Latest commit 78ac8e6
Jan 8, 2016
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.
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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 @22.214.171.124 +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