Kubernetes promtail sidecar:如何从父pod元数据中获取标签

Question

我有一些kubernetes应用程序，它们记录到文件而不是stdout/stderr，我用Promtail sidecars收集它们。但是由于侧车执行"；localhost"；target，我没有一个kubernetes_sd_config来为我的标签应用pod元数据。所以我只能静态地声明我的标签。

# ConfigMap
apiVersion: v1
kind: ConfigMap
metadata:
labels:
app: promtail
name: sidecar-promtail
data:
config.yml: |
client:
url: http://loki.loki.svc.cluster.local:3100/loki/api/v1/push
backoff_config:
max_period: 5m
max_retries: 10
min_period: 500ms
batchsize: 1048576
batchwait: 1s
external_labels: {}
timeout: 10s
positions:
filename: /tmp/promtail-positions.yaml
server:
http_listen_port: 3101
target_config:
sync_period: 10s
scrape_configs:
- job_name: sidecar-logs
static_configs:
- targets:
- localhost
labels:
job: sidecar-logs
__path__: "/sidecar-logs/*.log"
----
# Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
name: test-logger
spec:
selector:
matchLabels:
run: test-logger
template:
metadata:
labels:
run: test-logger
spec:
volumes:
- name: nfs
persistentVolumeClaim:
claimName: nfs-claim
- name: promtail-config
configMap:
name: sidecar-promtail
containers:
- name: sidecar-promtail
image: grafana/promtail:2.1.0
volumeMounts:
- name: nfs
mountPath: /sidecar-logs
- mountPath: /etc/promtail
name: promtail-config
- name: simple-logger         
image: foo/simple-logger
volumeMounts:
- name: nfs
mountPath: /logs

根据父pod的元数据标记收集的日志的最佳方式是什么？

Answer 1

您可以执行以下操作：

在sidecar容器中，将pod名称、节点名称和其他需要的信息作为环境变量公开，然后在promtail配置文件中添加标志'-config.expand-env'以启用环境扩展，例如：

...
- name: sidecar-promtail
image: grafana/promtail:2.1.0
# image: grafana/promtail:2.4.1 # use this one if environment expansion is not available in 2.1.0
args:
# Enable environment expansion in promtail config file
- '-config.expand-env'
env:
- name: NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
...

然后在configMap中，在static_config标签中添加环境变量，如下所示：

...
scrape_configs:
- job_name: sidecar-logs
static_configs:
- targets:
- localhost
labels:
job: sidecar-logs
pod: ${POD_NAME}
node_name: ${NODE_NAME}
__path__: "/sidecar-logs/*.log"
...