I'm trying to write a Dockerfile. From a directory structure such as:
something/Keep1
something/Keep2
something/... # lots of other files
otherthing/Keep1
otherthing/Keep2
otherthing/...
I would like my dockerfile to import the Keep1 and Keep2 files, without the rest of the files / folders.
Ideally, this would be a simple COPY or ADD command, but I can't seem to get that to work - e.g. COPY */Keep1 ./ only shows a single Keep1, in the current directory, presumably the last one copied.
I could import the whole folder structure and delete anything that isn't Keep1 or Keep2 - but I don't know how this will affect my storage space - presumably all the files will still exist in the layer files?
(Probably not important, but for context, what I'm actually trying to do is import Gemfile and Gemfile.lock files so that I can run bundler from the project folders during docker's build phase and save spin-up time. The Dockerfile bridges several ruby projects that need to co-exist within the same container - but I don't want to hardcode those folder names)
Related
Starting to use Docker here.
Right now im facing an issue with my project, where I need to copy multiple files from multiple directories to the docker image on start up.
Here is my current code
FROM heroiclabs/nakama:3.11.0
COPY src/*.lua /nakama/data/modules
COPY src/database/*.lua /nakama/data/modules
COPY src/managers/*.lua /nakama/data/modules
COPY src/modules/*.lua /nakama/data/modules
COPY local.yml /nakama/data
What is happening so far is that docker copies only the main.lua file from the starting directory, it either dont copy the remaining ones or copy them with the current data structure.
How can I actually copy it in order to get the lua files from database, manages and modules into the same root directory as main.lua?
To add to this, I get this error on the Nakama console that indicates that a file searched by main.lua module its not found.
{"level":"fatal","ts":"2022-04-28T21:19:51.163Z","caller":"main.go:154","msg":"Failed initializing runtime modules","error":"/nakama/data/modules/src/main.lua:2: module economyManager not found:\n\tno field package.preload['economyManager']\n\tno cached module 'economyManager', \nstack traceback:\n\t[G]: in function 'require'\n\t/nakama/data/modules/src/main.lua:2: in main chunk\n\t[G]: ?"}
So far so good, the / at the end of each COPY line did not do the trick.
Edit:
This is the full directory structure:
src
-database
--luascripts.lua
-managers
--luascripts.lua
-modules
--luascripts.lua
-main.lua
intellisense
-nakama.lua
local.yml
dorckerfile
docker-compose.yml
This helps better illustrate the error. As you can se on the log, docker its copying src directory over to nakama/data/modules, what I aim to do is to copy ONLY the content from src, but not the src directory.
Same can be said for other directories to a lesser degree, my aim is to not carry over directory structure to the destination path
Your command seems to be right, just add a trailing / to the destination docker image's path.
For example,
COPY *.lua /nakama/data/modules/
The error was on the docker-compose file, I was double mounting a volume and that was causing errors on the whole COPY operation.
I have a question about the .dockerignore workflow which I wasn't really able to understand while browsing through the documentation and different internet topics.
Have the following folder structure:
home
|
|- folder_1
|- folder_2
Inside my dockerfile I want to copy the contents of home directory, so I use
COPY ./ /home
Inside .dockerignore I have:
*
!folder_1
!folder_3
I am referring to a non-existent folder - folder_3, which is supposed to be copied, right?
I ran it and it looks like there's no problem with that, thus .dockerignore somehow manages this situation.
If I tried to do the same thing without using .dockerignore, targeting a non-existent directory I would get an error.
If anybody can please clear this workflow, or if a duplicate, please attach some information so I can educate myself.
Thanks in advance!
First of all, .dockerignore works like .gitignore. Inside these files you set the rules on the basis of which files should be added, and which should not.
In your scenario you COPY the whole home directory which consists of folder_1 and folder_2. Your .dockerignore file sets the following rules:
* # ignore all files/directories
!folder_1 # do not ignore folder_1
!folder_3 # do not ignore folder_3
Regardless of whether there is a folder_1 or folder_3 in your local home directory or not, it won't show you any errors, because it just tries to find particular files/directories that are inside .dockerignore. If it finds this file/directory, it applies the rules. If it doesn't find this file/directory, it doesn't do anything with it.
Hope that's a little bit more clear now.
You'll occasionally see reference to a Docker build context. The build has two steps:
The docker build client application creates a tar file of its directory parameter, and sends it in an HTTP request to the Docker daemon.
The Docker daemon unpacks the tar file, finds the Dockerfile in it, and runs it using the file content it was given.
.dockerignore only affects the first step: it keeps docker build from sending the Docker daemon particular files. The .dockerignore file doesn't require there to be a folder_3 directory, it just says that if there is one it shouldn't be excluded. The second step on the Docker daemon side doesn't use .dockerignore at all, and when you COPY . /somewhere it copies the entire build context; that is, whatever was sent in the API request.
There are a couple of practical consequences of this workflow. If you have a very large local directory it can take time to send it to the Docker daemon, and the Docker daemon keeps a duplicate copy of it during the build, so it's often worthwhile to .dockerignore your .git directory and a build tree. This setup is also how docker build works with a Docker daemon on a different system or in a VM, and it's why if you try to COPY a file by name that doesn't exist (COPY folder_3 somewhere) you get an error message referencing a Docker-internal path.
I would like to copy multiple directories (with contents) to a single directory in my container while maintaining the original directory structure of my project. For example, the relevant line in my Dockerfile looks like this:
COPY bin env project ./projects/
The command above only copies files into my projects directory and also removes all of the original directory structure of bin, env, and project.
How can I copy several directories (with contents) such that the original directory structures are preserved? I did find this reference, but as the first commenter points out, directory structure is lost with this method.
you need to create the directory structure since COPY will only add files not the directory itself.
one approach will be aading them one by one.
RUN mkdir -p projects/{bin,env,project}
COPY bin projects/
COPY env projects/
COPY project projects/
or maybe using ADD will be a better approach since Add will decompress archives download files and more.
so you will need to archive directories first, then use add like below
ADD archive.tgz projects/
In a Dockerfile I want to copy a file relative to my local home inside the images's home.
So I have tried many variations of:
COPY "~/.m2/settings.xml" "$HOME/.m2/settings2.xml"
But I get errors like
COPY failed: stat /var/lib/docker/tmp/docker-builder635958043/~/.m2/settings.xml: no such file or directory
How can I copy a file relative to my local home inside the image?
The source for the COPY command is the build context. The build context is included in the last argument to the docker build command, often a . which means the current directory. This location is sent to the docker engine before running any steps of the Dockerfile, using a tar file, in the default/classic builder. Therefore, to keep builds running fast, you want to keep this directory small by not sending over the entire hard drive contents. This is even more important when building locally since you could potentially start sending files recursively if you were to include docker's temporary directory in the folders being sent.
All this means you should move any files you want to include in the COPY source parameter to be inside the build context, typically the same location as your Dockerfile.
in my dockerfile I have these two lines:
ADD /ansible/inventory /etc/ansible/hosts
ADD /ansible/. /ansiblerepo
The first line works, as I can run the container and see my hosts file has been populated with all the ips from my inventory file.
The second line doesn't appear to be working though. I'm just trying to copy all the files/subdirectories of ansible and copy them over to the ansiblerepo directory inside the new container.
There are no errors while building the image, but again ansiblerepo is just an empty directory and nothing has copied over to it. I assume I'm just missing a back slash or something.
Docker ADD and COPY commands work relative to the build directly, and only for files in that directory that weren't excluded with a .dockerignore file. The reason for this is that builds actually run on the docker host, which may be a remote machine. The first step of a docker build . is to package up all the files in the directory (in this case .) and send them to the host to run your build. Any absolute paths you provide are interpreted as relative to the build directory and anything you reference that wasn't sent to the server will be interpreted as a missing file.
The solution is to copy /ansible to your build directory (typically the same folder as your Dockerfile).
Make sure that in your ".dockerignore" file, it does not excluded everything. usually, dockerignore file has these lines
*
!obj\Docker\publish\*
!obj\Docker\empty\
this means that everything is ignored except publish and empty folders.
Removing trailing /. from source directory should fix the ADD command.
On a related note, Docker Best Practices suggest using COPY over ADD if you don't need the URL download feature.