This question already has an answer here:
MySQL container crash after /etc/mysql/my.cnf change, how to edit back?
(1 answer)
Closed 2 years ago.
Good morning.
I am currently using Docker version 19.03 on Mac OS X Catalina.
MariaDB 10.3 was installed in Docker, vim was installed to set the character-set, and /etc/mysql/my.cnf file was modified.
After modification, an attempt was made to restart to reflect, but it was not executed normally.
When I checked it with docker ps -a command, STATUS showed an Exited (1) error.
When I checked the log showing the error, I could check the following log.
unknown variable'collection-server=utf8_unicode_ci'
Stupidly there was a typo in the settings.
So I am trying to modify this setting, but there is no way to modify it because the docker container is not loaded.
docker-compose.yml is not in use.
The simplest way is to delete the Docker Container, reset it, but I don't think this is the right way.
Is there a way to modify /etc/mysql/my.cnf inside Docker Container without using docker-compose.yml?
You can use "docker config" to manage your configuration.
$ docker config --help
Usage: docker config COMMAND
Manage Docker configs
Options:
Commands:
create Create a configuration file from a file or STDIN as content
inspect Display detailed information on one or more config files
ls List configs
rm Remove one or more configuration filesRun ‘docker config COMMAND — help’ for more information on a command
You can create config and add or rm the config from the docker container. you can add configuration file to your docker container either using docker compose or using docker command.
Please check this awesome medium article which will help you to do hands on.
Related
I wanted to install CVAT for training an Object Detection AI using Docker. The install failed for some reason in the middle and it wasn't installed. But all the files were still occupying space on my machine. I tried reinstalling the CVAT and the files keep adding to the occupied space. How do I remove all of these files? I am using a MacBook Pro with MacOS Big Sur Beta 4.
Edit: https://github.com/opencv/cvat/blob/develop/cvat/apps/documentation/installation.md#mac-os-mojave
These are the commands I am running to install CVAT.
docker-compose build output: https://pastebin.com/7EkeQ289
docker-compose up -d output: https://pastebin.com/hF3GFDkX
docker exec -it cvat bash -ic 'python3 ~/manage.py createsuperuser output: https://pastebin.com/Mfh8CivL
If you are trying to remove the containers, attempt the following:
1. docker ps -a - lists all containers
2. docker stop [label or SHA of the containers you want to remove]
docker-compose down [YAML configuration file you targeted with docker-compose up] - this should stop all containers, teardown networks, etc. that docker-compose started with 'up'
docker container prune - removes all stopped containers
NOTE: If you have other stopped containers that you want to keep, do not run this, but remove them individually, as I suggested in the stricken-through step two above, or Konrad Botor's comment
https://docs.docker.com/compose/reference/down/
https://docs.docker.com/engine/reference/commandline/container_prune/
If you want to remove the images:
docker images
docker rmi [label or SHA] (RMI is the remove image command)
https://docs.docker.com/engine/reference/commandline/images/
https://docs.docker.com/engine/reference/commandline/rmi/
To speed up this process, analyze the YAML configuration file being targeted for your docker-compose build command, and/or reference the documentation for that specific project (CVAT) if available, to determine what containers (software) it is initializing (and how it is doing so, if necessary). It might help to paste its contents in the question.
Note: what is taking up space may be volumes which are not cleaned up properly by the docker build scripts for this project. See the following documentation on how to remove those:
https://docs.docker.com/engine/reference/commandline/volume_rm/
I might be missing some context, as I cannot access your pastebin links (behind a firewall at the moment).
I was following this post - the reference code is on GitHub. I have cloned the repository on my local.
The project has got a react app inside it. I'm trying to run it on my local following step 7 on the same post:
docker run -p 8080:80 shakyshane/cra-docker
This returns:
Unable to find image 'shakyshane/cra-docker:latest' locally
docker: Error response from daemon: pull access denied for shakyshane/cra-docker, repository does not exist or may require 'docker login'.
See 'docker run --help'.
I tried login to docker again but looks like since it belongs to #shakyShane I cannot access it.
I idiotically tried npm start too but it's not a simple react app running on node - it's in the container and containers are not controlled by npm
Looks like docker pull shakyshane/cra-docker:latest throws this:
Error response from daemon: pull access denied for shakyshane/cra-docker, repository does not exist or may require 'docker login'
So the question is how do I run this docker image on my local mac machine?
Well this is illogical but still sharing so future people like me don't get stuck.
The problem was that I was trying to run a docker image which doesn't exist.
I needed to build the image:
docker build . -t xameeramir/cra-docker
And then run it:
docker run -p 8080:80 xameeramir/cra-docker
In my case, my image had TAG specified with it and I was not using it.
REPOSITORY TAG IMAGE ID CREATED SIZE
testimage testtag 189b7354c60a 13 hours ago 88.3MB
Unable to find image 'testimage:latest' locally for this command docker run testimage
So specifying tag like this - docker run testimage:testtag worked for me
Posting my solution since non of the above worked.
Working on macbook M1 pro.
The issue I had is that the image was built as arm/64. And I was running the command:
docker run --platform=linux/amd64 ...
So I had to build the image for amd/64 platform in order to run it.
Command below:
docker buildx build --platform=linux/amd64 ...
In conclusion your docker image platform and docker run platform needs to be the same from what I experienced.
In my case, the docker image did exist on the system and still I couldn't run the container locally, so I used the exact image ID instead of image name and tag, like this:
docker run myContainer c29150c8588e
I received this error message when I typed the name/character wrong. That is, "name1\name2" instead of "name1/name2" (wrong slash).
In my case, I saw this error when I had logged in to the dockerhub in my docker desktop. The repo I was pulling was local to my enterprise. Once i logged out of dockerhub, the pull worked.
This just happened to me because my local docker vm on macos ran out of disk space.
I just deleted some old images using docker image prune and it started working correctly again.
shakyshane/cra-docker Does not exist in that user's repo https://hub.docker.com/u/shakyshane/
The problem is you are trying to run an imagen that does not exists. If you are executing a Dockerfile, the image was not created until Dockerfile pass with no errors; so when Dockerfile tries to run the image, it can't find it. Be sure you have no errors in the execution of your scripts.
The simplest answer can be the correct one!.. make sure you have permissions to execute the command, use:
sudo docker run -p 8080:80 shakyshane/cra-docker
In my case, I didn't realise there was a difference between docker run and docker start, and I kept using the run command when I should've been using the start command.
FYI, run is for building and creating the docker container, start is to just start a stopped container
Use -d
sudo docker run -d -p 8000:8000 rasa/duckling
learn about -d here
sudo docker run --help
At first, i build image on mac-m1-pro with this command docker build -t hello_k8s_world:0.0.1 ., when is run this image the issue appear.
After read Master Yi's answer, i realize the crux of the matter and rebuild my images like this docker build --platform=arm64 -t hello_k8s_world:0.0.1 .
Finally，it worked.
I've reviewed the documentation here:
https://docs.docker.com/docker-for-mac/install/#install-and-run-docker-for-mac
It doesn't say anything about boot2docker, although some other questions along these lines talk about this:
Mount volume to Docker image on OSX
So the question is – the Docker for Mac application provides File Sharing via Preferences -> File Sharing; how does one make use of these shared folders from the docker image (for example if one ssh's into the docker image)? When I say how, I don't mean "what are the use-cases", I mean "please show me an example of how to access a shared folder from the command line of the running container".
Ideally I'm trying to create a similar scenario to Vagrant's synched folders whereby I can edit files on my Host env, independently of the Docker Image but these are updated automatically to the Docker image on save.
UPDATE:
To be clear, the reason for asking this question is because I couldn't get the -v docker command to work. E.g.
docker run -v /Users/geoidesic/Documents/projects/arc/mysite/djangocms_demo:/home/djangocms/djangocms/djangocms_demo -d -p 8001:8000 --name test_shared_volumes bluszcz/djangocms
With the above command the container immediately stops, so if I run docker ps the list of running containers is empty.
However, if I run the container without the -v command, then it stays running as expected:
docker run -d -p 8001:8000 --name test_shared_volumes bluszcz/djangocms
Updated:
Well, if you want to share file/directory between host and container, you're gonna use Docker's bind-mount.
For example, if I want to share my host's /etc/resolv.conf to my container, I do the following:
docker run -v /etc/resolv.conf:/etc/resolv.conf <IMAGE>
In which the -v ... part tells the container to reuse host's /etc/resolve.conf. And whenever I edit this file, the changes will be immediately visible to the container.
In Linux, you can use this way to share almost any of your host files to containers. Unfortunately, this is not the case for Mac. As I mentioned in my old answer, by default you can only share /Users/, /Volumes/, /private/, and /tmp directly.
On my Mac, saying, I want to share the /data directory to a container. I run below command:
docker run -it --rm -v /data:/data busybox sh
Then it pops up an unhappy error:
docker: Error response from daemon: Mounts denied:
The path /data
is not shared from OS X and is not known to Docker.
You can configure shared paths from Docker -> Preferences... -> File Sharing.
See https://docs.docker.com/docker-for-mac/osxfs/#namespaces for more info.
So you see, this is where File Sharing comes up.
Then comes my answers to your questions:
File Sharing does not provide you a ready-to-use way to do the sharing as you have experienced in Vagrant;
To share file/folder between host and container, use Dockers bind-mount.
Hope that helps.
Old answer:
File Sharing is used by Docker's bind-mount feature. By default, you can bind-mount files in /Users/, /Volumes/, /private/, and /tmp directly. For other paths, you need to add them to Preferences -> File Sharing first.
Use cases for bind-mount:
Persisting data generated by the running container, so that you can backup or migrate data.
Sharing data amount multiple running containers.
Share host configuration files to containers.
Share source code between host and containers, to make debugging easier.
Note: For cases #1 and #2, consider using volumes instead of bind-mount.
First i just want to mention i am very new to docker.
I am using Win 10, "Docker for Windows".
I am using the default linux containers option.
I have downloaded the latest image from here,
https://github.com/camunda/docker-camunda-bpm-platform.
So now, my Docker is online, and the container + image are working. A tomcat server and a Camunda engine are online and working.
My problem is the following,
I need to do some changes and i cant find where Tomcat and Camunda are being stored. I need to edit some XML files both in the Camunda and in the Tomcat ( to setup which database to use for example ).
Can it be that it is not being stored on my local machine?
For example when i open the container with Kitematic ( Docker UI ) i can see environment variables for it, there is a SERVER_CONFIG and its value is /camunda/conf/server.xml ( this is one of the files i need to edit! but i cant find it or anything else anywhere on my local machine ).
you should access container using following command
sudo docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5e978f353734 camunda/camunda-bpm-platform:latest "/sbin/tini -- ./cam…" 4 days ago Up 4 days
the issie
sudo docker exec -it 5e978f353734 /bin/bash
then you will see the container insie via shell command. good luck!
You may want to consider using Camunda BPM RUN, which aims to allow configuration without having to change the WAR deployment or Tomcat. Instead configuration is done as described here:
https://docs.camunda.org/manual/latest/user-guide/camunda-bpm-run/
Config files can be mounted into the docker images, but you may prefer to compose your own docker image based on the Camunda BPM Run base image.
The example here shows another approach which sets Camunda properties from outside the docker image by passing the environment variable SPRING_APPLICATION_JSON into the docker image.
https://medium.com/#robert.emsbach/anyone-can-run-camunda-bpm-on-azure-in-10-minutes-4b4055cc8e9
Trying to fix errors and debug problems with my application that is split over several containers, I frequently edit files in containers:
either I am totally lazy and install nano and edit directly in container or
I docker cp the file out of the container, edit it, copy it back and restart the container
Those are intermediate steps before coming to new content for container build, which takes a lot longer than doing the above (which of course is only intermediate/fiddling around).
Now I frequently break the starting program of the container, which in the breaking cases is either a node script or a python webserver script, both typically fail from syntax errors.
Is there any way to save those containers? Since they do not start, I cannot docker exec into them, and thus they are lost to me. I then go the rm/rmi/build/run route after fixing the offending file in the build input.
How can I either edit files in a stopped container, or cp them in or start a shell in a stopped container - anything that allows me to fix this container?
(It seems a bit like working on a remote computer and breaking the networking configuration - connection is lost "forever" this way and one has to use a fallback, if that exists.)
How to edit Docker container files from the host? looks relevant but is outdated.
I had a problem with a container which wouldn't start due to a bad config change I made.
I was able to copy the file out of the stopped container and edit it. something like:
docker cp docker_web_1:/etc/apache2/sites-enabled/apache2.conf .
(correct the file)
docker cp apache.conf docker_web_1:/etc/apache2/sites-enabled/apache2.conf
Answering my own question.. still hoping for a better answer from a more knowledgable person!!
There are 2 possibilities.
1) Editing file system on host directly. This is somewhat dangerous and has a chance of completely breaking the container, possibly other data depending on what goes wrong.
2) Changing the startup script to something that never fails like starting a bash, doing the fixes/edits and then changing the startup program again to the desired one (like node or whatever it was before).
More details:
1) Using
docker ps
to find the running containers or
docker ps -a
to find all containers (including stopped ones) and
docker inspect (containername)
look for the "Id", one of the first values.
This is the part that contains implementation detail and might change, be aware that you may lose your container this way.
Go to
/var/lib/docker/aufs/diff/9bc343a9..(long container id)/
and there you will find all files that are changed towards the image the container is based upon. You can overwrite files, add or edit files.
Again, I would not recommend this.
2) As is described at https://stackoverflow.com/a/32353134/586754 you can find the configuration json config.json at a path like
/var/lib/docker/containers/9bc343a99..(long container id)/config.json
There you can change the args from e. g. "nodejs app.js" to "/bin/bash". Now restart the docker service and start the container (you should see that it now correctly starts up). You should use
docker start -i (containername)
to make sure it does not quit straight away. You can now work with the container and/or later attach with
docker exec -ti (containername) /bin/bash
Also, docker cp is rather useful for copying files that were edited outside of the container.
Also, one should only fall back to those measures if the container is more or less "lost" anyway, so any change would be an improvement.
You can edit container file-system directly, but I don't know if it is a good idea.
First you need to find the path of directory which is used as runtime root for container.
Run docker container inspect id/name.
Look for the key UpperDir in JSON output.
That is your directory.
If you are trying to restart an stopped container and need to alter the container because of misconfiguration but the container isn't starting you can do the following which works using the "docker cp" command (similar to previous suggestion). This procedure lets you remove files and do any other changes needed. With luck you can skip a lot of the steps below.
Use docker inspect to find entrypoint, (named Path in some versions)
Create a clone of the using docker run
Enter clone using docker exec -ti bash (if *nix container)
Locate entrypoint file location by looking though the clone to find
Copy the old entrypoint script using docker cp : ./
Modify or create a new entrypoint script for instance
#!/bin/bash
tail -f /etc/hosts
ensure the script has execution rights
Replace the old entrypoint using docker cp ./ :
start the old container using start
redo steps 6-9 until the starts
Fix issues in container
Restore entrypoint if needed and redo steps 6-9 as required
Remove clone if needed