\n' ',' | sed 's/,$//')
+  if [ -n "$REMAINING_GATES" ]; then
+    export OTEL_AGENT_FEATURE_GATE_ARG="--feature-gates=$REMAINING_GATES"
+  else
+    unset OTEL_AGENT_FEATURE_GATE_ARG
+  fi
+fi
+
+# Fall back to legacy schema when ClickHouse JSON exporter mode is enabled
+if [ "$HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE" = "true" ]; then
   export HYPERDX_OTEL_EXPORTER_CREATE_LEGACY_SCHEMA=true
 fi
 
@@ -39,7 +57,7 @@ if [ -z "$OPAMP_SERVER_URL" ]; then
     COLLECTOR_ARGS="$COLLECTOR_ARGS --config $CUSTOM_OTELCOL_CONFIG_FILE"
   fi
 
-  # Pass feature gates to the collector in standalone mode
+  # Pass remaining feature gates to the collector in standalone mode
   if [ -n "$OTEL_AGENT_FEATURE_GATE_ARG" ]; then
     COLLECTOR_ARGS="$COLLECTOR_ARGS $OTEL_AGENT_FEATURE_GATE_ARG"
   fi

docker/otel-collector/supervisor_docker.yaml.tmpl

@@ -23,8 +23,8 @@ agent:
 {{- if getenv "CUSTOM_OTELCOL_CONFIG_FILE" }}
     - {{ getenv "CUSTOM_OTELCOL_CONFIG_FILE" }}
 {{- end }}
-  args:
 {{- if getenv "OTEL_AGENT_FEATURE_GATE_ARG" }}
+  args:
     - {{ getenv "OTEL_AGENT_FEATURE_GATE_ARG" }}
 {{- end }}
 

packages/api/src/opamp/controllers/opampController.ts

@@ -82,6 +82,7 @@ type CollectorConfig = {
       logs_table_name: string;
       timeout: string;
       create_schema: string;
+      json: string;
       retry_on_failure: {
         enabled: boolean;
         initial_interval: string;
@@ -97,6 +98,7 @@ type CollectorConfig = {
       ttl: string;
       timeout: string;
       create_schema: string;
+      json: string;
       retry_on_failure: {
         enabled: boolean;
         initial_interval: string;
@@ -205,6 +207,7 @@ export const buildOtelCollectorConfig = (
         timeout: '5s',
         create_schema:
           '${env:HYPERDX_OTEL_EXPORTER_CREATE_LEGACY_SCHEMA:-false}',
+        json: '${env:HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE:-false}',
         retry_on_failure: {
           enabled: true,
           initial_interval: '5s',
@@ -221,6 +224,7 @@ export const buildOtelCollectorConfig = (
         timeout: '5s',
         create_schema:
           '${env:HYPERDX_OTEL_EXPORTER_CREATE_LEGACY_SCHEMA:-false}',
+        json: '${env:HYPERDX_OTEL_EXPORTER_CLICKHOUSE_JSON_ENABLE:-false}',
         retry_on_failure: {
           enabled: true,
           initial_interval: '5s',