How can I get an environment variable representing my machine ip?
I'm not sure how the scope of variables in /etc/environment works, nor when they get created, but I need a "global" environment variable that is populated with the ip address after a DHCP address is assigned so I can use that variable just like any variable defined in /etc/environment
For example, I assign hard-coded variables in /etc/environment such as:
TZ="America/New_York"
I can then use ${TZ} in **yml* configuration files and they will be populated with value assigned in /etc/environment
I need to be able to use ${ipv4} in my yml files which will have the machine's ip address (which is assigned via DHCP). How can I create this, keeping in mind I might not log into the machine.
I've done a little research and I know I can populate a value with the ip address by running the following executed from a bash prompt will populate foo with the correct ip.
foo=$(/sbin/ip -o -4 addr list enp0s3 | awk '{print $4}' | cut -d/ -f1)
ETA: Since my machine gets assigned an ip from my router's MAC address filtering option, I won't expect my ip to ever change unless I do so from the router, which I tend to do from time to time. So this is why I'm not hard coding the actual value into the file
boot 18.04 environment-variables
asked Feb 7 at 16:59
Mike FormanMike Forman
61
|
show 3 more comments
I'm not sure how the scope of variables in /etc/environment works, nor when they get created, but I need a "global" environment variable that is populated with the ip address after a DHCP address is assigned so I can use that variable just like any variable defined in /etc/environment
For example, I assign hard-coded variables in /etc/environment such as:
TZ="America/New_York"
I can then use ${TZ} in **yml* configuration files and they will be populated with value assigned in /etc/environment
I need to be able to use ${ipv4} in my yml files which will have the machine's ip address (which is assigned via DHCP). How can I create this, keeping in mind I might not log into the machine.
I've done a little research and I know I can populate a value with the ip address by running the following executed from a bash prompt will populate foo with the correct ip.
foo=$(/sbin/ip -o -4 addr list enp0s3 | awk '{print $4}' | cut -d/ -f1)
ETA: Since my machine gets assigned an ip from my router's MAC address filtering option, I won't expect my ip to ever change unless I do so from the router, which I tend to do from time to time. So this is why I'm not hard coding the actual value into the file
boot 18.04 environment-variables
asked Feb 7 at 16:59
Mike FormanMike Forman
61
Look into using the/etc/profilefile or creating a script in/etc/profile.d/folder that will run your command to set thefooas a global variable.
– Terrance
Feb 7 at 17:10
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to~/.bashrcwould run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your~/.profilefile, it would have to be sourced every time you wish to use it. You can source any file at any time.. /etc/profilewould source the file at that time.
– Terrance
Feb 7 at 19:04
Your~/.profilefile is sourced at login as well.
– Terrance
Feb 7 at 19:05
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14
|
show 3 more comments
I'm not sure how the scope of variables in /etc/environment works, nor when they get created, but I need a "global" environment variable that is populated with the ip address after a DHCP address is assigned so I can use that variable just like any variable defined in /etc/environment
For example, I assign hard-coded variables in /etc/environment such as:
TZ="America/New_York"
I can then use ${TZ} in **yml* configuration files and they will be populated with value assigned in /etc/environment
I need to be able to use ${ipv4} in my yml files which will have the machine's ip address (which is assigned via DHCP). How can I create this, keeping in mind I might not log into the machine.
I've done a little research and I know I can populate a value with the ip address by running the following executed from a bash prompt will populate foo with the correct ip.
foo=$(/sbin/ip -o -4 addr list enp0s3 | awk '{print $4}' | cut -d/ -f1)
ETA: Since my machine gets assigned an ip from my router's MAC address filtering option, I won't expect my ip to ever change unless I do so from the router, which I tend to do from time to time. So this is why I'm not hard coding the actual value into the file
boot 18.04 environment-variables
asked Feb 7 at 16:59
Mike FormanMike Forman
61
I'm not sure how the scope of variables in /etc/environment works, nor when they get created, but I need a "global" environment variable that is populated with the ip address after a DHCP address is assigned so I can use that variable just like any variable defined in /etc/environment
For example, I assign hard-coded variables in /etc/environment such as:
TZ="America/New_York"
I can then use ${TZ} in **yml* configuration files and they will be populated with value assigned in /etc/environment
I need to be able to use ${ipv4} in my yml files which will have the machine's ip address (which is assigned via DHCP). How can I create this, keeping in mind I might not log into the machine.
I've done a little research and I know I can populate a value with the ip address by running the following executed from a bash prompt will populate foo with the correct ip.
foo=$(/sbin/ip -o -4 addr list enp0s3 | awk '{print $4}' | cut -d/ -f1)
ETA: Since my machine gets assigned an ip from my router's MAC address filtering option, I won't expect my ip to ever change unless I do so from the router, which I tend to do from time to time. So this is why I'm not hard coding the actual value into the file
boot 18.04 environment-variables
boot 18.04 environment-variables
asked Feb 7 at 16:59
Mike FormanMike Forman
61
asked Feb 7 at 16:59
Mike FormanMike Forman
61
asked Feb 7 at 16:59
Mike FormanMike Forman
61
asked Feb 7 at 16:59
Mike FormanMike Forman
61
asked Feb 7 at 16:59
Mike FormanMike Forman
61
61
Look into using the/etc/profilefile or creating a script in/etc/profile.d/folder that will run your command to set thefooas a global variable.
– Terrance
Feb 7 at 17:10
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to~/.bashrcwould run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your~/.profilefile, it would have to be sourced every time you wish to use it. You can source any file at any time.. /etc/profilewould source the file at that time.
– Terrance
Feb 7 at 19:04
Your~/.profilefile is sourced at login as well.
– Terrance
Feb 7 at 19:05
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14
|
show 3 more comments
Look into using the/etc/profilefile or creating a script in/etc/profile.d/folder that will run your command to set thefooas a global variable.
– Terrance
Feb 7 at 17:10
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to~/.bashrcwould run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your~/.profilefile, it would have to be sourced every time you wish to use it. You can source any file at any time.. /etc/profilewould source the file at that time.
– Terrance
Feb 7 at 19:04
Your~/.profilefile is sourced at login as well.
– Terrance
Feb 7 at 19:05
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14
Look into using the
/etc/profile file or creating a script in /etc/profile.d/ folder that will run your command to set the foo as a global variable.– Terrance
Feb 7 at 17:10
Look into using the
/etc/profile file or creating a script in /etc/profile.d/ folder that will run your command to set the foo as a global variable.– Terrance
Feb 7 at 17:10
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to
~/.bashrc would run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your ~/.profile file, it would have to be sourced every time you wish to use it. You can source any file at any time. . /etc/profile would source the file at that time.– Terrance
Feb 7 at 19:04
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to
~/.bashrc would run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your ~/.profile file, it would have to be sourced every time you wish to use it. You can source any file at any time. . /etc/profile would source the file at that time.– Terrance
Feb 7 at 19:04
Your
~/.profile file is sourced at login as well.– Terrance
Feb 7 at 19:05
Your
~/.profile file is sourced at login as well.– Terrance
Feb 7 at 19:05
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14
|
show 3 more comments
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Look into using the
/etc/profilefile or creating a script in/etc/profile.d/folder that will run your command to set thefooas a global variable.– Terrance
Feb 7 at 17:10
Don't those only get executed upon login?
– Mike Forman
Feb 7 at 18:57
This all depends on why you need to know what your IP address is. The host is already named for localhost. Localhost is a global variable already to the system. And yes, the profile would be only run at login. Or if you added it to
~/.bashrcwould run on every time you launched a terminal window, but that is not global and is only used in the present terminal session. If you added it to your~/.profilefile, it would have to be sourced every time you wish to use it. You can source any file at any time.. /etc/profilewould source the file at that time.– Terrance
Feb 7 at 19:04
Your
~/.profilefile is sourced at login as well.– Terrance
Feb 7 at 19:05
I need to know the ip address the DHCP server hands out to this machine, and I need it after it is assigned and not before waiting for someone to login, much less having a kludge to auto-login. So after the login window appears, I'd like to have XXX=192.168.1.46
– Mike Forman
Feb 7 at 19:14