#13 nimon: support for writing to influx with extra http.prefix

[Nowa Ammerlaan]

Victoriametrics supports the influx protocol and has an optional "-http.pathPrefix" argument that when enabled causes the server to ignore write requests that lack the prefix. This is useful when running multiple servers behind a proxy.

Instead of "/write?db=njmon" the server then expects "/my/http/prefix/write?db=njmon".

Unfortunately it is currently not possible to write to the db with nimon if this parameter is enabled.

root# nimon -I -s 30 -i <myinflux>/my/http/prefix -p <myport> -ff -m /tmp -w -k -n
target_hostname=<myinflux>/my/http/prefix to IP address convertion failed, bailing out

Writing the hostname as an ip address directly does not resolve this problem. It would be awesome to have an extra argument for nimon where we can specify such a prefix. After reading the manual it seems that such an argument does not currently exist.

[Nigel Griffiths]

This features means breaking the InfluxDB API.
This is very Victoriametrics specific, so I suggest this is handled but a shell script variable.
something like NJMON_HTTP_PREFIX
For example:
export NJMON_HTTP_PREFIX=/some/random/text

then start nimon.

Should be in the next release for AIX and Linux.

[Nigel Griffiths]

Implemented in version 91 for AIX and Linux.
A beta is ready for some testing to confirm the feature.
I changed the shell variable name to NJMON_INFLUX_API_PREFIX
Example
export NJMON_INFLUX_API_PREFIX=/ABC/def

https://sourceforge.net/projects/nmon/files/njmon_linux_91beta.zip/download

https://sourceforge.net/projects/nmon/files/njmon_AIX_91beta.zip/download

Also implemented the InfluxDB timestamps using the -S flag.

[Nowa Ammerlaan]

Awesome, I tested the beta version and found that this works as expected:

NJMON_INFLUX_API_PREFIX="/metrics/short/" /usr/lbin/nimon_beta -I -s 30 -i <my host> -p <my port> -k -n -S

Thanks!