packer_base_centos_aws

Assets used to build a base AMI for Eurostar projects with daringly permissive adjustments to selinux and iptables, and a progressive attitude to rpm updates.

It is also responsible for the creation of the standard ec2-user.

ADD TO THIS LAYER THINGS THAT ARE AXIOMATIC FOR ANY EUROSTAR RHEL-BASED LINUX

BUILD

    # 1. export all user-defined env vars
    # 2. clone packer_includes in dir with this project's Makefile

    make build

• makefile inherits values from env vars. These are transformed and / or passed on to packer which maps them to packer user vars.

• Packer runs a few scripts under the yawn-inducingly-named scripts dir to provide the basic ami env.

CHANGES WORKFLOW

• make a git branch from master.

• make your changes and push to your branch.

  You won't be able to build if you have uncommitted changes in your local repo.

• build from your branch

• The AMI will have a channel tag, set to dev.

• After it is tested, tag your build commit and merge to master.

• On successful testing, the AMI's channel tag should be set to stable.

  Obviously, this should be automated ...

  It is this stable, tested ami that later ami layers will look for to use as a base.

  See examples of changing tags and discovering appropriate AMIs below.

OUTPUT

The resulting AMI is named:

    eurostar_aws-<os info>-<build git org>-<build time>

    e.g.

    eurostar_aws-centos-6.5-EurostarDigital-20160522105037

See generated value $AMI_NAME in Makefile for more details.

DISCOVERY

    e.g. find ami_id for latest stable from a EurostarDigital master branch:
    GIT_INFO="repo<*EurostarDigital/*>branch<master>"
    aws --cli-read-timeout 10 ec2 describe-images --region $AWS_REGION \
        --filters 'Name=manifest-location,Values=*/eurostar_aws*'      \
                  "Name=tag:build_git_info,Values=$GIT_INFO"           \
                  'Name=tag:channel,Values=stable'                     \
        --query 'Images[*].[ImageId,CreationDate]'                     \
        --output text                                                  \
        | sort -k2 | tail -1 | awk {'print $1'}

MARKING AS STABLE

    e.g. assumes you know the ami id

    aws ec2 create-tags --region=$AWS_REGION \
    --resources $AMI_ID                      \
    --tags 'Key=channel,Value=stable'