# Kubernetes使用

## 使用前提

已部署Kubernetes集群或[minikube](https://minikube.sigs.k8s.io/docs/start/)

具备访问Kubernetes集群的[kubectl](https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/)

## 采集Kubernetes容器日志

1\. 创建部署iLogtail的命名空间

将下面内容保存为ilogtail-ns.yaml

```yaml
apiVersion: v1
kind: Namespace
metadata:
  name: ilogtail
```

您也可以直接从下面的地址下载示例配置。

```bash
wget https://raw.githubusercontent.com/alibaba/ilogtail/main/example_config/start_with_k8s/ilogtail-ns.yaml
```

应用上述配置

```bash
kubectl apply -f ilogtail-ns.yaml
```

2\. 创建配置iLogtail的ConfigMap和Secret

将下面内容保存为ilogtail-user-configmap.yaml。该ConfigMap后续将作为配置目录挂载到iLogtail容器中，因此可包含多个采集配置。

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: ilogtail-user-cm
  namespace: ilogtail
data:
  nginx_stdout.yaml: |
    enable: true
    inputs:
      - Type: service_docker_stdout
        Stderr: false
        Stdout: true                # only collect stdout
        IncludeK8sLabel:
          app: nginx                # choose containers with this label
    processors:
      - Type: processor_regex       # structure log
        SourceKey: content
        Regex: '([\d\.:]+) - (\S+) \[(\S+) \S+\] \"(\S+) (\S+) ([^\\"]+)\" (\d+) (\d+) \"([^\\"]*)\" \"([^\\"]*)\" \"([^\\"]*)\"'
        Keys:
          - remote_addr
          - remote_user
          - time_local
          - method
          - url
          - protocol
          - status
          - body_bytes_sent
          - http_referer
          - http_user_agent
          - http_x_forwarded_for
    flushers:
      - Type: flusher_stdout
        OnlyStdout: true
```

将下面内容保存为ilogtail-secret.yaml。该Secret为可选，当需要将日志写入SLS时会用到。

```yaml
apiVersion: v1
kind: Secret
metadata:
  name: ilogtail-secret
  namespace: ilogtail
type: Opaque
data:
  access_key:     # base64 accesskey secret if you want to flush to SLS
  access_key_id:  # base64 accesskey id if you want to flush to SLS
```

您也可以直接从下面的地址下载示例配置。

```bash
wget https://raw.githubusercontent.com/alibaba/ilogtail/main/example_config/start_with_k8s/ilogtail-user-configmap.yaml
wget https://raw.githubusercontent.com/alibaba/ilogtail/main/example_config/start_with_k8s/ilogtail-secret.yaml
```

应用上述配置

```bash
kubectl apply -f ilogtail-user-configmap.yaml
kubectl apply -f ilogtail-secret.yaml
```

3\. 创建iLogtail DaemonSet

将下面内容保存为ilogtail-daemonset.yaml。

```yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: ilogtail-ds
  namespace: ilogtail
  labels:
    k8s-app: logtail-ds
spec:
  selector:
    matchLabels:
      k8s-app: logtail-ds
  template:
    metadata:
      labels:
        k8s-app: logtail-ds
    spec:
      tolerations:
        - operator: Exists                    # deploy on all nodes
      containers:
        - name: logtail
          env:
            - name: ALIYUN_LOG_ENV_TAGS       # add log tags from env
              value: _node_name_|_node_ip_
            - name: _node_name_
              valueFrom:
                fieldRef:
                  apiVersion: v1
                  fieldPath: spec.nodeName
            - name: _node_ip_
              valueFrom:
                fieldRef:
                  apiVersion: v1
                  fieldPath: status.hostIP
            - name: cpu_usage_limit           # iLogtail's self monitor cpu limit
              value: "1"
            - name: mem_usage_limit           # iLogtail's self monitor mem limit
              value: "512"
            - name: default_access_key_id     # accesskey id if you want to flush to SLS
              valueFrom:
                secretKeyRef:
                  name: ilogtail-secret
                  key: access_key_id
                  optional: true
            - name: default_access_key        # accesskey secret if you want to flush to SLS
              valueFrom:
                secretKeyRef:
                  name: ilogtail-secret
                  key: access_key
                  optional: true
          image: >-
            sls-opensource-registry.cn-shanghai.cr.aliyuncs.com/ilogtail-community-edition/ilogtail:latest
          imagePullPolicy: IfNotPresent
          resources:
            limits:
              cpu: 1000m
              memory: 1Gi
            requests:
              cpu: 400m
              memory: 384Mi
          volumeMounts:
            - mountPath: /var/run                       # for container runtime socket
              name: run
            - mountPath: /logtail_host                  # for log access on the node
              mountPropagation: HostToContainer
              name: root
              readOnly: true
            - mountPath: /usr/local/ilogtail/checkpoint # for checkpoint between container restart
              name: checkpoint
            - mountPath: /usr/local/ilogtail/user_yaml_config.d # mount config dir
              name: user-config
              readOnly: true
      dnsPolicy: ClusterFirstWithHostNet
      hostNetwork: true
      volumes:
        - hostPath:
            path: /var/run
            type: Directory
          name: run
        - hostPath:
            path: /
            type: Directory
          name: root
        - hostPath:
            path: /etc/ilogtail-ilogtail-ds/checkpoint
            type: DirectoryOrCreate
          name: checkpoint
        - configMap:
            defaultMode: 420
            name: ilogtail-user-cm
          name: user-config
```

您也可以直接从下面的地址下载示例配置。

```bash
wget https://raw.githubusercontent.com/alibaba/ilogtail/main/example_config/start_with_k8s/ilogtail-daemonset.yaml
```

添加参数示例

```
        - name: logtail
          command:
            - /usr/local/ilogtail/ilogtail_control.sh
          args:
            - "start_and_block"
            - "-dirfile_check_interval_ms=5000"
            - "-logtail_checkpoint_check_gc_interval_sec=120"
          env:
            - name: enable_containerd_upper_dir_detect
              value: "true"
```

应用上述配置

```bash
kubectl apply -f ilogtail-daemonset.yaml
```

4\. 部署用来测试的nginx

将下面内容保存为nginx-deployment.yaml。

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  namespace: default
  labels:
    app: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - image: 'nginx:latest'
          name: nginx
          ports:
            - containerPort: 80
              name: http
              protocol: TCP
          resources:
            requests:
              cpu: 100m
              memory: 100Mi
```

您也可以直接从下面的地址下载示例配置。

```bash
wget https://raw.githubusercontent.com/alibaba/ilogtail/main/example_config/start_with_k8s/nginx-deployment.yaml
```

应用上述配置

```bash
kubectl apply -f nginx-deployment.yaml
```

5\. 发送请求构造示例日志

```bash
kubectl exec nginx-<pod-id> -- curl localhost/hello/ilogtail
```

6\. 查看采集到的测试容器标准输出日志

```bash
kubectl logs ilogtail-ds-<pod-id> -n ilogtail
```

结果为

```json
2022-07-14 16:36:50 {"_time_":"2022-07-15T00:36:48.489153485+08:00","_source_":"stdout","_image_name_":"docker.io/library/nginx:latest","_container_name_":"nginx","_pod_name_":"nginx-76d49876c7-r892w","_namespace_":"default","_pod_uid_":"07f75a79-da69-40ac-ae2b-77a632929cc6","_container_ip_":"10.223.0.154","remote_addr":"::1","remote_user":"-","time_local":"14/Jul/2022:16:36:48","method":"GET","url":"/hello/ilogtail","protocol":"HTTP/1.1","status":"404","body_bytes_sent":"153","http_referer":"-","http_user_agent":"curl/7.74.0","http_x_forwarded_for":"-","__time__":"1657816609"}
```

## 采集模版

查看更多K8s采集日志模版（从容器中采集文件日等）： <https://github.com/alibaba/ilogtail/blob/main/k8s_templates>

了解采集配置结构： [采集配置](https://ilogtail.gitbook.io/ilogtail-docs/1.8.0/configuration/collection-config)

查看采集配置项： [数据流水线组件概览](https://ilogtail.gitbook.io/ilogtail-docs/1.8.0/data-pipeline/overview)

参考更多可组合的日志采集和处理配置样例： <https://github.com/alibaba/ilogtail/blob/main/example_config>