I have a debian package I am deploying that comes with a docker image. On upgrading the package, the prerm script stops and removes the docker image. As a fail safe, I have the preinst script do it as well to ensure the old image is removed before the installation of the new image. If there is no image, the following error reports to the screen: (for stop) No such image: <tag> and (for rmi): No such container: <tag>.
This really isn't a problem, as the errors are ignored by dpkg, but they are reported to the screen, and I get constant questions from the users is that error ok? Did the install fail? etc.
I cannot seem for find the correct set of docker commands to check if a container is running to stop it, and check to see if an image exists to remove it, so those errors are no longer generated. All I have is docker image tag to work with.
I think you could go one of two ways:
Knowing the image you could check whether there is any container based on that image. If yes, find out whether that container is running. If yes, stop it. If not running, remove the image. This would prevent error messages showing up but other messages regarding the container and image handling may be visible.
Redirect output of the docker commands in question, e.g. >/dev/null
you're not limited with docker-cli you know? you can always combine docker-cli commands with linux sh or dos commands as well and also you can write your own .sh scripts and if you don't want to see the errors you can either redirect them or store them to a file such as
to redirect: {operation} 2>/dev/null
to store : {operation} 2>>/var/log/xxx.log
Related
I'm new to Docker, and I'm not sure how to quite deal with this situation.
So I'm trying to run a docker container in order to replicate some results from a research paper, specifically from here: https://github.com/danhper/bigcode-tools/blob/master/doc/tutorial.md
(image link: https://hub.docker.com/r/tuvistavie/bigcode-tools/).
I'm using a windows machine, and every time I try to run the docker image (via: docker run -p 80:80 tuvistavie/bigcode-tools), it instantly closes. I've tried running other images, such as the getting-started, but that image doesn't close instantly.
I've looked at some other potential workarounds, like using -dit, but since the instructions require setting an alias/doskey for a docker run command, using the alias and chaining it with other commands multiple times results in creating a queue for the docker container since the port is tied to the alias.
Like in the instructions from the GitHub link, I'm trying to set an alias/doskey to make api calls to pull data, but I am unable to get any data nor am I getting any errors when performing the calls on the command prompt.
Sorry for the long question, and thank you for your time!
Going in order of the instructions:
0. I can run this, it added the image to my Docker Desktop
1.
Since I'm using a windows machine, I had to use 'set' instead of 'export'
I'm not exactly sure what the $ is meant for in UNIX, and whether or not it has significant meaning, but from my understanding, the whole purpose is to create a directory named 'bigcode-workspace'
Instead of 'alias,' I needed to use doskey.
Since -dit prevented my image from instantly closing, I added that in as well, but I'm not 100% sure what it means. Running docker run (...) resulted in the docker image instantly closing.
When it came to using the doskey alias + another command, I've tried:
(doskey macro) (another command)
(doskey macro) ^& (another command)
(doskey macro) $T (another command)
This also seemed to be using github api call, so I also added a --token=(github_token), but that didn't change anything either
Because the later steps require expected data pulled from here, I am unable to progress any further.
Looks like this image is designed to be used as a command-line utility. So it should not be running continuously, but you run it via alias docker-bigcode for your tasks.
$BIGCODE_WORKSPACE is an environment variable expansion here. So on a Windows machine it's %BIGCODE_WORKSPACE%. You might want to set this variable in Settings->System->About->Advanced System Settings, because variables set with SET command will apply to the current command prompt session only. Or you can specify the path directly, without environment variable.
As for alias then I would just create a batch file with the following content:
docker run -p 6006:6006 -v %BIGCODE_WORKSPACE%:/bigcode-tools/workspace tuvistavie/bigcode-tools %*
This will run the specified command appending the batch file parameters at the end. You might need to add double quotes if BIGCODE_WORKSPACE path contains spaces.
I have a weird problem with Docker and hope someone here can help me :)
I want to create a keycloak image that is derived from the image jboss/keycloak. The idea is that in the Dockerfile also a preconfigured standalone.xml is copied into the image and keycloak can start directly without manual work.
But as soon as I write for example a
"CMD touch /opt/test.txt"
into the file the container crashes with the message "12:02:14,290 INFO [org.jboss.modules] (main) JBoss Modules version 1.9.1.Final
WFLYSRV0073: Invalid option '/bin/sh'"
This is just a new file with no purpose, the changes to the .xml are not in there yet.
As soon as I put only the FROM back in and rebuild everything works again.
I thought through the layers in the container you could mod an image, but here it doesn't seem to work. Can someone tell me why ?
So far it has always worked with the alpine image, but I don't want to build the whole keycloak setup again myself, when there is already an official image for it.
This is basically what I had in mind:
FROM jboss/keycloak:X.XX
CMD rm /opt/jboss/keycloak/standalone/configuration/standalone.xml
COPY ./keycloak/standalone.xml /opt/jboss/keycloak/standalone/configuration/
Thanks for help :)
Change
CMD rm
to
RUN rm
RUN is part of building. every RUN command is executed while your image is built.
With CMD you define (or override) the default command when running/starting a container based on your image (and you don't want to change keycloaks default CMD)
I use Java S2I image for a container running in Openshift (on premise). My problem is that the output of the image is page-buffered and oc logs ... does not show me the last logs.
I could probably spin up my docker image that would do stdbuf -oL -e0 java ... but I would prefer to stick to the 'official' image (just adding the jar to /deployments). Is there any way to reduce buffering (use line-buffering instead of page-buffering), or flush the output on demand?
EDIT: It seems that I could update deployment config and pass stdbuf in there, but that means that I'd have to compose all the args myself. Ideal solution would be passing --tty do Docker, but I can't see how a custom arguments could be passed that way in Openshift.
In your repo, try creating the file .s2i/bin/run. In it add:
#/bin/bash
exec stdbuf -oL -e0 /usr/local/s2i/run
I always forget where the S2I assemble and run scripts are in the Java S2I image, so you may need to replace /usr/local/s2i with the correct path.
What adding this file does is that it will be run as the startup command instead of the original run script. You can then run the original script with stdbuf. Ensure you use exec so that the sub process replaces the current one, else signals will not be propagated through properly.
Even though this might work, am surprised logging isn't working in an unbuffered mode already. I expect there would be a better way of controlling it through some Java config instead.
Contents of the Dockerfile:
FROM XYZ
MAINTAINER ABC
RUN echo "hello world"
EXPOSE 80
ENTRYPOINT ["/usr/sbin/httpd","-D","FOREGROUND"]
When I try to build an image from this file, I see the following:
permission denied Removing intermediate container
when docker tries to execute the RUN command
Observations:
This error is irrespective of the content of the RUN command.
Removing it ensures the build completes without issues.
I am able to build from the same docker file and image on another host.
"docker info" produced similar information on both machines.
How can I debug this further to see what the issue is?
Update (in response to the comments below):
I have been able to build the same image (and others) on this instance before
The issue occurred irrespective of the base image used
The issue was specific to this one instance which is running CentOS
The user I was logged in as was different from the user the daemon was running as (root)
Assuming the issue may have been because of the user mismatch, I changed to root and tried the command. It went through without issues. Then, I changed back to the original user, removed the image and tried again: it went through again! The original issue is not reproducible anymore.
So, I have been doing something I knew would end up bad, I used the docker rm -f flag to remove an image B because it kept on complaining that another image A was still using it and I didn't find that specific image A, couldn't see it, so I thought, I'll use '-f'.
Unfortunately, of course it did exist, and now I cannot remove image A anymore because I removed its dependency image B and I keep on getting
Error response from daemon: No such id <id-of-already-removed-image-with--f-option>
error: failed to remove one or more images
when I try to remove it.
So basically, can I remove this image that points to an image that's not present anymore?
Switched off docker through
service docker.io stop
changed the DOCKER_OPTS in /etc/default/docker.io to
DOCKER_OPTS="--graph=/home/kasper/dockerrepo"
restarted docker through
service docker.io start
and then removed Var/lib/docker. Didn't figure out a finer grained way of cleaning this up.