ServerA から ServerB へ ssh で自動バックアップを取る。

serverA でパスフレーズ無しの鍵を作成する。
<pre>$ ssh-keygen -t dsa -N “” -f ~/.ssh/backup_from_serverA_to_serverB
Generating public/private dsa key pair.
Your identification has been saved in
/home/userA/.ssh/backup_from_serverA_to_serverB.
Your public key has been saved in
/home/userA/.ssh/backup_from_serverA_to_serverB.pub.
The key fingerprint is:
xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx userA@serverA
The key’s randomart image is:
+–[ DSA 1024]—-+
  
+ . .
o o . .
+ .
S + .
. = o
*. ..
o++o .o
ooo++. E
+—————–+
</pre>
serverA から serverB へ公開鍵をコピーする。
<pre>$ scp ~/.ssh/backup_from_serverA_to_serverB.pub userB@serverB:~
</pre>
serverB で authorized_keys に公開鍵を追加する。
<pre>$ cat backup_from_serverA_to_serverB.pub » ~/.ssh/authorized_keys
</pre>
serverB で追加した公開鍵に制限を課す。パスフレーズなしのこの鍵では、特定の処理しかできないようにする。
<pre>$ vi ~/.ssh/authorized_keys
</pre>

<pre>from=”serverA”,command=”cat > /backup/serverA/proj_date +%Y%m%d_%H%M.tar”,no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty
ssh-dss xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
</pre>
serverA でバックアップスクリプトを cron で動作させる。
<pre>$ sudo vi /etc/cron.daily/backup
</pre>
<pre>#!/bin/sh

DATETIME=date +%Y%m%d_%H%M

echo “Archiving…“
tar zcf /tmp/proj_${DATETIME}.tgz /proj

echo “Sending the archive to serverB…“
cat /tmp/proj_${DATETIME}.tgz		 ssh -i ~/.ssh/backup_from_serverA_to_serverB serverB -l userB
</pre>