clouddns-sync

README

clouddns-sync

Utlity for syncing local DNS records to gcloud (and back).

Getting Started

Assuming yu have the gcloud command set up with access to Google Cloud console, the following should get you going:

(Figuring out the clicky web console equivalent is left as an exercise to the reader etc. etc.)

# Create a nice project just for dns
gcloud projects create mydnsproject

# Switch to the new project
gcloud config set project mydnsproject

# Enable Cloud DNS for this project
gcloud services enable dns.googleapis.com

# Set up your first zone. Note trailing period.
gcloud dns managed-zones create myzone \
    --dns-name=myzone.mydomain.tld. --description="My Zone"

# Set up a service account to admininster just DNS
gcloud iam service-accounts create cloud-dns-sync

# Add your service account to the DNS Administrator role for this project
gcloud projects add-iam-policy-binding myproject \
    --member=serviceAcount:cloud-dns-sync@mydnsproject.iam.gserviceaccount.com \
    --role=roles/dns.admin

# Generate a key for the service account. There's a more secure way of doing this with identity federation doodly do but who can be arsed.
gcloud iam service-accounts keys create cloud-dns-sync.key.json \
    --key-file-type=json \
    --iam-account=cloud-dns-sync@mydnsproject.iam.gserviceaccount.com

Now, delegate dns for the (sub)domain you want to whatever is in the output of gcloud dns managed-zones describe myzone

Congrats! you now have a useless DNS zone with no records! You can add them with the gcloud command if you like, refer to the docs.

Tool Usage

if you're using a JSON keyfile as above, you don't need to specify --cloud-project if the project is named there.

If you don't specify --json-keyfile then we'l try to use default credentials (i.e. the ones that the gcloud CLI uses). The examples below do this for clarity.

getzonefile and putzonefile - Zonefile Nonsense

If you want to spit out a mostly valid zonefile from your gcloud-dns zone, this will do it:

clouddns-sync --cloud-project=mydnsproject --cloud-dns-zone=myzone getzonefile

If you have a zonefile, slurp it into gcloud DNS by doing this:

clouddns-sync --cloud-project=mydnsproject --cloud-dns-zone=myzone --zonefile=myzonefile putzonefile

You can add --dry-run to putzonefile to see what we'd do. You can also add --prune-missing to remove RRs that aren't in your zonefile but are in gcloud.

My own use case is to do this once and then do future updates from a data source more reliable than your grandad's text file.

nomad_sync Update from Nomad cluster

clouddns-sync --cloud-project=mydnsproject --cloud-dns-zone=myzone --nomad-server-uri=http://anynomadserver:4646/ nomad_sync

Right now we build a list of A records by inspecting all allocs and pointing jobname.domain to all nodes that hold an alloc in that job. That might not be what you want, but the important thing is that it's what I want. Patches welcome!

dynrecord dyndns-style single record updating

This is if you have a DNS name you want to do 'dyndns' style updating for (i.e. we find out what our public IP is and set the specificed A record to that.)

clouddns-sync --cloud-project=mydnsproject --cloud-dns-zone=myzone --cloud-dns-dyn-record-name=myhomeip.domain.tld. dynrecord