New to docker and don't fully understand the workaround. I am trying to create a docker container to deploy a MongoDB instance. Since MongoDB requires a dbpath for setup, I am providing the dbpath as a volume. The problem I face is once the container is deleted I also lose the volume.
Now, how do I explicitly define the volume to localsystem or to a mount point.
docker run -d -p 2000:27017 -v /data/db --name mongoContainer mongo:4.2
If I am not wrong all the MongoDB collections created are being stored inside dbpath /data/db and once the container is deleted I lose the collections as well.
Here you define your local volume only.
docker run -d -p 2000:27017 -v /data/db --name mongoContainer mongo:4.2
You MUST map your local directory to docker image folder
docker run -d -p 2000:27017 -v /data/db:/inside/mongo_image/path --name mongoContainer mongo:4.2
Always -v /your/local/directory:/docker/directory
/inside/mongo_image/path this should be the right path where mongodb will look for files.
Related
I'm using the official postgresql docker image to start a container.
Afterwards, I install some software and use psql to create some tables etc. I am doing this by first starting the postgres container as follows:
docker run -it --name="pgtestcontainer" -e POSTGRES_PASSWORD=postgres -p 5432:5432 postgres:9.6.6
Then I attach to this container with
docker exec -it pgtestcontainer bash
and I install software, create db tables etc.
Afterwards, I first quit from the second terminal session (that I used to install software) and do a ctrl + c in the first one to stop the postgres container.
At this point my expectation is that if I commit this postgres image with
docker commit xyz...zxy pg-commit-test
and then run a new container based on the committed image with:
docker run -it --name="modifiedcontainer" -e POSTGRES_PASSWORD=postgres -p 5432:5432 pg-commit-test
then I should have all the software and tables in place.
The outcome of the process above is that the software I've installed is in the modifiedcontainer but the sql tables etc are gone. So my guess is my approach is more or less correct but there is something specific to postgres docker image I'm missing.
I know that it creates the db from scratch if no external directory or docker volume is bound to
/var/lib/postgresql/data
but I'm not doing that and after the commit I'd expect the contents of the db to stay as they are.
How do I follow the procedure above (or the right one) and keep the changes to database(s)?
The postgres Dockerfile creates a mount point at /var/lib/postgresql/data which you must mount an external volume onto if you want persistent data.
ENV PGDATA /var/lib/postgresql/data
RUN mkdir -p "$PGDATA" && chown -R postgres:postgres "$PGDATA" && chmod 777 "$PGDATA" # this 777 will be replaced by 700 at runtime (allows semi-arbitrary "--user" values)
VOLUME /var/lib/postgresql/data
https://docs.docker.com/engine/reference/builder/#notes-about-specifying-volumes
You can create a volume using
docker volume create mydb
Then you can use it in your container
docker run -it --name="pgtestcontainer" -v mydb:/var/lib/postgresql/data -e POSTGRES_PASSWORD=postgres -p 5432:5432 postgres:9.6.6
https://docs.docker.com/engine/admin/volumes/volumes/#create-and-manage-volumes
In my opinion, the best way is to create your own image with a /docker-entrypoint-initdb.d folder and your script inside.
Look How to extend this image
But without volume you can't (I think) save your datas.
I solved this by passing PGDATA parameter with a value that is different than the path that is bound to docker volume as suggested in one of the responses to this question.
I'm running a dockerized mongo container.
I'd like to create a mongo image with some initialized data.
Any ideas?
A more self-contained approach:
create javascript files that initialize your database
create a derived MongoDB docker image that contains these files
There are many answers that use disposable containers or create volumes and link them, but this seems overly complicated. If you take a look at the mongo docker image's docker-entrypoint.sh, you see that line 206 executes /docker-entrypoint-initdb.d/*.js files on initialization using a syntax: mongo <db> <js-file>. If you create a derived MongoDB docker image that contains your seed data, you can:
have a single docker run command that stands up a mongo with seed data
have data is persisted through container stops and starts
reset that data with docker stop, rm, and run commands
easily deploy with runtime schedulers like k8s, mesos, swarm, rancher
This approach is especially well suited to:
POCs that just need some realistic data for display
CI/CD pipelines that need consistent data for black box testing
example deployments for product demos (sales engineers, product owners)
How to:
Create and test your initialization scripts (grooming data as appropriate)
Create a Dockerfile for your derived image that copies your init scripts
FROM mongo:3.4
COPY seed-data.js /docker-entrypoint-initdb.d/
Build your docker image
docker build -t mongo-sample-data:3.4 .
Optionally, push your image to a docker registry for others to use
Run your docker image
docker run \
--name mongo-sample-data \
-p 27017:27017 \
--restart=always \
-e MONGO_INITDB_DATABASE=application \
-d mongo-sample-data:3.4
By default, docker-entrypoint.sh will apply your scripts to the test db; the above run command env var MONGO_INITDB_DATABASE=application will apply these scripts to the application db instead. Alternatively, you could create and switch to different dbs in the js file.
I have a github repo that does just this - here are the relevant files.
with the latest release of mongo docker , something like this works for me.
FROM mongo
COPY dump /home/dump
COPY mongo_restore.sh /docker-entrypoint-initdb.d/
the mongo restore script looks like this.
#!/bin/bash
# Restore from dump
mongorestore --drop --gzip --db "<RESTORE_DB_NAME>" /home/dump
and you could build the image normally.
docker build -t <TAG> .
First create a docker volume
docker volume create --name mongostore
then create your mongo container
docker run -d --name mongo -v mongostore:/data/db mongo:latest
The -v switch here is responsible for mounting the volume mongostore at the /data/db location, which is where mongo saves its data. The volume is persistent (on the host). Even with no containers running you will see your mongostore volume listed by
docker volume ls
You can kill the container and create a new one (same line as above) and the new mongo container will pick up the state of the previous container.
Initializing the volume
Mongo initializes a new database if none is present. This is responsible for creating the initial data in the mongostore. Let's say that you want to create a brand new environment using a pre-seeded database. The problem becomes how to transfer data from your local environment (for instance) to the volume before creating the mongo container. I'll list two cases.
Local environment
You're using either Docker for Mac/Windows or Docker Toolbox. In this case you can easily mount a local drive to a temporary container to initialize the volume. Eg:
docker run --rm -v /Users/myname/work/mongodb:/incoming \
-v mongostore:/data alpine:3.4 cp -rp /incoming/* /data
This doesn't work for cloud storage. In that case you need to copy the files.
Remote environment (AWS, GCP, Azure, ...)
It's a good idea to tar/compress things up to speed the upload.
tar czf mongodata.tar.gz /Users/myname/work/mongodb
Then create a temporary container to untar and copy the files to the mongostore. the tail -f /dev/null just makes sure that the container doesn't exit.
docker run -d --name temp -v mongostore:/data alpine:3.4 tail -f /dev/null
Copy files to it
docker cp mongodata.tar.gz temp:.
Untar and move to the volume
docker exec temp tar xzf mongodata.tar.gz && cp -rp mongodb/* /data
Cleanup
docker rm temp
You could also copy the files to the remote host and mounting from there but I tend to avoid interacting with the remote host at all.
Disclaimer. I'm writing this from memory (no testing).
Here is how its done with docker-compose. I use an older image of mongo but the docker-entrypoint.sh accepts *.js and *.sh files for all versions of the image.
docker-compose.yaml
version: '3'
services:
mongo:
container_name: mongo
image: mongo:3.2.12
ports:
- "27017:27017"
volumes:
- mongo-data:/data/db:cached
- ./deploy/local/mongo_fixtures /fixtures
- ./deploy/local/mongo_import.sh:/docker-entrypoint-initdb.d/mongo_import.sh
volumes:
mongo-data:
driver: local
mongo_import.sh:
#!/bin/bash
# Import from fixtures
mongoimport --db wcm-local --collection clients --file /fixtures/properties.json && \
mongoimport --db wcm-local --collection configs --file /fixtures/configs.json
And my monogo_fixtures json files are the product of monogoexport which have the following format:
{"_id":"some_id","field":"value"}
{"_id":"another_id","field":"value"}
This should help those using this without a custom Dockefile, just using the image straight away with the right entrypoint setup right in your docker-compose file. Cheers!
I've found a way that is somehow easier for me.
Say you have a database in a docker container on your server, and you want to back it up, here’s what you could do.
What might differ from your setup to mine is the name of your mongo docker container [mongodb] (default when using elastic_spence). So make sure you start your container first with --name mongodb to match the following steps:
$ docker run \
--rm \
--link mongodb:mongo \
-v /root:/backup \
mongo \
bash -c ‘mongodump --out /backup --host $MONGO_PORT_27017_TCP_ADDR’
And to restore the database from a dump.
$ docker run \
--rm \
--link mongodb:mongo \
-v /root:/backup \
mongo \
bash -c ‘mongorestore /backup --host $MONGO_PORT_27017_TCP_ADDR’
If you need to download the dump from to your server you can use scp:
$ scp -r root#IP:/root/backup ./backup
Or upload it:
$ scp -r ./backup root#IP:/root/backup
P.S: Original source by Tim Brandin available at https://blog.studiointeract.com/mongodump-and-mongorestore-for-mongodb-in-a-docker-container-8ad0eb747c62
Thank you!
I have a data only postgresql container
docker create -v /var/lib/postgresql/data --name bevdata mdillon/postgis /bin/true
I have a running Postgis container
docker run --name bevaddress -e POSTGRES_USER=bevsu -e POSTGRES_DB=bevaddress -P -d --volumes-from bevdata mdillon/postgis
I have made a backup of that database into the bavaddress container into directory /var/lib/postgresql/backup
I think this means that the backup data is in container bevaddress (the running process) and NOT the data only container bevdata which I think is good.
Now if I docker pull mdillon/postgis to a new version, how can I attach the folder /var/lib/postgresql/backup of container bevaddress so that a new instance and version of mdillon/postgis can access that folder to restore the database?
To the best of my knowledge, you cannot. The file system in your running container only exists for the duration of the run. Without mounting a volume, you have no way to allow a second container access to the backup.
For future backups, you could create a second volume only container that mounts /var/lib/postgresql/backup.
Create data only container:
docker create -v /mongodb_data --name mongodb_data mongo
Create monogdb container:
docker run --volumes-from mongodb_data --name mongo_db --restart always -d mongo
Then to use mongodb in my own container I use the link command:
--link mongo_db:mongo
So everything works fine. Now I want to backup the mongodb according to the docs: http://docs.docker.com/userguide/dockervolumes/#backup-restore-or-migrate-data-volumes and this command:
docker run --volumes-from mongodb_data -v $(pwd):/backup busybox tar cvf /backup/backup.tar /mongodb_data
However the created tar file has just an empty /mongodb_data folder. The folder contains not a single file.
Any ideas whats wrong? I am using docker 1.7 on ubuntu 14.04 LTS.
The problem is your data only container. You make your volume with path /mongodb_data which doesn't store any mongo db data. By default, the mongo db storage path is /data/db (according to this #Where to Store Data Section)
As the result, your mongodb data is not saved in your data only container. So here is a workaround:
copy /data/db to /mongodb_data in your mongodb container docker exec -it mongo_db bash then cp -r /data/db/* /mongodb_data/
make a backup by following the doc you mentioned
build a new data only container and load the backup
remove current mongo_db container and recreate a new one with the new data only container
OR, you can modify your mongodb config, to change the default directory to /mongodb_data once you copied all data from /data/db to /mongodb_data. You may find this useful Changing MongoDB data store directory
You can use this image that provides docker container for many jobs ( import, export , dump )
I have a data container with Dockerfile:
from ubuntu:latest
VOLUME ["/var/lib/postgresql/9.3/main"]
and a postgresql service container:
#install stuff
............
# Set the default command to run when starting the container
CMD ["/usr/lib/postgresql/9.3/bin/postgres", "-D", "/var/lib/postgresql/9.3/main", "-c", "config_file=/etc/postgresql/9.3/main/postgresql.conf"]
then I start the data container and postgresql container:
docker run -i -t -d --name data docker:data
docker run -i -t -p 49131:5432 --name postgresql --volumes-from data --rm docker:postgresql
it says :
FATAL: data directory "/var/lib/postgresql/9.3/main" has wrong ownership
HINT: The server must be started by the user that owns the data directory.
it seems like the /var/lib/postgresql/9.3/main folder belong to the root user in the data container. Then i attach to the container, add user and change owner of that folder to postgres:
docker attach data
useradd postgres -s /bin/bash
chown -R postgres:postgres /var/lib/postgresql
then try again with the same error.
what is the problem and what am i missing?
The postgres user probably hasn't been assigned the same UID in the separate containers.
There's no need to make it this difficult though, just use the postgres image to create your data container e.g:
docker run --name data-container postgres echo "Data Container"
That way all the permissions will be set up correctly. For more information see:
http://container42.com/2014/11/18/data-only-container-madness/ and
http://container-solutions.com/2014/12/understanding-volumes-docker/