Proxy Access Logs
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Envoy Gateway provides observability for the ControlPlane and the underlying EnvoyProxy instances. This task show you how to config proxy access logs.
Prerequisites
Follow the steps from the Quickstart to install Envoy Gateway and the example manifest. Before proceeding, you should be able to query the example backend using HTTP.
Envoy Gateway provides an add-ons Helm Chart, which includes all the needing components for observability. By default, the OpenTelemetry Collector is disabled.
Install the add-ons Helm Chart:
helm install eg-addons oci://docker.io/envoyproxy/gateway-addons-helm --version v1.1.1 --set opentelemetry-collector.enabled=true -n monitoring --create-namespace
By default, the Service type of loki is ClusterIP, you can change it to LoadBalancer type for further usage:
kubectl patch service loki -n monitoring -p '{"spec": {"type": "LoadBalancer"}}'
Expose endpoints:
LOKI_IP=$(kubectl get svc loki -n monitoring -o jsonpath='{.status.loadBalancer.ingress[0].ip}')
Default Access Log
If custom format string is not specified, Envoy Gateway uses the following default format:
{
"start_time": "%START_TIME%",
"method": "%REQ(:METHOD)%",
"x-envoy-origin-path": "%REQ(X-ENVOY-ORIGINAL-PATH?:PATH)%",
"protocol": "%PROTOCOL%",
"response_code": "%RESPONSE_CODE%",
"response_flags": "%RESPONSE_FLAGS%",
"response_code_details": "%RESPONSE_CODE_DETAILS%",
"connection_termination_details": "%CONNECTION_TERMINATION_DETAILS%",
"upstream_transport_failure_reason": "%UPSTREAM_TRANSPORT_FAILURE_REASON%",
"bytes_received": "%BYTES_RECEIVED%",
"bytes_sent": "%BYTES_SENT%",
"duration": "%DURATION%",
"x-envoy-upstream-service-time": "%RESP(X-ENVOY-UPSTREAM-SERVICE-TIME)%",
"x-forwarded-for": "%REQ(X-FORWARDED-FOR)%",
"user-agent": "%REQ(USER-AGENT)%",
"x-request-id": "%REQ(X-REQUEST-ID)%",
":authority": "%REQ(:AUTHORITY)%",
"upstream_host": "%UPSTREAM_HOST%",
"upstream_cluster": "%UPSTREAM_CLUSTER%",
"upstream_local_address": "%UPSTREAM_LOCAL_ADDRESS%",
"downstream_local_address": "%DOWNSTREAM_LOCAL_ADDRESS%",
"downstream_remote_address": "%DOWNSTREAM_REMOTE_ADDRESS%",
"requested_server_name": "%REQUESTED_SERVER_NAME%",
"route_name": "%ROUTE_NAME%"
}
Note: Envoy Gateway disable envoy headers by default, you can enable it by setting
EnableEnvoyHeaderstotruein the ClientTrafficPolicy CRD.
Verify logs from loki:
curl -s "http://$LOKI_IP:3100/loki/api/v1/query_range" --data-urlencode "query={job=\"fluentbit\"}" | jq '.data.result[0].values'
Disable Access Log
If you want to disable it, set the telemetry.accesslog.disable to true in the EnvoyProxy CRD.
kubectl apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: eg
spec:
controllerName: gateway.envoyproxy.io/gatewayclass-controller
parametersRef:
group: gateway.envoyproxy.io
kind: EnvoyProxy
name: disable-accesslog
namespace: envoy-gateway-system
---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
name: disable-accesslog
namespace: envoy-gateway-system
spec:
telemetry:
accessLog:
disable: true
EOF
OpenTelemetry Sink
Envoy Gateway can send logs to OpenTelemetry Sink.
kubectl apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: eg
spec:
controllerName: gateway.envoyproxy.io/gatewayclass-controller
parametersRef:
group: gateway.envoyproxy.io
kind: EnvoyProxy
name: otel-access-logging
namespace: envoy-gateway-system
---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
name: otel-access-logging
namespace: envoy-gateway-system
spec:
telemetry:
accessLog:
settings:
- format:
type: Text
text: |
[%START_TIME%] "%REQ(:METHOD)% %REQ(X-ENVOY-ORIGINAL-PATH?:PATH)% %PROTOCOL%" %RESPONSE_CODE% %RESPONSE_FLAGS% %BYTES_RECEIVED% %BYTES_SENT% %DURATION% "%REQ(X-FORWARDED-FOR)%" "%REQ(USER-AGENT)%" "%REQ(X-REQUEST-ID)%" "%REQ(:AUTHORITY)%" "%UPSTREAM_HOST%"
sinks:
- type: OpenTelemetry
openTelemetry:
host: otel-collector.monitoring.svc.cluster.local
port: 4317
resources:
k8s.cluster.name: "cluster-1"
EOF
Verify logs from loki:
curl -s "http://$LOKI_IP:3100/loki/api/v1/query_range" --data-urlencode "query={exporter=\"OTLP\"}" | jq '.data.result[0].values'
gGRPC Access Log Service(ALS) Sink
Envoy Gateway can send logs to a backend implemented gRPC access log service proto. There’s an example service here, which simply count the log and export to prometheus endpoint.
kubectl apply -f https://raw.githubusercontent.com/envoyproxy/gateway/main/examples/kubernetes/envoy-als.yaml -n monitoring
The following configuration sends logs to the gRPC access log service:
kubectl apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: eg
spec:
controllerName: gateway.envoyproxy.io/gatewayclass-controller
parametersRef:
group: gateway.envoyproxy.io
kind: EnvoyProxy
name: als
namespace: envoy-gateway-system
---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
name: als
namespace: envoy-gateway-system
spec:
telemetry:
accessLog:
settings:
- sinks:
- type: ALS
als:
backendRefs:
- name: envoy-als
namespace: monitoring
port: 8080
type: HTTP
EOF
Verify logs from envoy-als:
curl -s "http://$(kubectl get svc envoy-als -n monitoring -o jsonpath='{.status.loadBalancer.ingress[0].ip}'):19001/metrics" | grep log_count
CEL Expressions
Envoy Gateway provides CEL expressions to filter access log .
For example, you can use the expression 'x-envoy-logged' in request.headers to filter logs that contain the x-envoy-logged header.
kubectl apply -f - <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: eg
spec:
controllerName: gateway.envoyproxy.io/gatewayclass-controller
parametersRef:
group: gateway.envoyproxy.io
kind: EnvoyProxy
name: otel-access-logging
namespace: envoy-gateway-system
---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: EnvoyProxy
metadata:
name: otel-access-logging
namespace: envoy-gateway-system
spec:
telemetry:
accessLog:
settings:
- format:
type: Text
text: |
[%START_TIME%] "%REQ(:METHOD)% %REQ(X-ENVOY-ORIGINAL-PATH?:PATH)% %PROTOCOL%" %RESPONSE_CODE% %RESPONSE_FLAGS% %BYTES_RECEIVED% %BYTES_SENT% %DURATION% "%REQ(X-FORWARDED-FOR)%" "%REQ(USER-AGENT)%" "%REQ(X-REQUEST-ID)%" "%REQ(:AUTHORITY)%" "%UPSTREAM_HOST%"
matches:
- "'x-envoy-logged' in request.headers"
sinks:
- type: OpenTelemetry
openTelemetry:
host: otel-collector.monitoring.svc.cluster.local
port: 4317
resources:
k8s.cluster.name: "cluster-1"
EOF
Verify logs from loki:
curl -s "http://$LOKI_IP:3100/loki/api/v1/query_range" --data-urlencode "query={exporter=\"OTLP\"}" | jq '.data.result[0].values'
Additional Metadata
Envoy Gateway provides additional metadata about the K8s resources that were translated to certain envoy resources.
For example, details about the HTTPRoute and GRPCRoute (kind, group, name, namespace and annotations) are available
for access log formatter using the METADATA operator. To enrich logs, users can add log operator such as:
%METADATA(ROUTE:envoy-gateway:resources)% to their access log format.
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