As you can tell I work a bit with ansible. Once you get a few longer playbooks, or have to deploy to hundreds of hosts it can get a bit tedious to search through the output to find “ok, what changed?”
ARA can be a big help in such situations, but good old sed will also do nicely in a pinch: sed -n '/^--- before/,/^changed/p' ansible_output for bonus points you can pipe the output to colordiff
A reader contacted me with useful information regarding my previous posting about Exim and multidomain DKIM I updated it with newer information in case anyone stumbles across it via google.
In a nutshell it was mostly more elegant solutions and a fix for the broken example published on the debian-administration.org website.
One of the changes with ansible 2.7 is how you are supposed to pass a list of packages to a package module. instead of passing a list via with_items (which then get’s squashed into one call anyway), you just pass the whole list.
Apt as an example:
ansible <= 2.6
1 2 3 4 | - name: Install packages apt: pkg: "{{ item }}" state: present with_items: "{{ packages }" |
ansible <= 2.7
1 2 3 4 | - name: Install packages apt: pkg: "{{ packages }}" state: present |
What the documentation doesn’t touch is how to pass multiple lists.
The error output suggests using ['{{ list1 }}', '{{ list2 }}'], but ansible throws a fit if you do that. Turns out you can also concatenate lists with the + sign. So the solution looks like this:
1 2 3 4 | - name: Install packages apt: pkg: "{{ packages + more_packages }}" state: present |
About once a year one of my outgoing email servers will magically pop up on Microsofts blacklist of email servers. The exact status in SNDS is “Blocked due to user complaints or other evidence of spamming“, which is a bit ironic since the weekly volume of emails that go to Microsoft controlled domains seldom is higher than 5 and they are all personal emails.
The error message the MTA recieves is “550 5.7.1 Unfortunately, messages from [xxx.xxx.xxx.xxx] weren’t sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors.” in case anyone ends up here via google.
I’m not going to bitch and moan or attempt to guess why the server ends up on the list since it isn’t something I can influence
(just submit a support request and wait), instead I’ll post some tips and pointers to useful tools you should be using:
SPF – Sender Policy Framework
Specify which IPs are allowed too send mail for your domains, also determine what should happen with mail that is recieved from unauthorized IPs.
DKIM – DomainKeys Identified Mail
Outgoing mail servers for a domain can sign the emails and thereby allow recipients to verify that the email really came from a valid mail server and is not from a spoofed sender.
DMARC – Domain-based Message Authentication, Reporting & Conformance
DMARC allows you to specify policies for domains or subdomains in regards to “what should happen if an email fails DKIM or SPF” and where/if to send reports for Emails recieved by other mail servers.
SNDS – Smart Network Data Service
Allows you to monitor the IPs of your mailservers as viewed by the Outlook.com system.
JMRP – Junk Email Reporting Program
Forwards the full message with headers of any email marked as “junk” or “phishing” by Outlook.com users
MX Toolbox
MXtoolbox is a great website for testing your mail server settings, they also have a free_monitoring service for one IP, so you can get alerted if your IP shows up on a Blacklist.
Last but not least I use the following small script to monitor the status of my servers according to Microsoft. I call the script via a daily cronjob, and if a server is blacklisted, it sends an alert. Go to Automated Data Access first to generate an API key.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | #!/usr/bin/env bash sdns_key="<<insert API key here>>" recipient="<<email to send alerts to>>" if [[ "${sdns_key}" == '' ]]; then exit 0 fi _URL_ip="https://sendersupport.olc.protection.outlook.com/snds/ipStatus.aspx?key=${sdns_key}" _URL_data="https://sendersupport.olc.protection.outlook.com/snds/data.aspx?key=${sdns_key}" content="$(curl -s "${_URL_ip}")" if [[ ${#content} -gt 0 ]]; then { echo "${content}" echo curl -s "${_URL_data}" } | mailx -s "Microsoft SNDS status" ${recipient} exit 1 fi |
And if all else fails and your IP does end up blacklisted in SNDS, you can go here to submit a ticket to get back off (although I’d suggest checking your mail server logs and the status of the IP on other RBLs first, just to make sure).
http://go.microsoft.com/fwlink/?LinkID=614866
It’s been quiet here lately. I moved back to Germany and have taken on new responsibilities at work. We are slowly getting settled in, although i still have to get the network at the new apartment up and running the way I want it. I expect to post here more often once I have more time for side projects.
One thing I recently acquired and really like, is a new case for my Odroid XU4.
The small 5v Noctua fan fits very nicely in it and is virtually silent, together with the large heatsink it stays cool enough and seldom has to throttle the CPU.
I prefer the odroid over a raspberry pi for “small server” tasks since it has a Gbit interface (that isn’t shared on the USB bus) and supports eMMC modules (no one enjoys waiting on I/O).