（注意：儘管我已經回答了幾個自己的問題，但在這篇文章的底部我仍然有一個未回答的問題。）
當我從 bash 命令列運行以下命令時，它起作用了。
ssh -t -v [email protected] sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
ssh 詳細輸出為：
OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 192.168.29.205 [192.168.29.205] port 22.
debug1: Connection established.
debug1: identity file /home/my-rails-project/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.29.205:22 as 'my-rails-project'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:EnDsn2kFQgiA56e4B2UuvDr3ajTLlN7/15lxLItnjUQ
debug1: Host '192.168.29.205' is known and matches the ECDSA host key.
debug1: Found key in /home/my-rails-project/.ssh/known_hosts:1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/my-rails-project/.ssh/id_rsa
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.29.205 ([192.168.29.205]:22).
debug1: channel 0: new [client-session]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype [email protected] want_reply 0
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending command: sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
bash 腳本中有完全相同的行，我得到
OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 192.168.29.205 [192.168.29.205] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.29.205:22 as 'my-rails-project'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:EnDsn2kFQgiA56e4B2UuvDr3ajTLlN7/15lxLItnjUQ
debug1: Host '192.168.29.205' is known and matches the ECDSA host key.
debug1: Found key in /root/.ssh/known_hosts:1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Trying private key: /root/.ssh/id_ecdsa
debug1: Trying private key: /root/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).
兩個輸出在該行處分歧（腳本）
debug1: Found key in /root/.ssh/known_hosts:1
（命令列）
debug1: Found key in /home/my-rails-project/.ssh/known_hosts:1
我不知道這種分歧是否顯示了問題所在。
所以我的問題是：
為什麼 ssh 在從腳本運行時查看 /root/.ssh/known_hosts 而在從命令列運行時查看 /home/my-rails-project/.ssh/known_hosts ？
回答上面我自己的問題：
好吧，當我寫這篇文章時，分歧的答案變得清晰起來：我正在運行腳本
sudo myScript
所以我的進一步問題是：如何告訴 ssh 使用 /home/my-rails-project/.ssh/known_hosts 作為known_hosts？
立即回答我自己的問題
一些研究讓我找到了答案https://stackoverflow.com/questions/10765946/ssh-use-known-hosts-other-than-home-ssh-known-hosts
所以現在我的命令列看起來像
ssh -o UserKnownHostsFile=/home/my-rails-project/.ssh/known_hosts -t -v [email protected] sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
當我前面沒有 sudo 時，上面的命令列再次起作用。當我在它前面使用 sudo 時它會失敗。詳細輸出是：
my-rails-project@my-rails-project:~$ sudo ssh -o UserKnownHostsFile=/home/my-rails-project/.ssh/known_hosts -t -v [email protected] sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
[sudo] password for my-rails-project:
OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 192.168.29.205 [192.168.29.205] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.29.205:22 as 'my-rails-project'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:EnDsn2kFQgiA56e4B2UuvDr3ajTLlN7/15lxLItnjUQ
debug1: Host '192.168.29.205' is known and matches the ECDSA host key.
debug1: Found key in /home/my-rails-project/.ssh/known_hosts:1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Trying private key: /root/.ssh/id_ecdsa
debug1: Trying private key: /root/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).
my-rails-project@my-rails-project:~$
並且 sudo 和非 sudo 詳細輸出在詳細列表末尾附近出現分歧
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug1: Trying private key: /root/.ssh/id_ecdsa
debug1: Trying private key: /root/.ssh/id_ed25519
debug1: No more authentication methods to try.
Permission denied (publickey).
my-rails-project@my-rails-project:~$
問題：
如何告訴 ssh 使用 /home/my-rails-project/.ssh 而不是 /root/.ssh 作為我的私鑰，並且仍然在目標系統上使用 sudo？
回答上面我自己的問題：
看著http://manpages.ubuntu.com/manpages/trusty/man1/ssh.1.html
所以現在 ssh 命令列是（添加-我選項）
ssh -o UserKnownHostsFile=/home/my-rails-project/.ssh/known_hosts -i /home/my-rails-project/.ssh/id_rsa -t -v [email protected] sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
然後我就成功了，除了某些東西（ssh？）要求輸入密碼。現在的輸出如下圖所示：
my-rails-project@my-rails-project:~$ sudo ssh -o UserKnownHostsFile=/home/my-rails-project/.ssh/known_hosts -i /home/my-rails-project/.ssh/id_rsa -t -v [email protected] sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
OpenSSH_7.2p2 Ubuntu-4ubuntu2.4, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 192.168.29.205 [192.168.29.205] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /home/my-rails-project/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /home/my-rails-project/.ssh/id_rsa-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.29.205:22 as 'my-rails-project'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:EnDsn2kFQgiA56e4B2UuvDr3ajTLlN7/15lxLItnjUQ
debug1: Host '192.168.29.205' is known and matches the ECDSA host key.
debug1: Found key in /home/my-rails-project/.ssh/known_hosts:1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/my-rails-project/.ssh/id_rsa
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
Enter passphrase for key '/home/my-rails-project/.ssh/id_rsa':
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.29.205 ([192.168.29.205]:22).
debug1: channel 0: new [client-session]
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype [email protected] want_reply 0
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending command: sudo /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
問題：
我收到以下提示：
Enter passphrase for key '/home/my-rails-project/.ssh/id_rsa':
如何抑制此密碼請求？
我已經透過在我的兩台機器（Ralph07 和 Ralph12）上修改 /etc/sudoers.d/ralph 來抑制大部分密碼請求
# This script should only be run on Ralph07
my-rails-project ALL=(ALL:ALL) NOPASSWD: /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12
# This script should only be run on Ralph12
my-rails-project ALL=(ALL:ALL) NOPASSWD: /home/my-rails-project/x/pg_rsync_ralph07_to_ralph12_finish
答案1
由於您的 ssh 金鑰是使用密碼建立的，因此會顯示「輸入金鑰的密碼」提示。
您可以使用以下命令從 ssh 密鑰中刪除密碼：
ssh-keygen -p -N '' -f ~/my-rails-project/.ssh/id_rsa
或者您可以建立一個沒有密碼的新金鑰：
ssh-keygen -q -t rsa -b 4096 -N '' -C '' -f ~/my-rails-project/.ssh/id_rsa
您也可以查看sshpass可用於為 ssh 命令提供密碼的工具，但不建議使用，因為它會帶來一些安全性問題。