I created one Docker Image for a custom application which needs some license files (some files and one directory) to run, so I'm using the COPY command in the Dockerfile to copy license file to the image:
# Base image: Application installed on Debian 10 but unlicensed
FROM me/application-unlicensed
# Copy license files
COPY *.license /opt/application/
COPY application-license-dir /var/lib/application-license-dir
I use this Dockerfile to build a new image with the license for a single container. As I have 5 different licenses I created 5 different images each with one specific license file and directory.
The licenses are also fixed to a MAC Address, so when I run one of the five container I specify its own MAC Address with the --mac-address parameter:
docker run --rm --mac-address AB:CD:EF:12:34:56 me/application-license1
This work, but I wish to have a better and smarter way to manage this:
As with docker-compose is it possible to specify the container MAC Address, could I just use the unlicensed base image and copy license files and the license directory when I build the 5 containers with docker-compose?
Edit: let me better explain the structure of license files
The application is deployed into /opt/application directory into the Docker image.
License files (*.license) are into the /opt/application at the same level of the application itself, to they cannot be saved into a Docker volume unless I create some symlinks (but I have to check if the application will work this way).
The directory application-license-dir needs to be at /var/lib/application-license-dir, so it can be mounted into a Docker volume (I have to check if the application will work but I think so).
Both *.license files and the files into the application-license-dir are binary, so I cannot script or create them at runtime.
So:
can docker-compose create a local directory on the Docker host
server before binding and mounting it to a Docker volume?
can docker-compose copy my licenses file and my license directory from
the GIT repository (locally cloned) to the local directory created
during the step 1?
can docker-compose create some symlinks into the
container's /opt/application directory for the *.license files
stored into the volume?
For things that are different every time you run a container or when you run a container on a different system, you generally don't want to specify these in a Dockerfile. This includes the license files you show above; things like user IDs also match this pattern; depending on how fixed your configuration files are they can also count. (For things that are the same every time you run the container, you do want these in your image; especially this is the application source code.)
You can use a Docker bind mount to inject files into a container at run time. There is Compose syntax for bind mounts using the volumes: directive.
This would give you a Compose file roughly like:
version: '3'
services:
app1:
image: me/application-unlicensed
volumes:
- './app1.license:/opt/application/app.license'
- './application-license-dir:/var/lib/application-license-dir'
mac_address: 'AB:CD:EF:12:34:56'
Bind mounts like this are a good match for pushing configuration files into containers. They can provide an empty host directory into which log files can be written, but aren't otherwise a mechanism for copying data out of an image. They're also useful as a place to store data that needs to outlive a container, if your application can't store all of its state in an external database.
According to this commit docker-compose has mac_address support.
Mounting license files with -v could be an option.
You can set mac_address for the different containers as
mac_address: AB:CD:EF:12:34:12. For documentation reference see this
For creating multiple instances from the same image, you will have to copy paste each app block 5 times in your docker-compose file and in each you can set a different mac_adddress
Related
I am trying to develop a project locally using Docker Compose and to prevent re-building my image on every update, I've added a bind-mount that maps my src directory to my WORDIR in Docker. All changes made on my local machine are then reflected in my Docker container...EXCEPT for one file. For some reason, there's a single file in my project, that when I change its contents, the change is not reflected in the Docker container even though other files adjacent to this file DO detect file changes. Which leads me to believe that the directory is mapped correctly but it's some other issue with the file itself?
docker-compose.yaml
graphql:
build:
context: .
dockerfile: ./app/graphql/src/Dockerfile
target: development
volumes:
- ./app/graphql/src:/workspace
- /workspace/node_modules/
Dockerfile
# ------------> Base Image
FROM node:14 AS base
WORKDIR /workspace
COPY ./app/graphql/src .
# ------------> Development Image
FROM base AS development
CMD ["npm", "run", "dev"]
I haven't figured out how to show directory structure but the files that I am modifying are located in:
/app/graphql/src/api/graphql
Where file a.ts detects changes and is reflected in the Docker container but b.ts does not. I read about how Docker depends on the inode of the file to match if bind mounting specific files. I'm mounting a directory, but for a sanity check, I ran:
ls -i
in both the host and container and confirmed that the inodes matched.
I have two M1 Mac computers and I confirmed that this is a problem between both machines.
Any additional thoughts to debug this problem? My only other thought is that I hit a max number of files that can be tracked, but that's why I removed the node_modules. Any assistance would be really helpful!
EDIT: I created a new file, c.ts and duplicated the contents of b.ts (the file that wasn't changing between host and container)...and c.ts detects changes properly! Is there a way to inspect why a certain file isn't broadcasting changes? This is so strange.
You should remove COPY ./app/graphql/src . directive from your Dockerfile because this folder will mounted to container as volume.
How can I change my / Prometheus/ Prometheus.yml on the container itself
I want it to track
1) my appserver - an Node application in a docker container
2) my postgres db
3) my apached and nginx web server
I do know that one has to change the Prometheus.yml file and add targets
Generic mechanisms to change docker images are
Mount your configuration file at the desired path.
Create a new image by copying the co fig file in the new Dockerfile. Not recommended if you have to use different configs for different environments/apps
Change the file on the running container if the application (peomerheus in this case) supports it. I know that some of the apps like Kibana do this. Good for debugging, not recommended for production environments.
It's hard to be precise with an answer given the lack of details but in general, you place your modified prometheus.yml file within the Docker context and modify your Dockerfile to add the instruction
COPY prometheus.yml /path/to/prometheus.yml
I want to deploy vueJS app inside a docker nginx container but before that container runs the vueJS source has to be compiled via npm run build I want to compilation to run in a container and then exit leaving only the compiled result for the nginx container.
Every time docker-compose up is run the vueJS app has to be recompiled as there is a .env file on the host OS that has to be volume mounted and the variables in here could be updated.
The ideal way I think would be some way of creating stages for docker compose like in gitlab ci so there would be a build stage and when that's finished the nginx container starts. But when I looked this up I couldn't see a way to do this.
What would be the best way to compile my vueJS app every time docker-compose up is run?
If you're already building your Vue.js app into a container (with a Dockerfile), you can make use of the build directive in your docker-compose.yml file. That way, you can use docker-compose build to create containers manually, or use run --build to build containers before they launch.
For example, this Compose file defines a service using a container build file, instead of a prebuilt image:
version: '3'
services:
vueapp:
build: ./my_app # There should be a Dockerfile in this directory
That means I can both build containers and run services separately:
docker-compose build
docker-compose up
Or, I can use the build-before-run option:
# Build containers, and recreate if necessary (build cache will be used)
docker-compose up --build
If your .env file changes (and containers don't pick up changes on restart), you might consider defining them in container build file. Otherwise, consider putting the .env file into a directory (and mount the directory, not the file, because some editors will use a swap file and change the inode - and this breaks the mount). If you mount a directory and change files within the directory, the changes will reflect in the container, because the parent directory's inode didn't change.
I ended up having an nginx container that reads the files from a volume mount and a container that builds the app and places the files in the same volume mount. While the app is compiling, nginx reads the old version and when the compilation is finished the files get replaced with the new ones.
I'm writing a Dockerfile for a java application but I'm struggling with volumes: the mounted volumes are empty.
I've read the Dockerfile reference guide and the best pratice to write Dockerfiles, but, for a start, my example is quite complicated.
What I want to do is to be able to have the following items on the host (in a mounted volume):
configuration folder,
log folder,
data folder,
properties files
Let me summarize :
When the application is installed (extracted from the tar.gz with the RUN command), it writes a bunch of files and directories (including log and conf).
When the application is started (with CMD or ENTRYPOINT), it creates a data folder if it doesn't exist and put data files in it.
I'm only interested in:
/rootapplicationfolder/conf_folder
/rootapplicationfolder/log_folder
/rootapplicationfolder/data_folder
/rootapplicationfolder/properties_files
I'm not interested in /rootapplicationfolder/binary_files
There is something taht I dont't see. I've read and applied the information found in the two following links without success.
Questions:
Should I 'mkdir'only the top level dir on the host to be mapped with /rootapplicationfolder ?What about the files ?
Is the order of 'VOLUME' in my Dockerfile important ?
Does it need to be placed before or after the deflating (RUN tar zxvf compressed_application) ?
https://groups.google.com/forum/#!topic/docker-user/T84nlzw_vpI
Docker on Linux - Empty mounted volumes
Try using Docker-compose, use the volumes property to set what path you want to mount between your machine and your container.
version 2 Example
web:
image: my-web-app
build:.
command: bash -c "npm start"
ports:
- "8888:8888"
volumes:
- .:/home/app/code (This mount your current path with /home/app/code)
- /home/app/code/node_modules/ (unmount sub directory)
environment:
NODE_ENV: development
You can look at this repository too.
https://github.com/williamcabrera4/docker-flask/blob/master/docker-compose.yml
Well, I've managed to get want I want.
First, I haven't ant VOLUME directive in my Dockerfile.
All the shared directories are created with the -v option of the docker run command.
After that, I had issues with extracting the archive whenever the "extracting" would overwrite an existing directory mounted with -v because it's simply not possible.
So, I deflate the archive somewhere where the -v mounted volumes don't exist and AFTER this step, I mv the contents of deflated/somedirectory to -vMountedSomeDirectory.
I still had issues with docker on CentOS, the mv would copy the files to the destination but would be unable to delete them at the source after the move. I got tired and simply use a debian distribution instead.
Maybe I'm missing this when reading the docs, but is there a way to overwrite files on the container's file system when issuing a docker run command?
Something akin to the Dockerfile COPY command? The key desire here is to be able to take a particular Docker image, and spin several of the same image up, but with different configuration files. (I'd prefer to do this with environment variables, but the application that I'm Dockerizing is not partial to that.)
You have a few options. Using something like docker-compose, you could automatically build a unique image for each container using your base image as a template. For example, if you had a docker-compose.yml that look liked:
container0:
build: container0
container1:
build: container1
And then inside container0/Dockerfile you had:
FROM larsks/thttpd
COPY index.html /index.html
And inside container0/index.html you had whatever content you
wanted, then running docker-compose build would generate unique
images for each entry (and running docker-compose up would start
everything up).
I've put together an example of the above
here.
Using just the Docker command line, you can use host volume mounts,
which allow you to mount files into a container as well as
directories. Using my thttpd as an example again, you could use the
following -v argument to override /index.html in the container
with the content of your choice:
docker run -v index.html:/index.html larsks/thttpd
And you could accomplish the same thing with docker-compose via the
volume entry:
container0:
image: larsks/thttpd
volumes:
- ./container0/index.html:/index.html
container1:
image: larsks/thttpd
volumes:
- ./container1/index.html:/index.html
I would suggest that using the build mechanism makes more sense if you are trying to override many files, while using volumes is fine for one or two files.
A key difference between the two mechanisms is that when building images, each container will have a copy of the files, while using volume mounts, changes made to the file within the image will be reflected on the host filesystem.