DanyC97

AWS CloudFormation YAML template - appending to list parameter types

Documenting this here, as I often forget (what I have found) is the best way to do this at the moment.

For example, you have a list of two existing security groups given to a stack and wish to create (and use) a third - attaching all to an ALB:

AWSTemplateFormatVersion: "2010-09-09"
Description: "Example template"

Parameters:

DanyC97

Libvirt

yum group install -y "Development Tools"
yum -y install qemu-kvm libvirt virt-install bridge-utils libvirt-devel  libxslt-devel libxml2-devel libvirt-devel libguestfs-tools-c

echo "net.ipv4.ip_forward = 1"|sudo tee /etc/sysctl.d/99-ipforward.conf
sysctl -p /etc/sysctl.d/99-ipforward.conf

DanyC97

Tabs and Windows

Function	Shortcut
Fullscreen	⌘+ Enter
Previous Tab	⌘+ Left Arrow
Next Tab	⌘+ Right Arrow
Go to Tab	⌘ + Number
Go to Window	⌘ + Option + Number
Go to Split Pane by Direction	⌘ + Option + Arrow

DanyC97

Generating CloudFormation Templates from YAML Dictionaries

The security group and Network ACLs parts of CloudFormation templates can be difficult to read. This template containing Jinja macros converts easier-to-read YAML dictionaries of security group and NACL rules into JSON.

Here ais a generic macro template and some example files showing how to use it.

• cloudformation.macros.j2 - the macros
• cf_vars.yml - YAML dictionaly of security groups and NACLs, including some complex rules for both
• test.template.j2 - a simple CloudFormation template that uses the macro file
• cf_test.yml - a simple Ansible playbook that generates CloudFormation JSON from thr previous file.

DanyC97

# shortform git commands
alias g='git'

# pretty tab'd git log
git log --graph --pretty="tformat:%h*(%ar)*<%an>*%d %s" $* | sed -Ee 's/(^[^<]*) ago\)/\1)/' | sed -Ee 's/(^[^<]*), [[:digit:]]+ .*months?\)/\1)/' | column -s '*' -t | cat

# change author of all git repos
git filter-branch -f --env-filter "GIT_AUTHOR_NAME='yourname'; GIT_AUTHOR_EMAIL='youremail@example.com'; GIT_COMMITTER_NAME='yourname'; GIT_COMMITTER_EMAIL='youremail@example.com';" HEAD;

# stage only deleted files

DanyC97

function decode-authorization-failure-message {
    if [ $# -ne 1 ] || [ "$1" = -h ] || [ "$1" = --help ]; then
        cat <<'EOT'
Usage: decode-authorization-failure-message <message>

Use this when Amazon gives you an "Encoded authorization failure message" and
you need to turn it into something readable.
EOT
        return 1
    fi

DanyC97

---
AWSTemplateFormatVersion: 2010-09-09
Description: Copy tags from EC2 to associated resources

Resources:

  Role:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:

DanyC97

#
# CORS header support
#
# One way to use this is by placing it into a file called "cors_support"
# under your Nginx configuration directory and placing the following
# statement inside your **location** block(s):
#
#   include cors_support;
#
# As of Nginx 1.7.5, add_header supports an "always" parameter which