A Jira search that I find useful (show tickets you created and haven’t been updated in a while) since I often have to track tickets I created across different projects. You can subscribe to searches and get an email sent with the results.
reporter = currentUser() AND updated < -90d AND resolution = Unresolved ORDER BY updatedDate DESC
I recently upgraded my Ubuntu box to 17.04.
Much to my surprise DNS starting behaving strangely, so I checked my DNS server … worked fine if I queried it directly, so I checked if DHCP was giving out the wrong DNS IP … nope, that was fine too. I checked /etc/nsswitch.conf , and that looked fine too so I checked what was ending up in /etc/resolv.conf and was surprised that it contains nameserver 127.0.0.53 instead of the “real” DNS server.
After a bit of research I found out that Ubuntu switched over to using systemd-resolved, which shoves itself between user land and the DNS servers and (at least in Ubuntu 17.04) has problems with servers that support DNSSEC. Very frustrating when you know everything is OK and worked in the past, just systemd messing with stuff and breaking it.
My workaround was to turn of DNSSEC validation. Not pretty but better than no DNS at all, until Ubuntu get’s their problems sorted out.
1 2 3 4 | mkdir /etc/systemd/resolved.conf.d printf "[Resolve]\nDNSSEC=no\n" >> /etc/systemd/resolved.conf.d/no-dnssec.conf dpkg-reconfigure resolvconf # Say 'yes' to 'prepare /etc/resolve.conf for dynamic updates' |
Here is a wonderful github repository for playing around with BPF https://github.com/iovisor/bcc
Recently I needed to fetch IP ranges from SPF records. After looking at different python/ruby/perl modules I came to the conclusion that a fancy module (sometimes with wonky dependencies) was overkill just to parse a simple SPF record. So I threw together a simple bash script that is mainly just fetching the SPF record with dig and grep:
1 | dig txt "${fqdn}"|grep -oE 'v=spf[0-9] [^"]+' |
It iterates through the options (it currently recognizes a, mx, ip4, ip6, include, and redirect), and then sorts the output by ipv4, then ipv6.
1 2 3 4 5 6 | fetch_spf.sh ryanschulze.net 138.201.86.179 138.201.86.184 192.249.58.230 2a01:4f8:172:2270:1::102 2604:180::ef4b:4638 |
Download URL: fetch_spf.sh
This is a little function I use to compare package version strings. Sometimes they can get complex with multiple different delimiters or strings in them. I cheated a bit by using sort –version-sort for the actual comparison. If you are looking for a pure bash version to compare simpler strings (e.g. compare 1.2.4 with 1.10.2), I’d suggest this stackoverflow posting.
The function takes three parameters (the version strings and the comparison you want to apply) and uses the return code to signal if the result was valid or not. This gives the function a somewhat natural feel, for example compare_version 3.2.0-113.155 “<” 3.2.0-130.145 would return true. Aside from < and > you can also use a few words like bigger/smaller, older/newer or higher/lower for comparing the strings.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | compare_version() { local versionOne="${1}" local comparision="${2}" local versionTwo="${3}" local result= local sortOpt= local returncode=1 if [[ "${versionOne}" == "${versionTwo}" ]] ; then return 3 fi case ${comparision} in lower|smaller|older|lt|"<" ) sortOpt= ;; higher|bigger|newer|bt|">" ) sortOpt='r' ;; * ) return 2 ;; esac result=($(printf "%s\n" "${versionOne}" "${versionTwo}" | sort -${sortOpt}V )) if [[ "${versionOne}" == "${result[0]}" ]] ; then returncode=0 fi return ${returncode} } # end of function compare_version |
List of return codes and meanings:
1 2 3 4 | 0: Comparison is true 1: Comparison is false 2: Did not recognize the comparison 3: Both version strings are identical |