Add --fqdn-policy option to deploy-webapp-from-registry. (#802)

This add a new option `--fqdn-policy` to the `deploy-webapp-from-registry`.

The default policy, `prohibit` means that `ApplicationDeploymentRequests` which specify a FQDN will be rejected.  The `allow` policy will cause them to be processed.  The `preexisting` policy will only process them if an existing `DnsRecord` exists in the registry with the correct ownership.

The latter would be useful in conjunction with a pre-checking scheme in the UI (eg, that the DNS entry is properly configured, the domain is under the control of the requestor, etc.)  Only after all the checks were successful would the `DnsRecord` be created, allowing for `ApplicationDeploymentRequests` to use it.

Reviewed-on: #802
Reviewed-by: David Boreham <dboreham@noreply.git.vdb.to>
Co-authored-by: Thomas E Lackey <telackey@bozemanpass.com>
Co-committed-by: Thomas E Lackey <telackey@bozemanpass.com>

stack_orchestrator/deploy/webapp/deploy_webapp_from_registry.py

@@ -39,11 +39,12 @@ def process_app_deployment_request(
     app_deployment_request,
     deployment_record_namespace,
     dns_record_namespace,
-    dns_suffix,
+    default_dns_suffix,
     deployment_parent_dir,
     kube_config,
     image_registry,
     force_rebuild,
+    fqdn_policy,
     logger
 ):
     logger.log("BEGIN - process_app_deployment_request")
@@ -56,14 +57,15 @@ def process_app_deployment_request(
     requested_name = hostname_for_deployment_request(app_deployment_request, laconic)
     logger.log(f"Determined requested name: {requested_name}")
 
-    # HACK
     if "." in requested_name:
-        raise Exception("Only unqualified hostnames allowed at this time.")
-
-    fqdn = f"{requested_name}.{dns_suffix}"
+        if "allow" == fqdn_policy or "preexisting" == fqdn_policy:
+            fqdn = requested_name
+        else:
+            raise Exception(f"{requested_name} is invalid: only unqualified hostnames are allowed.")
+    else:
+        fqdn = f"{requested_name}.{default_dns_suffix}"
 
     # 3. check ownership of existing dnsrecord vs this request
-    # TODO: Support foreign DNS
     dns_crn = f"{dns_record_namespace}/{fqdn}"
     dns_record = laconic.get_record(dns_crn)
     if dns_record:
@@ -75,7 +77,9 @@ def process_app_deployment_request(
             logger.log(f"Matched DnsRecord ownership: {matched_owner}")
         else:
             raise Exception("Unable to confirm ownership of DnsRecord %s for request %s" %
-                            (dns_record.id, app_deployment_request.id))
+                            (dns_crn, app_deployment_request.id))
+    elif "preexisting" == fqdn_policy:
+        raise Exception(f"No pre-existing DnsRecord {dns_crn} could be found for request {app_deployment_request.id}.")
 
     # 4. get build and runtime config from request
     env_filename = None
@@ -191,6 +195,7 @@ def dump_known_requests(filename, requests, status="SEEN"):
 @click.option("--state-file", help="File to store state about previously seen requests.")
 @click.option("--only-update-state", help="Only update the state file, don't process any requests anything.", is_flag=True)
 @click.option("--dns-suffix", help="DNS domain to use eg, laconic.servesthe.world")
+@click.option("--fqdn-policy", help="How to handle requests with an FQDN: prohibit, allow, preexisting", default="prohibit")
 @click.option("--record-namespace-dns", help="eg, crn://laconic/dns")
 @click.option("--record-namespace-deployments", help="eg, crn://laconic/deployments")
 @click.option("--dry-run", help="Don't do anything, just report what would be done.", is_flag=True)
@@ -201,7 +206,7 @@ def dump_known_requests(filename, requests, status="SEEN"):
 @click.pass_context
 def command(ctx, kube_config, laconic_config, image_registry, deployment_parent_dir,  # noqa: C901
             request_id, discover, state_file, only_update_state,
-            dns_suffix, record_namespace_dns, record_namespace_deployments, dry_run,
+            dns_suffix, fqdn_policy, record_namespace_dns, record_namespace_deployments, dry_run,
             include_tags, exclude_tags, force_rebuild, log_dir):
     if request_id and discover:
         print("Cannot specify both --request-id and --discover", file=sys.stderr)
@@ -220,6 +225,10 @@ def command(ctx, kube_config, laconic_config, image_registry, deployment_parent_
             print("--dns-suffix, --record-namespace-dns, and --record-namespace-deployments are all required", file=sys.stderr)
             sys.exit(2)
 
+    if fqdn_policy not in ["prohibit", "allow", "preexisting"]:
+        print("--fqdn-policy must be one of 'prohibit', 'allow', or 'preexisting'", file=sys.stderr)
+        sys.exit(2)
+
     # Split CSV and clean up values.
     include_tags = [tag.strip() for tag in include_tags.split(",") if tag]
     exclude_tags = [tag.strip() for tag in exclude_tags.split(",") if tag]
@@ -334,6 +343,7 @@ def command(ctx, kube_config, laconic_config, image_registry, deployment_parent_
                     kube_config,
                     image_registry,
                     force_rebuild,
+                    fqdn_policy,
                     logger
                 )
                 status = "DEPLOYED"