Rango is a general purpose websocket server which dispatch public and private messages from RabbitMQ. Rango is made as a drop-in replacement of Ranger built in ruby. It was designed to be very fast, scalable with a very low memory footprint.


To simplify the migration from Ranger all environement variables are the same:

RANGER_HOST Hostname to expose the websocket connection
RANGER_PORT 8080 Websocket server port
RABBITMQ_HOST localhost RabbitMQ hostname to connect to
RABBITMQ_PORT 5672 RabbitMQ port
RABBITMQ_USER guest Username used to authenticate to RabbitMQ
RABBITMQ_PASSWORD guest Password used to authenticate to RabbitMQ


Rango exposes metrics in Prometheus format on the port 4242.

Rango metrics

rango_hub_clients_count gauge Number of clients currently connected
rango_hub_subscriptions_count gauge Number of user subscribed to a topic

HTTP metrics

promhttp_metric_handler_requests_in_flight gauge Current number of scrapes being served.
promhttp_metric_handler_requests_total counter Total number of scrapes by HTTP status code.

Process metrics

process_cpu_seconds_total counter Total user and system CPU time spent in seconds.
process_max_fds gauge Maximum number of open file descriptors.
process_open_fds gauge Number of open file descriptors.
process_resident_memory_bytes gauge Resident memory size in bytes.
process_start_time_seconds gauge Start time of the process since unix epoch in seconds.
process_virtual_memory_bytes gauge Virtual memory size in bytes.
process_virtual_memory_max_bytes gauge Maximum amount of virtual memory available in bytes.

Go standard metrics

go_gc_duration_seconds{quantile} summary A summary of the pause duration of garbage collection cycles.
go_goroutines gauge Number of goroutines that currently exist.
go_info{version} gauge Information about the Go environment.
go_memstats_alloc_bytes gauge Number of bytes allocated and still in use.
go_memstats_alloc_bytes_total counter Total number of bytes allocated, even if freed.
go_memstats_buck_hash_sys_bytes gauge Number of bytes used by the profiling bucket hash table.
go_memstats_frees_total counter Total number of frees.
go_memstats_gc_cpu_fraction gauge The fraction of this program's available CPU time used by the GC since the program started.
go_memstats_gc_sys_bytes gauge Number of bytes used for garbage collection system metadata.
go_memstats_heap_alloc_bytes gauge Number of heap bytes allocated and still in use.
go_memstats_heap_idle_bytes gauge Number of heap bytes waiting to be used.
go_memstats_heap_inuse_bytes gauge Number of heap bytes that are in use.
go_memstats_heap_objects gauge Number of allocated objects.
go_memstats_heap_released_bytes gauge Number of heap bytes released to OS.
go_memstats_heap_sys_bytes gauge Number of heap bytes obtained from system.
go_memstats_last_gc_time_seconds gauge Number of seconds since 1970 of last garbage collection.
go_memstats_lookups_total counter Total number of pointer lookups.
go_memstats_mallocs_total counter Total number of mallocs.
go_memstats_mcache_inuse_bytes gauge Number of bytes in use by mcache structures.
go_memstats_mcache_sys_bytes gauge Number of bytes used for mcache structures obtained from system.
go_memstats_mspan_inuse_bytes gauge Number of bytes in use by mspan structures.
go_memstats_mspan_sys_bytes gauge Number of bytes used for mspan structures obtained from system.
go_memstats_next_gc_bytes gauge Number of heap bytes when next garbage collection will take place.
go_memstats_other_sys_bytes gauge Number of bytes used for other system allocations.
go_memstats_stack_inuse_bytes gauge Number of bytes in use by the stack allocator.
go_memstats_stack_sys_bytes gauge Number of bytes obtained from system for stack allocator.
go_memstats_sys_bytes gauge Number of bytes obtained from system.
go_threads gauge Number of OS threads created.

Start the server


Connect to public channel

wscat --connect localhost:8080/public

Connect to private channel

wscat --connect localhost:8080/private --header "Authorization: Bearer ${JWT}"


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