CODEWITHSUNDEEP
dockerdocker-compose
ugur
ugur

Reputation: 410

Mount a volume without deleting files

I am trying to use a folder named tmp as a volume in docker container in order to do it I am using the following docker-compose.yml file

version: "3"

services:
  master:
    image: singularities/spark
    command: start-spark master
    hostname: master
    ports:
      - "6066:6066"
      - "7070:7070"
      - "8080:8080"
      - "50070:50070"
      - "7077:7077"
    volumes:
      - "../data:/tmp/"
    deploy:
      placement:
        constraints:
          - node.role == manager
  worker:
    image: singularities/spark
    command: start-spark worker master
    environment:
      SPARK_WORKER_CORES: 1
      SPARK_WORKER_MEMORY: 4g
    links:
      - master
    volumes:
      - "../data:/tmp/"

tmp folder exist in singularities/spark image. After I run following command, folders and files under tmp folder are deleted.

docker-compose up -d

Upvotes: 2

Views: 5883

Answers (3)

Moritz Vogt
Moritz Vogt

Reputation: 159

This does only work with single files 

    volumes:
  - "../data/config.properties:/tmp/config.properties"

For example

Upvotes: 1

vivekyad4v
vivekyad4v

Reputation: 14843

When you do a docker-compose up -d, while creating containers docker mounts your ../data host directory to /tmp which cleans up /tmp of the image/container & puts everything you have inside ../data of the host machine.

You might have to choose some other container path other than /tmp to ensure it has the data created by singularities/spark image.

EDIT 1

docker cp command can help you copy files FROM/TO host/container.

You want to copy from /tmp of the image to host & then copy host to tmp (Not sure why you wanna do this, not suggested & extremely rare scenario )

However, you can utilize docker run with a named volume or a host bind volume to start a container & get the data. Following a docker cp to copy data FROM & TO the host or container.

Upvotes: 1

PaulNUK
PaulNUK

Reputation: 5209

The clue is in the name. The /tmp folder gets cleared at boot time (i.e.at container startup). You'll have to use a different folder name if you want persistent data.

Upvotes: 0

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