I wanted to make some changes in redis.conf, so that whenever i type redis-cli it connects me to redis installed on remote server.
I know that we can connect to redis installed on remote server by :
redis-cli -h 'IP-Address-Of-Server'.
But actually, I have some bash scripts and in those scripts i have used redis-cli at many place. So instead of replacing redis-cli with redis-cli -h 'IP-Address-Of-Server' in each file, I wanted to somehow change redis configuration, so that by default it connects me to the remote server. I hope it make sense :)
there is no good reason to touch redis conf for this.
just make a script that wraps redis-cli with the desired parameters to connect to the remote host
eg. create a redis-cli-remotename.sh
#!/bin/sh
redis-cli -h remote.host_name
and give it +x permissions (eg. chmod +x redis-cli-remotename.sh)
Like Tommaso said, this is no good reason to touch the redis conf for this purpose. Instead what you can do is use environment variables to in your bash scripts to execute the command and then use that environment variable wherever you've used redis-cli directly.
For eg. $REDIS_CONNECTION="redis-cli -h "
If at any future point in time, you decide to change the host you want to connect to, its simply a matter of changing the env variables value.
Replacing redis-cli with the environment variable is pretty straightforward with sed in all the files. So that shouldn't be much of a hassle.
Related
I have a free-tier Redis Enterprise instance on AWS. I am running the latest stable version of redis on my Mac. I can connect to my Redis Enterprise instance using redis-cli with the -h parameter, and I get an interactive session which allows me to create and retrieve keys. However, the command prompt shows the full host url, which takes up most of the width of default terminal window. Is there a way to change the command prompt text (like Export PS1="" in bash) in redis-cli? Is there a redis-cli command, or a config file I can change?
Thanks,
Eric
No. Regrettably there is no way to customize the prompt displayed by redis-cli.
However, instead of using the long hostname, you can replace it with -h ip-address that is usually shorter.
Also, as a workaround, you could define the endpoint's hostname in your (where redis-cli is running) /etc/hosts as something shorter, e.g.:
very.long.host.name.that.you.are.using shorty
and then call the cli with it:
redis-cli -h shorty
To test ssh I read you need to use something like ssh -T user#domain.com:
According to man ssh:
-T Disable pseudo-terminal allocation.
-t Force pseudo-terminal allocation. This can be used to execute arbitrary screen-based programs on a remote
machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty alloca-
tion, even if ssh has no local tty.
but I'm still not clear, even after reading this, what the purpose of using -T is when testing SSH.
I read up on pseudo-terminals (https://linux.die.net/man/7/pty) but that didn't seem to help.
To have interactive prompt in your ssh shell, you need to have allocated PTY also on the server side. It is done automatically when you call ssh host.
When you allocate this PTY on server, then your local terminal and the remote one are exchanging some additional messages (Terminal control characters), which give the remote shell information about the size of your local terminal, the remote can update title of your window and so on. This is something you really don't want when you want to transfer files or just pass the output "as it is". It would modify that and you would get generally something else. Again, this is done automatically in case you use scp or just noninteractive script as ssh host my_script.
So far good. You don't need the switches. But things might not be always so simple.
You might want to invoke some interactive shell as a command, for example ssh host /bin/zsh. This would work, but it will not be interactive. In this case, you need to use the -t switch to make it working properly: ssh -t host /bin/zsh.
The same thing can go other way round. You might have server set up, that it will give you some output regardless the command you ask for. In that case, you really don't want to mess it up with any terminal control characters and then you might want to use ssh -T host to avoid this clutch.
You can consider the -T also as the way to safe resources on server and as some "second line of defense". You can disable the TTY allocation in the server configuration, but what if ...
The most common use case for the -T switch is
ssh -T git#github.com
to verify that you have set up your ssh keys properly to authenticate to github.
I am using ssh to connect to a remote machine.
Is there a way i can copy an entire directory from a local machine to the remote machine?
I found this link to do it the other way round i.e copying from remote machine to local machine.
Easiest way is scp
scp -r /path/to/local/storage user#remote.host:/path/to/copy
rsync is best for when you want to update versions where it has been previously copied.
If that doesn't work, rerun with -v and see what the error is.
It is very easy with rsync as well:
rsync /path/to/local/storage user#remote.host:/path/to/copy
I recommend the usage of rsync over scp, because it is highly likely that you will one day need a feature that rsync offers and then you benefit from your experience with the tool.
This is worked for me
rsync -avz -e 'ssh' /path/to/local/dir user#remotehost:/path/to/remote/dir
this is if you have to used another ssh port other than 22
rsync -avzh -e 'ssh -p sshPort' /my/local/dir/ remoteUser#host:/path/to/remote/dir
this works if your remote server uses default 22 port
rsync -avzh /my/local/dir/ remoteUser#host:/path/to/remote/dir
This worked for me.
Follow this link for detailed understanding.
we can do this by using scp command for example:
scp -r /path/to/local/machine/directory user#remotehost(server IP Address):/path/to/sever/directory
In case of differnt port
By default, the SCP protocol operates on port 22 but this can be overridden by supplying the -P flag, followed by the port number for example:
scp -P 8563 -r /path/to/local/machine/directory user#remotehost(server IP Address):/path/to/sever/directory
NOTE: we use -r flag to copy directory's files/folders recursively instead of a single file.
I'm using cygrunsrv and autossh on windows XP to create a service building a tunnel to a remote server but i also want to create another tunnel from the remote server to another server.
I can achieve it with this command line :
autossh -M 5432 serverA -t 'autossh -M 4321 serverB -N'
but when I want to set it up in cygwin through cygrunsrv to make it works as a service :
cygrunsrv -I TUNNEL -p /usr/bin/autossh -a "-M 5432 serverA -t 'autossh -M 4321 serverB -N'" -e AUTOSSH_NTSERVICE=yes -e AUTOSSH_POLL=20 -e AUTOSSH_GATETIME=30
It's not fully working. The service is creating the tunnel correctly to ServerA but it's not sending the autossh command "autossh -M 4321 serverB -N" to ServerA.
I tried to escape the quote but all my efforts didn't make any difference and I'm not seeing any command sent in the autossh logs.
I think the problem is related to pseudo terminal that is not created through the cygrunsrv.
I'd like to know if there's a way to fix my cygrunsrv command line to make it work or should I consider a different approach ?
Lionel, try removing the AUTOSSH_NTSERVICE=yes from the cygrunsrv invocation. As /usr/share/doc/autossh/README.Cygwin explains:
Setting AUTOSSH_NTSERVICE=yes in the calling environment ...
change[s] autossh's behavior in three useful
ways:
(1) Add an -N flag to each invocation of ssh, thus disabling shell
access. The idea is that if you're running autossh as a system
service, you're using it to forward ports; it wouldn't make sense to
run a shell session as a system service. (If you think this reasoning
is wrong, please send a bug report to the author or Cygwin maintainer,
and tell us what you're trying to do.)
Despite what the above says, it seems that you may have a good reason for not wanting -N (which suppresses command execution) in your service's ssh invocation. Removing AUTOSSH_NTSERVICE=yes should take care of it. It will have a couple of other minor disadvantages, but you can probably live with it. Read the rest of README.Cygwin for the details.
I work with several different servers, and it would be useful to be able to set some environment variables such that they are active on all of them when I SSH in. The problem is, the contents of some of the variables contain sensitive information (hashed passwords), and so I don't want to leave it lying around in a .bashrc file -- I'd like to keep it only in memory.
I know that you can use SSH to forward the DISPLAY variable (via ForwardX11) or an SSH Agent process (via ForwardAgent), so I'm wondering if there's a way to automatically forward the contents of arbitrary environment variables across SSH connections. Ideally, something I could set in a .ssh/config file so that it would run automatically when I need it to. Any ideas?
You can, but it requires changing the server configuration.
Read the entries for AcceptEnv in sshd_config(5) and SendEnv in ssh_config(5).
update:
You can also pass them on the command line:
ssh foo#host "FOO=foo BAR=bar doz"
Regarding security, note than anybody with access to the remote machine will be able to see the environment variables passed to any running process.
If you want to keep that information secret it is better to pass it through stdin:
cat secret_info | ssh foo#host remote_program
You can't do it automatically (except for $DISPLAY which you can forward with -X along with your Xauth info so remote programs can actually connect to your display) but you can use a script with a "here document":
ssh ... <<EOF
export FOO="$FOO" BAR="$BAR" PATH="\$HOME/bin:\$PATH"
runRemoteCommand
EOF
The unescaped variables will be expanded locally and the result transmitted to the remote side. So the PATH will be set with the remote value of $HOME.
THIS IS A SECURITY RISK Don't transmit sensitive information like passwords this way because anyone can see environment variables of every process on the same computer.
Something like:
ssh user#host bash -c "set -e; $(env); . thescript.sh"
...might work (untested)
Bit of a hack but if you cannot change the server config for some reason it might work.