I have a problem with my docker container. I need to import data, something like .csv file from my computer to docker container, but I don't know how. I found a command like "docker insert" but it doesn't work.
You can do this using Docker volumes.
docker run -i -t -v /home/user/stuff:/data ubuntu /bin/bash
Where in this example /home/user/stuff is a directory OUTSIDE the container and /data is the directory where that content will be located INSIDE the container.
Related
I'm trying to docker-containerize PostgreSQL server and this container will have many other applications as well. The need is that, PostgreSQL server data should be mapped to the host volume so that when container is stopped, we won't lose the data. Also that, the next time when we start the container, the same directory can be mapped again and postgres can use the old data. Below is the DOCKERFILE. Note that I'm using ubuntu 22.04 on the host.
FROM ubuntu:22.04
ENV DEBIAN_FRONTEND noninteractive
RUN apt install -y postgresql
ENTRYPOINT ["tail", "-f", "/dev/null"]
Docker image is built using the command
docker build -t pg_test .
and the container is run using the command
docker run --name test -v /home/me/data:/var/lib/postgresql/14/main pg_test
'/home/me/data' is the host directory which is empty where I want to map the postgres server data. '/var/lib/postgresql/14/main' is the directory inside the docker container where the postgres is supposed to store the data.
Once the docker container starts, I enter the docker container using the command
docker exec -it test bash
and once I'm inside, I'm trying to start the PostgreSQL service. But PostgreSQL fails to start as there is no data in '/var/lib/postgresql/14/main' directory. I understand that since I have mapped an empty host directory to '/var/lib/postgresql/14/main' directory, postgres doesn't have the files required to start.
I understand that I'm doing it the wrong way, but I couldn't find a way around it. Can anyone please help me to do this the right way, if there is one?
Any help would be appreciable.
You should use the postgres docker image, it will set up the db for you when you start the container, you can find instructions on https://hub.docker.com/_/postgres
If you must use a custom image, you will need to initialize the db yourself, usually by running initdb or whatever your system provides.
But really you should use the appropriate docker image, and if you need more services you start them in their own container and connect them to the postgres one
I have a running postgreSQL docker container and need to add a volume mount.
I followed the steps from How can I add a volume to an existing Docker container?, (ran docker commit on the container to save it as an image, and spun up another container based on that image with a named volume mounted in). All the data files from the first container are present in /var/lib/postgres/data of the second container.
However, when I try to query this second postgres database, I cannot see any tables that are in the first container. Been trying to fix this for a few days with no luck, am I missing something here (does mounting a volume obscure the existing data in /var/lib/postres/data)?
Commit will not work as there is the volume defined in the Dockerfile.
Volumes are useful in many cases, for example, for running
database-storage. However, since volumes are not 'part' of a
container, it makes containers no longer portable - which seems in
direct conflict with the slogan "Build once... Run anywhere.."
docker commit data container with VOLUME
One option that you can try is copying data folder to host from an existing container and then launch the container with mount path.
docker cp my_db_cotainer:/var/lib/postgresql/data db_data
then start a new container with this path so it will contain the same data as the previous one
docker run -d --name some-postgres -v $PWD/db_data/:/var/lib/postgresql/data postgres
same for mysql
docker cp some-mysql-old:/var/lib/mysql db_backup
docker run --rm --name some-mysql-new -v $PWD/db_backup:/var/lib/mysql -it mysql
I wish to store my persists data in my local D:\dockerData\postgres9.6. Below is my docker command
docker pull postgres
docker run -d -v /d/dockerData/postgres9.6:/var/lib/postgresql/data -p 5432:5432 postgres
It successful create a container and I can use pgAdmin to access and create database.
But I found out that there is no file in my D:\dockerData\postgres9.6. I exec bash into the container, there is at least 20+ files inside /var/lib/postgresql/data.
Anyone can point out which part goes wrong?
It depends what kind of Docker you are using on Windows:
Docker Toolbox with VirtualBox: only C:\Users\mylogin is shared by default. D:\ is not mounted.
Docker for Windows with HyperV: only C:\ is mounted by default. Make sure D:\ is a shared drive: see image
Previously, to access a file in a running dokku instance I would run:
docker ps to get the container ID followed by
ls /var/lib/docker/aufs/diff/<container-id>/app/...
note: I'm just using 'ls' as an example command. I ultimately want to reference a particular file.
This must have changed, as the container ID is no longer accessible via this path. There are loads of dirs in that folder, but none that match any of the running containers.
It seems like mounting a volume for the entire container would be overkill in this scenario. I know I can access the file system using dokku run project-name ls, and also docker exec <container-id> ls, but neither of those will satisfy my use case.
To explain a bit more fully, in my dokku project, I have some .sql files that I'm using to bootstrap my postgres DB. These files get pushed up via git push with the rest of the project.
I'm hoping to use the postgres dokku plugin to run the following:
dokku postgres:connect db-name < file-name.sql
This is what I had previously been doing using:
dokku postgres:connect db-name < /var/lib/docker/aufs/diff/<container-id>/app/file-name.sql but that no longer works.
Any thoughts on this? Am I going about this all wrong?
Thanks very much for any thoughts.
Here's an example:
dokku apps:list
=====> My Apps
DummyApp
dokku enter DummyApp
Enter bash to the DummyApp container.
Never rely on the /var/lib/docker file system paths as most of the data stored there is dependent on the storage driver currently in use so it is subject to change.
cat the file from an existing container
docker exec <container> cat file.sql | dokku postgres:connect db-name
cat the file from an image
docker run --rm <image> cat file.sql | dokku postgres:connect db-name
Copy file from an existing container
docker cp <container>:file.sql file.sql
dokku postgres:connect db-name < file.sql
I'm on windows 10 with docker version 1.9.1 using docker toolbox
I wanted to put up a quick postgres container, something I've done before with a dockerfile I had laying around.
FROM postgres
ADD create-db.sql /tmp/
ADD drop_create_table.sql /tmp/
ADD db.sql /tmp/
ADD create-db.sh /docker-entrypoint-initdb.d/
It's pretty simple.
and when i run the resulting image. it starts fine.
However at the end it says:
...
server started ALTER ROLE
/docker-entrypoint-sh: running
/docker-entrypoint-initdb.d/create-db.sh :No such file or directory
If I try to do docker run -it <imagename> //bin/bash I can see that the file is indeed there:
root#xxxx:/docker-entrypoint-initdb.d# ls
create-db.sh
but whenever I run it it tells me it's not.
The container promptly stops when it doesn't find the file, so I can't try to ssh into the running container.