feat: use loopback ip address instead of alias to improve compatibility

[reubenmiller]

Proposed changes

Some Linux distributions installations where the /etc/hosts file is not defined, the loopback address (127.0.0.1), the localhost alias does not get resolved to 127.0.0.1. And devices which have a read-only rootfs, can't even add a manual entry to the list, so the only option is to change the tedge.toml values (which is not ideal for such basic settings).

Changing the defaults from localhost to 127.0.0.1 improves the out of the box compatibility.

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

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA (in all commits with git commit -s)
• I ran cargo fmt as mentioned in CODING_GUIDELINES
• I used cargo clippy 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

[github-actions]

Robot Results

✅ Passed	❌ Failed	⏭️ Skipped	Total	Pass %	⏱️ Duration
453	0	3	453	100	1h0m38.032027s

[reubenmiller]

Ok, seems like the mosquitto TLS cert generation might need to change to also support TLS connections when using the loopback address, currently it only supports the hostname, or localhost.

Update

Addressed by 05ca442

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.2%. Comparing base (ed0b7fd) to head (e54f81a).
Report is 1 commits behind head on main.

Additional details and impacted files

Files	Coverage Δ
crates/common/mqtt_channel/src/config.rs	45.9% <100.0%> (ø)
.../tedge_config/src/tedge_config_cli/tedge_config.rs	76.8% <100.0%> (ø)
...s/core/tedge/src/bridge/common_mosquitto_config.rs	75.3% <100.0%> (ø)
crates/extensions/c8y_mapper_ext/src/converter.rs	84.1% <100.0%> (ø)
crates/extensions/tedge_mqtt_bridge/src/config.rs	96.1% <100.0%> (ø)

... and 1 file with indirect coverage changes

[didier-wenzek]

Approved