I had assumed that docker-compose volumes are mounted before the container's service is started. Is this the case?
I ask, since I've got a docker-compose.yml that, amongst other things, fires up a parse-server container, and mounts a host directory in the container, which contains some code the service should run (Cloud Code).
I can see the directory is mounted correctly after docker-compose up by shelling into the container; the expected files are in the expected place. But the parse-server instance doesn't trigger the code in the mounted directory (I checked it by adding some garbage; no errors).
Is it possible the volume is being mounted after the parse-server service starts?
This is my docker-compose.yml:
version: "3"
volumes:
myappdbdata:
myappconfigdata:
services:
# MongoDB
myappdb:
image: mongo:3.0.8
volumes:
- myappdbdata:/data/db
- myappconfigdata:/data/configdb
# Parse Server
myapp-parse-server:
image: parseplatform/parse-server:2.7.2
environment:
- PARSE_SERVER_MASTER_KEY=someString
- PARSE_SERVER_APPLICATION_ID=myapp
- VERBOSE=1
- PARSE_SERVER_DATABASE_URI=mongodb://myappdb:27017/dev
- PARSE_SERVER_URL=http://myapp-parse-server:1337/parse
- PARSE_SERVER_CLOUD_CODE_MAIN = /parse-server/cloud/
depends_on:
- myappdb
ports:
- 5000:1337
volumes:
- ./cloud:/parse-server/cloud
I'm not sure of the response as I can't find this information in the docs. But I had problems with volumes when I needed them mounted before the container was really running. Sometimes the configuration files were not loaded for example.
The only way to deal with it, is to create a Dockerfile, copy what you want, and use this image for your container.
Hth.
Sadly enough, the biggest issue here was whitespace
PARSE_SERVER_CLOUD_CODE_MAIN = /parse-server/cloud/
should have been
PARSE_SERVER_CLOUD=/parse-server/cloud/
Used 1.5 days chasing this; fml.
Related
I set up a Github codespaces environment using devcontainer.json and docker-compose.yaml. Everything works fine, but the postgres database defined in docker-compose.yml loses its data every time the container needs to be re-built.
Here's the bottom part of the docker-compose.yml
db:
image: postgres:latest
restart: unless-stopped
volumes:
- postgres-data:/var/lib/postgresql/data
environment:
POSTGRES_USER: test_user
POSTGRES_DB: test_db
POSTGRES_PASSWORD: test_pass
volumes:
postgres-data:
as you can see, I am trying to map the postgres data volume into a postgres-data volume, but this doesn't work for some reason.
What am I doing wrong that's preventing postgres data from persisting between container builds?
Another option would be to look into using Spawn. (Disclaimer - I'm one of the devs working on it).
We've written some documentation about exactly how to use Spawn-hosted databases with GitHub codespaces here: https://docs.spawn.cc/blog/2021/08/01/spawn-and-codespaces
This will allow you to provision a database thats independent from the GitHub codespace and preserve data between restarts.
You get some extra features with Spawn like arbitrary save points, resets and loading back to saved revisions with Spawn - but the key functionality of spinning up a database for a GitHub codespace and preserving data is one of the things it works extremely well for.
according to https://docs.github.com/en/codespaces/customizing-your-codespace/configuring-codespaces-for-your-project#dockerfile ,
only docker images can be pulled from source and set-up, nowhere they mention that volume persistence is guaranteed.
and after going through this https://code.visualstudio.com/docs/remote/devcontainerjson-reference looks like mounts and few other features related to volumes are not supported for codespaces.
workspaceMount : Not yet supported in Codespaces or when using Clone Repository in Container Volume.
workaround :
in .devcontainer folder where your dockerfile is present add a line like this
RUN curl https://<your_public_cloud>/your_volume.vol -O
here <your_public_cloud> can be google drive, aws or any endpoint where you have access to download the volume. its also the volume you needed to be persist.
and once its downloaded you can mount the volume to postgres service or make a hotswap.
and when you want to save, just upload the volume to your cloud storage provider.
repeat the process every time you build, and save and upload before "unbuild" or dismissing your codespace whatever you like to call.
hope that eases your issue, happy coding!
As long as you don't remove the volume with docker-compose down --volumes as an example, the data should persist.
I had the same issue; and it turned out that I had put a crontab running docker system prune -af every 15 minutes!
You could just mount a host directory, instead of using a docker volume:
volumes:
- /home/me/postgres_data:/var/lib/postgresql/data
This guarantees that no volume cleanup (accidental or deliberate) nukes your database.
Indeed the postgres docs do this in their examples. See the PGDATA environment variable.
As you don't have access to VM, maybe the directory containing your docker-compose.yml changes.
In that case, volume name may change too.
Indeed, by default, your volume name would be the following :
<directory_name>_postgres-data
Could you try a named volume (starting with compose 3.4):
db:
image: postgres:latest
restart: unless-stopped
volumes:
- postgres-data:/var/lib/postgresql/data
environment:
POSTGRES_USER: test_user
POSTGRES_DB: test_db
POSTGRES_PASSWORD: test_pass
volumes:
postgres-data:
external: false
name: postgres-data
documentation of docker-compose can be found here :
https://docs.docker.com/compose/compose-file/compose-file-v3/#name
EDIT 1
If your VM is created at each build, docker dependencies too.
volumes, networks, etc...
A persistent volume is needed somewhere (surviving VM builds).
You may have to create a directory in your local workspace, like:
/local/workspace/postgres-data/
which become in codespaces according to my understanding :
./postgres-data
Check permissions, your user may not exist in the container.
As a result your compose file become:
db:
image: postgres:latest
restart: unless-stopped
volumes:
- ./postgres-data:/var/lib/postgresql/data
environment:
POSTGRES_USER: test_user
POSTGRES_DB: test_db
POSTGRES_PASSWORD: test_pass
I am running a simple django webapp with docker-compose. I define both a web service and a db service in a docker-compose.yml file:
version: "3.8"
services:
db:
image: postgres
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
- POSTGRES_DB=postgres
- POSTGRES_USER=postgres
- POSTGRES_PASSWORD=postgres
web:
build: .
command: python manage.py runserver 0.0.0.0:8000
ports:
- "8000:8000"
env_file:
- ./.env.dev
depends_on:
- db
volumes:
postgres_data:
I start the service by running:
docker-compose up -d
I can load some data in there with a custom django command that I wrote for my app. Everything is running fine (with data) on localhost:8000.
However, when I run
docker-compose down
(so without -v) and then again
docker-compose up -d
the database is empty again. The volume was not persisted. From what I read in the docker-compose docs and also in several posts here at SO, persisting the volume and reusing it when you start a new container should be the default behavior (which, if I understand it correctly, you can disable by using the --renew-anon-volumes flag).
However in my case, the volume is not persisted. Or maybe it is, but my data is gone.
By doing docker volume ls I can see that my volume (I'll use the name my_volume here) still exists after the docker-compose down command. However, the CreatedAt value has been changed. This makes me think it's a different volume with the same name, and my data is already gone, but I don't know how to confirm that.
This SO answer suggests to mount the volume on /var/lib/postgresql instead of /var/lib/postgresql/data. However, I've seen other resources (like this one) where the opposite is suggested. I've tried both, but neither option works.
Thanks for any advice.
It turns out that the Dockerfile of my app was using an entrypoint in which the following command was executed: python manage.py flush which clears all data in the database. As this gets executed every time the app container starts, it clears all data. It had nothing to do with docker-compose.
I'm trying to share a file from one container to another other. An essential detail is that (the machine running) my docker host does not have explicit access to the file: It pulls a git repo and doesn't know about the internal file organization of the repo (with the single exception of the docker-compose file). Hence, the approach of standard mapping <host-path>:<container-path> is not applicable; e.g. this is not possible for me: How to mount a single file in a volume
Below is the docker-compose file, stripped for increased readability. Say service_1 has the file /app/awesome.txt. We then want to mount it into service_2 as /opt/awesome.txt.
# docker-compose.yml
version: '3'
services:
service_1:
volumes:
- shared_vol:/public
# how to make service_1 map 'awesome.txt' into /public ?
service_2:
volumes:
- shared_vol/awesome.txt:/opt/awesome.txt
volumes:
shared_vol:
Working solutions that I have, but are not fond of,
running a script/cmd within service_1, copying the file into the shared volume: causes race-condition as service_2 needs the file upon startup
introducing a third service, which the other two depends_on, and does nothing but put the file in the shared volume
Any help, tips or guidance is most appreciated!
can you just do something like this
version: '3.5'
volumes:
xxx:
services:
service_1:
...
volumes:
- xxx:/app
service_2:
...
volumes:
- xxx:/opt
I've been playing with Docker for the past week and think the container idea is very useful, but despite reading everything I can for the past 3 days I can't get the volume mapping to work
get docker-compose to use my existing volume.
Docker Version: 18.03.1-ce
docker-compose version 1.21.1, build 7641a569
I created a volume using the following via a Dockerfile
# Reference SQL image
FROM microsoft/mssql-server-windows-developer
# Create directory within SQL container for database files mapped to the volume
VOLUME sqldata:c:/MSSQL
and here it shows:
C:\ProgramData\Docker\volumes>docker volume ls
local sqldata
Now I've tried probably 60+ different "solutions" based on StackOverflow and Docker forums, but none of them work. (Note despite the names below with Azure I am simply trying to get this to run locally, Azure is next hurdle)
Docker-compose.yaml:
version: '3.4'
services:
ws:
image: wsManager
container_name: azure-wcf
ports:
- "80"
depends_on:
- db
db:
image: dbimage:latest
container_name: azure-db
volumes:
- \sqldata:/mssql
# - type: volume
# source: sqldata
# target: /mssql
ports:
- "1433"
I've added a volumes section but it does not help,
volumes:
sqldata:
external:
name: sqldata
changed the - \sqldata:/mssql
to every possible slash .. . ~ whatever. Moved the file to yaml file
to C:\ProgramData\Docker\volumes - basically any suggestion that showed in my search results. The dbImage is a SQL Server image that I need to persist the data from but am wondering what the magic is as nothing I've tried works. Any help is GREATLY appreciated.
I'm running on Windows 10 Pro build 1803.
Why does this have to be so hard?
Than you to whomever knows how to make this actually work.
The solution is to reference the true path on Windows using the volumes: option as below:
sqldb:
image: sqlimage
container_name: azure-db
volumes:
- "C:\\ProgramData\\Docker\\volumes\\sqldata:c:\\mssql"
To persist the data I used the following:
environment:
- "sa_password=ddsql2017##"
- "ACCEPT_EULA=Y"
- 'attach_dbs= {"dbName":"MyDb","dbFiles":"C:\\MSSQL\\MyDb.mdf","C:\\MSSQL\\MyDb.ldf"]}]'
Hope this helps someone else as many of the examples I found searching both on SO and elsewhere did not work for me, and in the Docker forums there are a lot of posts saying mounting volumes not work for Windows.
For those who are using Ubunto WSL:
sudo mkdir /c
sudo mount --bind /mnt/c /c
navigate to your project file use new path ( /c/your-project-path and not /mnt/c/your-project-path)
edit your docker-compose.yml and use relative path for volume : ( like ./src instead of c/your-project-path/src)
docker-compose up
I was struggling with a similar problem when trying to mount a volume to a specific path of my Windows machine: basically it didn't work so every time I restarted my Docker instance I lose all my DB data.
I finally found out that it is because Docker for Windows by default cannot interpret Windows path so the flag COMPOSE_CONVERT_WINDOWS_PATHS has to be activated. To do so:
Run the command "set COMPOSE_CONVERT_WINDOWS_PATHS=1"
Restart Docker
Go to Settings > Shared Drives > Reset credentials and then select drive and then apply
From the command line, kill the containers (docker container rm -f )
Re-run the containers
Hope it helps
If your windows account credentials has been changed, you also have to reset credentials for shared drives. (Settings > Shared Drives > Reset credentials)
In my case, the password was changed by my company security policy.
Are you sure you really need to map to a certain host directory? If not, my solution is to create a volume beforehand and use it in docker-compose.yaml. I use the same scripts for both windows and linux. That is the beauty of docker.
Here is what I did to start both postgres and mysql:
create_db.sh (you can run it in git bash or similiar environment in windows):
docker volume create --name postgres-data -d local
docker volume create --name mysql-data -d local
docker-compose up -d
docker-compose.yaml:
version: '3'
services:
postgres:
image: postgres:latest
environment:
POSTGRES_DB: datasource
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
ports:
- 5432:5432
volumes:
- postgres-data:/var/lib/postgresql/data
mysql:
image: mysql:latest
environment:
MYSQL_DATABASE: 'train'
MYSQL_USER: 'mysql'
MYSQL_PASSWORD: 'mysql'
MYSQL_ROOT_PASSWORD: 'mysql'
ports:
- 3306:3306
volumes:
- mysql-data:/var/lib/mysql
volumes:
postgres-data:
external: true
mysql-data:
external: true
By default it looks that after installing Docker on Windows, sharing of drivers is disabled - so you won't be able to use volumes(that are stored on disks)
Enabling such sharing, through: Docker in tray - right click - Settings, helped to me, volumes started working fine.
Docker on Windows is having strange behavior as Windows has limitations with credentials and also with the virtual machine that Docker is using(Hyper-V , VirtualBox - depending on your Docker version and setup).
Basically, you are correct to map a folder in
volumes:
section in your service:
The path is
version: '3.4'
services:
db:
image: dbimage:latest
container_name: azure-db
volumes:
- c:/Temp/sqldata:/mssql
Important is that you do not need to explicitly create volume in volumes section, but the docker-compose up will create it(the same is for docker run).
Strange thing is that it will never show up in
docker volume ls
but it will be usable with the same files inside windows directory and inside container path /mssql
You can test it with:
docker run --rm -v c:/Temp/sqldata:/data alpine ls /data
or
docker run --rm -v c:/Temp:/data alpine ls /data
If it Disappear, probably it lost the credentials and Reset it via Docker->Settings->Shared Drives->Reset credentials.
I hope it was clear and covered all the aspects for you.
Launch Docker from your windows taskbar
Click on Settings icon on top
Click Resources
Click File Sharing
Click on (+) sign and add path of local folder in which you want to map the container volume.
It worked for me.
I have this docker-compose:
version: "2"
services:
api:
build: .
ports:
- "3007:3007"
links:
- mongo
mongo:
image: mongo
volumes:
- /data/mongodb/db:/data/db
ports:
- "27017:27017"
The volumes, /data/mongodb/db:/data/db, is the first part (/data/mongodb/db) where the data is stored inside the image and the second part (/data/db) where it's stored locally?
It works on production (ubuntu) but when i run it on my dev-machine (mac) I get:
ERROR: for mongo Cannot start service mongo: error while creating mount source path '/data/mongodb/db': mkdir /data/mongodb: permission denied
Even if I run it as sudo. I've added the /data directory in the "File Sharing"-section in the docker-program on the mac.
Is the idea to use the same docker-compose on both production and development? How do I solve this issue?
Actually it's the other way around (HOST:CONTAINER), /data/mongodb/db is on your host machine and /data/db is in the container.
You have added the /data in the shared folders of your dev machine but you haven't created /data/mongodb/db, that's why you get a permission denied error. Docker doesn't have the rights to create folders.
I get the impression you need to learn a little bit more about the fundamentals of Docker to fully understand what you are doing. There are a lot of potential pitfalls running Docker in production, and my recommendation is to learn the basics really well so you know how to handle them.
Here is what the documentation says about volumes:
[...] specify a path on the host machine (HOST:CONTAINER)
So you have it the wrong way around. The first part is the past on the host, e.g. your local machine, and the second is where the volume is mounted within the container.
Regarding your last question, have a look at this article: Using Compose in production.
Since Docker-Compose syntax version 3.2, you can use a long syntax of the volume property to specify the type of volume. This allows you to create a "Bind" volume, which effectively links a folder from a container to a folder in your host.
Here is an example :
version : "3.2"
services:
mongo:
container_name: mongo
image: mongo
volumes:
- type: bind
source: /data
target: /data/db
ports:
- "42421:27017"
source is the folder in your host and target the folder in your container
More information avaliable here : https://docs.docker.com/compose/compose-file/#long-syntax