how to build command that omhttp module of rsyslog.

rsyslog-omhttp_build-cmd.bash

# how to command ofbuilding rsyslog.
# env: Ubuntu, 4.15.0-1027-gcp #28~16.04.1-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux
# date: Fri Jan 18 10:10:51 UTC 2019 

# cloning repo rsyslog
git clone https://github.com/rsyslog/rsyslog
cd ./rsyslog

sudo apt update
sudo apt install autoconf automake libtool


vim ./configure.ac
## add LT_INIT, AC_PROG_RANLIB
# example:
#	AC_DEFINE(VERSION_MONTH, 1, [month part of real rsyslog version])
#	AC_PROG_RANLIB # <-- add
#	LT_INIT        # <-- add
#	
#	AM_INIT_AUTOMAKE([subdir-objects])

# prepare for build
autoheader
aclocal
automake -a -c
autoreconf -iv

sudo add-apt-repository ppa:adiscon/v8-stable
sudo apt-get update
sudo apt-get install pkg-config rsyslog libcurl4-openssl-dev \
     flex bison python-docutils uuid-dev libgcrypt20-dev \
     zlib1g-dev libfastjson-dev libestr-dev

ls -l /usr/share/aclocal/pkg.m4
aclocal --print-ac-dir
ACLOCAL_PATH=/usr/share/aclocal ./autogen.sh
./configure --enable-omhttp # check last message of build enabled omhttp
make

ls -la ./contrib/omhttp/.libs/omhttp.so 
sudo cp ./contrib/omhttp/.libs/omhttp.so /usr/lib/rsyslog/

ls -la /usr/lib/rsyslog/omhttp.so 

# set omhttp settings by rsyslog : https://www.rsyslog.com/doc/v8-stable/configuration/modules/omhttp.html#example-1

This was very helpful, thanks. I also formatted this as a Dockerfile.

FROM ubuntu:22.04
RUN apt-get -y update && \
    apt-get -y install git apt-utils make software-properties-common && \
    git clone https://github.com/rsyslog/rsyslog && \
    cd rsyslog && \
    apt-get -y update && \
    apt-get -y install autoconf automake libtool && \
    sed -i '8i AC_PROG_RANLIB' /rsyslog/configure.ac && \
    sed -i '9i LT_INIT' /rsyslog/configure.ac && \
    autoheader && \
    aclocal
#RUN cd rsyslog && automake -a -c  # causes failures
#RUN cd rsyslog && autoreconf -iv   # causes failures
RUN cd rsyslog && add-apt-repository ppa:adiscon/v8-stable && \
    apt-get -y update && \
    apt-get -y install pkg-config rsyslog libcurl4-openssl-dev \
         flex bison python3-docutils uuid-dev libgcrypt20-dev \
         zlib1g-dev libfastjson-dev libestr-dev && \
    aclocal --print-ac-dir && \
    ACLOCAL_PATH=/usr/share/aclocal ./autogen.sh
RUN cd rsyslog && \
    ./configure --enable-omhttp && \
    make && \
    cp ./contrib/omhttp/.libs/omhttp.so /usr/lib/rsyslog/ && \
    ls -la /usr/lib/rsyslog/omhttp.so