Coredns

coredns

Coredns is a fast and flexible, cloud native DNS server, written in Go programing language
Configuration of coredns check is stored k8s.ini file in conf directory.

Install
cd ${OE_AGENT_HOME}/checks_enabled
ln -s ../checks_available/check_coredns.py ./
Configure

If you are using default installation of ethd service, no additional configuration is needed. If you need to monitor etc in non default location, edit conf/k8s.ini section coredns and set metrics parameter with value matching your needs.

Before enabling check_coredns module you should enable metrics plugin at Coredns. Snippet above is an example of how metrics interface can be enabled in coredns

{
    prometheus localhost:9253
}

When config file is changes , you should restart coredns daemon to apply new settings. The metrics path at coredns is fixed to /metrics so make sure full URL of coredns metrics interface is written in conf/k8s.ini

[coredns]
metrics : http://127.0.0.1:9253/metrics
Restart
${OE_AGENT_HOME}/oddeye.sh restart
Provides
Name Description Type Unit
coredns_go_gc_duration_seconds_count A summary of the GC invocation durations. counter Seconds
coredns_go_gc_duration_seconds_sum A summary of the GC invocation durations. sum Seconds
coredns_go_goroutines Number of goroutines that currently exist. gauge Integer
coredns_go_memstats_alloc_bytes Number of bytes allocated and still in use. gauge Bytes
coredns_go_memstats_alloc_bytes_total Number of bytes allocated and still in use. total Bytes
coredns_go_memstats_buck_hash_sys_bytes Number of bytes used by the profiling bucket hash table. gauge Bytes
coredns_go_memstats_frees_total Total number of frees. counter Integer
coredns_go_memstats_gc_cpu_fraction The fraction of this program's available CPU time used by the GC since the program started. gauge Integer
coredns_go_memstats_gc_sys_bytes Number of bytes used for garbage collection system metadata. gauge Bytes
coredns_go_memstats_heap_alloc_bytes Number of heap bytes allocated and still in use. gauge Bytes
coredns_go_memstats_heap_idle_bytes Number of heap bytes waiting to be used. gauge Bytes
coredns_go_memstats_heap_inuse_bytes Number of heap bytes that are in use. gauge Bytes
coredns_go_memstats_heap_objectsNumber of allocated objects. gauge integer
coredns_go_memstats_heap_released_bytes Number of heap bytes released to OS. gauge Bytes
coredns_go_memstats_heap_sys_bytes Number of heap bytes obtained from system. gauge Bytes
coredns_go_memstats_last_gc_time_seconds Number of seconds since 1970 of last garbage collection. gauge Seconds
coredns_go_memstats_lookups_total Total number of pointer lookups. counter Integer
coredns_go_memstats_mallocs_total Total number of mallocs. counter Integer
coredns_go_memstats_mcache_inuse_bytes Number of bytes in use by mcache structures. gauge Bytes
coredns_go_memstats_mcache_sys_bytes Number of bytes used for mcache structures obtained from system. gauge Bytes
coredns_go_memstats_mspan_inuse_bytes Number of bytes in use by mspan structures. gauge Bytes
coredns_go_memstats_mspan_sys_bytes Number of bytes used for mspan structures obtained from system. gauge Bytes
coredns_go_memstats_next_gc_bytes Number of heap bytes when next garbage collection will take place. gauge Bytes
coredns_go_memstats_other_sys_bytes Number of bytes used for other system allocations. gauge Bytes
coredns_go_memstats_stack_inuse_bytes Number of bytes in use by the stack allocator. gauge Bytes
coredns_go_memstats_stack_sys_bytes Number of bytes obtained from system for stack allocator. gauge Bytes
coredns_go_memstats_sys_bytes Number of bytes obtained from system. gauge Bytes
coredns_go_threads Number of OS threads created. gauge Integer
coredns_health_request_duration_seconds_count Time each request took. counter Seconds
coredns_health_request_duration_seconds_sum Time each request took. sum Seconds
coredns_panic_count_total A metrics that counts the number of panics. counter Integer
coredns_process_cpu_seconds_total Total user and system CPU time spent in seconds. counter Seconds
coredns_process_max_fds Maximum number of open file descriptors. gauge Integer
coredns_process_open_fds Number of open file descriptors. gauge Integer
coredns_process_resident_memory_bytes Resident memory size in bytes. gauge Bytes
coredns_process_start_time_seconds Start time of the process since unix epoch in seconds. gauge Seconds
coredns_process_virtual_memory_bytes Virtual memory size in bytes. gauge Bytes
coredns_process_virtual_memory_max_bytes Maximum amount of virtual memory available in bytes. gauge Bytes