Add external provider

Before this change we had only one provider, so this was internal
implementation detail. This change adds the second provider, allowing
users to configure the provider in the environment file.

Replace the `external: true` option with `provider: external`. With this
we can remove the special handling or external cluster with calls to the
external provider which does the right thing.

The external provider basically does nothing, since we do not manage
this cluster. However in start() we ensure that the cluster exists and
then wait until the cluster is ready. This helps to debug issues with
external cluster and reduces log noise.

Signed-off-by: Nir Soffer <[email protected]>

test/README.md

@@ -539,9 +539,11 @@ $ drenv delete envs/example.yaml
 
 - `templates`: templates for creating new profiles.
     - `name`: profile name.
-    - `external`: true if this is existing external cluster. In this
-      case the tool will not start a minikube cluster and all other
-      options are ignored.
+    - `provider`: cluster provider. The default provider is "minikube",
+      creating cluster using VM or containers.  Use "external" to use
+      exsiting clusters not managed by `drenv`. Use the special value
+      "$provider" to select the best provider for the host. (default
+      "$provider")
     - `driver`: The minikube driver. On Linux, the default drivers are kvm2 and
       docker for VMs and containers. On MacOS, the defaults are hyperkit and
       podman. Use "$vm" and "$container" values to use the recommended VM and

test/drenv/__main__.py

@@ -359,14 +359,13 @@ def collect_addons(env):
 
 def start_cluster(profile, hooks=(), args=None, **options):
     provider = providers.get(profile["provider"])
-    if profile["external"]:
-        logging.debug("[%s] Skipping external cluster", profile["name"])
-    else:
-        existing = provider.exists(profile)
-        provider.start(profile, verbose=args.verbose)
-        provider.configure(profile, existing=existing)
-        if existing:
-            restart_failed_deployments(profile)
+    existing = provider.exists(profile)
+
+    provider.start(profile, verbose=args.verbose)
+    provider.configure(profile, existing=existing)
+
+    if existing:
+        restart_failed_deployments(profile)
 
     if hooks:
         execute(
@@ -391,19 +390,14 @@ def stop_cluster(profile, hooks=(), **options):
             allow_failure=True,
         )
 
-    provider = providers.get(profile["provider"])
-    if profile["external"]:
-        logging.debug("[%s] Skipping external cluster", profile["name"])
-    elif cluster_status != cluster.UNKNOWN:
+    if cluster_status != cluster.UNKNOWN:
+        provider = providers.get(profile["provider"])
         provider.stop(profile)
 
 
 def delete_cluster(profile, **options):
     provider = providers.get(profile["provider"])
-    if profile["external"]:
-        logging.debug("[%s] Skipping external cluster", profile["name"])
-    else:
-        provider.delete(profile)
+    provider.delete(profile)
 
     profile_config = drenv.config_dir(profile["name"])
     if os.path.exists(profile_config):

test/drenv/providers/external.py

@@ -0,0 +1,71 @@
+# SPDX-FileCopyrightText: The RamenDR authors
+# SPDX-License-Identifier: Apache-2.0
+
+import logging
+import time
+
+from drenv import cluster
+
+# Provider scope
+
+
+def setup():
+    logging.info("[external] Skipping setup for external provider")
+
+
+def cleanup():
+    logging.info("[external] Skipping cleanup for external provider")
+
+
+# Cluster scope
+
+
+def exists(profile):
+    return True
+
+
+def start(profile, verbose=False):
+    start = time.monotonic()
+    logging.info("[%s] Checking external cluster status", profile["name"])
+
+    # Fail fast if cluster is not configured, we cannot recover from this.
+    status = cluster.status(profile["name"])
+    if status == cluster.UNKNOWN:
+        raise RuntimeError(f"Cluster '{profile['name']}' does not exist")
+
+    # Otherwise handle temporary outage gracefuly.
+    cluster.wait_until_ready(profile["name"], timeout=60, log=logging.debug)
+
+    logging.info(
+        "[%s] Cluster ready in %.2f seconds",
+        profile["name"],
+        time.monotonic() - start,
+    )
+
+
+def configure(profile, existing=False):
+    logging.info("[%s] Skipping configure for external cluster", profile["name"])
+
+
+def stop(profile):
+    logging.info("[%s] Skipping stop for external cluster", profile["name"])
+
+
+def delete(profile):
+    logging.info("[%s] Skipping delete for external cluster", profile["name"])
+
+
+def suspend(profile):
+    logging.info("[%s] Skipping suspend for external cluster", profile["name"])
+
+
+def resume(profile):
+    logging.info("[%s] Skipping resume for external cluster", profile["name"])
+
+
+def cp(name, src, dst):
+    logging.warning("[%s] cp not implemented yet for external cluster", name)
+
+
+def ssh(name, command):
+    logging.warning("[%s] ssh not implemented yet for external cluster", name)

test/envs/external.yaml

@@ -1,12 +1,12 @@
 # SPDX-FileCopyrightText: The RamenDR authors
 # SPDX-License-Identifier: Apache-2.0
 
-# Example environment using external clusters. The cluster `test` must exist
-# when this environment is started.
+# Example environment using external clusters. The cluster must exist when this
+# environment is started.
 #
 # To try this example, create the cluster with:
 #
-#     drenv start envs/test.yaml
+#     drenv start envs/vm.yaml
 #
 # Now you can start this environment with:
 #
@@ -20,7 +20,7 @@
 name: external
 profiles:
   - name: cluster
-    external: true
+    provider: external
     workers:
       - addons:
           - name: example