FileCopy Issue: Broken Load+Publish+Install Cycle

Hey guys! It looks like we've hit a snag with the load, publish, and install cycle when using FileCopy in InterSystems Package Manager (IPM). Specifically, this issue is causing headaches in adopting IPM v0.10.x, particularly for Supply Chain implementations. Let's dive into the details and see what's going on.

The Problem: A Directory Disappearing Act

The core problem lies within how IPM handles directories during the publish phase. When you run load, then publish, and finally install, you might encounter an error that stops the installation in its tracks. The error message typically looks like this:

[fc-debug]      Activate FAILURE
ERROR! Error copying directory /usr/irissys/ipm/fc-debug/1.0.0/foo/bar/ to /usr/irissys/lib/foo/bar/
  > ERROR #5021: Directory '/usr/irissys/ipm/fc-debug/1.0.0/foo/bar/' does not exist.

This error indicates that the directory IPM is trying to copy during the installation phase simply doesn't exist. But why?

Diving Deeper: The publish Phase Transformation

The root cause is the Package phase within the publish process. During this phase, IPM transforms the directory structure, specifically renaming directories. In the example provided, a directory named foo gets renamed to .foo. Here’s a snippet from the logs illustrating this behavior:

[USER|fc-debug] Package START
Exported to /usr/irissys/mgr/Temp/dirj1zAaG/fc-debug-1.0.0/module.xml
Copying /home/irisowner/zpm/tests/integration_tests/Test/PM/Integration/_data/fc-debug/foo/bar/ to /usr/irissys/mgr/Temp/dirj1zAaG/fc-debug-1.0.0/.foo/bar/ as directory

As you can see, the original foo/bar/ directory is being copied to .foo/bar/. This renaming causes the subsequent install phase to fail because it's looking for the original directory structure, which no longer exists. This unexpected behavior breaks the expected workflow and leads to installation failures.

Impact on Supply Chain

This issue significantly impacts Supply Chain's adoption of IPM v0.10.x. The broken load+publish+install cycle makes it difficult to reliably deploy and manage modules, hindering the overall development and deployment pipeline. The renaming of directories during the packaging process introduces an unnecessary complexity that can lead to confusion and errors.

Reproducing the Issue: A Step-by-Step Guide

To better understand and address this issue, let's walk through the steps to reproduce it. This will help you see the problem firsthand and verify any potential solutions.

1. The module.xml Setup

First, you need a module.xml file that includes a FileCopy element. Here's a sample module.xml that you can use:

<?xml version="1.0" encoding="UTF-8"?>
<Export generator="Cache" version="25">
  <Document name="fc-debug.ZPM">
    <Module>
      <Name>fc-debug</Name>
      <Version>1.0.0</Version>
      <Packaging>module</Packaging>
      <FileCopy Name="foo/bar/" Target="${libdir}foo/bar/"/>
    </Module>
  </Document>
</Export>

This module.xml defines a module named fc-debug with a FileCopy instruction. The FileCopy element specifies that the contents of the foo/bar/ directory should be copied to the ${libdir}foo/bar/ directory during installation.

2. Directory Structure

Make sure you have the directory structure in place. Create a directory named foo and a subdirectory named bar. Place some files inside the bar directory. For example:

mkdir -p foo/bar
touch foo/bar/testfile.txt

This creates the necessary directory structure and a sample file to be copied.

3. Running the Commands

Now, run the following commands in your InterSystems IRIS environment:

zpm "load /path/to/your/module.xml"
zpm "publish fc-debug"
zpm "install fc-debug"

Replace /path/to/your/module.xml with the actual path to your module.xml file. After running these commands, you should see the error message indicating that the directory /usr/irissys/ipm/fc-debug/1.0.0/foo/bar/ does not exist.

4. Examining the Logs

Check the logs to confirm that the Package phase is indeed renaming the foo directory to .foo. This will confirm that you have successfully reproduced the issue. The logs should contain a line similar to:

Copying /path/to/your/module/foo/bar/ to /usr/irissys/mgr/Temp/dirj1zAaG/fc-debug-1.0.0/.foo/bar/ as directory

Potential Solutions and Workarounds

While a permanent fix is being developed, here are some potential workarounds and solutions to mitigate the issue:

1. Adjusting the module.xml

One approach is to modify the module.xml file to account for the directory renaming. However, this might not be a sustainable solution, as it requires you to anticipate the renaming behavior.

2. Manual Copying

Another workaround is to perform the file copying manually after the installation. This can be done using a post-install script that copies the files from the .foo/bar/ directory to the desired location. While this approach adds complexity, it can ensure that the files are correctly placed.

3. Using Symbolic Links

You can also try using symbolic links to create a link from the original directory name to the renamed directory. This can be done using the ln -s command in Unix-like systems. However, this approach might not be suitable for all environments.

4. Contributing to IPM

Consider contributing to the IPM project by submitting a pull request with a fix for this issue. This will not only help you but also the entire InterSystems community.

Digging into the Code: Understanding the Root Cause

To really squash this bug, we need to understand why the Package phase is renaming the directory. Is it intentional? Is it a side effect of some optimization? Let's put on our detective hats and poke around the IPM code.

First, let's find the code responsible for the Package phase. We need to trace the execution path of the publish command and identify where the directory renaming occurs. By examining the source code, we can determine the logic behind this behavior and identify any potential issues.

Identifying the Code

Start by looking at the entry point of the publish command. Trace the execution flow and identify the functions or methods responsible for packaging the module. Look for any code that manipulates the directory structure or renames directories.

Analyzing the Logic

Once you've identified the relevant code, analyze the logic behind the directory renaming. Is it based on certain conditions? Is it a global setting? Understanding the logic will help you determine whether it's intentional or a bug.

Proposing a Solution

Based on your analysis, propose a solution to prevent the directory renaming. This could involve modifying the code to preserve the original directory structure or providing an option to disable the renaming behavior. Make sure your solution doesn't introduce any new issues or break existing functionality.

Conclusion: Let's Get This Fixed!

So, there you have it, guys! A deep dive into the broken load+publish+install cycle with FileCopy in InterSystems IPM. This issue is definitely a roadblock for adopting IPM v0.10.x, especially for Supply Chain implementations. By understanding the problem, reproducing the issue, and exploring potential solutions, we can work together to get this fixed and make IPM a more reliable and user-friendly tool.

Remember, collaboration is key. Share your findings, propose solutions, and contribute to the IPM project. Together, we can make InterSystems IPM a better tool for everyone.