MySQL in Docker on Windows: World-writable files ignored - mysql

I'm using Docker-Compose with the MySQL Image to fire up a MySQL database as part of a larger project.
As documented in the MySQL image's documentation, I'm mapping in a custom configuration file to /etc/mysql/conf.d/config-file.cnf:
database:
environment:
MYSQL_ROOT_PASSWORD: foo
ports:
- "3306:3306"
volumes:
- "./mysql/conf.d/:/etc/mysql/conf.d"
image: mysql:5.5
This works perfectly fine when running on Mac OS X as the host system (using docker-machine), but it fails when running on Windows (also using docker-machine). MySQL complains about the fact that the /etc/mysql/conf.d/config-file.cnf is world-writable
Warning: World-writable config file '/etc/mysql/conf.d/config-file.cnf' is ignored
When entering the database container, the file is indeed shown as having 0777 permission. This seems to be due to the host file system's permissions (Windows).
Is there any way to change this? I've tried mounting the volume in read-only mode, but the file still has the same permissions.
Any other way around this problem? At the moment, I'm mounting the file to another folder in the container and then copying/chmod'ing it to the required location as part of the startup command:
database:
environment:
MYSQL_ROOT_PASSWORD: foo
ports:
- "3306:3306"
volumes:
- "./mysql/conf.d/:/usr/local/mysqlconf"
image: mysql:5.5
command: >
bash -c "
cp /usr/local/mysqlconf/*.cnf /etc/mysql/conf.d/
&& chmod 644 /etc/mysql/conf.d/*.cnf
&& /entrypoint.sh mysqld
"
Is there a better way to solve this issue?

When you start up a container with -v, --volumes or use volumes: in docker-compose.yml
docker run -v source:/dest:rw busybox ls -l /dest
Docker mounts the source directory from the Linux VM into a container as /dest. Docker mounted volumes only provide their own options rw and r and I think z for selinux. Owner and permission info will be passed through to the container exactly as the Linux VM sees them. If someone who clones your repo runs docker or docker-compose from their local host rather than on the VM, they will mount blank directories.
Docker Machine's Users share
A docker-machine created local VM will share your computer's local users directory by default. C:\Users on Windows and /Users on OSX. This is done as a VirtualBox shared folder called Users. This share is then mounted on the Linux side via VirtualBox's vboxsf mount tool as /Users or maybe /c/Users via a Linux startup script /etc/rc.d/vbox.
When you docker-machine ssh default you should be able to see all your computers file at /Users/nwinkler.
This share allows docker-compose to reference a relative, local directory within C:\Users and have it work on the Linux VM. Outside of C:\Users the data doesn't exist on the VM.
World readable files
I believe what you are seeing is vboxsf's POSIX representation of a Windows file system. If you run:
docker-machine ssh default
$ cd /Users/nwinkler/path/to/mysql-docker
$ ls -l
$ docker run -v $PWD:/mysql busybox ls -l /mysql
You should see all your files as world writable. The only way to change the represented permissions is via the vboxsf mounted share.
The mount options vboxsf provides are:
Available mount options are:
rw mount writable (the default)
ro mount read only
uid=UID set the default file owner user id to UID
gid=GID set the default file owner group id to GID
ttl=TTL set the "time to live" to TID for the dentry
dmode=MODE override the mode of all directories to (octal) MODE
fmode=MODE override the mode of all regular files to (octal) MODE
umask=UMASK set the umask to (octal) UMASK
dmask=UMASK set the umask applied to directories only
fmask=UMASK set the umask applied to regular files only
iocharset CHARSET use the character set CHARSET for I/O operations
(default set is utf8)
convertcp CHARSET convert the folder name from CHARSET to utf8
On the Docker Linux VM, edit /etc/rc.d/box and append the options to the mountOptions variable. These options will apply to all files and directories under /Users on that mount.
You could set an fmask=007 to remove other permissions from all files or fmode=750 to override all permissions for all files.
mountOptions='defaults,iocharset=utf8'
if grep -q '^docker:' /etc/passwd; then
mountOptions="${mountOptions},uid=$(id -u docker),gid=$(id -g docker),fmask=007"
fi
If you ever upgrade or recreate your docker-machine VM you will need to do this again.
I tend to skip relying on virtualbox shares and have local files monitored and synchronised to my hosts on change (fsevents and rsync).

Related

How to use external files as arguments in Docker images [duplicate]

I am trying to mount a host directory into a Docker container so that any updates done on the host is reflected into the Docker containers.
Where am I doing something wrong. Here is what I did:
kishore$ cat Dockerfile
FROM ubuntu:trusty
RUN apt-get update
RUN apt-get -y install git curl vim
CMD ["/bin/bash"]
WORKDIR /test_container
VOLUME ["/test_container"]
kishore$ tree
.
├── Dockerfile
└── main_folder
├── tfile1.txt
├── tfile2.txt
├── tfile3.txt
└── tfile4.txt
1 directory, 5 files
kishore$ pwd
/Users/kishore/tdock
kishore$ docker build --tag=k3_s3:latest .
Uploading context 7.168 kB
Uploading context
Step 0 : FROM ubuntu:trusty
---> 99ec81b80c55
Step 1 : RUN apt-get update
---> Using cache
---> 1c7282005040
Step 2 : RUN apt-get -y install git curl vim
---> Using cache
---> aed48634e300
Step 3 : CMD ["/bin/bash"]
---> Running in d081b576878d
---> 65db8df48595
Step 4 : WORKDIR /test_container
---> Running in 5b8d2ccd719d
---> 250369b30e1f
Step 5 : VOLUME ["/test_container"]
---> Running in 72ca332d9809
---> 163deb2b1bc5
Successfully built 163deb2b1bc5
Removing intermediate container b8bfcb071441
Removing intermediate container d081b576878d
Removing intermediate container 5b8d2ccd719d
Removing intermediate container 72ca332d9809
kishore$ docker run -d -v /Users/kishore/main_folder:/test_container k3_s3:latest
c9f9a7e09c54ee1c2cc966f15c963b4af320b5203b8c46689033c1ab8872a0eakishore$ docker run -i -t k3_s3:latest /bin/bash
root#0f17e2313a46:/test_container# ls -al
total 8
drwx------ 2 root root 4096 Apr 29 05:15 .
drwxr-xr-x 66 root root 4096 Apr 29 05:15 ..
root#0f17e2313a46:/test_container# exit
exitkishore$ docker -v
Docker version 0.9.1, build 867b2a9
I don't know how to check boot2docker version
Questions, issues facing:
How do I need to link the main_folder to the test_container folder present inside the docker container?
I need to make this automatically. How do I to do that without really using the run -d -v command?
What happens if the boot2docker crashes? Where are the Docker files stored (apart from Dockerfile)?
There are a couple ways you can do this. The simplest way to do so is to use the dockerfile ADD command like so:
ADD . /path/inside/docker/container
However, any changes made to this directory on the host after building the dockerfile will not show up in the container. This is because when building a container, docker compresses the directory into a .tar and uploads that context into the container permanently.
The second way to do this is the way you attempted, which is to mount a volume. Due to trying to be as portable as possible you cannot map a host directory to a docker container directory within a dockerfile, because the host directory can change depending on which machine you are running on. To map a host directory to a docker container directory you need to use the -v flag when using docker run, e.g.,:
# Run a container using the `alpine` image, mount the `/tmp`
# directory from your host into the `/container/directory`
# directory in your container, and run the `ls` command to
# show the contents of that directory.
docker run \
-v /tmp:/container/directory \
alpine \
ls /container/directory
The user of this question was using Docker version 0.9.1, build 867b2a9, I will give you an answer for docker version >= 17.06.
What you want, keep local directory synchronized within container directory, is accomplished by mounting the volume with type bind. This will bind the source (your system) and the target (at the docker container) directories. It's almost the same as mounting a directory on linux.
According to Docker documentation, the appropriate command to mount is now mount instead of -v. Here's its documentation:
--mount: Consists of multiple key-value pairs, separated by commas. Each key/value pair takes the form of a <key>=<value> tuple. The --mount syntax is more verbose than -v or --volume, but the order of the keys is not significant, and the value of the flag is easier to understand.
The type of the mount, which can be bind, volume, or tmpfs. (We are going to use bind)
The source of the mount. For bind mounts, this is the path to the file or directory on the Docker daemon host. May be specified as source or src.
The destination takes as its value the path where the file or directory will be mounted in the container. May be specified as destination, dst, or target.
So, to mount the the current directory (source) with /test_container (target) we are going to use:
docker run -it --mount src="$(pwd)",target=/test_container,type=bind k3_s3
If these mount parameters have spaces you must put quotes around them. When I know they don't, I would use `pwd` instead:
docker run -it --mount src=`pwd`,target=/test_container,type=bind k3_s3
You will also have to deal with file permission, see this article.
you can use -v option from cli, this facility is not available via Dockerfile
docker run -t -i -v <host_dir>:<container_dir> ubuntu /bin/bash
where host_dir is the directory from host which you want to mount.
you don't need to worry about directory of container if it doesn't exist docker will create it.
If you do any changes in host_dir from host machine (under root privilege) it will be visible to container and vice versa.
2 successive mounts:
I guess many posts here might be using two boot2docker, the reason you don't see anything is that you are mounting a directory from boot2docker, not from your host.
You basically need 2 successive mounts:
the first one to mount a directory from your host to your system
the second to mount the new directory from boot2docker to your container like this:
1) Mount local system on boot2docker
sudo mount -t vboxsf hostfolder /boot2dockerfolder
2) Mount boot2docker file on linux container
docker run -v /boot2dockerfolder:/root/containerfolder -i -t imagename
Then when you ls inside the containerfolder you will see the content of your hostfolder.
Is it possible that you use docker on OS X via boot2docker or something similar.
I've made the same experience - the command is correct but nothing (sensible) is mounted in the container, anyway.
As it turns out - it's already explained in the docker documentation. When you type docker run -v /var/logs/on/host:/var/logs/in/container ... then /var/logs/on/host is actually mapped from the boot2docker VM-image, not your Mac.
You'll have to pipe the shared folder through your VM to your actual host (the Mac in my case).
For those who wants to mount a folder in current directory:
docker run -d --name some-container -v ${PWD}/folder:/var/folder ubuntu
I'm just experimenting with getting my SailsJS app running inside a Docker container to keep my physical machine clean.
I'm using the following command to mount my SailsJS/NodeJS application under /app:
cd my_source_code_folder
docker run -it -p 1337:1337 -v $(pwd):/app my_docker/image_with_nodejs_etc
[UPDATE] As of ~June 2017, Docker for Mac takes care of all the annoying parts of this where you have to mess with VirtualBox. It lets you map basically everything on your local host using the /private prefix. More info here. [/UPDATE]
All the current answers talk about Boot2docker. Since that's now deprecated in favor of docker-machine, this works for docker-machine:
First, ssh into the docker-machine vm and create the folder we'll be mapping to:
docker-machine ssh $MACHINE_NAME "sudo mkdir -p \"$VOL_DIR\""
Now share the folder to VirtualBox:
WORKDIR=$(basename "$VOL_DIR")
vboxmanage sharedfolder add "$MACHINE_NAME" --name "$WORKDIR" --hostpath "$VOL_DIR" --transient
Finally, ssh into the docker-machine again and mount the folder we just shared:
docker-machine ssh $MACHINE_NAME "sudo mount -t vboxsf -o uid=\"$U\",gid=\"$G\" \"$WORKDIR\" \"$VOL_DIR\""
Note: for UID and GID you can basically use whatever integers as long as they're not already taken.
This is tested as of docker-machine 0.4.1 and docker 1.8.3 on OS X El Capitan.
Using command-line :
docker run -it --name <WHATEVER> -p <LOCAL_PORT>:<CONTAINER_PORT> -v <LOCAL_PATH>:<CONTAINER_PATH> -d <IMAGE>:<TAG>
Using docker-compose.yaml :
version: '2'
services:
cms:
image: <IMAGE>:<TAG>
ports:
- <LOCAL_PORT>:<CONTAINER_PORT>
volumes:
- <LOCAL_PATH>:<CONTAINER_PATH>
Assume :
IMAGE: k3_s3
TAG: latest
LOCAL_PORT: 8080
CONTAINER_PORT: 8080
LOCAL_PATH: /volume-to-mount
CONTAINER_PATH: /mnt
Examples :
First create /volume-to-mount. (Skip if exist)
$ mkdir -p /volume-to-mount
docker-compose -f docker-compose.yaml up -d
version: '2'
services:
cms:
image: ghost-cms:latest
ports:
- 8080:8080
volumes:
- /volume-to-mount:/mnt
Verify your container :
docker exec -it CONTAINER_ID ls -la /mnt
docker run -v /host/directory:/container/directory -t IMAGE-NAME /bin/bash
docker run -v /root/shareData:/home/shareData -t kylemanna/openvpn /bin/bash
In my system I've corrected the answer from nhjk, it works flawless when you add the -t flag.
On Mac OS, to mount a folder /Users/<name>/projects/ on your mac at the root of your container:
docker run -it -v /Users/<name>/projects/:/projects <container_name> bash
ls /projects
If the host is windows 10 then instead of forward slash, use backward slash -
docker run -it -p 12001:80 -v c:\Users\C\Desktop\dockerStorage:/root/sketches
Make sure the host drive is shared (C in this case). In my case I got a prompt asking for share permission after running the command above.
For Windows 10 users, it is important to have the mount point inside the C:/Users/ directory. I tried for hours to get this to work. This post helped but it was not obvious at first as the solution for Windows 10 is a comment to an accepted answer. This is how I did it:
docker run -it -p 12001:80 -v //c/Users/C/Desktop/dockerStorage:/root/sketches \
<your-image-here> /bin/bash
Then to test it, you can do echo TEST > hostTest.txt inside your image. You should be able to see this new file in the local host folder at C:/Users/C/Desktop/dockerStorage/.
As of Docker 18-CE, you can use docker run -v /src/path:/container/path to do 2-way binding of a host folder.
There is a major catch here though if you're working with Windows 10/WSL and have Docker-CE for Windows as your host and then docker-ce client tools in WSL. WSL knows about the entire / filesystem while your Windows host only knows about your drives. Inside WSL, you can use /mnt/c/projectpath, but if you try to docker run -v ${PWD}:/projectpath, you will find in the host that /projectpath/ is empty because on the host /mnt means nothing.
If you work from /c/projectpath though and THEN do docker run -v ${PWD}:/projectpath and you WILL find that in the container, /projectpath will reflect /c/projectpath in realtime. There are no errors or any other ways to detect this issue other than seeing empty mounts inside your guest.
You must also be sure to "share the drive" in the Docker for Windows settings.
Jul 2015 update - boot2docker now supports direct mounting. You can use -v /var/logs/on/host:/var/logs/in/container directly from your Mac prompt, without double mounting
I've been having the same issue.
My command line looked like this:
docker run --rm -i --name $NAME -v `pwd`:/sources:z $NAME
The problem was with 'pwd'. So I changed that to $(pwd):
docker run --rm -i --name $NAME -v $(pwd):/sources:z $NAME
How do I link the main_folder to the test_container folder present inside the docker container?
Your command below is correct, unless your on a mac using boot2docker(depending on future updates) in which case you may find the folder empty. See mattes answer for a tutorial on correcting this.
docker run -d -v /Users/kishore/main_folder:/test_container k3_s3:latest
I need to make this run automatically, how to do that without really
using the run -d -v command.
You can't really get away from using these commands, they are intrinsic to the way docker works. You would be best off putting them into a shell script to save you writing them out repeatedly.
What happens if boot2docker crashes? Where are the docker files stored?
If you manage to use the -v arg and reference your host machine then the files will be safe on your host.
If you've used 'docker build -t myimage .' with a Dockerfile then your files will be baked into the image.
Your docker images, i believe, are stored in the boot2docker-vm. I found this out when my images disappeared when i delete the vm from VirtualBox. (Note, i don't know how Virtualbox works, so the images might be still hidden somewhere else, just not visible to docker).
Had the same problem. Found this in the docker documentation:
Note: The host directory is, by its nature, host-dependent. For this reason, you can’t mount a host directory from Dockerfile, the VOLUME instruction does not support passing a host-dir, because built images should be portable. A host directory wouldn’t be available on all potential hosts.
So, mounting a read/write host directory is only possible with the -v parameter in the docker run command, as the other answers point out correctly.
I found that any directory laying under system directive like /var, /usr, /etc could not be mount under the container.
The directive should be at user's space -v switch instructs docker daemon to mount local directory to the container, for example:
docker run -t -d -v /{local}/{path}:/{container}/{path} --name {container_name} {imagename}
Here's an example with a Windows path:
docker run -P -it --name organizr --mount src="/c/Users/MyUserName/AppData/Roaming/DockerConfigs/Organizr",dst=/config,type=bind organizrtools/organizr-v2:latest
As a side note, during all of this hair pulling, having to wrestle with figuring out, and retyping paths over and over and over again, I decided to whip up a small AutoHotkey script to convert a Windows path to a "Docker Windows" formatted path. This way all I have to do is copy any Windows path that I want to use as a mount point to the clipboard, press the "Apps Key" on the keyboard, and it'll format it into a path format that Docker appreciates.
For example:
Copy this to your clipboard:
C:\Users\My PC\AppData\Roaming\DockerConfigs\Organizr
press the Apps Key while the cursor is where you want it on the command-line, and it'll paste this there:
"/c/Users/My PC/AppData/Roaming/DockerConfigs/Organizr"
Saves a lot to time for me. Here it is for anyone else who may find it useful.
; --------------------------------------------------------------------------------------------------------------
;
; Docker Utility: Convert a Windows Formatted Path to a Docker Formatter Path
; Useful for (example) when mounting Windows volumes via the command-line.
;
; By: J. Scott Elblein
; Version: 1.0
; Date: 2/5/2019
;
; Usage: Cut or Copy the Windows formatted path to the clipboard, press the AppsKey on your keyboard
; (usually right next to the Windows Key), it'll format it into a 'docker path' and enter it
; into the active window. Easy example usage would be to copy your intended volume path via
; Explorer, place the cursor after the "-v" in your Docker command, press the Apps Key and
; then it'll place the formatted path onto the line for you.
;
; TODO:: I may or may not add anything to this depending on needs. Some ideas are:
;
; - Add a tray menu with the ability to do some things, like just replace the unformatted path
; on the clipboard with the formatted one rather than enter it automatically.
; - Add 'smarter' handling so the it first confirms that the clipboard text is even a path in
; the first place. (would need to be able to handle Win + Mac + Linux)
; - Add command-line handling so the script doesn't need to always be in the tray, you could
; just pass the Windows path to the script, have it format it, then paste and close.
; Also, could have it just check for a path on the clipboard upon script startup, if found
; do it's job, then exit the script.
; - Add an 'all-in-one' action, to copy the selected Windows path, and then output the result.
; - Whatever else comes to mind.
;
; --------------------------------------------------------------------------------------------------------------
#NoEnv
SendMode Input
SetWorkingDir %A_ScriptDir%
AppsKey::
; Create a new var, store the current clipboard contents (should be a Windows path)
NewStr := Clipboard
; Rip out the first 2 chars (should be a drive letter and colon) & convert the letter to lowercase
; NOTE: I could probably replace the following 3 lines with a regexreplace, but atm I'm lazy and in a rush.
tmpVar := SubStr(NewStr, 1, 2)
StringLower, tmpVar, tmpVar
; Replace the uppercase drive letter and colon with the lowercase drive letter and colon
NewStr := StrReplace(NewStr, SubStr(NewStr, 1, 2), tmpVar)
; Replace backslashes with forward slashes
NewStr := StrReplace(NewStr, "\", "/")
; Replace all colons with nothing
NewStr := StrReplace(NewStr, ":", "")
; Remove the last char if it's a trailing forward slash
NewStr := RegExReplace(NewStr, "/$")
; Append a leading forward slash if not already there
if RegExMatch(NewStr, "^/") == 0
NewStr := "/" . NewStr
; If there are any spaces in the path ... wrap in double quotes
if RegExMatch(NewStr, " ") > 0
NewStr := """" . NewStr . """"
; Send the result to the active window
SendInput % NewStr
To get this working in Windows 10 I had to open the Docker Settings window from the system tray and go to the Shared Drives section.
I then checked the box next to C. Docker asked for my desktop credentials to gain authorisation to write to my Users folder.
Then I ran the docker container following examples above and also the example on that settings page, attaching to /data in the container.
docker run -v c:/Users/<user.name>/Desktop/dockerStorage:/data -other -options
boot2docker together with VirtualBox Guest Additions
How to mount /Users into boot2docker
https://medium.com/boot2docker-lightweight-linux-for-docker/boot2docker-together-with-virtualbox-guest-additions-da1e3ab2465c
tl;dr Build your own custom boot2docker.iso with VirtualBox Guest
Additions (see link) or download
http://static.dockerfiles.io/boot2docker-v1.0.1-virtualbox-guest-additions-v4.3.12.iso
and save it to ~/.boot2docker/boot2docker.iso.
Note that in Windows you'll have to provide the absolute path.
Host: Windows 10
Container: Tensorflow Notebook
Below worked for me.
docker run -t -i -v D:/projects/:/home/chankeypathak/work -p 8888:8888 jupyter/tensorflow-notebook /bin/bash
i had same issues , i was trying to mount C:\Users\ folder on docker
this is how i did it Docker Toolbox command line
$ docker run -it --name <containername> -v /c/Users:/myVolData <imagename>
You can also do this with Portainer web application for a different visual experience.
First pull the Portainer image:
docker pull portainer/portainer
Then create a volume for Portainer:
docker volume create portainer_data
Also create a Portainer container:
docker run -d -p 8000:8000 -p 9000:9000 --name=portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer
You will be able to access the web app with your browser at this URL: "http://localhost:9000". At the first login, you will be prompted to set your Portainer admin credentials.
In the web app, follow these menus and buttons: (Container > Add container > Fill settings > Deploy Container)
I had trouble to create a "mount" volume with Portainer and I realized I had to click "bind" when creating my container's volume. Below is an illustration of the volume binding settings that worked for my container creation with a mounted volume binded to the host.
P.S.: I'm using Docker 19.035 and Portainer 1.23.1
I had the same requirement to mount host directory from container and I used volume mount command. But during testing noticed that it's creating files inside container too but after some digging found that they are just symbolic links and actual file system used form host machine.
Quoting from the Official Website:
Make sure you don’t have any previous getting-started containers running.
Run the following command from the app directory.
x86-64 Mac or Linux device:
docker run -dp 3000:3000 \
-w /app -v "$(pwd):/app" \
node:12-alpine \
sh -c "yarn install && yarn run dev"
Windows (PowerShell):
docker run -dp 3000:3000 `
-w /app -v "$(pwd):/app" `
node:12-alpine `
sh -c "yarn install && yarn run dev"
Aple silicon Mac or another ARM64 device:
docker run -dp 3000:3000 \
-w /app -v "$(pwd):/app" \
node:12-alpine \
sh -c "apk add --no-cache python2 g++ make && yarn install && yarn run dev"
Explaining:
dp 3000:3000 - same as before. Run in detached (background) mode and create a port mapping
w /app - sets the “working directory” or the current directory that the command will run from
v "$(pwd):/app" - bind mount the current directory from the host into the /app directory in the container
node:12-alpine - the image to use.
Note that this is the base image for our app from the Dockerfile sh -c "yarn install && yarn run dev" - the command.
We’re starting a shell using sh (alpine doesn’t have bash) and running yarn install to install all dependencies and then running yarn run dev. If we look in the package.json, we’ll see that the dev script is starting nodemon.

Docker toolbox with mysql container problem on Windows 10 Home (and Pro)

I unable to run MySQL containers made from MySQL images with database volumes mapped to my host machine's folder.
It doesn't matter if the host folder is empty or with existing database files. I do know that Docker Toolbox could mount volumes on Windows only from c:\Users\ so my test folder is under that one.
I was trying different (official and not) MySQL images from 5.5 to latest with no result. Anytime when location /var/lib/mysql in container is pointing to a folder on my host machine (c:\Users\someuser\testfolder) I've got an error on container`s running with InnoDB error ("InnoDB: Operating system error number 22 in a file operation" or "InnoDB: File ./ib_logfile0: 'aio write' returned OS error 122").
I was trying to modify mysql container's /etc/my.cnf (under [mysqld] section, using "docker cp" command) adding "innodb_use_native_aio=OFF" or (sometimes even and) "innodb_use_native_aio=0" keys and even was trying to run "docker run" with "--user 1000:50" with no result either.
Just after I delete mount point from container's /var/lib/mysql to my host folder, the container runs normally.
There are many alike questions but no one has complete step by step solution how to run a MySQL container with a Docker Toolbox under Windows 10 (Home & Pro) to bring container work with an existing database on the host's volumes.
It took me a while to get an answer but finally everything worked! For those who are new to Docker and have problems mounting MySQL folder to the host here is a short guide. Please note I chose bitnami/mysql image for my experiments (for another images folders can be differ).
Create a folder c:\Users\[YourAccount]\MySQLData for MySQL data.
Create a folder c:\Users\[YourAccount]\MySQLConf for a custom MySQL config file.
Create a custom MySQL config file c:\Users\[YourAccount]\MySQLConf\my_custom.cnf and add two lines in it:
[mysqld]
innodb_use_native_aio=0
4. Now create and run the container mounting your custom config and data folder to it:
docker run -d --name mysql -e ALLOW_EMPTY_PASSWORD="yes" \
-v //c/Users/[YourAccount]/MySQLData:/bitnami/mysql/data \
-v //c/Users/[YourAccount]/MySQLConf/my_custom.cnf:/opt/bitnami/mysql/conf/my_custom.cnf:ro \ bitnami/mysql:latest
Hooray!

MySQL container crash after /etc/mysql/my.cnf change, how to edit back?

I changed some mysql config settings and set something wrong, now Docker container keeps restarting and I cannot find the my.cnf file to edit in host filesystem. I have tried aufs/diff folders but so far unable to find it. Also tried:
find / -name my.cnf -exec nano {} \;
But it does not bring up the file I changed. And I tried to change config.v2.json to start /bin/bash instead of mysqld and restarted docker, but yet it started mysqld (due supervisor or something?) using official mysql container image.
I am seeing two possible solutions for your problem:
Bypass the ENTRYPOINT for the MySQL image
Find your image name by running docker images then run:
docker run -it --entrypoint="/bin/sh" OPTIONS image
That should take you to the bash inside the container and from there you can execute all the commands you want to find your my.cnf file. Although I don't know if editing the file from there, save it and try to run it again will works. I didn't tried.
Delete the old image and use the proper way to edit the my.cnf file
Find your image name by running: docker images and then delete it by running docker rmi <image_name>
Check the docs for the default MySQL images at MySQL Dockerhub is pretty straight on this and I quote:
Using a custom MySQL configuration file The MySQL startup
configuration is specified in the file /etc/mysql/my.cnf, and that
file in turn includes any files found in the /etc/mysql/conf.d
directory that end with .cnf. Settings in files in this directory will
augment and/or override settings in /etc/mysql/my.cnf. If you want to
use a customized MySQL configuration, you can create your alternative
configuration file in a directory on the host machine and then mount
that directory location as /etc/mysql/conf.d inside the mysql
container.
If /my/custom/config-file.cnf is the path and name of your custom
configuration file, you can start your mysql container like this (note
that only the directory path of the custom config file is used in this
command):
$ docker run --name some-mysql -v /my/custom:/etc/mysql/conf.d -e
MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag
This will start a new
container some-mysql where the MySQL instance uses the combined
startup settings from /etc/mysql/my.cnf and
/etc/mysql/conf.d/config-file.cnf, with settings from the latter
taking precedence.
From that point and if you create the my.cnf file on your host then you'll never run into this problem again since you can edit the file as many times as you want.

Docker - Multiple duplicate volume declarations; what happens?

I'm trying to set up a persistent data volume for my MySQL docker container.
I'm using the official MySQL image which has this in the Dockerfile:
VOLUME /var/lib/mysql
If I invoke
-v /var/lib/mysql:/var/lib/mysql
during runtime, does my command take precedence, or do I have to remove the VOLUME declaration from the Dockerfile?
Take a look at https://docs.docker.com/reference/builder/#volume - the VOLUME command is declaring a mount point so it can be used by other hosts with the --volumes-from as well the VOLUME command tells docker that the contents of this directory is external to the image. While the -v /dir1/:/dir2/ will mount dir1 from the host into the running container at dir2 location.
In other words, you can use both together and docker will mount the -v properly.

AWS CentOS 6.5 Instance + AWS EBS volume for web hosting files and database?

I have an AWS instance running CentOS 6.5. It has been updated, secured, and setup for web hosting (LAMP). I attached an EBS volume to the instance and mounted it under /data.
Two questions:
How can I get MySQL to use the /data directory as its database storage location? (I don't want to run the program from the /data directory, just put the .sql file there.
How can I do the same for my web site? I plan on running a wordpress site and its current location is in the /var/www/html directory. I want to change this to /data/site.
I want to keep the web site files and database on a separate volume: /data. If my instance was to get corrupt or inaccessible, I can attach the EBS volume to a new instance.
I have read dozens of tutorials and articles on how to get MySQL moved to a different directory, but nothing is working. MySQL refuses to start up after. Can I keep MySQL installed as is, but have it read/write the database on a different directory like /data which is a mounted EBS volume or is this not possible at all with linux?
Here are some of the tutorials and articles I been following/testing with:
aws.amazon.com/articles/1663?_encoding=UTF8&jiveRedirect=1
spruce.it/noise/setting-up-a-proper-lamp-stack-on-aws-ec2-ebs/
EDIT:
This is what I am doing.
Create a new instance using this ami: https://aws.amazon.com/marketplace/pp/B00IOYDTV6?ref=cns_srchrow
Once the instance is up, I run updates using: sudo yum update -y
One updated, I set it up as a LAMP web server using these instructions: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/install-LAMP.html
In addition to the above steps, I allow port 80 tcp connections on the built-in firewall. I run these commands: sudo iptables -I INPUT -p tcp --dport 80 -j ACCEPT and sudo service iptables save
Once this is done, I test my site at http://IP-ADDRESS (this shows me the Apache Test Page)
Once LAMP is installed, I install the MySQL Server by running this: yum install mysql-server
After that is installed, I proceed to the "To secure the MySQL server" instructions on the previous Amazon document.
Next, I install PHPMyAdmin using these two tutorials: http://tecadmin.net/installing-apache-mysql-php-on-centos-redhat/# and http://tecadmin.net/how-to-install-phpmyadmin-on-centos-using-yum/
At this point, I have a fully functioning web server. Now, I want to use the AWS EBS volume to store all the databases and website files. First, I attach the newly create AWS EBS volume. I use this tutorial to do this: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-using-volumes.html
THIS IS WHERE THE PROBLEMS START.
Using the information in this tutorial: aws.amazon.com/articles/1663?_encoding=UTF8&jiveRedirect=1. It says FAILED.
So one thing you can do is the following that avoids copying all directories. You need to make sure that all permissions are setup correctly for it to work:
mysql dat dir:
mv /var/lib/mysql /var/lib/mysql.orig
mkdir -p /<your-new-ebs-mountpoint>/var/lib/mysql
chown mysql.mysql /<your-new-ebs-mountpoint>/var/lib/mysql
chmod 700 /<your-new-ebs-mountpoint>/var/lib/mysql
etc configs:
mkdir -p /<your-new-ebs-mountpoint>/etc
cp /etc/my.cnf /<your-new-ebs-mountpoint>/etc/my.cnf
mv /etc/my.cnf /etc/my.cnf.orig
ln -s /<your-new-ebs-mountpoint>/etc/my.cnf /etc/my.cnf
logs:
mkdir -p /<your-new-ebs-mountpoint>/var/log
mv /var/log/mysqld.log /var/log/mysqld.log.orig
touch /<your-new-ebs-mountpoint>/var/log/mysqld.log
chown mysql.mysql /<your-new-ebs-mountpoint>/var/log/mysqld.log
chmod 640 /<your-new-ebs-mountpoint>/var/log/mysqld.log
ln -s /<your-new-ebs-mountpoint>/var/log/mysqld.log /var/log/mysqld.log