[Docker](EN) Attach host file or directory to container using bind mounts
Post about docker bind mounts usage
Environment and Prerequisite
- Linux
- Docker
Bind Mounts
- Docker supports various ways to store files in container.
- In official doc, there are three ways like below picture.
- This post only summarize about
Bind mountsin below picture. There are several usages and options in official doc. Bind mountsenables a file or directory on the host machine to be mounted into a container.- Use via
--mountor-voption.
Bind Mounts Examples
Basic Usage Form
- Below example is from official doc.
- Add needed options after
--mount. - Add host’s file or directory to
sourceand container’s path totarget. - In below case, host’s
"$(pwd)"/targetdirectory becomes container’s/appdirectory. So result ofls "$(pwd)"/targetin host andls /appin container are same. - It is reference of host’s file or directory so change in container would be affect to host.
docker run -d \
-it \
--name devtest \
--mount type=bind,source="$(pwd)"/target,target=/app \
nginx:latest
- General form
docker run -d \
-it \
--name [CONTAINER NAME] \
--mount type=bind,source="[HOST PATH]",target="[TARGET PATH]" \
[IMAGE NAME]:[TAG]
Needed Files For Examples
- Host file
$ ls -al ~/test/test.txt
-rw-rw-r-- 1 twpower twpower 37 Feb 27 20:46 /home/twpower/test/test.txt
$ cat ~/test/test.txt
String
test string
Line in container
- Host directory
$ ls -al test-docker-bind/
total 16
drwxrwxr-x 2 twpower twpower 4096 Feb 27 21:17 .
drwxr-xr-x 30 twpower twpower 4096 Feb 27 21:17 ..
-rwxrwxr-x 1 twpower twpower 25 Feb 27 21:17 test.sh
-rw-rw-r-- 1 twpower twpower 19 Feb 26 22:59 test.txt
$ cat test-docker-bind/*
#!/bin/sh
echo "result"
String
test string
- Docker image:
ubuntu:18.04
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu 18.04 56def654ec22 5 months ago 63.2MB
Examples
Host file -> Container file
- Mount single host file to specific container’s file
- Need to specify file name to
target. - If file already exists in container, then file will be overwritten.
# Mount host file "/home/twpower/test/test.txt" to container directory "/root"
sudo docker run -d -it --name file-to-container --mount type=bind,source="/home/twpower/test/test.txt",target="/root/test.txt" ubuntu:18.04
- Name can be changed in container like below.
# Mount host file "/home/twpower/test/test.txt" to container directory "/root" with renaming
sudo docker run -d -it --name file-to-container --mount type=bind,source="/home/twpower/test/test.txt",target="/root/test-rename.txt" ubuntu:18.04
- If you additionally specify a directory that is not in the container, the directory is created and files are mounted.
# Mount host file "/home/twpower/test/test.txt" to container directory "/home/twpower/test/new-directory-in-container"
sudo docker run -d -it --name file-to-container --mount type=bind,source="/home/twpower/test/test.txt",target="/home/twpower/test/new-directory-in-container/test.txt" ubuntu:18.04
Host directory -> Container directory
- If you specify directory to each
sourceandtargetand mount, then it appears files and directories undersourcedirectory are shown intargetdirectory.
# Mount host directory "/home/twpower/test-docker-bind" to container directory "/root"
sudo docker run -d -it --name dir-to-container --mount type=bind,source="/home/twpower/test-docker-bind",target="/root" ubuntu:18.04
$ ls /home/twpower/test-docker-bind
test.sh test.txt
$ sudo docker exec -it dir-to-container ls /root
test.sh test.txt
- If you would like to make same directory under specific directory in container, then add directory name in the end.
# Mount host directory "/home/twpower/test-docker-bind" to container directory "/root/test-docker-bind"
sudo docker run -d -it --name dir-to-container --mount type=bind,source="/home/twpower/test-docker-bind",target="/root/test-docker-bind" ubuntu:18.04
$ ls /home/twpower/test-docker-bind
test.sh test.txt
$ sudo docker exec -it dir-to-container ls /root
test-docker-bind
$ sudo docker exec -it dir-to-container ls /root/test-docker-bind
test.sh test.txt