Dynamic ~/.ssh/config
I'd like make my ~/.ssh/config file dynamically generated by a shell script (or anything else that prints to STDOUT).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
What I'd like:
#!/bin/bash
echo "Hello World"
$ cat myfile
Hello World
bash ssh files stdout
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
add a comment |
I'd like make my ~/.ssh/config file dynamically generated by a shell script (or anything else that prints to STDOUT).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
What I'd like:
#!/bin/bash
echo "Hello World"
$ cat myfile
Hello World
bash ssh files stdout
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
1
This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the-Fflag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.
– jofel
Dec 2 '14 at 14:58
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
1
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45
add a comment |
I'd like make my ~/.ssh/config file dynamically generated by a shell script (or anything else that prints to STDOUT).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
What I'd like:
#!/bin/bash
echo "Hello World"
$ cat myfile
Hello World
bash ssh files stdout
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
I'd like make my ~/.ssh/config file dynamically generated by a shell script (or anything else that prints to STDOUT).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
What I'd like:
#!/bin/bash
echo "Hello World"
$ cat myfile
Hello World
bash ssh files stdout
bash ssh files stdout
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
asked Dec 2 '14 at 14:44
Daniel UptonDaniel Upton
150115
150115
1
This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the-Fflag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.
– jofel
Dec 2 '14 at 14:58
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
1
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45
add a comment |
1
This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the-Fflag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.
– jofel
Dec 2 '14 at 14:58
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
1
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45
1
1
This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the
-F flag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.– jofel
Dec 2 '14 at 14:58
This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the
-F flag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.– jofel
Dec 2 '14 at 14:58
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
1
1
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45
add a comment |
1 Answer
1
active
oldest
votes
The true question is: Why do you need dynamic configuration (and thus how to avoid having to generate configuration dynamically).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
Bash has a feature that does exactly that, it's named "Process Substitution" :
ssh -F <( echo "Host *"; echo " User dummy" ) ssh.example.com
Unfortunately, it won't work with openssh's ssh, as it dies with error:
Can't open user config file /dev/fd/63: No such file or directory
Also, some people seems to use complex scheme to use a FIFO file, like Multiple SSH client configuration files, but eventually they use an alias, and that can be simplified with something like :
alias ssh = '~/bin/gen_ssh_config.sh > /tmp/XX; ssh -F /tmp/XX'
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
If you usezshinstead ofbash, you can use the=(...)form of process substitution that uses temp files instead of pipes and /dev/fd:ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com
– Stéphane Chazelas
Mar 10 '16 at 15:21
add a comment |
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1 Answer
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active
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1 Answer
1
active
oldest
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oldest
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votes
The true question is: Why do you need dynamic configuration (and thus how to avoid having to generate configuration dynamically).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
Bash has a feature that does exactly that, it's named "Process Substitution" :
ssh -F <( echo "Host *"; echo " User dummy" ) ssh.example.com
Unfortunately, it won't work with openssh's ssh, as it dies with error:
Can't open user config file /dev/fd/63: No such file or directory
Also, some people seems to use complex scheme to use a FIFO file, like Multiple SSH client configuration files, but eventually they use an alias, and that can be simplified with something like :
alias ssh = '~/bin/gen_ssh_config.sh > /tmp/XX; ssh -F /tmp/XX'
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
If you usezshinstead ofbash, you can use the=(...)form of process substitution that uses temp files instead of pipes and /dev/fd:ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com
– Stéphane Chazelas
Mar 10 '16 at 15:21
add a comment |
The true question is: Why do you need dynamic configuration (and thus how to avoid having to generate configuration dynamically).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
Bash has a feature that does exactly that, it's named "Process Substitution" :
ssh -F <( echo "Host *"; echo " User dummy" ) ssh.example.com
Unfortunately, it won't work with openssh's ssh, as it dies with error:
Can't open user config file /dev/fd/63: No such file or directory
Also, some people seems to use complex scheme to use a FIFO file, like Multiple SSH client configuration files, but eventually they use an alias, and that can be simplified with something like :
alias ssh = '~/bin/gen_ssh_config.sh > /tmp/XX; ssh -F /tmp/XX'
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
If you usezshinstead ofbash, you can use the=(...)form of process substitution that uses temp files instead of pipes and /dev/fd:ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com
– Stéphane Chazelas
Mar 10 '16 at 15:21
add a comment |
The true question is: Why do you need dynamic configuration (and thus how to avoid having to generate configuration dynamically).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
Bash has a feature that does exactly that, it's named "Process Substitution" :
ssh -F <( echo "Host *"; echo " User dummy" ) ssh.example.com
Unfortunately, it won't work with openssh's ssh, as it dies with error:
Can't open user config file /dev/fd/63: No such file or directory
Also, some people seems to use complex scheme to use a FIFO file, like Multiple SSH client configuration files, but eventually they use an alias, and that can be simplified with something like :
alias ssh = '~/bin/gen_ssh_config.sh > /tmp/XX; ssh -F /tmp/XX'
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
The true question is: Why do you need dynamic configuration (and thus how to avoid having to generate configuration dynamically).
Is there a UNIX trick to make reading a file result in executing a command & reading it's STDOUT?
Bash has a feature that does exactly that, it's named "Process Substitution" :
ssh -F <( echo "Host *"; echo " User dummy" ) ssh.example.com
Unfortunately, it won't work with openssh's ssh, as it dies with error:
Can't open user config file /dev/fd/63: No such file or directory
Also, some people seems to use complex scheme to use a FIFO file, like Multiple SSH client configuration files, but eventually they use an alias, and that can be simplified with something like :
alias ssh = '~/bin/gen_ssh_config.sh > /tmp/XX; ssh -F /tmp/XX'
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
answered Mar 7 '15 at 18:16
Franklin PiatFranklin Piat
1,8941828
1,8941828
If you usezshinstead ofbash, you can use the=(...)form of process substitution that uses temp files instead of pipes and /dev/fd:ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com
– Stéphane Chazelas
Mar 10 '16 at 15:21
add a comment |
If you usezshinstead ofbash, you can use the=(...)form of process substitution that uses temp files instead of pipes and /dev/fd:ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com
– Stéphane Chazelas
Mar 10 '16 at 15:21
If you use
zsh instead of bash, you can use the =(...) form of process substitution that uses temp files instead of pipes and /dev/fd: ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com– Stéphane Chazelas
Mar 10 '16 at 15:21
If you use
zsh instead of bash, you can use the =(...) form of process substitution that uses temp files instead of pipes and /dev/fd: ssh -F =(echo "Host *"; echo " User dummy") ssh.example.com– Stéphane Chazelas
Mar 10 '16 at 15:21
add a comment |
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This would only possible be possible with a self-written filesystem, e.g. via FUSE, or depending on the ssh implementation with FIFOs. Maybe the
-Fflag of ssh which allows to pass an alternative user-config file helps you. You can also replace ssh with an wrapper script, which sets the config file before running the actual ssh.– jofel
Dec 2 '14 at 14:58
A colleague sent me this: github.com/markhellewell/sshconfigfs (which is an implementation of the FUSE idea)
– Daniel Upton
Dec 2 '14 at 15:16
1
This smells like the XY problem. Maybe if you explained why you want to do such a thing, there's a better way to accomplish it.
– Kenster
Dec 4 '14 at 20:39
Having a read of a file, trigger an execution of a program, can be dangerous. The execution would have to be done by the user that set it up, not the user that read the file. The program would therefore not have access to anything that the creator would not otherwise have access to.
– ctrl-alt-delor
Mar 7 '15 at 18:45