文档 | https://grafana.com/docs/alloy/latest/reference/components/discovery/
local.file_match | 文件匹配
https://grafana.com/docs/agent/latest/flow/reference/components/local.file_match/
loki.process | 修改日志
https://grafana.com/docs/agent/latest/flow/reference/components/loki.process/
discovery.file | 其用于发现抓取目标，与 Prometheus 相关
https://grafana.com/docs/agent/latest/flow/reference/components/discovery.file/
loki.write
https://grafana.com/docs/alloy/latest/reference/components/loki/loki.write/
discovery.relabel
https://grafana.com/docs/alloy/latest/reference/components/discovery/discovery.relabel/
添加标签：
...
rule {
replacement = "kubernetes-container"
target_label = "type"
}
...