如果使用原生kube-prometheus 安装的 kube-prometheus 只会监控 default kube-system monitoring（kube-prometheus 自己创建的ns）三个命名空间，而如果想要添加其他的命名空间，就需要定制化kube-prometheus

定制步骤

自动化脚本如下

# 所有操作均使用root账户
#安装golang并设置环境变量
dnf install -y git
curl -O https://dl.google.com/go/go1.15.2.linux-amd64.tar.gz
tar -xf go1.15.2.linux-amd64.tar.gz
mv go /usr/local
echo >> "export PATH=$PATH:/usr/local/go/bin" ~/.bashrc
echo >> "export PATH=$PATH:/root/go/bin" ~/.bashrc
echo >> "export GOPATH=/root/go" ~/.bashrc
echo >> "export GO111MODULE="on"" ~/.bashrc  
source ~/.bashrc
# 安装jsonnet 和 jb 工具 定制化 kube-prometheus 需要用到
#安装json-bundle
go get github.com/jsonnet-bundler/jsonnet-bundler/cmd/jb
#安装jsonnet
go get github.com/google/go-jsonnet/cmd/jsonnet
#clone kube-prometheus
git clone https://github.com/prometheus-operator/kube-prometheus.git
mkdir my-kube-prometheus
# 把clone下来的代码复制衣服，因为客户化的代码，不会生成CRD，但是会白manifests下的文件都删掉
cp -r kube-prometheus/* my-kube-prometheus
cd my-kube-prometheus
# 安装必要的jsonnet依赖库
jb install github.com/prometheus-operator/kube-prometheus/jsonnet/kube-prometheus
jb update
cat add-namespace.yaml << EOF
local kp = (import 'kube-prometheus/kube-prometheus.libsonnet') + {
  _config+:: {
    namespace: 'monitoring',

    prometheus+:: {
      namespaces+: ['default', 'kube-system','monitoring','rook-ceph'],
    },
  },
};

{ ['00namespace-' + name]: kp.kubePrometheus[name] for name in std.objectFields(kp.kubePrometheus) } +
{ ['0prometheus-operator-' + name]: kp.prometheusOperator[name] for name in std.objectFields(kp.prometheusOperator) } +
{ ['node-exporter-' + name]: kp.nodeExporter[name] for name in std.objectFields(kp.nodeExporter) } +
{ ['kube-state-metrics-' + name]: kp.kubeStateMetrics[name] for name in std.objectFields(kp.kubeStateMetrics) } +
{ ['alertmanager-' + name]: kp.alertmanager[name] for name in std.objectFields(kp.alertmanager) } +
{ ['prometheus-' + name]: kp.prometheus[name] for name in std.objectFields(kp.prometheus) } +
{ ['grafana-' + name]: kp.grafana[name] for name in std.objectFields(kp.grafana) }
EOF

如果要除了添加对应的namespace 还要添加对应点 servicemonitor，参看这里

生成客户化的kube-prometheus

./build.sh add-namespace.yaml
然后就可以看到

[root@k8smaster my-kube-prometheus]# ./build.sh add-namespace.jsonnet 
+ set -o pipefail
++ pwd
+ PATH=/root/my-kube-prometheus/tmp/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/go/bin:/usr/local/go/bin:/usr/local/go/bin:/usr/local/go/bin:/root/go/bin
+ rm -rf manifests
+ mkdir -p manifests/setup
+ jsonnet -J vendor -m manifests add-namespace.jsonnet
+ xargs '-I{}' sh -c 'cat {} | gojsontoyaml > {}.yaml' -- '{}'
+ find manifests -type f '!' -name '*.yaml' -delete
+ rm -f kustomization

最后通过对比，发现生成出来的文件，只有

• prometheus-roleSpecificNamespaces.yaml
• prometheus-roleBindingSpecificNamespaces.yaml 发生了变化

变化内容如下
prometheus-roleBindingSpecificNamespaces.yaml

- apiVersion: rbac.authorization.k8s.io/v1
  kind: RoleBinding
  metadata:
    name: prometheus-k8s
    namespace: default
  roleRef:
    apiGroup: rbac.authorization.k8s.io
    kind: Role
    name: prometheus-k8s
  subjects:
  - kind: ServiceAccount
    name: prometheus-k8s
    namespace: monitoring
- apiVersion: rbac.authorization.k8s.io/v1
  kind: RoleBinding
  metadata:
    name: prometheus-k8s
    namespace: kube-system
  roleRef:
    apiGroup: rbac.authorization.k8s.io
    kind: Role
    name: prometheus-k8s
  subjects:
  - kind: ServiceAccount
    name: prometheus-k8s
    namespace: monitoring
- apiVersion: rbac.authorization.k8s.io/v1
  kind: RoleBinding
  metadata:
    name: prometheus-k8s
    namespace: monitoring
  roleRef:
    apiGroup: rbac.authorization.k8s.io
    kind: Role
    name: prometheus-k8s
  subjects:
  - kind: ServiceAccount
    name: prometheus-k8s
    namespace: monitoring
- apiVersion: rbac.authorization.k8s.io/v1
  kind: RoleBinding
  metadata:
    name: prometheus-k8s
    namespace: rook-ceph
  roleRef:
    apiGroup: rbac.authorization.k8s.io
    kind: Role
    name: prometheus-k8s
  subjects:
  - kind: ServiceAccount
    name: prometheus-k8s
    namespace: monitoring

prometheus-roleSpecificNamespaces.yaml

- apiVersion: rbac.authorization.k8s.io/v1
  kind: Role
  metadata:
    name: prometheus-k8s
    namespace: default
  rules:
  - apiGroups:
    - ""
    resources:
    - services
    - endpoints
    - pods
    verbs:
    - get
    - list
    - watch
  - apiGroups:
    - extensions
    resources:
    - ingresses
    verbs:
    - get
    - list
    - watch
- apiVersion: rbac.authorization.k8s.io/v1
  kind: Role
  metadata:
    name: prometheus-k8s
    namespace: kube-system
  rules:
  - apiGroups:
    - ""
    resources:
    - services
    - endpoints
    - pods
    verbs:
    - get
    - list
    - watch
  - apiGroups:
    - extensions
    resources:
    - ingresses
    verbs:
    - get
    - list
    - watch
- apiVersion: rbac.authorization.k8s.io/v1
  kind: Role
  metadata:
    name: prometheus-k8s
    namespace: monitoring
  rules:
  - apiGroups:
    - ""
    resources:
    - services
    - endpoints
    - pods
    verbs:
    - get
    - list
    - watch
  - apiGroups:
    - extensions
    resources:
    - ingresses
    verbs:
    - get
    - list
    - watch
- apiVersion: rbac.authorization.k8s.io/v1
  kind: Role
  metadata:
    name: prometheus-k8s
    namespace: rook-ceph
  rules:
  - apiGroups:
    - ""
    resources:
    - services
    - endpoints
    - pods
    verbs:
    - get
    - list
    - watch
  - apiGroups:
    - extensions
    resources:
    - ingresses
    verbs:
    - get
    - list
    - watch