Hadoop集羣配置ssh免密碼登入

一、準備工作

1. 用客戶端工具（ssh client或者putty）連接到linux服務器。在root用戶下輸入命令
   vi /etc/hosts,用vi編輯hosts文件，如下：

#127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4

#::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

192.168.1.160 hadoop01

192.168.1.161 hadoop02

192.168.1.162 hadoop03

192.168.1.163 hadoop04

192.168.1.164 hadoop05

2. 輸入命令：

cd .ssh

進入rsa公鑰私鑰文件存放的目錄，刪除目錄下的id_rsa，id_rsa.pub文件。

二、在每臺機上產生新的rsa公鑰私鑰文件，並統一拷貝到一個authorized_keys文件中

1. 登錄hadoop01，在.ssh目錄下輸入命令：

ssh-keygen -t rsa

，三次回車後，該目錄下將會產生id_rsa，id_rsa.pub文件。其他主機也使用該方式產生密鑰文件。

2. 登錄hadoop01，輸入命令：

cat id_rsa.pub >> authorized_keys

,將id_rsa.pub公鑰內容拷貝到authorized_keys文件中。

3. 登錄其他主機，將其他主機的公鑰文件內容都拷貝到hadoop01主機上的authorized_keys文件中，命令如下：

 ssh-copy-id -i hadoop01 #登錄hadoop02,將公鑰拷貝到hadoop01的authorized_keys中
    
    ssh-copy-id -i hadoop01#登錄hadoop03,將公鑰拷貝到hadoop01的authorized_keys中
    
    ssh-copy-id -i hadoop01#登錄hadoop04,將公鑰拷貝到hadoop01的authorized_keys中
    
    ssh-copy-id -i hadoop01 #登錄hadoop05,將公鑰拷貝到hadoop01的authorized_keys中，最終authorized_keys文件內容如下：

  [root@hadoop01 .ssh]# more authorized_keys
    
    ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAp7jp4a1/deK4B/eZW8kdiCQvzpKe4Id0uP0DdONFW85r
    
    20rpH4ZpNSB7JNYFiqjMUPQ/2EWLXh7xoa9UntKsMVVcZr3BTiXRZ0Gx7IDacwz8Cq0qYrwUCMTKt7QF
    
    xK5RwXyuZqDFjc2yC3/ZoqeyeLERFTll3ZLGeFsXhJjlkPTvtnvx0zX6lacPZL4VguoM5YHw3KaJg8bd
    
    qehJzbQoPS8sm00ES4iygbR+Ixz1cnGTrtNU1S3lh4/y0PC6spMs9Z2Mf097FTLQJXJDiGqU9Tq3MHvl
    
    srZFx92H4yeiJuYWJaZImuiq/feRIo30Dig6obEfuAn13vevdXozcXNlYQ== root@hadoop03
    
    ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAwpEgmBzfGw1mrKy3Ho8k/h4jrZlRdIzuLs6PKqDPV/Cw
    
    2kjSYXV7tyGklUYWPWr1Dt6kw5+Ojr7zv+cFnFWKzTTAJz3V4md0RyQ11Kb+IJA7b88SRHcVLlNF2GDX
    
    N2pVqh9lf6Zu6zfpnAjCg/mU8qzTrZfFZdzPtBppimMq+l0bolvgnxEEkpFTNkpHB8+cD732WL+KiW52
    
    7nt0LGBbVbZz9mUa+0bsPGK7ySfk1SPUkGyNXXqVjEydyjvRY8bob7Q3mFX3MpDT696R8n7U7hQ7u4b8
    
    gbe3rIuQcWwGseEQrGjIDhLb9am3dbgDuFeg73RJqFZMOp2y6zQF3jQIew== root@hadoop02
    
    ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAmc2M6Bzw1cPaDwjbtgynJPWRKv9pDnHjBSn5BDbIX0po
    
    8GHHGr1pvYMGu4XWlIa76O44+bmF32K/9ECzBcNVL6a+aN5HWdUPpE6zagFUcaewXu2p4+FCZWpoTZbj
    
    zHKGeay35Id+mpltZUWZlR5lOX+G/veNzuZNpKXnVYoZdAaJ3XlH6IVhKlGOuZkXxvD7e+YD4oxZw+4o
    
    iaav/QtAhZHXWcAt2eVj9xw+j/3Ip5ImmIWHv5/AOFrgiY6c6U+2g5xOGONINbh9CxQ1L4HbQVAx8hYC
    
    stWUm0LfFAcMwXDwb8RAFj+cH+D/xG6CrORLb4UfroJHa6N64rx/5dmz7w== root@hadoop04
    
    ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAxAsHr8Jp4vXI7bPGmSsO/+bT43GsxQ4GKdGf8qLPsFY+
    
    /KluWl0TrRLwBVHGc94gpN2JOqtvKYYDSHw4Fj6KPSk/6Nt8CutZAwASoVxzexTFMOSwNFpTMsLc7Oza
    
    Q3XG6v6PgtBEJqdUdl4zIFAZnkZjKmZp8SWG1jGo/vl3jsbrnmFQFeH04MdVcm9r1wvl80bdF9YvYEtg
    
    ymHO4/tANKWSNKGw2EcthNWyQiN4hIYOoBQaUA3FlAXyqcD2+Q+2frf0gNF5KfKKLXmmlAuS9Oi6JqFJ
    
    f1BLmMquI4n02owzU0zlkj3Px5IcCfQbDQ/JedHcjxEKP2S+9m3yxG4h2Q== root@hadoop05
    
    ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAyS1PbXTgFqHcGV/k0QUZni5xB5+q71qx4r5xto+WLkVQ
    
    MiS3gR/VYZoyDLrQRVf5t0JiliCgHeU0MG/ASd1LPbsVYCX5V9cmcm1hMByDKJ6FwIxz5cY4y1dBpwAZ
    
    2E24CQWfZuevaeIFnL80RGGLhRgCxbLb3aPvRZuV34utD+5kgAFJwYCQYN4KnFG1S5e4X6U5J3FsCDby
    
    GD7dhtWWktMV2SAnWjrmULguaVRqO0sDIEiVSc9+KKqAmlOab+5SbZAI5+3hzJog5c3i4f5fHXWnxYqy
    
    LNo3yYSWraV5KcYIlNPqX6iJKvjLWbNDwD3+70u4nWjBSXXufhff71LdHw== root@hadoop01

三、授權authorized_keys文件

1. 登錄hadoop01,在.ssh目錄下輸入命令：

      chmod 600 authorized_keys
   

效果如下：

  [root@hadoop01 .ssh]# ls -al
        total 28
        drwx------.  2 root root 4096 Oct 24 12:27 .
        
        dr-xr-x---. 22 root root 4096 Oct 24 19:20 ..
        
        -rw-------.  1 root root 1975 Oct 24 12:27 authorized_keys
        
        -rw-------.  1 root root 1975 Oct 24 12:09 authorized_keys_20141024
        
        -rw-------.  1 root root 1675 Oct 24 12:23 id_rsa
        
        -rw-r--r--.  1 root root  395 Oct 24 12:23 id_rsa.pub
        
        -rw-r--r--.  1 root root 2020 Oct 24 12:10 known_hosts

四、將授權文件分配到其他主機上

1. 登錄hadoop01,將授權文件拷貝到hadoop02、hadoop03…,命令如下：

    scp /root/.ssh/authorized_keys hadoop02:/root/.ssh/ #拷貝到hadoop02上
    scp /root/.ssh/authorized_keys hadoop03:/root/.ssh/ #拷貝到hadoop03上
    scp /root/.ssh/authorized_keys hadoop04:/root/.ssh/ #拷貝到hadoop04上
    scp /root/.ssh/authorized_keys hadoop05:/root/.ssh/ #拷貝到hadoop05上
   

2. 至此，免密碼登錄已經設定完成，注意第一次ssh登錄時需要輸入密碼，再次訪問時即可免密碼登錄。

原文鏈接：https://www.cnblogs.com/ivan0626/p/4144277.html