feat: Allow [input.process] to take a relative path for command

[jarhodes314]

Proposed changes

Allow users to specify a relative path for the command in an [input.process], enabling people to ship the input script as part of the flow itself.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• Documentation Update (if none of the other choices apply)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

• allow relative path resolution for commands set in input.process.command #4167

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s. You can activate automatic signing by running just prepare-dev once)
• I ran just format as mentioned in CODING_GUIDELINES
• I used just check as mentioned in CODING_GUIDELINES
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

[codecov]

Codecov Report

❌ Patch coverage is 98.30508% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
crates/extensions/tedge_flows/src/config.rs	98.30%	0 Missing and 1 partial ⚠️

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[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
911	2	4	913	99.78	2h49m37.034058999s

Failed Tests

Name	Message	⏱️ Duration	Suite
Consuming messages from a process stdout	Matching messages on topic 'log/journalctl-follow' is less than minimum. wanted: 10 got: 0 messages: [] [RETRY] FAIL on 3. retry.	32.388 s	Tedge Flows
Consuming messages from a process stdout, periodically	Matching messages on topic 'log/journalctl-cursor' is less than minimum. wanted: 1 got: 0 messages: [] [RETRY] FAIL on 3. retry.	30.736 s	Tedge Flows

[albinsuresh]

LGTM.

[didier-wenzek]

Even if controlling dependencies seems to be a lost battle, I wonder. Wouldn't canonicalize be enough?

[jarhodes314]

Almost certainly, I didn't realise we already depended on two crates that do this same thing (path-clean is not a new dependency)

[didier-wenzek]

Beware, the command is not a path but a command line possibly with arguments.

We to call first `shell_words::split().

We can also consider to:

• normalize not only the command path but any argument looking akin to a path.
• properly type InputConfig::Process::command as an array of String.

[didier-wenzek]

For instance the following test is red:

    #[test]
    fn relative_process_paths_are_cleaned_up() {
        let flow_toml = r#"
        [input.process]
        command = "./../flows/./my_flow/../test.sh foo /../bar"
        interval = "1s"
        "#;

        let flow: FlowConfig = toml::from_str(flow_toml).unwrap();
        let resolved = flow
            .input
            .resolve_relative_process_paths(Utf8Path::new("/flows"));
        assert_eq!(
            resolved,
            InputConfig::Process {
                topic: None,
                command: "/flows/test.sh foo /../bar".into(),
                interval: Some(IntervalConfig::Duration(Duration::from_secs(1))),
            }
        )
    }