a command line tool for generating DNS records from EC2 instances
Ruby Shell
Latest commit 78ac8e6 Jan 8, 2016 @solidsnack solidsnack Support reversal of the distinguished public IP
This helps to resolve difficulties that arise when multiple IPs are present.
Fog picks among the secondary public and private DNS names seemingly at random
when there is more than one to choose from.

README

SYNOPSIS
       zonify ... (-h|-[?]|--help) ...
       zonify ec2 <rewrite rules>* > zone.ec2.yaml
       zonify ec2/r53 <domain> <rewrite rules>* > changes.yaml
       zonify r53 <domain> > zone.r53.yaml
       zonify diff zone.r53.yaml zone.ec2.yaml > changes.yaml
       zonify rewrite <rewrite rules>* < zone.ec2.yaml
       zonify summarize < changes.yaml
       zonify apply < changes.yaml
       zonify sync <domain> <rewrite rules>*
       zonify normalize <domain>
       zonify eips

DESCRIPTION
       The  zonify  tool  allows  one to create DNS entries for all instances,
       tags and load balancers in EC2 and synchronize a  Route  53  zone  with
       these entries.

       The  zonify tool and libraries intelligently insert a final and initial
       '.' as needed to conform to DNS conventions. One may enter the  domains
       at the command line as example.com or example.com.; it will work either
       way.

       For access to AWS APIs, zonify uses the  the  conventional  environment
       variables to select regions and specify credentials:

       AWS_ACCESS_KEY AWS_ACCESS_KEY_ID
       AWS_SECRET_KEY AWS_SECRET_ACCESS_KEY
       EC2_URL

       These  variables  are used by many AWS libraries and tools. As a conve-
       nience, the environment variable AWS_REGION may  be  used  with  region
       nicknames:

       AWS_REGION=eu-west-1

       One  may  specify --use-iam-profile option to configure the zonify tool
       with AWS IAM-provided access and secret keys. This capability is avail-
       able only when running the tool on an EC2 instance with an IAM role.

       The  Zonify  subcommands  allow  staged  generation, transformation and
       auditing of entries as well as straightforward,  one-step  synchroniza-
       tion.

          ec2 (--srv-singleton|--no-srv-singleton)?
                 Organizes  instances,  load  balancers,  security  groups and
                 instance metadata into DNS entries, with the  generic  suffix
                 '.' (intended to be transformed by later commands).

          ec2/r53 (--types CNAME,SRV)? (--srv-singleton|--no-srv-singleton)?
                 Creates  a  changes  file,  describing  how records under the
                 given suffix would be created and deleted to bring it  in  to
                 sync with EC2. By default, only records of type CNAME and SRV
                 are examined and changed.

          r53    Capture all Route 53 records under the given suffix.

          diff (--types CNAME,SRV,A,MX,...)?
                 Describe changes (which can be fed to the  apply  subcommand)
                 needed to bring a Route 53 domain in the first file into sync
                 with domain described in the second file. The suffix is taken
                 from  the  first  file.  The  default with diff (unlike other
                 zonify subcommands) is to examine all record types.

          rewrite (--srv-singleton|--no-srv-singleton)?
                 Apply rewrite rules to the domain file.

          summarize
                 Summarize changes in a changes file, writing to STDOUT.

          apply  Apply a changes file.

          sync (--types CNAME,SRV)? (--srv-singleton|--no-srv-singleton)?
                 Sync the given domain with EC2. By default, only  records  of
                 type CNAME and SRV are examined and changed.

          normalize
                 Create  CNAMEs  for  SRV records that have only one server in
                 them and rebase records on to the given domain.

          eips   List all Elastic IPs and DNS entries that map to them.

       The --[no-]srv-singleton options control creation of CNAMEs for single-
       ton  SRV  records. They are enabled by default; but it can be useful to
       disable them for pre-processing the YAML and then adding them with nor-
       malize. For example:

       zonify r53 amz.example.com > r53.yaml
       zonify ec2 --no-srv-singleton > ec2.yaml
       my-yaml-rewriter < ec2.yaml > adjusted.yaml
       zonify normalize amz.example.com < adjusted.yaml > normed.yaml
       zonify diff --types CNAME,SRV r53.yaml normed.yaml | zonify apply

       The  --[no-]srv-singleton  options  also  control  creation of weighted
       round-robin CNAMEs, an infelicity in nomenclature.

SYNC POLICY
       Zonify assumes the domain given on the command line is  entirely  under
       the  control of Zonify; records not reflecting the present state of EC2
       are scheduled for deletion in the generated  changesets.  This  can  be
       controlled to some degree with the --types option.

       The sync scopes over the domain and not necessarily the entire Route 53
       zone.  Say, for example, one has example.com in a Route 53 zone and one
       plans to use amz.example.com for Amazon instance records.  In this sce-
       nario, Zonify will only specify changes that delete or  create  records
       under amz.example.com; www.example.com, s0.mobile.example.com and simi-
       lar records will not be affected.

YAML OUTPUT
       All records and change sets are sorted by name on output. The data com-
       ponents of records are also sorted. This ensures consistent output from
       run to run; and allows the diff tool to return meaningful results  when
       outputs are compared.

       One  exception  to this rule is the r53 subcommand, which preserves the
       order of data as it was found in Route 53.

REWRITE RULES
       Rewrite rules take the  form  <domain>(:<domain>)+.  To  shorten  names
       under the apache security group to web.amz.example.com, use:

       apache.sg:web

       To keep both forms, use the rule:

       apache.sg:apache.sg:web

GENERATED RECORDS AND QUERYING
       For  records  where  there  are  potentially  many  servers -- security
       groups, tags, load balancers -- Zonify creates SRV records. When a  SRV
       record  has  only one entry under it, a simple CNAME is created. When a
       SRV record contains multiple  records,  multiple  weighted  round-robin
       CNAMEs are created, one for each server in the SRV record.

       Records created include:

          i-ABCD1234.inst.
                 Individual instances.

          _*._*.<value>.<key>.tag.
                 SRV records for tags.

          _*._*.<name>.sg.
                 SRV records for security groups.

          _*._*.<name>.elb
                 SRV records for instances behind Elastic Load Balancers.

          domU-*.priv., ip-*.priv
                 Records  pointing  to  the default hostname, derived from the
                 private DNS entry, set by many AMIs.

       A list of all instances is placed under inst  --  continuing  with  our
       example above, this would be the SRV record _*._*.inst.amz.example.com.
       To obtain the list of all instances with dig:

       dig @8.8.8.8 +tcp +short _*._*.inst.amz.example.com SRV | cut -d' ' -f4

       The cut call is necessary to remove some  values,  always  nonces  with
       Zonify, that are part of standard format SRV records.

EXAMPLES
       # Create records under amz.example.com, with instance names appearing
       # directly under .amz.example.com.
       zonify sync amz.example.com name.tag:.
       # Similar to above but stores changes to disk for later application.
       zonify ec2/r53 amz.example.com name.tag:. > changes.yaml