Kubernetes 上部署的 mongo 认证

Question

我尝试mongo在 kubernetes 集群上配置身份验证。我部署了以下内容yaml：

kind: StatefulSet
metadata:
  name: mongo
spec:
  serviceName: "mongo"
  replicas: 1
template:
  metadata:
    labels:
      app: mongo
  spec:
    containers:
    - name: mongodb
      image: mongo:4.0.0
      env:
      - name: MONGO_INITDB_ROOT_USERNAME
        value: "admin"
      - name: MONGO_INITDB_ROOT_PASSWORD
# Get password from secret
        value: "abc123changeme"
      command:
      - mongod
      - --auth
      - --replSet
      - rs0
      - --bind_ip
      - 0.0.0.0
      ports:
      - containerPort: 27017
        name: web
      volumeMounts:
      - name: mongo-ps
        mountPath: /data/db
    volumes:
    - name: mongo-ps
      persistentVolumeClaim:
        claimName: mongodb-pvc

当我尝试使用用户名“admin”和密码“abc123changeme”进行身份验证时，我收到了"Authentication failed.".

如何配置 mongo 管理员用户名和密码（我想从秘密中获取密码）？

谢谢

Answer 1

环境变量不起作用的原因是 MONGO_INITDB 环境变量被图像中的 docker-entrypoint.sh 脚本使用（https://github.com/docker-library/mongo/tree/master/4.0）但是当您在 kubernetes 文件中定义“命令：”时，您会覆盖该入口点（请参阅注释https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/）

请参阅下面的 YML，它改编自我在网上找到的一些示例。记下我的学习要点

1. cvallance/mongo-k8s-sidecar 查找与命名空间的 POD 标签 REGARDLESS 匹配的任何 mongo 实例，因此它会尝试连接集群中的任何旧实例。这让我头疼了几个小时，因为我从示例中删除了 environment= 标签，因为我们使用命名空间来隔离我们的环境......回想起来很愚蠢而且很明显......一开始非常混乱（mongo 日志正在抛出各种由于串扰导致的身份验证错误和服务关闭类型错误）

2. 我是 ClusterRoleBindings 的新手，我花了一段时间才意识到它们是集群级别，我知道这似乎很明显（尽管需要提供一个命名空间来让 kubectl 接受它）但是导致我的在每个命名空间之间被覆盖，所以请确保你为每个环境创建唯一的名称，以避免在一个命名空间中的部署弄乱另一个命名空间，因为 ClusterRoleBinding 如果它们在集群中不是 unqiue 就会被覆盖

3. MONGODB_DATABASE 需要设置为“admin”才能进行身份验证。

4. 我按照这个例子来配置依赖于 sleep5 的身份验证，希望守护进程在尝试创建 adminUser 之前启动并运行。我发现这还不够长，所以最初升级它，因为未能创建 adminUser 显然会导致连接被拒绝的问题。后来我更改了 sleep 以使用 while 循环和更万无一失的 mongo ping 来测试守护程序。

5. 如果您在无法访问系统中所有可用 RAM的容器（例如 lxc、cgroups、Docker 等）中运行 mongod ，则必须将 --wiredTigerCacheSizeGB 设置为小于可用 RAM 量的值容器。确切的数量取决于容器中运行的其他进程。

   6. Mongo 集群中至少需要 3 个节点！

下面的 YML 应该启动并在 kubernetes 中配置一个 mongo 副本集，并启用持久存储和身份验证。如果您连接到 pod...

kubectl exec -ti mongo-db-0 --namespace somenamespace /bin/bash

mongo shell 安装在映像中，因此您应该能够使用...

mongo mongodb://mongoadmin:adminpassword@mongo-db/admin?replicaSet=rs0

并看到您得到 rs0:PRIMARY> 或 rs0:SECONDARY，表明这两个 pod 位于 mongo 复制集中。使用 rs.conf() 从 PRIMARY 验证。

#Create a Secret to hold the MONGO_INITDB_ROOT_USERNAME/PASSWORD
#so we can enable authentication
apiVersion: v1
data:
     #echo -n "mongoadmin" | base64
    init.userid: bW9uZ29hZG1pbg==
    #echo -n "adminpassword" | base64
    init.password: YWRtaW5wYXNzd29yZA==
kind: Secret
metadata:
  name: mongo-init-credentials
  namespace: somenamespace
type: Opaque
---
# Create a secret to hold a keyfile used to authenticate between replicaset members
# this seems to need to be base64 encoded twice (might not be the case if this
# was an actual file reference as per the examples, but we're using a simple key
# here
apiVersion: v1
data:
  #echo -n "CHANGEMECHANGEMECHANGEME" | base64 | base64
  mongodb-keyfile: UTBoQlRrZEZUVVZEU0VGT1IwVk5SVU5JUVU1SFJVMUYK
kind: Secret
metadata:
  name: mongo-key
  namespace: somenamespace
type: Opaque
---
# Create a service account for Mongo and give it Pod List role
# note this is a ClusterROleBinding - the Mongo Pod will be able
# to list all pods present in the cluster regardless of namespace
# (and this is exactly what it does...see below)
apiVersion: v1
kind: ServiceAccount
metadata:
  name: mongo-serviceaccount
  namespace: somenamespace
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: mongo-somenamespace-serviceaccount-view
  namespace: somenamespace
subjects:
- kind: ServiceAccount
  name: mongo-serviceaccount
  namespace: somenamespace
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: pod-viewer
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: pod-viewer
  namespace: somenamespace
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["list"]
---
#Create a Storage Class for Google Container Engine
#Note fstype: xfs isn't supported by GCE yet and the
#Pod startup will hang if you try to specify it.
kind: StorageClass
apiVersion: storage.k8s.io/v1beta1
metadata:
  namespace: somenamespace
  name: mongodb-ssd-storage
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-ssd
allowVolumeExpansion: true
---
#Headless Service for StatefulSets
apiVersion: v1
kind: Service
metadata:
  namespace: somenamespace
  name: mongo-db
  labels:
    name: mongo-db
spec:
 ports:
 - port: 27017
   targetPort: 27017
 clusterIP: None
 selector:
   app: mongo
---
# Now the fun part
#
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
  namespace: somenamespace
  name: mongo-db
spec:
  serviceName: mongo-db
  replicas: 3
  template:
    metadata:
      labels:
        # Labels MUST match MONGO_SIDECAR_POD_LABELS
        # and MUST differentiate between other mongo
        # instances in the CLUSTER not just the namespace
        # as the sidecar will search the entire cluster
        # for something to configure
        app: mongo
        environment: somenamespace
    spec:
      #Run the Pod using the service account
      serviceAccountName: mongo-serviceaccount
      terminationGracePeriodSeconds: 10
      #Prevent a Mongo Replica running on the same node as another (avoid single point of failure)
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
              - key: app
                operator: In
                values:
                - mongo
            topologyKey: "kubernetes.io/hostname"
      containers:
        - name: mongo
          image: mongo:4.0.12
          command:
            #Authentication adapted from https://gist.github.com/thilinapiy/0c5abc2c0c28efe1bbe2165b0d8dc115
            #in order to pass the new admin user id and password in
          - /bin/sh
          - -c
          - >
            if [ -f /data/db/admin-user.lock ]; then
              echo "KUBERNETES LOG $HOSTNAME- Starting Mongo Daemon with runtime settings (clusterAuthMode)"
              #ensure wiredTigerCacheSize is set within the size of the containers memory limit
              mongod --wiredTigerCacheSizeGB 0.5 --replSet rs0 --bind_ip 0.0.0.0 --smallfiles --noprealloc --clusterAuthMode keyFile --keyFile /etc/secrets-volume/mongodb-keyfile --setParameter authenticationMechanisms=SCRAM-SHA-1;
            else
              echo "KUBERNETES LOG $HOSTNAME- Starting Mongo Daemon with setup setting (authMode)"
              mongod --auth;
            fi;
          lifecycle:
              postStart:
                exec:
                  command:
                  - /bin/sh
                  - -c
                  - >
                    if [ ! -f /data/db/admin-user.lock ]; then
                      echo "KUBERNETES LOG $HOSTNAME- no Admin-user.lock file found yet"
                      #replaced simple sleep, with ping and test.
                      while (! mongo --eval "db.adminCommand('ping')"); do sleep 10; echo "KUBERNETES LOG $HOSTNAME - waiting another 10 seconds for mongo to start" >> /data/db/configlog.txt; done;
                      touch /data/db/admin-user.lock
                      if [ "$HOSTNAME" = "mongo-db-0" ]; then
                        echo "KUBERNETES LOG $HOSTNAME- creating admin user ${MONGODB_USERNAME}"
                        mongo --eval "db = db.getSiblingDB('admin'); db.createUser({ user: '${MONGODB_USERNAME}', pwd: '${MONGODB_PASSWORD}', roles: [{ role: 'root', db: 'admin' }]});" >> /data/db/config.log
                      fi;
                      echo "KUBERNETES LOG $HOSTNAME-shutting mongod down for final restart"
                      mongod --shutdown;
                    fi;
          env:
            - name: MONGODB_USERNAME
              valueFrom:
                secretKeyRef:
                  name: mongo-init-credentials
                  key: init.userid
            - name: MONGODB_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mongo-init-credentials
                  key: init.password
          ports:
            - containerPort: 27017
          livenessProbe:
            exec:
              command:
              - mongo
              - --eval
              - "db.adminCommand('ping')"
            initialDelaySeconds: 5
            periodSeconds: 60
            timeoutSeconds: 10
          readinessProbe:
            exec:
              command:
              - mongo
              - --eval
              - "db.adminCommand('ping')"
            initialDelaySeconds: 5
            periodSeconds: 60
            timeoutSeconds: 10
          resources:
            requests:
              memory: "350Mi"
              cpu: 0.05
            limits:
              memory: "1Gi"
              cpu: 0.1
          volumeMounts:
            - name: mongo-key
              mountPath: "/etc/secrets-volume"
              readOnly: true
            - name: mongo-persistent-storage
              mountPath: /data/db
        - name: mongo-sidecar
          image: cvallance/mongo-k8s-sidecar
          env:
            # Sidecar searches for any POD in the CLUSTER with these labels
            # not just the namespace..so we need to ensure the POD is labelled
            # to differentiate it from other PODS in different namespaces
            - name: MONGO_SIDECAR_POD_LABELS
              value: "app=mongo,environment=somenamespace"
            - name: MONGODB_USERNAME
              valueFrom:
                secretKeyRef:
                  name: mongo-init-credentials
                  key: init.userid
            - name: MONGODB_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mongo-init-credentials
                  key: init.password
            #don't be fooled by this..it's not your DB that
            #needs specifying, it's the admin DB as that
            #is what you authenticate against with mongo.
            - name: MONGODB_DATABASE
              value: admin
      volumes:
      - name: mongo-key
        secret:
          defaultMode: 0400
          secretName: mongo-key
  volumeClaimTemplates:
  - metadata:
      name: mongo-persistent-storage
      annotations:
        volume.beta.kubernetes.io/storage-class: "mongodb-ssd-storage"
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

Answer 2

假设你创建了一个秘密：

apiVersion: v1
kind: Secret
metadata:
  name: mysecret
type: Opaque
data:
  username: YWRtaW4=
  password: MWYyZDFlMmU2N2Rm

下面是从 kubernetes yaml 文件中的秘密中获取值的片段：

 env:
      - name: MONGO_INITDB_ROOT_PASSWORD
        valueFrom:
          secretKeyRef:
            name: mysecret
            key: password