docker logs -f after container restart - docker

I am using docker logs -f mycontainer to check the logs. If I restart mycontainer by docker rm -f mycontainer then docker run -d --name mycontainer, I need to use Ctrl-C then rerun the docker logs command to get the logs. I wonder if there is a better way for me to keep receiving the logs even after the container restarts.

As other commenters have mentioned, the "rm" command is destroying your container, not restarting it.
But to answer your question you could use something like this:
watch -n 0 "docker logs mycontainer"
The docker logs command doesn't keep running for a stopped container, but you can achieve a similar effect using the "watch" command. And since it's not a Docker command, it doesn't care if the container is running or not.
If you're on a Mac you might not have watch. It can be installed using pip. The same thing can be achieved with a one-liner bash script but I find watch to be much neater.

2 things
with docker rm -f mycontainer you are not stopping your container, you are killing it, then you start another brand new after
you can use docker stop mycontainer and start or simply docker restart mycontainer to keep logs.
Because container are stateless, you will lost logs if you delete your container. In that case, you have to use a volume where to write your application logs. They will be on the host instead of into your container.

Related

What to do if the docker container hangs and does not respond to any command other than ctrl+c?

I have been running a nvidia docker image since 13 days and it used to restart without any problems using docker start -i <containerid> command. But, today while I was downloading pytorch inside the container, download got stuck at 5% and gave no response for a while.
I couldn't exit the container either by ctrl+d or ctrl+c. So, I exited the terminal and in new terminal I ran this docker start -i <containerid> again. But ever since this particular container is not responding to any command. Be it start/restart/exec/commit ...nothing! any command with this container ID or name is just non-responsive and had to exit out of it only after ctrl+c
I cannot restart the docker service since it will kill all running docker containers.
Cannot even stop the container using this docker container stop <containerid>
Please help.
You can make use of docker RestartPolicy:
docker update --restart=always <container>
while mindful of caveats on the docker version you running.
or explore an answer by #Yale Huang from a similar question: How to add a restart policy to a container that was already created
I had to restart docker process to revive my container. There was nothing else I could do to solve it. used sudo service docker restart and then revived my container using docker run. I will try to build the dockerfile out of it in order to avoid future mishaps.

How to start an existing image as container so it runs in the background [duplicate]

Running the docker registry with below command always throws an error:
dev:tmp me$ docker run \
-d --name registry-v1 \
-e SETTINGS_FLAVOR=local \
-e STORAGE_PATH=/registry \
-e SEARCH_BACKEND=sqlalchemy \
-e LOGLEVEL=DEBUG \
-p 5000:5000 \
registry:0.9.1
Error response from daemon: Conflict. The name "registry-v1" is already in use by container f9e5798a82e0. You have to delete (or rename) that container to be able to reuse that name.
How can I prevent this error ?
I got confused by this also. There are two commands relevant here:
docker run # Run a command in a **new** container
docker start # Start one or more stopped containers
That means you have already started a container in the past with the parameter
docker run --name registry-v1 ...
You need to delete that first before you can re-create a container with the same name with
docker rm registry-v1
When that container is sill running you need to stop it first before you can delete it with
docker stop registry-v1
Or simply choose a different name for the new container.
To get a list of existing containers and their names simply invoke
docker ps -a
Here what i did, it works fine.
step 1:(it lists docker container with its name)
docker ps -a
step 2:
docker rm name_of_the_docker_container
When you are building a new image you often want to run a new container each time and with the same name. I found the easiest way was to start the container with the --rm option:
--rm Automatically remove the container when it exits
e.g.
docker run --name my-micro-service --rm <image>
Sadly it's used almost randomly in the examples from the docs
Edit: Read Lepe's comment below.
Just to explain what others are saying (it took me some time to understand) is that, simply put, when you see this error, it means you already have a container and what you have to do is run it. While intuitively docker run is supposed to run it, it doesn't. The command docker run is used to only START a container for the very first time. To run an existing container what you need is docker start $container-name. So much for asking developers to create meaningful/intuitive commands.
You have 2 options to fix this...
Remove previous container using that name, with the command docker rm $(docker ps -aq --filter name=myContainerName)
OR
Rename current container to a different name i.e change this portion --name registry-v1 to something like --name myAnotherContainerName
You are getting this error because that container name ( i.e registry-v1) was used by another container in the past...even though that container may have exited i.e (currently not in use).
Cause
A container with the same name is still existing.
Solution
To reuse the same container name, delete the existing container by:
docker rm <container name>
Explanation
Containers can exist in following states, during which the container name can't be used for another container:
created
restarting
running
paused
exited
dead
You can see containers in running state by using :
docker ps
To show containers in all states and find out if a container name is taken, use:
docker ps -a
Here is how I solved this on ubuntu 18:
$ sudo docker ps -a
copy the container ID
For each container do:
$ sudo docker stop container_ID
$ sudo docker rm container_ID
removing all the exited containers
docker rm $(docker ps -a -f status=exited -q)
The Problem: you trying to create new container while in background container with same name is running and this situation causes conflicts.
The error would be like:
Cannot create continer for service X :Conflict. The name X is already in use by container abc123xyz. You have to remove ot delete (or rename) that container to be able to reuse that name.
Solution rename the service name in docker-compose.yml or delete the running container and rebuild it again (this solution related to Unix/Linux/macOS systems):
get all running containers sudo docker ps -a
get the specific container id
stop and remove the duplicated container / force remove it
sudo docker stop <container_id>
sudo docker rm <container_id>
or
sudo docker rm --force <container_id>
You can remove it with command sudo docker rm YOUR_CONTAINER_ID, then run a new container with sudo docker run ...;
or restart an existing container with sudo docker start YOUR_CONTAINER_ID
I was running into this issue that when I run docker rm (which usually works) I would get:
Error: No such image
The easiest solution to this is removing all stopped containers by running:
docker container prune
I have solved the issue by doing following steps and I hope it helps.
Type docker ps -a to list all the containers in your system.
Check the NAMES part where you have initialized your docker container.
Then type docker rm --force name_of_container
Install the docker container as you wish.
I had problem using NIFI and I have removed and reinstalled using docker. Good luck.
TL:DR;
List all containers:
docker ps -a
Remove the concerned container by id:
docker container rm <container_id>
I'm just learning docker and this got me as well. I stopped the container with that name already and therefore I thought I could run a new container with that name.
Not the case. Just because the container is stopped, doesn't mean it can't be started again, and it keeps all the same parameters that it was created with (including the name).
when I ran docker ps -a that's when I saw all the dummy test containers I created while I was playing around.
No problem, since I don't want those any more I just did docker rm containername at which point my new container was allowed to run with the old name.
Ah, and now that I finish writing this answer, I see Slawosz's comment on Walt Howard's answer above suggesting the use of docker ps -a
The OP's problem is the error. Deleting state isn't the only solution - or even a good one. The problem is docker run isn't re-entrant, and docker start is impotent w/o run. So we have to combine them.
For example to run Postgres w/o destroying previous state, try this:
docker start postgres || docker run -d -p 5432:5432 --name postgres -e POSTGRES_PASSWORD=password postgres:13-alpine
Ok, so I didn't understand either, then I left my pc, went to do other things, and upon my return, it clicked :D
You download a docker image file. docker pull *image-name* will just pull the image from docker hub without running it.
Now, you use docker run, and give it a name (e.g. newWebServer).
docker run -d -p 8080:8080 -v volume --name newWebServer image-name/version
You perhaps only need docker run --name *name* *image*, but the other stuff will become useful quickly.
-d (detached) - means the container will exit when the root process used to run the container exits.
-p (port) - specify the container port and the host port. Kind of the internal and external port. The internal one being the port the container uses, and the external one is the port you use outside of it and probably the one you need to put in your web browser if that's how you access your app.
--name (what you want to call this instance of the container) - you could have several instances of the same container all with different names, which is useful when you're trying to test something.
image-name/version is the actual image you want to create the container from. You can see a list of all the images on your system with docker images -a. You may have more than one version, so make sure you choose the correct one/tag.
-v (volume) - perhaps not needed initially, but soon you'll want to persist data after your container exits.
OK. So now, docker run just created a container from your image. If it isn't running, you can now start it with it's name:
docker start newWebServer
You can check all your containers (they may or may not be running) with
docker ps -a
You can stop and start them (or pause them) with their name or the container id (or just the first few characters of it) from the CONTAINER ID column e.g:
docker stop newWebServer
docker start c3028a89462c
And list all your images, with
docker images -a
In a nutshell, download an image; docker run creates a container from it; start it with docker start (name or container id); stop it with docker stop (name or container id).
I had this issue because I had two or more containers with the same container_name in the docker-compose.yml file.
Simple Solution: Goto your docker folder in the system and delete .raw file or docker archive with large size.
For me, the issue was that I used an image name more than once in the dockerfile.
This happened to me on the docker tutorial! The port I tried to use was taken, but docker still created.. an image? A process to run docker? I'll find out soon. Anyways, to choose a different port, I had to remove the older image, and then docker run again.
Sometimes a tutorial can be too terse. What you want is concise, not terse, or even succinct.

How to see the docker state instead of interacting with the shell?

I use following command to build web server
docker run --name webapp -p 8080:4000 mypyweb
When it stopped and I want to restart, I always use:
sudo docker start webapp && sudo docker exec -it webapp bash
But I can't see the server state as the first time:
Digest: sha256:e61b45be29f72fb119ec9f10ca660c3c54c6748cb0e02a412119fae3c8364ecd
Status: Downloaded newer image for ericgoebelbecker/stackify-tutorial:1.00
* Running on http://0.0.0.0:4000/ (Press CTRL+C to quit)
How can I see the state instead of interacting with the shell?
When you use docker run, the default behavior is to run the container detached. This runs in the background and is detached from your shell's stdin/out.
To run the container in the foreground and connected to stdin/out:
docker run --interactive --tty --publish=8080:4000 mypyweb
To docker start a container, similarly:
docker start --interactive --attach [CONTAINER]
NB --attach rather than -tty
You may list (all add --all) running containers:
docker container ls
E.g. I ran Nginx:
CONTAINER ID IMAGE PORTS NAMES
7cc4b4e1cfd6 nginx 0.0.0.0:8888->80/tcp nostalgic_thompson
NB You may use the NAME or any uniquely identifiable subset of the ID to reference the container
Then:
docker stop nostalgic_thompson
docker start --interative --attach 7cc4
You may check the container's logs (when running detached or from another shell) by grabbing the container's ID or NAMES
docker logs nostalgic_thompson
docker logs 7cc4
HTH!
Using docker exec is causing the shell to attach to the container. If you are comparing the behavior of docker run versus docker start, they behave differently, and it is confusing. Try this:
$ sudo docker start -a webapp
the -a flag tells docker to attach stdout/stderr and forward signals.
There are some other switches you can use with the start command (and a huge number for the run command). You can run docker [command] --help to get a summary of the options.
One other command that you might want to use is logs which will show the console output logs for a running container:
$ docker ps
[find the container ID]
$ docker logs [container ID]
If you think your container's misbehaving, it's often not wrong to just delete it and create a new one.
docker rm webapp
docker run --name webapp -p 8080:4000 mypyweb
Containers occasionally have more involved startup sequences and these can assume they're generally starting from a clean slate. It should also be extremely routine to delete and recreate a container; it's required for some basic tasks like upgrading the image underneath a container to a newer version or changing published ports or environment variables.
docker exec probably shouldn't be part of your core workflow, any more than you'd open a shell to interact with your Web browser. I generally don't tend to docker stop containers, except to immediately docker rm them.

Docker container keeps restarting

I was trying rancher.
I used the command:
sudo docker run -d --restart=always -p 8080:8080 rancher/server
to start run it.
Then I stopped the container and removed it. But if I stop and restart the docker daemon or reboot my laptop, and lookup running containers using docker ps command, it will have rancher server running again. How do I stop/remove it completely and make sure it will not run again.
Note: following issue 11008 and PR 15348 (commit fd8b25c, docker v1.11.2), you would avoid the issue with:
sudo docker run -d --restart=unless-stopped -p 8080:8080 rancher/server
In your current situation, thanks to PR 19116, you can use docker update to update the restart policy.
docker update --restart=unless-stopped <yourContainerID_or_Name>
Then stop your container, restart your docker daemon: it won't restart said container.
The OP codefire points to another reason in the comments:
When I first ran the start rancher server command, I didn't notice that it was being downloaded. So I may have retried that command a couple times.
That must be why the job kept on restarting even after stopping and removing containers that was started as rancher server.
After stopping and removing 8+ containers, it finally stopped
That is why I have aliases to quickly remove any stopped containers.
it keeps restarting because you're using --restart=always flag
Run
docker logs <CONTAINER_ID>
to see if your code is encountering any errors that does not allow the container to run properly
Thanks for the answers, but for me even using the answer von VonC the problem continues.
After researching Kubernetes was running the image again and again.
Use kubectl get nodes to get the nodes u have and later run:
kubectl drain NODE_ID --delete-emptydir-data --ignore-daemonsets
These solutions are correct! But for me there was a situation when these answers did not work out. That's because I was running service in the background I did not remove it so it keeps running even you remove container it will restart it again and so on...
So answer to that specific problem is
docker service rm service name or id
Docker run in your locahost if you shutdown/kill docker damen then docker stop and inside in docker container delete data if you not save your data in external volume.
docker run -d nginxlogs:/var/log/nginx -p 5000:80 nginx

How can I stop and delete a docker container launched with restart always option?

I run some containers with the option --restart always.
It works good, so good, that I have now difficulties to stop these containers now :)
I tried :
sudo docker stop container && sudo docker rm -f container
But the container still restarts.
The docker documentation explains the restart policies, but I didn't find anything to resolve this issue.
Just
sudo docker rm -f container
will kill the process if it is running and remove the container, in one step.
That said, I couldn't replicate the symptoms you described. If I run with --restart=always, docker stop will stop the process and it remains stopped.
I am using Docker version 1.3.1.
docker update --restart=no <container>
Many thanks for those who takes time to respond.
If you use docker directly, Bryan is right sudo docker rm -f container is enough.
My problem was mainly that I use puppet to deploy docker images and run containers. I use this module and it creates entries in /etc/init for the upstart process manager.
I think, my problem whas that, some kind of incompatibilities between the process manager and docker.
In this situation, to halt a container, simply sudo stop docker-container.
More informations on managing docker container run can be found on the docker website

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