ubuntu - 为什么这个 bash 脚本在控制台工作但在作为 cron 作业运行时失败？

Question

我有以下 bash 脚本，它在 CLI 中运行没有问题，但在作为 cron 作业运行时失败。

#!/bin/bash

cd /home/oompah/scripts/tests/
scp -P 12345 file1 oompah@someserver.com:~/uploads

if scp -P 12345 oompah@someserver.com:/path/to/file2.dat local.dat >&/dev/null ; then 
    echo "INFO: transfer OK" ; 
else 
    echo "ERROR: transfer failed" ; 
fi

当我将它作为 cron 作业运行时，我收到的错误消息(重定向到日志文件)是:

ERROR: transfer failed

我在收件箱中收到的错误消息是:

Permission denied (publickey).
lost connection

第一个 scp(复制)也失败了(虽然我没有检查它)。有谁知道为什么会这样，我该如何解决？

顺便说一句:我在 Ubuntu 10.0.4 LTS 上运行它

[编辑]

我向 scp 添加了 -i 选项(脚本中的第一个命令)，还添加了调试(使用 v 选项)。这是完整的调试跟踪:

Executing: program /usr/bin/ssh host 12.34.56.78, user oompah, command scp -v -t ~/uploads
OpenSSH_5.3p1 Debian-3ubuntu6, OpenSSL 0.9.8k 25 Mar 2009
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 12.34.56.78 [12.34.56.78] port 12345.
debug1: Connection established.
debug1: identity file /home/oompah/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3p1 Debian-3ubuntu3
debug1: match: OpenSSH_5.3p1 Debian-3ubuntu3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.3p1 Debian-3ubuntu6
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host '[12.34.56.78]:12345' is known and matches the RSA host key.
debug1: Found key in /home/oompah/.ssh/known_hosts:3
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /home/oompah/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
debug1: read_passphrase: can't open /dev/tty: No such device or address
debug1: No more authentication methods to try.
Permission denied (publickey).
lost connection
Permission denied (publickey).

希望这能提供更多线索

Answer 1

您可能正在使用 ssh-agent 运行或者已经专门授权了您的私钥。当您在 cron 中运行时，您没有 session ，并且您没有任何与 session 相关的东西，例如 ssh-agent 或 ttys从中读取密码。

创建无密码 key 并将公钥添加到~target/.ssh/authorized_keys 下的目标帐户。然后，您将能够使用刚刚通过 scp 创建的 key 来验证和复制文件。

仅供引用:您可能需要阅读有关命令 key 的 ssh 服务器手册页以及 key 访问和身份验证的工作原理。