我正在尝试通过 R 中的 SSH 隧道连接到 postgreSQL 数据库（托管在 AWS RDS 上）。到目前为止，我已经能够使用以下方法进行连接：
1.----------------------------
使用在我的终端（MacOs）中打开 ssh 隧道
ssh -i {key file path} -f -N -L 5432:{db host}:5432 {ssh user}@{ssh host} -v
然后使用连接到数据库
psql -hlocalhost -U{db user} -p5432 -dpostgres
2.----------------------------
在我的终端中打开 ssh 隧道，然后在 R 中运行以下代码进行连接
conn <- dbConnect(
RPostgres::Postgres(),
dbname = db_name,
user = db_user,
password = db_password,
host = "127.0.0.1",
port = db_port
)
3.----------------------------
这就是问题发生的地方。我可以通过在 R 中（在后台环境中）打开 ssh 隧道来连接
tunnel_process <- callr::r_bg(
function(ssh_host, ssh_user, ssh_key, db_host, db_port) {
session <- ssh::ssh_connect(host = glue::glue("{ ssh_user }@{ ssh_host }"),
keyfile = ssh_key,
verbose = 3)
ssh::ssh_tunnel(session = session,
port = db_port,
target = glue::glue("{ db_host }:{ db_port }"))
},
args = list(ssh_host, ssh_user, ssh_key, db_host, db_port),
stdout = nullfile(),
stderr = nullfile()
)
但后来我无法使用与上面相同的“dbConnect”代码进行连接。它只给我以下错误消息
Error: could not connect to server: Connection refused
Is the server running on host "127.0.0.1" and accepting
TCP/IP connections on port 5432?
但是，我可以使用第1部分中的连接代码直接从终端连接。但前提是我运行psql -hlocalhost -U{db user} -p5432 -dpostgres，然后在 R 中重新运行 ssh 隧道代码，然后才在终端中输入我的密码。我似乎每次尝试连接时都会关闭 SSH 隧道，因此我必须在提交密码之前重新启动它。
问题 - - - - - - - - - - - - - -
从我刚才详述的情况来看，似乎是：
一个。我的数据库是可访问的，因为我可以通过终端轻松连接
湾。我的 R 代码有效，因为我能够使用它成功打开 SSH 隧道并连接到数据库。由于某种原因，我无法同时使用两者。
C。每当我尝试连接到数据库时，我通过 R 打开的隧道都会中断。我直接在终端打开的隧道不是这种情况。
由于我希望能够直接从 R 完成所有操作，这里有人对可能导致问题的原因有任何想法吗？
编辑 - - - - - - - - - - - - - -
这是我尝试连接到数据库时在 R 中获得的日志，就在它关闭隧道之前：
> ssh::ssh_tunnel(session = session,
+ port = db_port,
+ target = glue::glue("{ db_host }:{ db_port }"))
\ Waiting for connetion on port 5432... client connected!
channel_open: Creating a channel 43 with 64000 window and 32768 max packet
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=124,padding=18,comp=105,payload=105]
channel_open: Sent a SSH_MSG_CHANNEL_OPEN type direct-tcpip for channel 43
ssh_packet_socket_callback: packet: read type 80 [len=492,padding=16,comp=475,payload=475]
ssh_packet_process: Dispatching handler for packet type 80
ssh_packet_global_request: Received SSH_MSG_GLOBAL_REQUEST packet
ssh_packet_global_request: UNKNOWN SSH_MSG_GLOBAL_REQUEST hostkeys-00@openssh.com 0
ssh_packet_process: Couldn't do anything with packet type 80
packet_send2: packet: wrote [len=12,padding=6,comp=5,payload=5]
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
ssh_packet_socket_callback: packet: read type 91 [len=28,padding=10,comp=17,payload=17]
ssh_packet_process: Dispatching handler for packet type 91
ssh_packet_channel_open_conf: Received SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 43:0
ssh_packet_channel_open_conf: Remote window : 2097152, maxpacket : 32768
| Tunneled -1 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=28,padding=10,comp=17,payload=17]
channel_write_common: channel_write wrote 8 bytes
| Tunneled 7 bytes...ssh_packet_socket_callback: packet: read type 94 [len=28,padding=17,comp=10,payload=10]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 1 bytes data in 0 (local win=64000 remote win=2097144)
channel_default_bufferize: placing 1 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=63999 remote win=2097144)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=28,padding=18,comp=9,payload=9]
grow_window: growing window (channel 43:0) to 1280000 bytes
ssh_channel_read_timeout: Read (1) buffered : 1 bytes. Window: 1280000
- Tunneled 8 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=316,padding=17,comp=298,payload=298]
channel_write_common: channel_write wrote 289 bytes
/ Tunneled 297 bytes...ssh_packet_socket_callback: packet: read type 94 [len=3964,padding=12,comp=3951,payload=3951]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 3942 bytes data in 0 (local win=1280000 remote win=2096855)
channel_default_bufferize: placing 3942 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1276058 remote win=2096855)
ssh_channel_read_timeout: Read (3942) buffered : 3942 bytes. Window: 1276058
\ Tunneled 4239 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=156,padding=8,comp=147,payload=147]
channel_write_common: channel_write wrote 138 bytes
- Tunneled 4377 bytes...ssh_packet_socket_callback: packet: read type 94 [len=76,padding=15,comp=60,payload=60]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 51 bytes data in 0 (local win=1276058 remote win=2096717)
channel_default_bufferize: placing 51 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1276007 remote win=2096717)
ssh_channel_read_timeout: Read (51) buffered : 51 bytes. Window: 1276007
| Tunneled 4428 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=140,padding=14,comp=125,payload=125]
channel_write_common: channel_write wrote 116 bytes
\ Tunneled 4544 bytes...ssh_packet_socket_callback: packet: read type 94 [len=60,padding=8,comp=51,payload=51]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 42 bytes data in 0 (local win=1276007 remote win=2096601)
channel_default_bufferize: placing 42 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1275965 remote win=2096601)
ssh_channel_read_timeout: Read (42) buffered : 42 bytes. Window: 1275965
/ Tunneled 4586 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=60,padding=19,comp=40,payload=40]
channel_write_common: channel_write wrote 31 bytes
- Tunneled 4617 bytes...packet_send2: packet: wrote [len=12,padding=6,comp=5,payload=5]
ssh_channel_send_eof: Sent a EOF on client channel (43:0)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=12,padding=6,comp=5,payload=5]
ssh_channel_close: Sent a close on client channel (43:0)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
tunnel closed!
作为参考，这是使用3中详述的解决方法时相同日志的样子。（ssh_tunnel在终端中提交我的密码之前重新运行正确）：
> ssh::ssh_tunnel(session = session,
+ port = db_port,
+ target = glue::glue("{ db_host }:{ db_port }"))
\ Waiting for connetion on port 5432... client connected!
channel_open: Creating a channel 43 with 64000 window and 32768 max packet
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=124,padding=18,comp=105,payload=105]
channel_open: Sent a SSH_MSG_CHANNEL_OPEN type direct-tcpip for channel 43
ssh_packet_socket_callback: packet: read type 80 [len=492,padding=16,comp=475,payload=475]
ssh_packet_process: Dispatching handler for packet type 80
ssh_packet_global_request: Received SSH_MSG_GLOBAL_REQUEST packet
ssh_packet_global_request: UNKNOWN SSH_MSG_GLOBAL_REQUEST hostkeys-00@openssh.com 0
ssh_packet_process: Couldn't do anything with packet type 80
packet_send2: packet: wrote [len=12,padding=6,comp=5,payload=5]
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
ssh_packet_socket_callback: packet: read type 91 [len=28,padding=10,comp=17,payload=17]
ssh_packet_process: Dispatching handler for packet type 91
ssh_packet_channel_open_conf: Received SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
ssh_packet_channel_open_conf: Received a CHANNEL_OPEN_CONFIRMATION for channel 43:0
ssh_packet_channel_open_conf: Remote window : 2097152, maxpacket : 32768
| Tunneled -1 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=28,padding=10,comp=17,payload=17]
channel_write_common: channel_write wrote 8 bytes
| Tunneled 7 bytes...ssh_packet_socket_callback: packet: read type 94 [len=28,padding=17,comp=10,payload=10]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 1 bytes data in 0 (local win=64000 remote win=2097144)
channel_default_bufferize: placing 1 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=63999 remote win=2097144)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=28,padding=18,comp=9,payload=9]
grow_window: growing window (channel 43:0) to 1280000 bytes
ssh_channel_read_timeout: Read (1) buffered : 1 bytes. Window: 1280000
- Tunneled 8 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=316,padding=17,comp=298,payload=298]
channel_write_common: channel_write wrote 289 bytes
\ Tunneled 297 bytes...ssh_packet_socket_callback: packet: read type 94 [len=3964,padding=12,comp=3951,payload=3951]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 3942 bytes data in 0 (local win=1280000 remote win=2096855)
channel_default_bufferize: placing 3942 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1276058 remote win=2096855)
ssh_channel_read_timeout: Read (3942) buffered : 3942 bytes. Window: 1276058
/ Tunneled 4239 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=156,padding=8,comp=147,payload=147]
channel_write_common: channel_write wrote 138 bytes
| Tunneled 4377 bytes...ssh_packet_socket_callback: packet: read type 94 [len=76,padding=15,comp=60,payload=60]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 51 bytes data in 0 (local win=1276058 remote win=2096717)
channel_default_bufferize: placing 51 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1276007 remote win=2096717)
ssh_channel_read_timeout: Read (51) buffered : 51 bytes. Window: 1276007
- Tunneled 4428 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=140,padding=14,comp=125,payload=125]
channel_write_common: channel_write wrote 116 bytes
/ Tunneled 4544 bytes...ssh_packet_socket_callback: packet: read type 94 [len=60,padding=8,comp=51,payload=51]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 42 bytes data in 0 (local win=1276007 remote win=2096601)
channel_default_bufferize: placing 42 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1275965 remote win=2096601)
ssh_channel_read_timeout: Read (42) buffered : 42 bytes. Window: 1275965
\ Tunneled 4586 bytes...ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=92,padding=12,comp=79,payload=79]
channel_write_common: channel_write wrote 70 bytes
- Tunneled 4656 bytes...ssh_packet_socket_callback: packet: read type 94 [len=380,padding=15,comp=364,payload=364]
ssh_packet_process: Dispatching handler for packet type 94
channel_rcv_data: Channel receiving 355 bytes data in 0 (local win=1275965 remote win=2096531)
channel_default_bufferize: placing 355 bytes into channel buffer (stderr=0)
channel_rcv_data: Channel windows are now (local win=1275610 remote win=2096531)
ssh_channel_read_timeout: Read (355) buffered : 355 bytes. Window: 1275610
| Tunneled 5011 bytes...
最后，这是运行时的日志ssh_connect：
> session <- ssh::ssh_connect(host = glue::glue("{ ssh_user }@{ ssh_host }"),
+ keyfile = ssh_key,
+ verbose = 3)
ssh_pki_import_privkey_base64: Trying to decode privkey passphrase=false
ssh_connect: libssh 0.8.6 (c) 2003-2018 Aris Adamantiadis, Andreas Schneider and libssh contributors. Distributed under the LGPL, please refer to COPYING file for information about your rights, using threading threads_pthread
ssh_socket_connect: Nonblocking connection socket: 50
ssh_connect: Socket connecting, now waiting for the callbacks to work
ssh_connect: Actual timeout : 10000
ssh_socket_pollcallback: Received POLLOUT in connecting state
socket_callback_connected: Socket connection callback: 1 (0)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
callback_receive_banner: Received banner: SSH-2.0-OpenSSH_7.4
ssh_client_connection_callback: SSH server banner: SSH-2.0-OpenSSH_7.4
ssh_analyze_banner: Analyzing banner: SSH-2.0-OpenSSH_7.4
ssh_analyze_banner: We are talking to an OpenSSH client version: 7.4 (70400)
ssh_known_hosts_read_entries: Failed to open the known_hosts file '/etc/ssh/ssh_known_hosts': No such file or directory
ssh_client_select_hostkeys: Changing host key method to "ecdsa-sha2-nistp256,ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ssh-rsa,ssh-dss"
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=644,padding=9,comp=634,payload=634]
ssh_packet_socket_callback: packet: read type 20 [len=1276,padding=10,comp=1265,payload=1265]
ssh_packet_process: Dispatching handler for packet type 20
ssh_kex_select_methods: Negotiated curve25519-sha256,ecdsa-sha2-nistp256,aes256-ctr,aes256-ctr,hmac-sha2-256,hmac-sha2-256,none,none,,
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=44,padding=6,comp=37,payload=37]
ssh_packet_socket_callback: packet: read type 31 [len=260,padding=11,comp=248,payload=248]
ssh_packet_process: Dispatching handler for packet type 31
ssh_packet_dh_reply: Received SSH_KEXDH_REPLY
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=12,padding=10,comp=1,payload=1]
ssh_client_curve25519_reply: SSH_MSG_NEWKEYS sent
ssh_packet_socket_callback: Processing 112 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 21 [len=12,padding=10,comp=1,payload=1]
ssh_packet_process: Dispatching handler for packet type 21
ssh_packet_newkeys: Received SSH_MSG_NEWKEYS
crypt_set_algorithms2: Set output algorithm to aes256-ctr
crypt_set_algorithms2: Set HMAC output algorithm to hmac-sha2-256
crypt_set_algorithms2: Set input algorithm to aes256-ctr
crypt_set_algorithms2: Set HMAC input algorithm to hmac-sha2-256
ssh_packet_newkeys: Signature verified and valid
ssh_packet_socket_callback: Processing 96 bytes left in socket buffer
ssh_packet_socket_callback: packet: read type 7 [len=60,padding=6,comp=53,payload=53]
ssh_packet_process: Dispatching handler for packet type 7
ssh_packet_ext_info: Received SSH_MSG_EXT_INFO
ssh_packet_ext_info: Follows 1 extensions
ssh_packet_ext_info: Extension: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
ssh_connect: current state : 7
packet_send2: packet: wrote [len=28,padding=10,comp=17,payload=17]
ssh_service_request: Sent SSH_MSG_SERVICE_REQUEST (service ssh-userauth)
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
ssh_packet_socket_callback: packet: read type 6 [len=28,padding=10,comp=17,payload=17]
ssh_packet_process: Dispatching handler for packet type 6
ssh_packet_service_accept: Received SSH_MSG_SERVICE_ACCEPT
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=44,padding=4,comp=39,payload=39]
ssh_packet_socket_callback: packet: read type 51 [len=60,padding=15,comp=44,payload=44]
ssh_packet_process: Dispatching handler for packet type 51
ssh_packet_userauth_failure: Access denied for 'none'. Authentication that can continue: publickey,gssapi-keyex,gssapi-with-mic
ssh_packet_userauth_failure: Access denied for 'none'. Authentication that can continue: publickey,gssapi-keyex,gssapi-with-mic
ssh_key_algorithm_allowed: Checking rsa-sha2-512 with list <ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss>
ssh_key_algorithm_allowed: Checking rsa-sha2-512 with list <ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss>
ssh_key_algorithm_allowed: Checking rsa-sha2-512 with list <ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss>
ssh_socket_unbuffered_write: Enabling POLLOUT for socket
packet_send2: packet: wrote [len=636,padding=11,comp=624,payload=624]
ssh_packet_socket_callback: packet: read type 52 [len=12,padding=10,comp=1,payload=1]
ssh_packet_process: Dispatching handler for packet type 52
ssh_packet_userauth_success: Authentication successful