Managed Cassandra

Emulates the control plane of Azure Managed Instance for Apache Cassandra — the ARM API (under Cosmos DB) that provisions a Cassandra-compatible cluster and its data centers. CQL data operations are out of scope, so it has its own driver. A cluster carries a Cassandra version, delegated subnet, authentication method, and backup/repair config; data centers under it hold the actual nodes.

Reach for it when your provisioning or IaC code creates a cluster, adds data centers, deallocates and starts it, or runs a maintenance command — without a real (billed) cluster. Served as ARM REST/JSON under Microsoft.DocumentDB/cassandraClusters, so a real armcosmos CassandraClusters/CassandraDataCenters client with a custom endpoint works unchanged.

Drive it with the real SDK#

Run cloudemu as a server and point an armcosmos client factory at it. Start it with cloudemu serve (or docker run --rm -p 4568:4568 ghcr.io/stackshy/cloudemu), which serves the Azure API on https://localhost:4568 (self-signed TLS):

cloudemu serve   # Azure API on https://localhost:4568 (self-signed TLS)

Point the factory's Cloud.ResourceManager endpoint at https://localhost:4568. Mutating operations complete synchronously, so the SDK's LRO pollers terminate on the first response:

import (
    "github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/cosmos/armcosmos/v3"
)

// armcosmos.NewClientFactory(subID, cred, opts) with opts pointing Cloud.ResourceManager
// at https://localhost:4568 — see the SDK-Compat page for the ARM/TLS setup.
cc := factory.NewCassandraClustersClient()
poller, _ := cc.BeginCreateUpdate(ctx, "rg1", "cass", armcosmos.ClusterResource{
    Location: to.Ptr("eastus"),
    Properties: &armcosmos.ClusterResourceProperties{
        DelegatedManagementSubnetID: to.Ptr("/subnets/sn"),
        CassandraVersion:            to.Ptr("3.11"),
    },
}, nil)
created, _ := poller.PollUntilDone(ctx, nil)

See the SDK-Compat Server page for the Azure ARM/TLS setup.

In-process (Go unit tests)#

For Go unit tests written inside cloudemu-aware code, stand the same wire server up in-process with httptest.NewTLSServer and point the client at ts.URL. The Drivers you pass name exactly the drivers this service needs:

import (
    "github.com/stackshy/cloudemu/v2"
    azureserver "github.com/stackshy/cloudemu/v2/server/azure"
)

cp := cloudemu.NewAzure()
ts := httptest.NewTLSServer(azureserver.New(azureserver.Drivers{
    ManagedCassandra: cp.ManagedCassandra,
}))
defer ts.Close()
// point the same armcosmos factory at ts.URL instead of the running endpoint

Call the driver directly#

For in-process setup or assertions you can skip the HTTP hop and call the driver:

import mcdriver "github.com/stackshy/cloudemu/v2/services/managedcassandra/driver"

cluster, _ := azure.ManagedCassandra.CreateOrUpdateCluster(ctx, mcdriver.CreateClusterConfig{
    Name: "cass", ResourceGroup: "rg1", Location: "eastus",
    CassandraVersion:            "3.11",
    DelegatedManagementSubnetID: "/subnets/sn",
})

azure.ManagedCassandra.CreateOrUpdateDataCenter(ctx, mcdriver.CreateDataCenterConfig{
    ClusterName: "cass", ResourceGroup: "rg1", Name: "dc1",
    DataCenterLocation: "eastus", NodeCount: 3,
})

DeallocateCluster/StartCluster model the stop/start lifecycle; ClusterStatus reports per-node health; InvokeCommand runs a maintenance command (e.g. nodetool).

Behavior & fidelity#

SDK-compat — Live#

Real armcosmos CassandraClusters/CassandraDataCenters clients drive it end-to-end (Microsoft.DocumentDB/cassandraClusters) — see SDK-Compat for the full operation list.