Docker Copy Failed File Not Found In Build Context (Dockerfile)

The Docker COPY instruction is a fundamental command in our Dockerfile that facilitates injecting our application code into the Docker image we are creating. It has two main arguments, the source and the destination. When the Docker engine receives a `COPY` command, it analyses the source target from the build context, not from your local filesystem.

You may encounter a “COPY failed: file not found in build context” or similar error if the Docker engine cannot find the source file(s) in the build context. This usually happens when you mention an incorrect path or name in your Dockerfile, attempt to access a file outside your defined docker build context, or precisely fail to include a requisite file in your context before initiating the build process.

To resolve these issues, firstly confirm the availability of the requisite file or directory in your Docker build context ^{[1](https://docs.docker.com/engine/reference/builder/#copy)}. Secondly, inspect the `COPY` command syntax to ensure it is correctly formatted. For instance,

# Copy 'source_dir' from the local system to 'destination_dir' within the docker container
COPY source_dir /destination_dir

Next, perpetually verify that your `docker build` command states the correct build context:

# '.' signifies that the build context is the current directory
docker build -t your-image-tag .

Lastly but importantly, try to maintain clarity in your project structure and Dockerfiles to avoid misplacement and unexpected errors during builds. Understanding the behavior and quirks of docker context can save a lot of debugging time and hence is worth investing some time in learning about ^{[2](https://www.docker.com/what-docker)}.

Understanding Docker’s build context is essential to resolving the problem of “Docker Copy Failed: File Not Found In Build Context (Dockerfile)”. The Docker build context includes all files and directories located in the specified PATH or URL. When building an image, Docker takes this complete directory known as the context and transmits it to the Docker daemon.

The issue of “file not found in build context” arises when Docker attempts to find a file reference that doesn’t exist within the specified build context. To illustrate, we take the following structure:

/app
|– Dockerfile
|– /some_directory
|– some_file.txt
/home
|– other_file.txt

Implying our build command is

docker build -t myimage .

, Docker sets the context as everything inside the /app directory. This means if you’re trying to copy from the root directory or another location outside of the current directory where Dockerfile resides (

/home/other_file.txt

for instance), it won’t be able to locate the referenced files resulting in the “file not found in build context” error.

To resolve this problem, verify the following points concerning your build context:

• Relevant Files Exist: Make sure the necessary resources are present within the Docker build context. Earlier in the example, the Dockerfile should specify copying

  some_directory/some_file.txt

  , given it is present in the defined context, rather than attempting to copy

  other_file.txt

  that exists outside the Docker build context.

• Correct Paths in the Dockerfile: Double-check the file paths in your Dockerfile. Every path must be relative to the build context. Utilizing a COPY or ADD command wrong can lead to the discussed error. Suppose your Dockerfile comprised the line

  COPY /home/other_file.txt .

  . As Docker expects references starting from the build context, changing the command to

  COPY some_directory/some_file.txt .

  or moving

  other_file.txt

  into the

  app

  directory will likely resolve this problem.

• Avoid Large Context: A practicable rule of thumb is to maintain the smallest possible Docker build context by including files strictly essential to build the Docker image. Enlarge contexts may slow down the build process and might include unnecessary or sensitive files.

For further information on Docker build context, refer to this.

Here’s a basic Dockerfile example:

# Use an official Python runtime as a parent image
FROM python:2.7-slim

# Set working directory in the container
WORKDIR /app

# Copy the current directory contents into the container at /app
COPY . /app

# Install any needed packages specified in requirements.txt
RUN pip install --trusted-host pypi.python.org -r requirements.txt

# Make port 80 available to the world outside this container
EXPOSE 80

# Define environment variable
ENV NAME World

# Run app.py when the container launches
CMD ["python", "app.py"]

This Dockerfile contains a basic layout of commands and instructions typically included in many Dockerfiles. If interpreted correctly, no error should occur. However, if a file isn’t found in the build context depending on the COPY command, it will return the error message “file not found in build context”. Hence, understanding Docker’s build context helps diagnose such problems quicker and rectify accordingly.

Docker is a highly popular platform that developers use for mainly distributing application across different environments. One of the central concepts in Docker is Dockerfile. I’ll discuss this first, then dive into how it’s related to the common issue ‘Docker Copy Failed: File Not Found In Build Context (Dockerfile)’.

A Dockerfile essentially is a text document containing commands you’d run from the command line to build a Docker image. Just like compiling source code and building an executable, Docker images are built from a Dockerfile. A Dockerfile lets you create a ‘recipe’ for your environment so to say, defining what OS, language, environmental variables etc. your app needs to run. For example, if your application requires Node.js, you can specify this in your Dockerfile:

FROM node:12

The power of a Dockerfile comes when used with the docker build command. This command takes a Dockerfile and builds an image based on the instructions given in the Dockerfile. So, by running the command:

docker build .

Docker would look for a file named Dockerfile in the current directory, then build an image using that Dockerfile’s instructions.

The COPY instruction is one of many that can be used within a Dockerfile. Its purpose is to let files from your host (for instance, application source code) be replicated in the image. If you have a web app written in Python with main script as main.py, here’s how you’d create a Dockerfile to include that script:

FROM python:3
COPY ./main.py /app/

In this case, main.py from your local system is copied to the “/app” directory in the Docker image. Remember, paths specified in Dockerfile are relative to the build context, which is typically the location of Dockerfile itself.

Now, coming to the ‘Docker Copy Failed: File Not Found In Build Context’ problem. This error usually surfaces when Docker cannot find the file or directory you’re trying to copy from your host into your Docker image. The most frequent causes being:

• File path specified incorrectly.
• Docker build context configured inaccurately.
• Typos or casesensitive issues in the filename.

Therefore, make sure that the file or directory does indeed exist, and the path is accurate relative to the build context. Confirm the casing in the file or directory name especially if your operating system is casesensitive like Linux. Also, ensure you’re running the build command in correct directory – which matches your intentions for build context.

To summarize, the Dockerfile is a potent tool that makes containerizing your applications seamless. But, attention must be paid to correctly define the paths and context, otherwise errors such as ‘Docker Copy Failed: File Not Found In Build Context’ may occur. Keeping these details in mind will aid you in leveraging Docker at its best.

Sure. The

Docker Copy Failed - File Not Found

error is commonly seen when you are trying to build a Docker image using a Dockerfile and the COPY or ADD command cannot locate the specified file or directory in your build context. So, let’s dive into understanding why this happens and how we can resolve this issue.

Firstly, we need to recognize that the Docker build context is essentially the set of files at a specified location PATH or URL, and the Docker Engine uses the contents here for building Docker images.

Now, when a Dockerfile contains commands like COPY or ADD, they search for the specified file or directory within this build context. Like so:

  COPY myfile /app/
  # or
  ADD myfolder /app/

If Docker fails to find ‘myfile’ or ‘myfolder’ in your build context, it throws the error: Docker Copy Failed – File Not Found.

That said, there are several reasons that could lead to this situation:
* The source file or directory simply does not exist.
* There is a typo or case sensitivity issue in the file or directory name.
* The file or directory is located outside of the Docker build context.
* The .dockerignore file (if any) might be instructing Docker to ignore the file or directory directly or indirectly by ignoring its parent folders.

To fix the issue, follow these steps:

* Cross verify the existence of the file or the directory you are specifying.
* Check for and correct typos, case sensitivity or path issue, ensuring that the specified file/path exactly matches with what’s present.
* Make sure that the file or directory is present inside the Docker build context.

For instance, if you’re executing the docker build command from “/project” like below,

docker build -t myimage:1.0 .

In this scenario, Docker will consider everything inside “/project” as part of the build context. So ensure your referred file/folder resides within “project” directory.

* Review your .dockerignore file, if there is one. If required, remove entries that direct Docker to ignore your required file or directory. Remember, the .dockerignore syntax is quite similar to .gitignore, where wildcards, directories, negations etc. can be used.

Finally, to help you conceptualize, here’s a sample project structure:

If Dockerfile has a COPY/ADD statement referring to “myfile” or “myfolder”, Docker should successfully locate them given the build command is run from “/project”.

In essence, it’s all about keeping track of your Docker build context and the explicit paths you reference in your Dockerfile. Happy Dockerizing!As a professional coder who works often with Docker, I’ve encountered an issue several times: `Docker Copy Failed File Not Found in Build Context (Dockerfile)`. Let’s break down the reasons behind this failure while building Docker images:

Very often, the major cited reasons are:

• Incorrect file paths
• Typos or incorrect syntax in the Dockerfile
• File or directory not included in the build context

Incorrect File Paths:

Using incorrect file paths in the

COPY

or

ADD

commands is one of the most common errors. Docker builds are always run from a specific build context, usually the current directory (denoted by “.”) unless specified otherwise. Any file paths provided should be relative to this build context. In the Dockerfile, use some code snippet like this:

FROM node:14  
WORKDIR /app  
COPY ./package.json ./

The COPY command here is copying package.json file from your current directory (outside the image) into the ‘/app’ directory inside the working directory of the Docker container.

Typos or Incorrect Syntax in the Dockerfile:

A typo or incorrect syntax in the Dockerfile can cause errors during the build process. Always make sure that all commands, file paths, and syntax in the Dockerfile are correct. Errors are often made in the

COPY

or

ADD

commands.

Here’s an example of the correct

COPY

command syntax:

COPY [--chown=:] ... 

The

--chown

flag is optional and allows you to change the ownership of the copied files. The

is the path to the source file or directory on your local machine, while

is the destination path in the Docker image.

File or Directory Not Included in the Build Context:

The build context for Docker is the set of files at a specified location PATH or URL, that the Docker daemon processes to build the Docker image. If the file or directory you’re asking Docker to copy isn’t included in the build context, Docker won’t be able to find it, leading to a Docker Copy Failed error.

When running a Docker build like this:

docker build -t my-image .

The “.” stands for the current directory, which is used as the build context by default. Only files and directories within the build context can be added into the Docker image.

If the Docker daemon is unable to find the file inside the build context, it will throw a Docker Copy Fail error. You need to ensure the files or folders you’re adding or copying exist in the build context. It doesn’t matter if they exist in the system, if they don’t exist in the context of the build, it’ll cause failure.

Reading up on these topics from the official Docker documentation would provide more insight and help rectify the issues causing failure in Docker builds.

We hope that analyzing these common reasons helps in mitigating the Docker Copy Failure. Familiarizing yourself with the Docker syntax, verifying file paths, and making sure your targeted files are within the defined build context will go a long way in ensuring seamless Docker builds.The Docker

FILE

directive sets up a context of operations inside the Dockerfile. It instructs Docker to complete subsequent actions in the defined location or directory. This directive is decidedly useful in organizing and structuring Dockerfiles for better visibility and management.

Speaking of file operations, some users may encounter an error message that reads something like “Docker Copy Failed File Not Found In Build Context”. There might be confusion when you’ve double-checked and certain that your file resides within the working directory or build context.

Understanding The Build Context

The error often stems from misunderstanding how Docker’s build context functions. When you run a Docker build command and indicate the path, the path isn’t only about where the Dockerfile resides—it pertains to what Docker refers as the “build context”. So when Docker starts building your image, it sends a context of all files residing in the specified path to its daemon. The docker daemon uses this context to get hold of files required in building the Docker image.

For instance, if you execute the below line:

docker build -f /path/to/Dockerfile

You should understand that ‘/path/to’ becomes the build context, and not just the location of the Dockerfile. Therefore, when you use the Docker COPY instructions in your Dockerfile, it must reference files within this specific build context.

As a result, a phrase “

COPY ./app /app

” copies the ‘/app’ folder from ‘/path/to/app’, which is your base directory (or build context), into the container.

Here’s some more detail on how everything works.

Solutions To ‘Docker Copy Failed File Not Found In Build Context’

– Relocate Your Files: If you receive this error, the problem typically arises due to misplacement of your file locations. Simply move them into the right directories aligned with the build context.

– Path Alignment: Another issue could be that the paths defined in your Dockerfile’s COPY directive aren’t congruous to your project’s structure. Make sure the relative paths match entirely to avoid ‘file not found’ predicaments.

Consider two scenarios here:

1. Dockerfile is located at ./Dockerfile and you’re running a command from this path. Here, the mentioned Dockerfile will acknowledge all the files and directories of ‘./’ as its build context.

2. Dockerfile is situated at ./path/to/Dockerfile and you’re launching a command from this path (‘./’). Any Docker COPY commands inside this Dockerfile will refer to ‘./’ as its build context.

In both examples, correction would mean matching the paths to align with your project structure.

FROM python:3.8-slim-buster
COPY ./app /app 
WORKDIR /app  
RUN pip install -r requirements.txt  
CMD [ "python", "./your-daemon-or-script.py" ]

In this Dockerfile snippet, the Docker daemon expects the app directory, requirements.txt file, and the ‘your-daemon-or-script.py’ file to exist within the parent directory, since the build context is based on where the command is executed—like so:

docker build -t your-imagename:tagname -f ./Dockerfile .

Note: Ensure that ‘.’ denotes the correct build context. A common pitfall is to forget including the period sign in the build command, leading to the error.

With these insights, handling FILE directives and troubleshooting COPY commands related to the Docker context should be done with ease. Remember to ensure you have the correct build context.In Docker, a common error that developers may come across is the failure to copy files due to incorrect relative paths leading to “file not found in build context” errors. To set correct relative paths in your Dockerfiles, it’s crucial to understand the implications of working directories and context.

The build context for Docker includes all the contents of the supplied path or URL. Docker uses this context (known as the build environment) to search for the ‘things’ needed such as source code files, dependencies, assets, etc., when constructing an image.

Understanding the Build Context:

Referencing Docker documentation, if you run the command:

docker build .

This dot tells Docker to use the current directory (and its subdirectories) as the build context.

This is where relative paths come into play in your Dockerfile. If your file structure looks like this:

/myapp
  /src
    Dockerfile
    main.py

And the Dockerfile reads like this:

COPY main.py .

Even though they are both in the ‘src’ directory, running the docker build command from the ‘myapp’ directory could result in a ‘file not found’ error.

Setting Relative Paths Correctly in a Dockerfile:

You must specify the relative path in correlation with your build context. Given the previous file structure, the correct COPY command would be:

COPY ./src/main.py .

This instructs Docker to look for the main.py file in the ‘src’ directory within the build context. Avoiding absolute file paths improves the portability of your Dockerfiles across different environments.

To change the working directory, use the WORKDIR instruction:

WORKDIR /usr/src/myapp

Any subsequent instructions in the Dockerfile will operate within this specified directory.

Remember, while managing Dockerfile paths:

• The Dockerfile PATHS are interpreted as relative to the current build context.
• The Workdir (WORKDIR) will alter the working directory and influences the following instructions that interact with the filesystem.

Just make sure you’re navigating your file tree correctly relative to your build context. If done correctly, you’ll evade the “Docker COPY failed: file not found in build context” error numerous developers encounter.Battling issues like “Docker Copy Failed File Not Found In Build Context” can be a daunting task, especially if you are new to Docker. Let me walk you through how to address this in a detailed manner.

The `COPY` command in the Dockerfile is used to add files from your Docker’s build context into the image it’s constructing. If Docker cannot find the specified file or directory, the infamous “Docker Copy Failed File Not Found In Build Context” error surfaces.

For instance, consider an example such as:

FROM node:12-alpine
WORKDIR /app
COPY package*.json ./

In the above code snippet, the `COPY` command tries to copy any file starting with “package” and ending with “.json” from the build context of Docker(the place where Docker runs) to the image being built.

If you are receiving the “File not found in build context” error, it implies that within your build context, Docker is unable to locate the source file(s). This could be due to several reasons including:

– The source file(s) might not exist.
– You may have accidentally misspelled the name of the source file(s).
– Docker’s build context might be different from what you anticipate.

That said, here are potential solutions to debug the “Docker Copy Failed” error:-

– Carefully verify the spelling of the source file(s) in your `COPY` command, paying extra attention to case sensitivity; remember ‘file.txt’ and ‘File.txt’ are two distinct entities.

– Double-check if the file exists in the first place. A command like `ls -la` on the terminal window will list the contents of the directory.

– Confirm that the Docker’s build context aligns with your anticipation. Notably, the output in the terminal from running a Docker build displays the build context.

Remember, the build context in Docker is the set of files located at `` or `` specified at the end of the Docker build command.
For instance, for a command like `docker build .`, the build context is the current directory ‘.’

Likewise, when running `docker build `, the directory denoted by becomes the build context. It implies that all Docker commands, including COPY, function relative to that directory, and Docker searches for the files to copy inside that context.

Therefore, always ensure that the files you want to copy into the Docker image reside within the Docker build context.

To supplement your knowledge about handling COPY commands in Dockerfile, take a dive [here](https://docs.docker.com/engine/reference/builder/#copy).

One common best practice is having the Dockerfile at the root level of your project. It places everything in your repository inside the Docker’s build context, making it easier to include any file you need.

Here’s a typical example of a correct Docker file structure I always advise my peers to emulate:

-root-directory
|
— Dockerfile
— src
|
— app.js
— package.json

With the above structure, your Docker COPY command will look something similar to:

FROM node:12-alpine
WORKDIR /app
COPY package*.json ./
COPY ./src ./

This COPY command will happily copy the necessary files from your build context right into the Docker image without spitting out any weird errors. Nifty, isn’t it?While working with local files and volumes in Docker, often developers encounter issues such as the “Docker Copy Failed: File Not Found in Build Context”. This error typically arises due to one of two reasons: misplaced Dockerfile or an incorrect path specified for copies.

Dockerfile Location

The Docker build context is defined by the file location that you provide to the docker build command. Generally, the Dockerfile should be located at the root of your project directory:

Project
|-- Dockerfile            |--> Your Dockerfile here.
|-- src                   |--> Source directory.
    |-- app.py            |--> Application source code.
|-- requirements.txt      |--> Application dependencies.

Should you run

docker build -t my_app .

in the ‘Project’ directory, Docker considers everything in this directory (and its subdirectories) to be in the build context. Conversely, running the command elsewhere will lead to the error we are addressing. Ideally, always keep your Dockerfile at the root location of your project.

The COPY command in Dockerfile

Consider a typical line in a Dockerfile:

COPY ./src /app.

Here:

• The left argument, ./src, indicates the source file or directory in your local system, relative to the build context.
• The right argument, /app, is the destination inside the running Docker container.
In our Project example, if you tried to

COPY ./not_here /app,

it would fail because there’s no not_here directory in your current context.

Solutions

When encountering the Docker Copy Failed error, consider the following principles to troubleshoot effectively:

• Ensure the Dockerfile is in the correct location: Keep Dockerfile at the root of your project directory, which makes it easier to manage context for Docker.

• Verify the paths in your COPY instructions: Check whether all copied files/directories exist in the build context, and ensure that their paths are correctly referenced in your Dockerfile.

• Use a .dockerignore file: If your context includes many unnecessary files, create a .dockerignore file in the same directory as your Dockerfile to include patterns for files/directories to ignore.

Written from practical experience, applying these principles when working with local files and volumes in Docker should minimize errors related to missing files in build context. Moreover, they can help optimize your Docker image build time and reduce resulting images’ size, enhancing your overall work productivity.

Refer to Docker’s official documentation on Best practices for writing Dockerfiles for more details. Remember, getting acquainted with coding principles takes time, and troubleshooting forms an integral part of the learning process while improving your coding efficiency over time.

Here is a sample Dockerfile showing the usage of the COPY command:

# Use an official Python runtime as a parent image
FROM python:3.7-slim

WORKDIR /app

COPY requirements.txt .

RUN pip install --no-cache-dir -r requirements.txt

# Copy the current directory contents into the container at /app
COPY . /app

CMD ["python", "app.py"]

Remember, the ‘.’ after the COPY command refers to the current build context (the location where you’re running the docker build command). Hence, understanding how build context works and setting it appropriately helps to avoid the “File Not Found” error.Building a robust and seamless environment is crucial for any professional coding project, especially when Docker comes into play. Docker is an open-source platform that developers use to automate the deployment, scaling, and management of applications. It’s known for its efficiency, but it can sometimes throw errors, such as ‘Docker copy failed: file not found in build context (Dockerfile)’. This issue crops up when Docker cannot find a referenced file because it isn’t located in the ‘build context’.

See also

Linux

E: Package Python-Pip Has No Installation Candidate

Here are some best practices on how to effectively navigate around this issue:

Ensure all files are within the build context:
The build context typically contains your Dockerfile alongside other resources required by your app. If you refer to a file outside the build context, Docker won’t be able to access it, resulting in the error at hand. Hence, make sure the related files are in the same directory:

.
├── myapp
│   ├── app.js
│   ├── package.json
└── Dockerfile

In this scenario, the ‘Dockerfile’ is in the root directory, and the application’s code (‘app.js’ and ‘package.json’) is in the ‘myapp’ subdirectory.

Correct reference to files in your Dockerfile:
Taking the previous directory structure, if you want Docker to copy the ‘app.js’ into the container, you may write the following line in your Dockerfile:

COPY ./myapp/app.js /app/

It signifies that Docker should copy ‘app.js’ from the ‘myapp’ directory (relative to the Dockerfile) in the host system to the ‘/app/’ directory in the container.

Use .dockerignore file:
Just like you use ‘.gitignore’ to exclude certain files from being tracked by Git, similarly ‘.dockerignore’ prevents files from being included in the build context sent to Docker. By including unnecessary files or directories, you may inflate the size of the build context, slowing down the build process or inadvertently include sensitive information. Explore Docker’s official documentation to understand how to use ‘.dockerignore’.

Order your instructions carefully:
Ensure that Docker layers are used efficiently. For instance, placing commands that change frequently towards the end of the Dockerfile allows previously built layers to be reused, substantially reducing build times. This means it’s beneficial to place your ‘COPY’ instructions after your ‘RUN’ instructions. Since application code changes often lead to frequent builds, managing them rightly can save time.

# Base Image
FROM node:10

# Install dependancies first (this doesn’t change often)
WORKDIR /app
COPY ./myapp/package*.json ./
RUN npm install 

# Then copy the rest of your app source code from your host to your image filesystem.
COPY ./myapp .

EXPOSE 8080
CMD [ "npm", "start" ]

Using these suggestions, you’ll create a more efficient Docker build process that minimizes problems like ‘Docker copy failed: file not found in build context (Dockerfile)’. If you need further assistance, Docker’s official best practices for working with Dockerfiles could be of help. Happy coding!Alright! If you’re dealing with the issue of Docker Copy Failed File Not Found in Build Context within your Dockerfile, it’s crucial that you ensure an efficient cleaning procedure for dangling images or containers. This issue typically occurs when the path to the file which needs to be copied is wrong or the file does not exist. However, inefficient handling of dangling image or container files can add up to this problem.

Here are the factors to consider for effective management:

Docker Build Context

When you initiate a docker build command, all files and directories present at the root level in the specified context are sent to the Docker daemon. These files form the “build context” and Docker uses them in conjunction with the instructions in the Dockerfile to build the image.

For instance:

docker build -t myimagename .

The dot (.) specifies the current directory as the build context.

If you incorrectly specify the context, Docker may not find the file or directory you want to copy in the Dockerfile. This is a common cause of the ‘Docker Copy Failed File Not Found In Build Context’ error.

Efficient Handling of Dangling Images

Dangling images refer to the layers of Docker Images that do not have any relation to any tagged images. They are created either when we re-build our Docker images or by building new ones.

You can delete these dangling docker images to recover disk space with the prune command:

docker image prune

Or alongside the docker build command:

docker build --force-rm -t myimage .

With the –force-rm flag, Docker removes the intermediate containers after a successful build.

Eradicating Dangling Containers

Deleting old containers and keeping your environment clean is also important part of Docker maintenance.

Again, this can be done with the Docker prune command:

docker container prune

This command will remove all stopped containers.

So next time, if you encounter the ‘Docker Copy Failed File Not Found In Build Context’ issue, make sure to check your Dockerfile and build path. Also, it’s good practice to keep cleaning up the irrelevant dangling images or old containers so as to maintain a healthy Docker environment.

One key to remember is that managing Docker efficiently involves balancing the size of your images and build contexts, understanding where files reside during the build process, and regularly pruning obsolete or dangling images and containers. For more information on best practices on Dockerfile optimization you might find Dockerfile Best Practices to be a good starting point for exploring more about optimizing Dockerfiles and manage Docker resources efficiently.Maintaining a clean project structure while using Docker can vastly improve your workflow and make error troubleshooting, such as the “Docker Copy Failed File Not Found In Build Context (Dockerfile)” issue, much more manageable.

As you may already know, Docker allows you to automate the deployment, scaling, and management of applications through containerization. Part of this process includes building an image based on a Dockerfile you provide. Unfortunately, errors often arise during this phase, especially the infamous “COPY failed: file not found in build context”. This is predominantly caused by misunderstanding the Docker build context, which is related to your project structure.

Understanding Docker Build Context

In simplest terms, the Docker build context is the set of files available to the

Dockerfile

during the build process. It’s usually specified as the path following the build command like so:

docker build [options] .

The

.

refers to the current directory and sets it as the context. Every file and directory found here is packaged into a context archive and sent to the Docker daemon.

The Role of Project Structure

Often, the ‘Docker COPY failed’ error will persist due to an improper or convoluted project structure, making the application source code inaccessible to the Dockerfiles. Here’s what an exemplary project structure could look like: