event on update_package_repository

[h4l0gen]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind documentation

/kind tests

/kind feature

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area commands

/area pkg

/area events

What this PR does / why we need it:
This PR triggers sandbox rule update package repository
Which issue(s) this PR fixes:

Fixes #120

Special notes for your reviewer:

[poiana]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: h4l0gen
Once this PR has been reviewed and has the lgtm label, please assign fededp for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[h4l0gen]

@leogr @FedeDP Here I first check whether that file exists or not. Then open the file in writing mode. Please provide your feedback and any changes if you need them. Thank You!!

and this rule triggered successfully

[leogr]

@leogr @FedeDP Here I first check whether that file exists or not. Then open the file in writing mode. Please provide your feedback and any changes if you need them. Thank You!!

and this rule triggered successfully

Does the rule trigger when the file does not exist?
If yes, avoid the check
If not, there're to options when the file does not exist:

• create (and then cleanup) the file
• or skip the action (with a proper log message)

[h4l0gen]

@leogr The rule is not triggering when the file doesn't exist. So I made these changes:

If the file doesn't exist:

• Create the file.
• Open it in write-only mode.
• Remove the file after processing.

If the file already exists:

• Open it in write-only mode
• Close the file after processing

[leogr]

Thank you,

SGTM. Just, I'd like to get a second look from @FedeDP 🙏

[FedeDP]

LGTM too!

[GLVSKiriti]

@FedeDP Cant we write the code like this. WDYT? Like writing defer statement before, bcz it executes after function return so it cleanups perfectly. Also tested with this code and rule triggers fine in both cases file exists and not exists

func UpdatePackageRepository(h events.Helper) error {
	path := "/etc/apt/sources.list"

	// Check if the file exists and remove it if it is created by you
	if _, err := os.Stat(path); err != nil {
		defer os.Remove(path)
	}
	// Open file with writeonly access, create a file if there is none
	if _, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE, os.FileMode(0755)); err != nil {
		return err
	}
	return nil
}

[FedeDP]

@GLVSKiriti even if more compact, i think it is less readable:

if _, err := os.Stat(path); err != nil {
		defer os.Remove(path)
	}

defer the remove when stat gives an error is super hard to read if one does not know the full context :)

[h4l0gen]

Thank you, @FedeDP, @leogr and @GLVSKiriti, for your feedback. I agree with @FedeDP; as this project continues to evolve and attract new contributors, it's beneficial to maintain readable code as much as possible. Clear code reduces confusion for newcomers, helping them understand it easily.

[leogr]

We are not calling Close() in this branch. Is it intended?

[h4l0gen]

Completely agree with this @leogr, we should close it first. While researching about it found this

• Each open file is associated with a file descriptor, which is a reference to the open file If you remove the file without closing it, the file descriptor may still be in use.

• It is quite often employed in Unix-only software to store temporary data:

• A temporary file is created
• It is then immediately removed on the filesystem (while being kept open).
• It is then used via the file descriptor for any amount of time.
• When the descriptor is closed, the filesystem finally reclaims the space the file's data were occupying.

Hence instead of creating space and other potential issues, its preferable to close file first.
@leogr @FedeDP Please provide your thoughts on this.