check_dns does not work on Solaris/Omnios

[miesi]

Describe the bug
check_dns does not work for long resource record names. Validation of _acme-challenge.abrechnung.spi-kg.de. fails on SunOS.

To Reproduce
Steps to reproduce the behaviour:

code is

check_result=$($DNS_CHECK_FUNC $DNS_CHECK_OPTIONS TXT "${rr}" "@${ns}" \
                      | grep -i "^${rr}" \
                      | grep 'IN\WTXT'|awk -F'"' '{ print $2}')

this does not work for

dig TXT _acme-challenge.abrechnung.spi-kg.de @ns1123.ui-dns.de | grep -i "^${rr}" 

; <<>> DiG 9.16.13 <<>> TXT _acme-challenge.abrechnung.spi-kg.de @ns1123.ui-dns.de
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8706
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
;; QUESTION SECTION:
;_acme-challenge.abrechnung.spi-kg.de. IN TXT

;; ANSWER SECTION:
_acme-challenge.abrechnung.spi-kg.de. 60 IN TXT "AlWd1_kDahAKaVroDRKmvXLPZ6pOOg9yWuAyGOsuB0Q"

;; Query time: 12 msec
;; SERVER: 2001:8d8:fe:53:0:d9a0:507b:100#53(2001:8d8:fe:53:0:d9a0:507b:100)
;; WHEN: Mo. Aug. 16 17:27:20 CEST 2021
;; MSG SIZE  rcvd: 121

I think the \W is only correctly interpreted by GNU grep. The default grep on Solaris/OmniOS is POSIX.1 grep.

using gawk the greps can be avoided and the command looks like this:

dig TXT _acme-challenge.abrechnung.spi-kg.de @ns1123.ui-dns.de | gawk -F'"' '/^'${rr}'.*IN\WTXT.*/{print $2}'

Alternatively check for uname == SunOS and -d /usr/gnu/bin and then PATH=/usr/gnu/bin:$PATH

Operating system (please complete the following information):
uname -a
SunOS serverle-g10p 5.11 omnios-r151038-c078b41acd i86pc i386 i86pc
bash --version
GNU bash, version 5.1.4(1)-release (x86_64-pc-solaris2.11)
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

[timkimber]

Hi @miesi

Thanks for reporting this, I'll fix

[miesi]

I sketched something like

 elif [[ ${uname_res} == "SunOS" ]]; then
    os="solaris"
    if [ -d /usr/gnu/bin ]; then
      export PATH=/usr/gnu/bin:$PATH
    else
      echo "required GNU Tools not found, exiting"
      exit 1
    fi

in my fork. If this acceptable, I can create a pull request.