I've downloaded two docker containers and already configure them.
So, now all I want is to start them on system startup.
They are in a path like
/home/user/docker-mailserver
/home/user/docker-webserver
Hosted on a Ubuntu 18.04.01 (x64)
On boot those docker containers are not running.
On login, those docker containers are starting.
I already tried to do something like
docker run -it --restart unless-stopped fancydockercontainer:latest
docker run -dit --restart unless-stopped fancydockercontainer:latest
But then when I do docker ps there where new containers added to the pool.
Is there a way to "re-route" the start process of those container to system start without completely delete / remove them?
Addition:
I started them like docker-compose up -d mailserver
After #KamilCuk gave a hint to solve this with service, this was a possible solution.
Looks like this:
Create service file with command:
nano /etc/systemd/system/docker-mail.service
Done stuff like that in the file
[Unit]
Description=Docker Mailserver
Requires=docker.service
After=docker.service
[Service]
Restart=always
RemainAfterExit=yes
WorkingDirectory=/home/user/docker-mailserver
ExecStart=/usr/bin/docker-compose up -d mail
ExecStop=/usr/bin/docker-compose stop -d mail
[Install]
WantedBy=default.target
Adding the new service to systemctl with systemctl enable docker-mail.service
After rebooting the server, this mailserver is available.
At this point, I was able to see the startup log with journalctl -u docker-mail.service -b (-b is just "boot")
Related
Created flask application and deploying on gunicorn server on docker.
I want to write shell script to create linux service inside docker container, so I can start, stop and restart my flask app inside container.
Dockerfile:
FROM python
COPY ./app /app
WORKDIR /app
RUN pip install -r requirements.txt
EXPOSE 9003
CMD ["gunicorn", "-b", "0.0.0.0:9003", "main:app"]
Build it and run using command : docker run -p 9003:9003 myapp.
What I have tried opened docker container cli: docker exec -it <container_id> bash . You can find container id by command docker ps.
Step 1: changed directory to /etc/init.d and created myservice.service file.
[Unit]
Description=Gunicorn instance to serve app
[Service]
WorkingDirectory=/home/app
ExecStart=gunicorn --workers 3 --bind 0.0.0.0:9003 unix:app.sock -m 007 main:app
Restart=always
[Install]
WantedBy=multi-user.target
step 3: I enable service by first running cd /etc/rc3.d and then run ln -s ../init.d/{SERVICENAME} S95{SERVICENAME}
step 4: Give permission : chmod +x /etc/init.d/{SERVICENAME}
step 5: start service : `service myservice start
But this give me error
enter image description here
Docker container OS: Debian 10
Why its giving me Unit not found? any idea? How to resolve?
Why its giving me Unit not found? any idea? How to resolve?
You are improperly creating the file in wrong directory and creating unrelated links. You seem to be mixing rc-scripts with systemd. They are not alike, they are completely different. Toss aside rc-scripts and forget /etc/rc.d ever existed. Re-read and follow a good tutorial on how to add a systemd service file to your system.
want to write shell script to create linux service inside docker container
This will make no difference, as the container you are running does not run systemd - you run only CMD ["gunicorn"..., so your service will never be running. Typically in docker, multiple services are run with a shell script or in more complicated cases with a supervisord. In your case, there is no need to setup anything - just let the docker run the service as its pid 0 process, it's only one process. Re-research how docker works and research how services are written in docker.
What you may want to create is a service file on host, not inside docker container.
Thanks for answer.
Using Window 10
please see references and way what I was doing.
Created myproject.service in /etc/systemd/system inside docker container.
[Unit]
Description=Gunicorn instance to serve myproject
After=network.target
[Service]
User=sammy
Group=www-data
WorkingDirectory=/home/sammy/myproject
Environment="PATH=/home/sammy/myproject/myprojectenv/bin"
ExecStart=/home/sammy/myproject/myprojectenv/bin/gunicorn --workers 3 --bind unix:myproject.sock -m 007 wsgi:app
this newly created service is not catched and when I try to start this service using command service myproject start, It gives error unrecognized service: myproject.
How will OS know that new service has been created and to reload it.
In Linux, by running daemon-reload, It catches all new created services. But In case of docker, how to do this?
Reference: https://www.digitalocean.com/community/tutorials/how-to-serve-flask-applications-with-gunicorn-and-nginx-on-ubuntu-18-04
For rc script, Reference: https://unix.stackexchange.com/questions/106656/how-do-services-in-debian-work-and-how-can-i-manage-them
I have a container with a docker-compose like this
services:
app:
build:
context: app
restart: always
version: '3.5'
It launches a node app docker-compose run -d --name my-app app node myapp.js
the app is made to either run to completion or throw, and then the goal would be to have docker restart it in an infinite loop, regardless of the exit code. I'm unsure why but it doesn't restart it.
How can I debug this? I have no clue what exit code node is sending, nor do I know which exit code docker uses to decide to restart or not.
I am also on mac, haven't tested on linux yet. Edit: It does restart on linux, don't have another mac to see if the behavior is isolated to my mac only.
It is important to understand the following two concepts:
Ending your Node app doesn't mean the end of your container. Your container runs a shared process from your OS and your Node app is only a sub process of that. (Assuming your application runs with the Deamon)
The restart indicates the "starting" policy - it will never terminate and start your container again.
Having said that, what you need is a way you can really restart your container from within the application. The best way to do this is via Docker healthchecks:
https://docs.docker.com/engine/reference/builder/#healthcheck
Or, here are some answers on restarting a container from within the application.
Stopping docker container from inside
From Github Issue seems like it does not respect `--restart``, or from the #Charlie comment seems like its vary from platform to platform.
The docker-compose run command is for running “one-off” or “adhoc” tasks.The run command acts like docker run -ti in that it opens an interactive terminal to the container and returns an exit status matching the exit status of the process in the container.
docker-compose run
Also if its like docker run -it then I am not seeing an option for restart=always but it should then respect ``restart` option in compose.
Usage:
run [options] [-v VOLUME...] [-p PORT...] [-e KEY=VAL...] [-l KEY=VALUE...]
SERVICE [COMMAND] [ARGS...]
Options:
-d, --detach Detached mode: Run container in the background, print
new container name.
--name NAME Assign a name to the container
--entrypoint CMD Override the entrypoint of the image.
-e KEY=VAL Set an environment variable (can be used multiple times)
-l, --label KEY=VAL Add or override a label (can be used multiple times)
-u, --user="" Run as specified username or uid
--no-deps Don't start linked services.
--rm Remove container after run. Ignored in detached mode.
-p, --publish=[] Publish a container's port(s) to the host
--service-ports Run command with the service's ports enabled and mapped
to the host.
--use-aliases Use the service's network aliases in the network(s) the
container connects to.
-v, --volume=[] Bind mount a volume (default [])
-T Disable pseudo-tty allocation. By default `docker-compose run`
allocates a TTY.
-w, --workdir="" Working directory inside the container
I'm trying to configure my CoreOS server with Terraform, using cloud-config file for CoreOS. I am currently trying to set up a Mongo database in a Docker container.
Here is my config file:
write_files:
- path: "/home/core/keyfile"
permissions: "0600"
owner: "999"
content: |
hUoQVrERB0*** <here is my key for MongoDB>
coreos:
units:
- name: "dockerstart.service"
command: "start"
content: |
[Unit]
Description=Start
Author=Me
[Service]
Restart=always
ExecStart=/usr/bin/docker run --name mongo -v /home/core:/opt --add-host node1.example.com:127.0.0.1 -p 27017:27017 -d mongo:2.6.5 --smallfiles --keyFile /opt/keyfile --replSet "rs0"
ExecStop=/usr/bin/docker rm -f mongo
I am not sure how to use coreOS units (when I ssh into the server, the docker container is not running, so the config file is not correct). According to CoreOS Validator, my file is valid. Also, I am not sure if that is the simplest way to deploy a MongoDB server.
How to properly use CoreOS units ? Any thoughts on a way to improve how deploy a Mongo Database ?
Any help, comments, suggestions are appreciated !
I finally found the solution.
Actually running docker run with -d option daemonizes the command. So, when systemd founds out that this action runs in the background, it considers that Docker is crashing.
Here is journalctl -u dockerstart.service result on server :
docker[1237]: ace3978442a729420ecb87af224bd146ec6ac7912c5cc452570735f4a3be3a79
docker[1297]: mongo
systemd[1]: dockerstart.service: Service hold-off time over, scheduling restart.
systemd[1]: Stopped Start.
systemd[1]: Started Start.
Here you can clearly see that systemd stops and restarts the Start service.
So the solution for this might be removing -d from the docker run command.
If help you in the future, you can use a Container Linux Config file format for setup the initial config for CoreOS:
I published an example that create an ignition config based on a Container Linux Config file applied to Terraform in: https://github.com/joariasl/terraform-ansible-docker-swarm-coreos-aws/tree/feature/coreos-etcd
About this: https://coreos.com/os/docs/latest/provisioning.html
The default DNS for Docker (e.g. 8.8.8.8) is blocked where I work, so I want to change the default. I've been able to do this using
$ docker daemon --dns <mydnsaddress>
but I want to do this using a systemd drop-in instead, since the official Docker docs recommend this way. I've made a /etc/systemd/system/docker.service.d/dns.conf file, and used things like this:
[Service]
DNS=<mydnsaddress>
But I just have no idea what the variable name is supposed to be. How do I set this? More importantly, is there a page that documents all config variables that can be used in systemd drop-ins for Docker?
(btw, this is Docker 1.9 on Ubuntu 15.10, although I don't suspect any bugs)
All .conf files in /etc/systemd/system/docker.service.d overrule the settings from the /usr/lib/systemd/system/docker.service file, which is almost what you tried.
Instead of putting a DNS=.. line in, you need to copy the ExecStart= part from the /usr/lib/systemd/system/docker.service file to dns.conf (or mydocker.conf). Add --dns $ip after the daemon part of the ExecStart. E.g.:
[Service]
ExecStart=
ExecStart=/usr/bin/docker daemon --dns 192.168.1.1 -H fd://
Where the 192.168.1.1 is the ip of the dns server.
Now restart docker via systemctl and docker should now restart with your own dns. (Checkable via systemctl status docker.service | grep dns).
Note that the empty ExecStart= is required, as systemctl only will overrule the ExecStart if it is cleared first.
Also note that a systemctl daemon-reload is needed after editing files in /etc/systemd/system/.
Last remark is that on some systems docker.service is not located in /usr/lib/systemd/system/, but in /lib/systemd/system/.
Yes I agreed to previous answer given by #steviethecat but this changes overwrite to default when docker restart so I followed below steps. Using Docker version 18.09.2,
I followed link https://success.docker.com/article/using-systemd-to-control-the-docker-daemon
sudo systemctl edit docker //this opens new file use as overwrite file.
add below lines. Make sure you have ExecStart= before setting this value. Above given link having details.
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd --dns 192.168.1.1 -H fd://
once above lines added to file, execute below lines.
sudo systemctl daemon-reload
systemctl restart docker
systemctl status docker
I'm doing some initial tests with docker. At moment i have my images and I can put some containers running, with:
docker ps
I do docker attach container_id and start apache2 service.
Then from the main console I commit the container to the image.
After exiting the container, if I try to start the container or try to run one new container from the committed image, the service is always stopped.
How can create or restart one container with the services started, for example apache?
EDIT:
I've learned a lot about Docker since originally posting this answer. "Starting services automatically in Docker containers" is not a good usage pattern for Docker. Instead, use something like fleet, Kubernetes, or even Monit/SystemD/Upstart/Init.d/Cron to automatically start services that execute inside Docker containers.
ORIGINAL ANSWER:
If you are starting the container with the command /bin/bash, then you can accomplish this in the manner outlined here: https://stackoverflow.com/a/19872810/2971199
So, if you are starting the container with docker run -i -t IMAGE /bin/bash and if you want to automatically start apache2 when the container is started, edit /etc/bash.bashrc in the container and add /usr/local/apache2/bin/apachectl -f /usr/local/apache2/conf/httpd.conf (or whatever your apache2 start command is) to a newline at the end of the file.
Save the changes to your image and restart it with docker run -i -t IMAGE /bin/bash and you will find apache2 running when you attach.
An option that you could use would to be use a process manager such as Supervisord to run multiple processes. Someone accomplished this with sshd and mongodb: https://github.com/justone/docker-mongodb
I guess you can't. What you can do is create an image using a Dockerfile and define a CMD in that, which will be executed when the container starts. See the builder documentation for the basics (https://docs.docker.com/reference/builder/) and see Run a service automatically in a docker container for information on keeping your service running.
You don't need to automate this using a Dockerfile. You could also create the image via a manual commit as you do, and run it command line. Then, you supply the command it should run (which is exactly what the Dockerfile CMD actually does). You can also override the Dockerfiles CMD in this way: only the latest CMD will be executed, which is the command line command if you start the container using one. The basic docker run -i -t base /bin/bash command from the documentation is an example. If your command becomes too long you could create a convenience script of course.
By design, containers started in detached mode exit when the root process used to run the container exits.
You need to start a Apache service in FOREGROUND mode.
docker run -p 8080:80 -d ubuntu/apache apachectl -D FOREGROUND
Reference: https://docs.docker.com/engine/reference/run/#detached-vs-foreground
Try to add start script to entrypoint in dockerfile like this;
ENTRYPOINT service apache2 restart && bash