I have created a new service named some-service. The shell script is present in /etc/init.d/some-service I have the same shell script file in /usr/local/bin/some-service which is a copy of some-service.
i ran the below command to create a daemon service:
os-svc-daemon -i $INSTALLDIR -d some-service some-service root some-service
This created a /etc/init/some-service.conf
start on runlevel [2345]
stop on runlevel [016]
env OS_SVC_ENABLE_CONTROL=1
export OS_SVC_ENABLE_CONTROL
pre-start script
mkdir -p /var/run/some-service
chown -R root:root /var/run/some-service
end script
respawn
# the default post-start of 1 second sleep delays respawning enough to
# not hit the default of 10 times in 5 seconds. Make it 2 times in 5s.
respawn limit 2 5
exec start-stop-daemon --start -c root --exec **INSTALLDIR**/bin/some-service --
post-start exec sleep 1
to reload the changes ran the below command
initctl reload-configuration
in tried to start the service but it never runs.
initctl start some-service
What am i doing wrong here? Also is it safe to use shell script to start it and not a python bin file?
Use os-svc-enable servicename and try start servicename
Related
When I am running a command bitcore-node start it starts two services.
Screenshot of ps aux is attached.
I created a service in /etc/init.d
description "Bitcoin Core for Bitcore"
author "BitPay, Inc."
limit nofile 20000 30000
start on runlevel [2345]
stop on runlevel [016]
kill timeout 300
kill signal SIGINT
# user/group for bitcore daemon to run as
setuid ubuntu
setgid ubuntu
# home dir of the bitcore daemon user
env HOME=/home/ubuntu
respawn
respawn limit 5 15
script
exec bitcore-node -conf=/home/ubuntu/love/data/bitcoin.conf -datadir=/home/ubuntu/love/data -testnet
end script
I am getting error to while running it.
qT.png
Any Idea ?
You have written a script as an Upstart Init Script, and executed it as a SysV init using the systemd init systemd.
You could try placing the script in /etc/init/ instead of
/etc/init.d. That way, it might be processed as the Upstart init script that it actually is.
However, Upstart is being replaced with systemd, so following a tutorial on translating your Upstart init script into a systemd .service file is recommended.
I have tried following some tutorials and documentation on dockerizing my web server, but I am having trouble getting the service to run via the docker run command.
This is my Dockerfile:
FROM ubuntu:trusty
#Update and install stuff
RUN apt-get update
RUN apt-get install -y python-software-properties aptitude screen htop nano nmap nginx
#Add files
ADD src/main/resources/ /usr/share/nginx/html
EXPOSE 80
CMD service nginx start
I create my image:
docker build -t myImage .
And when I run it:
docker run -p 81:80 myImage
it seems to just stop:
docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
90e54a254efa pms-gui:latest /bin/sh -c service n 3 seconds ago Exit 0 prickly_bohr
I would expect this to be running with port 81->80 but it is not. Running
docker start 90e
does not seem to do anything.
I also tried entering it directly
docker run -t -i -p 81:80 myImage /bin/bash
and from here I can start the service
service nginx start
and from another tab I can see it is working as intended (also in my browser):
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
408237a5e10b myImage:latest /bin/bash 12 seconds ago Up 11 seconds 0.0.0.0:81->80/tcp mad_turing
So I assume it is something I am doing wrong with my Dockerfile? Could anyone help me out with this, I am quite new to Docker. Thank you!
SOLUTION: Based on the answer from Ivant I found another way to start nginx in the foreground. My Dockerfile CMD now looks like:
CMD /usr/sbin/nginx -g "daemon off;"
As of now, the official nginx image uses this to run nginx (see the Dockerfile):
CMD ["nginx", "-g", "daemon off;"]
In my case, this was enough to get it to start properly. There are tutorials online suggesting more awkward ways of accomplishing this but the above seems quite clean.
Docker container runs as long as the command you specify with CMD, ENTRTYPOINT or through the command line is running. In your case the service command finishes right away and the whole container is shut down.
One way to fix this is to start nginx directly from the command line (make sure you don't run it as a daemon).
Another option is to create a small script which starts the service and then sleeps forever. Something like:
#!/bin/bash
service nginx start
while true; do sleep 1d; done
and run this instead of directly running the service command.
A third option would be to use something like runit or similar program, instead of the normal service.
Using docker-compose:
To follow the recommended solution, add to docker-compose.yml:
command: nginx -g "daemon off"
I also found I could simply add to nginx.conf:
daemon off;
...and continue to use in docker-compose.yml:
command: service nginx start
...although it would make the config file less portable outside docker.
Docker as a very nice index of offical and user images. When you want to do something, chances are someone already did it ;)
Just search for 'nginx' on index.docker.io, you will see, there is an official nginx image: https://registry.hub.docker.com/_/nginx/
There you have a full guide to help you start your webserver.
Feel free to take a look at other users nginx image to see variants :)
The idea is to start nginx in foreground mode.
If you run "service nginx start", it is a parent process which will start a child process of nginx. If you run "service nginx start" as CMD in a container, the Process ID 1 for the container will be "service nginx start" or ServiceManager (SystemD), while actual nginx would be running as a child process.
If you run "service nginx start", and then "ps -ef", you will get output as below. I have run it my host OS.
root#ip-172-31-85-74:/home/ubuntu# service nginx start
root#ip-172-31-85-74:/home/ubuntu#
root#ip-172-31-85-74:/home/ubuntu# ps -ef | grep nginx
root 18593 1 0 12:27 ? 00:00:00 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;
www-data 18595 18593 0 12:27 ? 00:00:00 nginx: worker process
root 18599 17918 0 12:27 pts/0 00:00:00 grep --color=auto nginx
So, here the process ID 18593 is the child process which has parent process 1.
Container exits when their Process ID 1 exits. And in case of CMD "service nginx start", the PID 1 is the process manager, may be SystemD. It starts nginx as a child process, and exits itself, hence the container exits.
Similarly, if you run a shell script (for eg : start.sh) in CMD, as soon as the script ends, the container will exit. Even though the script starts some services (eg - nginx) in its execution, as soon as the script ends, the container will exit, because the PID 1 will be of the shell script. The parent process will be "./start.sh", and the services started by script will be child processes. In case you want to use a shell script in CMD, and want the container to run indefinitely, you need a command at last of the script which doesn't let it end. Something as shown below:
#!/bin/bash
service nginx start
while true; do sleep 1d; done
I'm setting up a simple image: one that holds Riak (a NoSQL database). The image starts the Riak service with riak start as a CMD. Now, if I run it as a daemon with docker run -d quintenk/riak-dev, it does start the Riak process (I can see that in the logs). However, it closes automatically after a few seconds. If I run it using docker run -i -t quintenk/riak-dev /bin/bash the riak process is not started (UPDATE: see answers for an explanation for this). In fact, no services are running at all. I can start it manually using the terminal, but I would like Riak to start automatically. I figure this behavior would occur for other services as well, Riak is just an example.
So, running/restarting the container should automatically start Riak. What is the correct approach of setting this up?
For reference, here is the Dockerfile with which the image can be created (UPDATE: altered using the chosen answer):
FROM ubuntu:12.04
RUN apt-get update
RUN apt-get install -y openssh-server curl
RUN curl http://apt.basho.com/gpg/basho.apt.key | apt-key add -
RUN bash -c "echo deb http://apt.basho.com precise main > /etc/apt/sources.list.d/basho.list"
RUN apt-get update
RUN apt-get -y install riak
RUN perl -p -i -e 's/(?<=\{http,\s\[\s\{")127\.0\.0\.1/0.0.0.0/g' /etc/riak/app.config
EXPOSE 8098
CMD /bin/riak start && tail -F /var/log/riak/erlang.log.1
EDIT: -f changed to -F in CMD in accordance to sesm his remark
MY OWN ANSWER
After working with Docker for some time I picked up the habit of using supervisord to tun my processes. If you would like example code for that, check out https://github.com/Krijger/docker-cookbooks. I use my supervisor image as a base for all my other images. I blogged on using supervisor here.
To keep docker containers running, you need to keep a process active in the foreground.
So you could probably replace that last line in your Dockerfile with
CMD /bin/riak console
Or even
CMD /bin/riak start && tail -F /var/log/riak/erlang.log.1
Note that you can't have multiple lines of CMD statements, only the last one gets run.
Using tail to keep container alive is a hack. Also, note, that with -f option container will terminate when log rotation happens (this can be avoided by using -F instead).
A better solution is to use supervisor. Take a look at this tutorial about running Riak in a Docker container.
The explanation for:
If I run it using docker run -i -t quintenk/riak-dev /bin/bash the riak process is not started
is as follows. Using CMD in the Dockerfile is actually the same functionality as starting the container using docker run {image} {command}. As Gigablah remarked only the last CMD is used, so the one written in the Dockerfile is overwritten in this case.
By using CMD /bin/riak start && tail -f /var/log/riak/erlang.log.1 in the Buildfile, you can start the container as a background process using docker run -d {image}, which works like a charm.
"If I run it using docker run -i -t quintenk/riak-dev /bin/bash the riak process is not started"
It sounds like you only want to be able to monitor the log when you attach to the container. My use case is a little different in that I want commands started automatically, but I want to be able to attach to the container and be in a bash shell. I was able to solve both of our problems as follows:
In the image/container, add the commands you want automatically started to the end of the /etc/bash.bashrc file.
In your case just add the line /bin/riak start && tail -F /var/log/riak/erlang.log.1, or put /bin/riak start and tail -F /var/log/riak/erlang.log.1 on separate lines depending on the functionality desired.
Now commit your changes to your container, and run it again with: docker run -i -t quintenk/riak-dev /bin/bash. You'll find the commands you put in the bashrc are already running as you attach.
Because I want a clean way to have the process exit later I make the last command a call to the shell's read which causes that process to block until I later attach to it and hit enter.
arthur#macro:~/docker$ sudo docker run -d -t -i -v /raid:/raid -p 4040:4040 subsonic /bin/bash -c 'service subsonic start && read -p "waiting"'
WARNING: Docker detected local DNS server on resolv.conf. Using default external servers: [8.8.8.8 8.8.4.4]
f27229a260c9
arthur#macro:~/docker$ sudo docker ps
[sudo] password for arthur:
ID IMAGE COMMAND CREATED STATUS PORTS
35f253bdf45a subsonic:latest /bin/bash -c service 2 days ago Up 2 days 4040->4040
arthur#macro:~/docker$ sudo docker attach 35f253bdf45a
arthur#macro:~/docker$ sudo docker ps
ID IMAGE COMMAND CREATED STATUS PORTS
as you can see the container exits after you attach to it and unblock the read.
You can of course use a more sophisticated script than read -p if you need to do other clean up, such as stopping services and saving logs etc.
I use a simple trick whenever I start building a new docker container. To keep it alive, I use a ping in the entrypoint script.
So in the Dockerfile, when using debian, for instance, I make sure I can ping.
This is btw, always nice, to check what is accessible from within the container.
...
RUN DEBIAN_FRONTEND=noninteractive apt-get update \
&& apt-get install -y iputils-ping
...
ENTRYPOINT ["entrypoint.sh"]
And in the entrypoint.sh file
#!/bin/bash
...
ping 10.10.0.1 >/dev/null 2>/dev/null
I use this instead of CMD bash, as I always wind up using a startup file.
I'm using the following Upstart script to keep Nginx up and running on Ubuntu server:
start on (filesystem and net-device-up IFACE=lo)
stop on runlevel [!2345]
env DAEMON=/usr/sbin/nginx
env CONF=/etc/nginx/nginx.conf
respawn
respawn limit 10 5
pre-start script
$DAEMON -t
if [ $? -ne 0 ]; then
exit $?
fi
end script
exec $DAEMON -c $CONF -g "daemon off;" > /dev/null 2>&1
This script works fine except when I'm killing the Nginx master process using the kill command. After killing the master process /var/run/nginx.pid remains the same but Nginx pid keeps changing every few seconds (this means Nginx is restarting all the time?). Any idea how to fix this?
My stack is nginx that runs python web.py fast-cgi scripts using spawn-fcgi. I am using runit to keep the process alive as a Daemon. I am using unix sockets fior the spawed-fcgi.
The below is my runit script called myserver in /etc/sv/myserver with the run file in /etc/sv/myserver/run.
exec spawn-fcgi -n -d /home/ubuntu/Servers/rtbTest/ -s /tmp/nginx9002.socket -u www-data -f /home/ubuntu/Servers/rtbTest/index.py >> /var/log/mylog.sys.log 2>&1
I need to push changes to the sripts to the production servers. I use paramiko to ssh into the box and update the index.py script.
My question is this, how do I gracefully reload the index.py using best practice to update to the new code.
Do I use:
sudo /etc/init.d/nginx reload
Do I restart the the runit script:
sudo sv start myserver
Or do I use both:
sudo /etc/init.d/nginx reload
sudo sv start myserver
Or none of the above?
Basically you have to re-start the process that's loaded your Python script. This is spawn-cgi and not nginx itself. nginx only communicates with spawn-cgi via the Unix socket and will happily re-connect if the connection is lost due to a restart of the spawn-cgi process.
Therefore I'd suggest a simple sudo sv restart myserver. No need to re-start/re-load nginx itself.