VSCode Remote-ssh 远程连接Linux问题排查

VSCode 的 Remote-ssh 连接远程 Linux 服务器时，不需要 Linux 服务器也安装 VSCode，但是需要Linux安装 openssh-server并启动。

通过 VSCode 的 Remote-ssh 去连接Kylin操作系统时，报错 Failed to set up dynamic port forwarding connection over SSH to the VS Code Server.。无法通过VSCode sever的SSH进行动态端口转发。
此时根据Log信息已经设置了 AllowTcpForwarding yes，并重启服务后依旧报错。
主要原因是sshd_config中的参数设置，让端口转发被禁用，因此需要对其进行设置。

1、编辑 `sshd_config` 中的对应参数

# 打开ssh配置文件，需要root权限
sudo vim /etc/ssh/sshd_config

设置配置中的关键参数如下：


AllowAgentForwarding yes
AllowTcpForwarding yes   # 允许端口转发
GatewayPorts yes
X11Forwarding yes

# 允许通道打开
PermitTunnel yes

# 当设置打开许可 PermitOpen none，这会禁用所有端口的转发，需要将其注释掉，否则会导致端口转发无法启动
#PermitOpen none

2、重启ssh服务，以让刚刚的修改生效

sudo systemctl restart sshd

【注】完整的 sshd_config 内容如下

Include /etc/ssh/sshd_config.d/*.conf

Port 22
Port 42717
#AddressFamily any
ListenAddress 0.0.0.0
#ListenAddress ::

#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_ecdsa_key
#HostKey /etc/ssh/ssh_host_ed25519_key

# Ciphers and keying
#RekeyLimit default none

# Logging
#SyslogFacility AUTH
#LogLevel INFO

# Authentication:

#LoginGraceTime 2m
PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#MaxSessions 10

PubkeyAuthentication yes

# Expect .ssh/authorized_keys2 to be disregarded by default in future.
#AuthorizedKeysFile     .ssh/authorized_keys .ssh/authorized_keys2

#AuthorizedPrincipalsFile none

#AuthorizedKeysCommand none
#AuthorizedKeysCommandUser nobody

# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes

# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication yes
#PermitEmptyPasswords no

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no

# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
#GSSAPIStrictAcceptorCheck yes
#GSSAPIKeyExchange no

# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication.  Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes

AllowAgentForwarding yes
AllowTcpForwarding yes
GatewayPorts yes
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PermitTTY yes
PrintMotd no
#PrintLastLog yes
#TCPKeepAlive yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS no
#PidFile /var/run/sshd.pid
#MaxStartups 10:30:100
PermitTunnel yes
#ChrootDirectory none
#VersionAddendum none

# no default banner path
Banner /etc/issue.net

# Allow client to pass locale environment variables
AcceptEnv LANG LC_*

# override default of no subsystems
Subsystem       sftp    /usr/lib/openssh/sftp-server

# Example of overriding settings on a per-user basis
#Match User anoncvs
        X11Forwarding yes
        AllowTcpForwarding yes
#       PermitTTY no
#       ForceCommand cvs server
#PermitOpen none