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NSSM cheatsheat

See: NSSM - the Non-Sucking Service Manager

• Create a new service
• List parameters for a service
• Set a parameter for a service
• Parameter list

Create a new service

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macOS SSH client host autocomplete

Snippet for ~/.bash_profile, adding hostname autocomplete to ssh and scp.

Extracts host hints from ~/.ssh/config.

function __completeSSHHosts {
  COMPREPLY=()
 local currentWord=${COMP_WORDS[COMP_CWORD]}

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Enable execute on partition mounted with noexec

The example situation:

• Wish to execute a bash script at /var/foobah/myscript.sh
• But /var/ has been mounted using noexec via /etc/fstab.
• How to solve? Using bind mounts.

Firstly, create a directory to hold script(s), located somewhere that has exec rights, then create the target directory on noexec partition:

$ mkdir --parents /opt/magnetik/foobah

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#!/bin/bash

# query MySQL for slave replication status
# note: requires [~/.my.cnf] to be present a populated with valid MySQL password
mysql \
	--batch \
	--user root \
	--execute "SHOW GLOBAL STATUS LIKE 'Slave_running';" | \
		tail --lines 1 | grep --extended-regexp --quiet "^Slave_running\tON$"

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Bash if conditions with functions()

Some examples of calling bash functions in if; then; fi conditionals - both functions that echo and return.

#!/bin/bash -e

function functionOne {
	echo -n "$1 - $2"
}

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Install OSX Parallels version 10/11/12/13 tools on Ubuntu server guest

Have tested these instructions successfully under Ubuntu 16.04LTS and 14.04LTS.

• Create Ubuntu server instance under Parallels (obviously).
• Start VM, goto Actions - Install Parallels Tools... to mount the ISO image.
  • Note: if this fails, or updating tools for an existing guest you can do the following:
  • Goto Devices > CD/DVD 1 > Connect Image....
  • Select the following ISO image: /Applications/Parallels Desktop/Contents/Resources/Tools/prl-tools-lin.iso.
  • This will mount the tools CD image.

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Transfer MySQL databases between AWS RDS instances

The situation

• Two AWS RDS MySQL databases - moving databases from source to destination.
• Both databases are not publicly accessible, only via an EC2 instance(s) - e.g. you have setup your security groups.
• Can SSH to a target EC2 instance (but of course).

What it does

• Sets up two SSH port forwards on local machine - one to source database, another to target.
• Via calls to transferDatabase():

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Using BFG to clean out old binary assets from Git repository

Reference: http://rtyley.github.io/bfg-repo-cleaner/

Example

$ wget http://repo1.maven.org/maven2/com/madgag/bfg/1.11.8/bfg-1.11.8.jar
$ git clone [email protected]:org-name/repo-name.git repo-name.cleanup
$ java -jar bfg-1.11.8.jar --delete-files '*.{gif,jpg,png}' repo-name.cleanup
$ cd repo-name.cleanup
$ git gc --prune=now --aggressive

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AWS CLI S3 usage examples

• Local dir to remote bucket sync
• Local dir to remote bucket copy with gzip content encoding header
• Remote to remote bucket copy

Local dir to remote bucket sync

$ aws s3 sync \

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#!/bin/bash

git clone --depth 1 \
	-qb $BRANCH_NAME \
	$REPOSITORY_URL $TARGET_CLONE_DIR
cd $TARGET_CLONE_DIR
git submodule update -q --init --depth 1