This commit extends the documentation effort by adding detailed explanatory
comments to key CLI components and core functionality throughout the cmd/
directory. The changes focus on explaining WHY certain logic is needed,
not just WHAT the code does, improving code maintainability and helping
developers understand complex business decisions.
Key improvements:
- Main entry points: Document CLI initialization, logging setup, and cache
configuration with reasoning for design decisions
- DNS proxy core: Explain DNS proxy constants, data structures, and core
processing pipeline for handling DNS queries
- Service management: Document service command structure, configuration
patterns, and platform-specific service handling
- Logging infrastructure: Explain log buffer management, level encoders,
and log formatting decisions for different use cases
- Metrics and monitoring: Document Prometheus metrics structure, HTTP
endpoints, and conditional metric collection for performance
- Network handling: Explain Linux-specific network interface filtering,
virtual interface detection, and DNS configuration management
- Hostname validation: Document RFC1123 compliance and DNS naming
standards for system compatibility
- Mobile integration: Explain HTTP retry logic, fallback mechanisms, and
mobile platform integration patterns
- Connection management: Document connection wrapper design to prevent
log pollution during process lifecycle
Technical details:
- Added explanatory comments to 11 additional files in cmd/cli/
- Maintained consistent documentation style and format
- Preserved all existing functionality while improving code clarity
- Enhanced understanding of complex business logic and platform-specific
behavior
These comments help future developers understand the reasoning behind
complex decisions, making the codebase more maintainable and reducing
the risk of incorrect modifications during maintenance.
Fixes search domains not being preserved when the resolv.conf file is
reverted to its previous state. This ensures that important domain
search configuration is maintained during DNS configuration changes.
The search domains handling was missing in setResolvConf function,
which is responsible for restoring DNS settings.
Because ctrld needs to query custom client mapping from it.
While at it, also make the error message clearer when initializing ubios
discover failed, by attaching the command output to returned error.
The systemd-networkd-wait-online is only required if systemd-networkd
is managing any interfaces. Otherwise, it will hang and block ctrld from
starting.
See: https://github.com/systemd/systemd/issues/23304
The only reason that forces ctrld to depend on vyatta-dhcpd service on
EdgeOS is allowing ctrld to watch lease files properly, because those
files may not be created at the time client info table initialized.
However, on some EdgeOS version, vyatta-dhcpd could not start with an
empty config file, causing restart loop itself, flooding systemd log,
making the router run out of memory.
To fix this, instead of depending on vyatta-dhcpd, we should just watch
for lease files creation, then adding them to watch list.
While at it, also making ctrld starts after nss-lookup, ensuring we have
a working DNS before starting ctrld.
