Why docker container can't see volume on different container? - docker

I have 2 containers that I fire up using docker-compose up.
The first I just pull from the docker hub nginx:stable
The second one I build on top of the php from the hub
dockerfile
FROM composer:1.9.3
RUN mkdir /fatfree
RUN ["composer","require","bcosca/fatfree-core","--working-dir","/fatfree"]
FROM php:7.4-fpm
COPY --from=0 /fatfree /fatfree
I also tried VOLUME /fatfree in the above file to no avail.
docker-compose.yml
version: "3.7"
services:
webserver:
image: nginx:stable
ports:
- "80:8080"
volumes:
- ./www:/www
- fatfree:/fatfree
links:
- php
php:
build:
context: .
dockerfile: dockerfile
volumes:
- ./www:/www
- "fatfree:/fatfree"
volumes:
fatfree:
If I interpreted correctly the docker documentation, my www/index.php should be able to see whatever is in /fatfree, but it doesn't. The folder itself shows up, but it appears empty.
If I run the dockerfile interactively docker container run -i -t test bash , the /fatfree folder exists and it has all the files I expect it to have.
There are plenty of stackoverflow questions asking how to achieve this, and they all seem to suggest that what I'm doing is actually ok, but it doesn't work, and I have no clue why.
Any suggestion is appreciated.

Your mapping is incorrect.
You want:
volumes:
- /fatfree:/www
The first entry /fatfree refers to the path on your host machine.
The second entry /www refers to the path in the container.
In my example, your host's /fatfree directory (and content) will be mapped to the container's /www directory.
Change as desired.

Related

How to copy files inside container with docker-compose

I have a simple image that runs a jar file. That jar file inside the image needs a special configuration file in order to run.
In the location with the docker-compose.yml I have a folder named "carrier" and under this folder I have that file.
The docker-compose.yml:
version: "3.3"
services:
web:
image: "myimage:1.80.0.0"
ports:
- "61003:61003"
volumes:
- ./carrier:/var/local/Config/
When I hit docker-compose up it complains that the file is not there, so it doesn't copy it.
If I do another option like I did in the .sh command, something like this:
volumes:
- ./carrier:/var/local/Config/:shared
It complains about another error:
C:\Tasks\2246>docker-compose up
Removing 2246_web_1
Recreating 1fbf5d2bcea4_2246_web_1 ... error
ERROR: for 1fbf5d2bcea4_2246_web_1 Cannot start service web: path /host_mnt/c/Tasks/2246/carrier is mounted on / but it is not a shared mount
Can someone please help me?
Copy the files using Dockerfile, use below;
FROM myimage:1.80.0.0
RUN mkdir -p /var/local/Config/
COPY carrier /var/local/Config/
EXPOSE 61003
docker-compose.yml
version: "3.3"
services:
web:
build:
dockerfile: Dockerfile
context: '.'
ports:
- "61003:61003"
In the end, run below command to build new image and start container
docker-compose up -d --build
You can use Dockerfile if it does not copy.
Dockerfile;
FROM image
COPY files /var/local/Config/
EXPOSE 61003
Docker-compose;
version: "3.3"
services:
web:
build: . (path contains Dockerfile)
ports:
- "61003:61003"
volumes:
- ./carrier:/var/local/Config/
Remove the last /
volumes:
- ./carrier:/var/local/Config
I'm not sure but you can try to set full access permissions for all user to /carrier:
chmod -R 777 /carrier
Thanks all for all your answers.
Seems like finally docker warned me with some comparisons over the windows files vs Linux files when building the image. (Not with docker compose but with Dockerfile).
SECURITY WARNING: You are building a Docker image from Windows against a non-Windows Docker host. All files and directories added to build context will have '-rwxr-xr-x' permissions. It is recommended to double check and reset permissions for sensitive files and directories.
Tried it on linux and works.

Docker keeps data but creates a new volume from host folder every "run"

It seems to be a misunderstood point from me about volumes. I have a docker-compose file with two services : jobs which is a Flask api built from a Dockerfile (see below), and mongo which is from official MongoDb image.
I have two volumes : - .:/code is linked from my host working directory to /code folder in the container, and a named volume mongodata.
version: "3"
services:
jobs:
build: .
ports:
- "5000:5000"
volumes:
- .:/code
environment:
FLASK_ENV: ${FLASK_ENV}
FLASK_APP: ${FLASK_APP}
depends_on:
- mongo
mongo:
image: "mongo:3.6.21-xenial"
restart: "always"
ports:
- "27017:27017"
volumes:
- mongodata:/data/db
environment:
MONGO_INITDB_ROOT_USERNAME: ${MONGO_INITDB_ROOT_USERNAME}
MONGO_INITDB_ROOT_PASSWORD: ${MONGO_INITDB_ROOT_PASSWORD}
volumes:
mongodata:
Dockerfile for jobs service :
FROM python:3.7-alpine
WORKDIR /code
ENV FLASK_APP=job-checker
ENV FLASK_ENV=development
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
EXPOSE 5000
COPY . .
CMD ["flask", "run", "--host=0.0.0.0"]
Every time I remove these container and re-run, everything is fine, I still have my data in mongodata volume. But when I check the volume list I can see that a new volume is created from - .:/code with a long volume name, for example :
$ docker volume ls
DRIVER VOLUME NAME
local 55c08cd008a1ed1af8345cef01247cbbb29a0fca9385f78859607c2a751a0053
local abe9fd0c415ccf7bf8c77346f31c146e0c1feeac58b3e0e242488a155f6a3927
local job-checker_mongodata
Here I ran docker-compose up, then I removed containers, then ran up again, so I have two volumes from my working folder.
Is this normal that every up create a new volume instead of using the previous one ?
Thanks
Hidden at the end of the Docker Hub mongo image documentation is a note:
This image also defines a volume for /data/configdb...
The image's Dockerfile in turn contains the line
VOLUME /data/db /data/configdb
When you start the container, you mount your own volume over /data/db, but you don't mount anything on the second path. This causes Docker to create an anonymous volume there, which is the volume you're seeing with only a long hex ID.
It should be safe to remove the extra volumes, especially if you're sure they're not attached to a container and they don't have interesting content.
This behavior has nothing to do with the bind mount in the other container; bind mounts never show up in the docker volume ls listing at all.

Docker container not updating on code change

I have a Dockerfile to build my node container, it looks as follows:
FROM node:12.14.0
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 4500
CMD ["npm", "start"]
based on this docker file, I am using docker compose to run this container and link it to a mongo container such that it refers to mongo-service. The docker-compose.yml looks as follows
version: '3'
services:
backend:
container_name: docker-node-mongo-container
restart: always
build: .
ports:
- '4700:4500'
links:
- mongo-service
mongo-service:
container_name: mongo-container
image: mongo
ports:
- "27017:27017"
Expected behavior: Everytime I make a new change to the project on my local computer, I want the docker-compose to restart so that the new changes are reflected.
Current behavior: To make the new changed reflect on docker-compose, I have to do docker-compose down and then delete images. I am guessing that it has to rebuild images. How do I make it so that whenever I make change, the dockerfile builds a new image?
I understand that need to use volumes. I am just failing to understand how. Could somebody please help me here? docker
When you make a change, you need to run docker-compose up --build. That will rebuild your image and restart containers as needed.
Docker has no facility to detect code changes, and it is not intended as a live-reloading environment. Volumes are not intended to hold code, and there are a couple of problems people run into attempting it (Docker file sync can be slow or inconsistent; putting a node_modules tree into an anonymous volume actively ignores changes to package.json; it ports especially badly to clustered environments like Kubernetes). You can use a host Node pointed at your Docker MongoDB for day-to-day development, and still use this Docker-based setup for deployment.
In order for you to 'restart' your docker application, you need to use docker volumes.
Add into your docker-compose.yml file something like:
version: '3'
services:
backend:
container_name: docker-node-mongo-container
restart: always
build: .
ports:
- '4700:4500'
links:
- mongo-service
volumes:
- .:/usr/src/app
mongo-service:
container_name: mongo-container
image: mongo
ports:
- "27017:27017"
The volumes tag is a simple saying: "Hey, map the current folder outside the container (the dot) to the working directory inside the container".

Docker / Docker-compose volume fill & share issue

I have a few questions about Docker volumes. I have installed Docker and docker-compose on a fresh host running debian stretch. I managed to get a docker-compose file running for a simple nginx/php-fpm project, both containers mounted on the directory containing the source code. I wanted to try to create a single volume that would be shared across my containers but I have a few issue, and my understanding of the official documentation is not helping.
So this is an idea of what I'm trying to achieve :
Question 1 : Trying to create a volume from a dockerfile on a directory mounted from host
docker-compose.yml :
version: '3'
services:
php:
build:
context: .
dockerfile: php.dockerfile
volumes:
- ./host-project-directory:/project
php.dockerfile :
FROM php:7-fpm
VOLUME project
from my understanding, when running docker-compose we should have a volume created on host containing all files from /project from container. And /project from container should contain all files from ./host-project-directory from host.
If I ls the content of /project on container I can see the files from host, but using docker volume list, there are no volumes created on host, why ?
Question 2 : How to populate and use this volume from another container ?
version: '3'
services:
php:
build:
context: .
dockerfile: php.dockerfile
volumes:
- named-volume:/project
web:
image: nginx
links:
- php
volumes:
- named-volume:/project
volumes:
named-volume:
This should create a volume called 'named-volume' and bind it to /project directories on both containers php and web.
Now, how to populate this volume with content from ./host-project-directory ?
I've tried adding a dockerfile like
ADD ./host-project-directory /project
But nothing changed and the volume remained empty.
I'm sorry if this is due to my lack of experience using Docker but I can't figure out how to make this simple thing work.
Thank you for your time !
For the first question, I try a simple docker file like this:
FROM php:7-fpm
COPY ./project /project
And a docker-compose like this:
version: '3'
services:
php:
build: .
volumes:
- named-volume:/project
web:
image: nginx
links:
- php
volumes:
- named-volume:/project
volumes:
named-volume:
Since you create the volume on docker-compose you don't need to create that in the Dockerfile.
Running docker volume list, I'm able to see the volume created with a local driver. Making ls inside the folder I'm also able to see the file. It's important to note, that the file present in you local directory it's not the same that the file inside the container. So if you edit the files in the host this will not change the files in container. That's because you have your volume created in another path, probably at: /var/lib/docker/volumes/...
This happens because you map the volume to the path, but you not specifies where you want the volume. To do that just make your docker-compose like this:
version: '3'
services:
php:
build: .
volumes:
- ./project:/project
web:
image: nginx
links:
- php
volumes:
- ./project:/project
Making this I'm still able to see the volume with the volume list command but without a name.
So I don't know why you are not able to see the volume in the list.
For question 2:
Doing the example above I have the files inside the container that exists in my local "project" folder.
Please check that the path to the local folder is correct.
A bind mount is not the same thing as a volume. You're defining a named volume here, but wanting the functionality of a bind mount.
Try this
version: '3'
services:
php:
build:
context: .
dockerfile: php.dockerfile
volumes:
- ./host-project-directory:/project
web:
image: nginx
links:
- php
volumes:
- ./host-project-directory:/project

Docker ADD folder during build and then expose to VOLUME

I am using docker-compose for a basic web app. When the image is built, it copies the static JS files in (ADD) and then builds them.
I then want to expose that directory to other containers, using VOLUME.
E.g.
Dockerfile
ADD ./site/static /site/static
WORKDIR /site/static
RUN gulp
docker-compose.yml
app:
build: .
volumes:
- /site/static
http:
image: nginx
volumes_from:
- app
nginx.conf
location /static {
alias /site/static
}
(Note, this is just an example)
The problem is that it seems to work the first time (i.e. when the volume does not exist), but is then never overwritten by the modified image. If I was using purely a Dockerfile, I could achieve this by putting VOLUME after ADD.
Is there a way to allow this, or am I approaching it completely wrong?
Thanks
Possible solution 1
I might be wrong, but I think the trouble is that when (and if) you do
docker-compose down && docker-compose up
your containers are recreated, and new "anonymous" volume is created.
You can check my guess running:
docker volume ls
I would try to use named volume, like so:
version: "2"
volumes:
app-volume: ~
services:
app:
build: .
volumes:
- app-volume:/site/static
http:
image: nginx
volumes:
- app-volume:/site/static
You need docker-compose 1.6.0+ and require a Docker Engine of version 1.10.0+ for usinng version 2 of docker-compose file.
Possible solution 2
just
app:
build: .
volumes:
- ./site/static:/site/static # maps host directory `./site/static` (relative to docker-compose.yml) to /site/static inside container
http:
image: nginx
volumes_from:
- app
And remove
ADD ./site/static /site/static
from your Dockerfile

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