4.5. 访问registry的指标数据（metrics）

OpenShift Container Registry 为 Prometheus metrics 提供了一个端点。Prometheus是一个独立的开源系统监视和警报工具包。

metrics 可以通过registry端点的/extensions/v2/metrics路径获得。

流程

您可以通过两种方式访问指标数据：运行指标数据查询或使用集群角色。

指标数据查询

  1. 运行指标查询，例如： 

    $ curl --insecure -s -u <user>:<secret> \ 1
    https://image-registry.openshift-image-registry.svc:5000/extensions/v2/metrics | grep imageregistry | head -n 20

    输出示例

    # HELP imageregistry_build_info A metric with a constant '1' value labeled by major, minor, git commit & git version from which the image registry was built.
# TYPE imageregistry_build_info gauge
imageregistry_build_info{gitCommit="9f72191",gitVersion="v3.11.0+9f72191-135-dirty",major="3",minor="11+"} 1
# HELP imageregistry_digest_cache_requests_total Total number of requests without scope to the digest cache.
# TYPE imageregistry_digest_cache_requests_total counter
imageregistry_digest_cache_requests_total{type="Hit"} 5
imageregistry_digest_cache_requests_total{type="Miss"} 24
# HELP imageregistry_digest_cache_scoped_requests_total Total number of scoped requests to the digest cache.
# TYPE imageregistry_digest_cache_scoped_requests_total counter
imageregistry_digest_cache_scoped_requests_total{type="Hit"} 33
imageregistry_digest_cache_scoped_requests_total{type="Miss"} 44
# HELP imageregistry_http_in_flight_requests A gauge of requests currently being served by the registry.
# TYPE imageregistry_http_in_flight_requests gauge
imageregistry_http_in_flight_requests 1
# HELP imageregistry_http_request_duration_seconds A histogram of latencies for requests to the registry.
# TYPE imageregistry_http_request_duration_seconds summary
imageregistry_http_request_duration_seconds{method="get",quantile="0.5"} 0.01296087
imageregistry_http_request_duration_seconds{method="get",quantile="0.9"} 0.014847248
imageregistry_http_request_duration_seconds{method="get",quantile="0.99"} 0.015981195
imageregistry_http_request_duration_seconds_sum{method="get"} 12.260727916000022

    1
    <user>可以是任意的，但<secret>必须与registry配置中指定的值匹配。

集群角色

  1. 如果还没有一个访问指标的集群角色，创建一个集群角色： 

    $ cat <<EOF | oc create -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: prometheus-scraper
rules:
- apiGroups:
  - image.openshift.io
  resources:
  - registry/metrics
  verbs:
  - get
EOF

  2. 将此角色添加到用户，运行以下命令： 

    $ oc adm policy add-cluster-role-to-user prometheus-scraper <username>

  3. 使用集群角色访问指标数据。配置文件中与指标数据相关的部分应如下所示： 

    openshift:
  version: 1.0
  metrics:
    enabled: true
...