I am new to docker. I want to run tinyproxy within docker. Here is the image I used to create a docker container: "https://hub.docker.com/r/dtgilles/tinyproxy/".
For some unknown reason, when I mount the log file to the host machine, I can see the .conf file, but I can't see log file and the proxy server seems doesn't work.
Here is the command I tried:
docker run -v $(pwd):/logs -p 8888:8888 -d --name tiny
dtgilles/tinyproxy
If I didn't mount the file, then every time when run a container, I need to change its config file inside container.
Does anyone has any ideas about saving the changes in container?
Question
How to save a change committed by/into a container?
Answer
The command docker commit creates a new image from a container's changes (from the man page).
Best Practice
You actually should not do this to save a configuration file. A Docker image is supposed to be immutable. This increases sharing, and image customization through mounted volume.
What you should do is create the configuration file on the host and share it at through parameters with docker run. This is done by using the option -v|--volume. Check the man page, you'll then be able to share files (or directories) between host and containers allowing to persists the data through different runs.
Related
I need to work with all the files from a docker container, my approach is to copy all the list of files from the container to my host.
I'm using the next docker commands, for example with the postgres image:
docker create -ti --name dummy_1 postgres bash
docker cp dummy_1:/. Documents/docker/dockerOne
With this I have all the container folders and files in my host.
And then the idea is to transverse all the files with the java API, and work with them and finally delete the files and folders from local, but I would like to know if is it a better approach, maybe with Java and access directly to the container files, instead of create a local copy of the container files in my host.
Any ideas?
You can build a small server app inside your docker container which feeds you the information you need at an exposed port. Thats how i would have done it.
Maybe I don't understand the question, but you can mount a volume when you run, not create the container
docker run -v /host/path:/container/path your_container
Any code in the container (e.g. Java) that modifies files at /container/path will be reflected on the host, and not need to be copied back in/out. Similarly, any modifications on the host filesystem will be seen in the container.
I don't think I can implement an API in the docker container
Yes you can. You bind a TCP port using -p flag
I'm fairly new to using Docker and Docker Compose (using Docker Compose for this particular problem). Here is what I know so far about the problem I am facing: When using volumes when there are contents available in the host folder as well as the container's folder, the files inside the container's folder are hidden and the host's files are then made available to the container.
I want to use it the other way round. I would like to make available the container's files (that were copied into the image in the Dockerfile) to the host folder.
Is there a way to do that?
Here are a bunch of screenshots of my Dockerfile and Docker Compose to show my setup.
Dockerfile Screenshot
DockerCompose Screenshot
Thanks in advance! :)
I've come across the same thing many times and the way I go about it is as follows.
As the host volume will always take priority over the container filesystem, you have to copy the files out of the container to the host first, then volume mount them back - this way you get what was there originally, and also what might change in the future (by the container).
The following is all pseudo code, but should hopefully simulate the concept:
First run the main container:
docker run --rm -d --name my-container registry/image-name
Then copy the files you want from it to the local filesystem
docker cp my-container:/files/i/want ./files
Then stop the original container
docker stop my-container
Then mount them back into the container on the next run
docker run --rm -d --name my-container -v ./files:/files/i/want registry/image-name
Obviously you've mentioned compose there also, so just reflect the volume mapping into the compose format - the copy stuff will need to be done via standard docker however in line with the above.
Note: I wrote the above commands blind, but will check them over at lunch and correct any mistypes - but the concept is correct
I downloaded the official node-red container.
I noticed that the file 'setting.js' is missing inside it.
I tried to insert it manually inside the container but it is not read when node-red is started. I was wondering if there was a way to insert it or anyway an alternative way to set the credentials to access the admin page of node-red.
I pull nodered/node-red-docker:0.18.4-v8.
Usually setting.js file is inside .node-red/setting.js, but not in this case. This container have the path: /usr/src/node-red/ and when I enter with command docker exec -it container_name bash, i'm inside the directory node-red. I tried to put the setting.js in this path but not work
You should not change the copy of settings.js in /usr/src/node-red this is the default and should be left alone. Also editing this file after starting the container will not work as it is copied to the userDir the first time Node-RED is started.
If you want to include your own version you should mount it into the /data directory as this is the userDir for the system when running.
You can use the docker -v option to mount a local copy of the file into the container.
docker -v /path/to/settings.js:/data/settings.js ...
I have a directory in my Docker container, and I'm trying to make it available locally using -v screenshots:/srv/screenshots in my docker run command but it's not available.
Do I need to add something else to my command?
Host volumes are mapped from the host into the container, not the other way around. This is one way to have persistent storage (so the data don't disappear when the container is re-created).
You can copy the screenshot folder to your host with docker cp and map them in.
You will have your screenshots in the local screenshots folder. Mapping them in with -v screenshots:/srv/screenshots makes them appear in /srv/screenshots in the container, but these files are really on the host.
See: Mount a host directory as data volume
have an application running inside docker container. the application writes log messages into local log files. how can i make the log file persistent in case the docker container stops or crashes?
Since the container are run time entity ,when i stop the image my logs/data is gone.
Thanks,
Sohan
You can do this using docker volumes:
https://docs.docker.com/userguide/dockervolumes/
For example:
docker run -v /var/log/docker:/var/log your-image
will mount the log directory on your local file system. You can also get much fancier, creating containers just for data. It's all explained in the above link.