Sending dynamically generated email every hour from server

Question

On debian 8.9

I want to check my ip address and send email every hour.

what I want to do is

1.Check my server ip address -> curl globalip.me 2.Send ip address by email.

A. I know how to send mail in command line. B. I know how to setup crond.

However A requires manual response, so I don't know how to use A in B setting.

Is there any good way ??

Answer 1

cron will send the output of a process to whatever it is told to in the MAILTO variable. You can execute curl or find your IP with any number of tools.

More importantly you need to make sure that your system can send mail and have it accepted wherever you are intending to read it. If you get a public IP via DHCP your ISP might block SMTP, test this with something simple like a cron entry to send the hostname or some such.

Answer 2

curl globalip.me | mail -s "my new ip" [e-mail]

Here -s "my new ip" is subject of the message. You may want to try man mail for more options like email for 'CC' or 'BCC' fields etc.

Answer 3

if you wish to have your internal network/private ip ( rather than the public one provided by the curl command in ~Putnik 's answer you could use

ip r | grep -i wlp3s0 | grep -i src | cut -d' ' -f9  
#note, the wlp3s0 interface name could/will be different on your machine

then, as Putnik rightly answers, pipe that into mail...

ip r | grep -i wlp3s0 | grep -i src | cut -d' ' -f9  | mail -s "$HOSTNAME new ip" [e-mail]

next, we need to add this command to your crontab, so

vim /etc/crontab

and add to the last line...

0 * * * * <$YOUR_USER_NAME> ip r | grep -i wlp3s0 | grep -i src | cut -d' ' -f9  | mail -s "$HOSTNAME new ip" [e-mail] 

BONUS :: Cronjobs can fail! Monitor your important cronjob by pasting the following snippet at the end of the crontab entry. Make sure to replace the with your email address and some name for your cronjob. Should your cron job fail or not even start, you will receive an alert email.

&& curl -sm 30 k.wdt.io/<email-address>/<cronjob-name>?c=0_*_*_*_*