71 lines
3.1 KiB
Markdown
71 lines
3.1 KiB
Markdown
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---
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title: "Securing Datanodes"
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date: "2019-April-03"
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weight: 2
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summary: Explains different modes of securing data nodes. These range from kerberos to auto approval.
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icon: th
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---
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<!---
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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Datanodes under Hadoop is traditionally secured by creating a Keytab file on
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the data nodes. With Ozone, we have moved away to using data node
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certificates. That is, Kerberos on data nodes is not needed in case of a
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secure Ozone cluster.
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However, we support the legacy Kerberos based Authentication to make it easy
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for the current set of users.The HDFS configuration keys are the following
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that is setup in hdfs-site.xml.
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Property|Example Value|Comment
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--------|--------------|--------------
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dfs.datanode.keytab.file| /keytab/dn.service.keytab| Keytab file.
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dfs.datanode.kerberos.principal| dn/_HOST@REALM.TLD| principal name.
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## How a data node becomes secure.
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Under Ozone, when a data node boots up and discovers SCM's address, the first
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thing that data node does is to create a private key and send a certificate
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request to the SCM.
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<h3>Certificate Approval via Kerberos <span class="badge badge-secondary">Current Model</span></h3>
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SCM has a built-in CA, and SCM has to approve this request. If the data node
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already has a Kerberos key tab, then SCM will trust Kerberos credentials and
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issue a certificate automatically.
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<h3>Manual Approval <span class="badge badge-primary">In Progress</span></h3>
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If these are band new data nodes and Kerberos key tabs are not present at the
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data nodes, then this request for the data nodes identity certificate is
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queued up for approval from the administrator(This is work in progress,
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not committed in Ozone yet). In other words, the web of trust is established
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by the administrator of the cluster.
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<h3>Automatic Approval <span class="badge badge-secondary">In Progress</span></h3>
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If you running under an container orchestrator like Kubernetes, we rely on
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Kubernetes to create a one-time token that will be given to data node during
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boot time to prove the identity of the data node container (This is also work
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in progress.)
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Once a certificate is issued, a Data node is secure and Ozone manager can
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issue block tokens. If there is no data node certificates or the SCM's root
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certificate is not present in the data node, then data node will register
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itself and down load the SCM's root certificate as well get the certificates
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for itself.
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