I want to set target to service in CentOS7 (Systemd).
I want to know following.
How to set target to service.
How to show target of service.
In other words, I want to know substitution for following commands.
$ sudo chkconfig --level=2345 mysql on (<- set runlevel)
$ chkconfig --list mysql (<- show runlevel)
I understood that "runlevel" in CentOS6 changed "target" in CentOS7and I should use "systemctl" command.
But problems were not solved.
I heard that following command is replacement for "chkconfig --list"
, but I can't check target and can't set target.
systemctl list-unit-files
Setting the target is done in the unit file for the service. For example:
[Install]
WantedBy=multi-user.target
Then you run systemctl enable $service_name to create a symlink which enables the service to start as part of a particular target. You could also create the symlinks manually. The enable command will print out the paths of the symlinks it's creating.
I think systemctl --reverse list-dependencies $service is the way to find what services and targets depend on a specific services to boot.
Related
Which config files could disable the automatically starting ssh server, so a headless connect becomes impossible?
I need to know the config files that might interfere with the ssh server to normally start up at boot.
I believe that you are looking for the following commands (assuming you are running the last version of raspbian):
sudo systemctl stop sshd
sudo systemctl disable sshd
sudo systemctl mask sshd
stop Basically stops the service immediately. disable disables the service from starting at bootup. Additionally, mask will make it impossible to load the service.
Digging deeper into what each command does, on modern linux distributions there are configuration files for each service called unit files. They are stored (usually) in /usr/lib/systemd. These are basically the evolution of scripts to start services.
the stop command just calls the sshd.service unit file with a stop parameter, in order to shut down the server.
the disable (or enable) command removes(or creates) a symlink of the unit file in a directory where systemd looks into when booting services (usually, /etc/systemd/system).
systemctl mask creates a symlink to /dev/null instead of the unit file. That way the service cant be loaded.
I made this service:
#!/bin/bash
node ../../home/NodeServer/server.js
All it should do is start the server on bootup, so i wanted to do
sudo systemctl enable startServer.service
But I got this error:
startServer.sh.service is not a native service, redirecting to systemd-sysv-insall.
Executing: /lib/systemd/systemd-sysv-install enable startServer.sh
update-rc.d: error: startServer.sh Default-Start contains no runlevels, aborting.
When i try to do
sudo systemctl start startServer.service
it works like intended.
I had the same problem. I solve it typing again the file because it seems that there was a strange character that was broken the parser. Hope this helps!
You want to execute a script, which is not the same as a service.
You can make a file called startServer.service and write the following into it:
[Unit]
Description=Start server that does a thing
[Service]
ExecStart=node /home/NodeServer/server.js
If you want to enable the service, do the following:
sudo ln -s /home/NodeServer/startServer.service /etc/systemd/system/
and now you should be able to start the service.
Getting access denied error while running the systemctl command in a pod.
Whenever try to start any service, for example, MySQL or tomcat server in a pod, it gives access denied error.
Is there any way by which I can run systemctl within a pod.
This is a problem related to Docker, not Kubernetes.
According to the page Run multiple services in a container in docker docs:
It is generally recommended that you separate areas of concern by
using one service per container
However if you really want to use a process manager, you can try supervisord, which allows you to use supervisorctl commands, similar to systemctl. The page above explains how to do that:
Here is an example Dockerfile using this approach, that assumes the
pre-written supervisord.conf, my_first_process, and my_second_process
files all exist in the same directory as your Dockerfile.
FROM ubuntu:latest
RUN apt-get update && apt-get install -y supervisor
RUN mkdir -p /var/log/supervisor
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
COPY my_first_process my_first_process
COPY my_second_process my_second_process
CMD ["/usr/bin/supervisord"]
That's a rather short question. The 'systemctl' command does try to talk to the systemd daemon which is not running in a pod by default (it could however). Running multiple services is yet another question about service management. It both cases it could help to use a tool like the docker-systemctl-replacement overwriting /usr/bin/systemctl and registering it as the init-CMD of the container.
I'm running Ubuntu 18.04 and I've installed haproxy 1.8.8. I want to modify the config so that the "-f" option will read a directory rather than a single haproxy.cfg file.
I see /lib/systemd/system/haproxy.service and also /etc/init.d/haproxy were installed. I think systemd is managing haproxy. But I've read that I'm not supposed to modify the installed haproxy.service.
I copied haproxy.service to /etc/systemd/system/ and edited it there. The changes I made were not picked up when I ran sudo systemctl daemon-reload; sudo service haproxy restart.
Which file do I need to modify and then get systemd to recognize the changes? TIA
As you suspected, you should not edit the unit-files (provided by the OS packager) directly. You can supply a drop-in-snippet using the command
systemctl edit haproxy
and customize the relevant directives (ExecStart)
I need to copy a bunch of files into some folder every time the httpd service restarts
e.g.:
yes | cp ./dynamic/*.file /folder/inside/my/webapp
is there a way to run some additional commands when the httpd is restarted?
According to this: https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units
You can edit the httpd service file with:
sudo systemctl edit --full httpd.service
You should be able to add more directives to the service unit, such as running your additional commands.