sysops.md

Linux performance

• http://www.brendangregg.com/linuxperf.html

VPN

Helpers/Easy VPN setup

• https://github.com/hwdsl2/setup-ipsec-vpn
• https://github.com/jlund/streisand

Emails

SPF, DKIM, DMARC and e-mail tools

• http://mxtoolbox.com/SuperTool.aspx?action=spf%3ayourdomain.com&run=toolpage
• https://en.wikipedia.org/wiki/Sender_Policy_Framework
• http://stackoverflow.com/questions/28311649/are-sites-without-wildcard-spf-records-vulnerable-to-subdomain-spoofing-attacks
• sa-test@sendmail.net
• 5 Ways to Check Your Sending Reputation: https://sendgrid.com/blog/5-ways-check-sending-reputation/

Spam traps

• http://blog.mailchimp.com/where-spam-traps-come-from-and-how-they-work/

Google Cloud restrictions for SMTP ports

• Google cloud blocks port 25, we need to use 2525 port for google cloud postfix.
• https://cloud.google.com/vpc/docs/firewalls#blockedtraffic

Microsoft (outlook) smpt servers block lists

• https://answers.microsoft.com/en-us/outlook_com/forum/all/hotmailoutlook-block-list-s3140-blocks-all-new/699f3a56-406e-4804-97e2-cbe23b9bb01c
• https://blog.paranoidpenguin.net/2020/08/outlook-com-is-no-longer-blocking-my-mail-server/
• https://sendersupport.olc.protection.outlook.com/snds/

MySQL

MySQL memory

• https://github.com/MarkLeith/dbahelper
• https://bugs.mysql.com/bug.php?id=72322

MySQL SQL dialect

• https://www.jooq.org/translate/

MySQL Developers DBs

• https://habr.com/en/company/citymobil/blog/492172/

SSH

• https://www.blackmoreops.com/2016/11/08/top-30-ssh-shenanigans/
• https://medium.com/uber-security-privacy/introducing-the-uber-ssh-certificate-authority-4f840839c5cc#.s7j1vkoat
• https://gravitational.com/blog/replace-static-ssh-keys-with-github-oauth/
• https://smallstep.com/blog/diy-single-sign-on-for-ssh/

Git

• https://jwiegley.github.io/git-from-the-bottom-up/
• https://hackernoon.com/lesser-known-git-commands-151a1918a60#.l48pn1p8i

How to undo stuff in git

• https://github.blog/2015-06-08-how-to-undo-almost-anything-with-git/
• https://medium.com/@CarrieGuss/how-to-recover-from-a-git-hard-reset-b830b5e3f60c#.353djvmkb

Systemd

• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sect-Managing_Services_with_systemd-Unit_Files.html
• https://fedoramagazine.org/systemd-converting-sysvinit-scripts/
• https://www.linux.com/topic/networking/5-systemd-tools-you-should-start-using-now/

Logging

Ownership of nginx log directory and issues around that

• http://serverfault.com/questions/639128/nginx-logging-to-access-log-1-instead-of-access-log-logrotate-failing

rsyslog

• http://www.rsyslog.com/doc/master/index.html
• https://github.com/rsyslog/rsyslog/blob/master/ChangeLog

Multiple SSL-TLS remote targets for rsyslog

• http://stackoverflow.com/questions/22052111/rsyslog-logging-to-multiple-servers-with-different-tls-configurations

rsyslog rulesets

• http://www.rsyslog.com/doc/v8-stable/concepts/multi_ruleset.html

Authentication

2FA

• https://code.google.com/p/google-authenticator-apache-module/wiki/GoogleAuthenticatorApacheModule
• https://factored.readthedocs.org/en/latest/

OAuth

• https://github.com/bitly/oauth2_proxy

AWS

AWS SSO explained

• You only need to callaws sso login once for all your profiles: https://ben11kehoe.medium.com/you-only-need-to-call-aws-sso-login-once-for-all-your-profiles-41a334e1b37e
• AWS configuration files, explained: https://ben11kehoe.medium.com/aws-configuration-files-explained-9a7ea7a5b42e

Util to check which instances are covered by reserved instances

• https://github.com/balanced-ops/ec2-cost-tools

Install ec2-cost-tools

git clone git@github.com:balanced-ops/ec2-cost-tools.git
cd ec2-cost-tools
pip install -e .
export AWS_ACCESS_KEY_ID=<Your aws access key>
export AWS_SECRET_ACCESS_KEY=<Your aws secret key>

ec2-costs us-east-1

S3 Bucket ACLs

• https://blogs.aws.amazon.com/security/post/Tx1P2T3LFXXCNB5/Writing-IAM-policies-Grant-access-to-user-specific-folders-in-an-Amazon-S3-bucke

Kubernetes

• https://aws.amazon.com/blogs/opensource/introducing-fine-grained-iam-roles-service-accounts/

Security

• Top 10 security best practices for securing backups in AWS: https://aws.amazon.com/blogs/security/top-10-security-best-practices-for-securing-backups-in-aws/

Inventory

• AWS Cloud Scanners: https://heldsteel7.medium.com/aws-cloud-scanners-10024e4bb16f

GCP

• Get Performance, Costs, Security recommendation in GCP: https://console.cloud.google.com/home/recommendations?referrer=search&project=my-project

IaaS providers

Cheap ones

• https://www.digitalocean.com/

Sysdig

• https://www.wireshark.org/docs/dfref/s/sysdig.html
• https://groups.google.com/forum/#!topic/sysdig/Jblu9qumGH4
• https://github.com/draios/sysdig/wiki/Sysdig-User-Guide
• https://sysdig.com/fascinating-world-linux-system-calls/
• https://wiki.mikejung.biz/Sysdig#Sysdig_Process_and_Thread_Related_Fields
• http://bencane.com/2014/04/18/using-sysdig-to-troubleshoot-like-a-boss/
• http://www.sysdig.org/wiki/sysdig-user-guide/
• http://www.sysdig.org/wiki/sysdig-examples/

EFI

• https://habrahabr.ru/post/314412/

Kernel

• Which process has PID 0? https://unix.stackexchange.com/questions/83322/which-process-has-pid-0

Sync

Rsync

• The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs): https://gist.github.com/KartikTalwar/4393116

Backup

• Why should I switch from Restic to Borg? https://www.reddit.com/r/BorgBackup/comments/v3bwfg/why_should_i_switch_from_restic_to_borg/
• BorgBackup (short: Borg) is a deduplicating backup program. https://borgbackup.readthedocs.io/en/stable/index.html
• borgmatic is simple, configuration-driven backup software for servers and workstations. https://projects.torsion.org/borgmatic-collective/borgmatic
• Restic is a fast and secure backup program. https://restic.readthedocs.io/en/latest/010_introduction.html

Software updates

• S.U.P.E.R.M.A.N. optimizes the macOS software update experience: https://github.com/Macjutsu/super