Refactor database naming strategy

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Added
+
+- `PostgresDatabase` Resource - Add database naming strategy [#38](https://github.com/mruoss/kompost/pull/38), [#42](https://github.com/mruoss/kompost/pull/42)
+
 ## [0.3.0] - 2023-07-13
 
 ### Changed

docs/postgres/postgres_database.md

@@ -10,22 +10,6 @@ Once your [`PostgresInstance`](postgres_instance.md) or
 [`PostgresClusterInstance`](postgres_cluster_instance.md) is set up and
 connected, you can declare your database resources.
 
-```yaml
-apiVersion: kompost.chuge.li/v1alpha1
-kind: PostgresDatabase
-metadata:
-  name: some-database
-  namespace: default
-spec:
-  instanceRef:
-    name: staging-server  
-```
-
-Based on the CRD definition above, it will create a database called `default_some_database`, 
-where the appended prefix `default_` is the previously informed namespaced.
-To avoid the use of the namespace you can set the `usingPrefixNamingStrategy` 
-attribute to false. See example bellow:
-
 ```yaml
 apiVersion: kompost.chuge.li/v1alpha1
 kind: PostgresDatabase
@@ -35,11 +19,8 @@ metadata:
 spec:
   instanceRef:
     name: staging-server
-  usingPrefixNamingStrategy: false
 ```
 
-In this case the final name of the database will be `some_database`.
-
 ## Connection Details
 
 Once applied to the cluster, Kompost creates a database and **two users**. One
@@ -85,6 +66,44 @@ data:
   DB_USER: ZGVmYXVsdF9zb21lX2RhdGFiYXNlX2FwcA==
 ```
 
+## Database Naming Strategy
+
+The field `databaseNamingStrategy` controls how the database name is derived
+from the resource name. Possible values are `resource_name` and
+`prefix_namespace`. The default strategy is `prefix_namespace`.
+
+### Strategies
+
+- `resource_name`: Use the resource name as database name
+- `prefix_namespace`: Prefix the resource name with the namespace to get a
+  cluster-wide unique name.
+
+### Example
+
+Taking the [basic usage example](#basic-usage) from above, the resulting
+database on the server is named `default_some_database`.
+
+```yaml
+apiVersion: kompost.chuge.li/v1alpha1
+kind: PostgresDatabase
+metadata:
+  name: some-database
+  namespace: default
+spec:
+  instanceRef:
+    name: staging-server
+  databaseNamingStrategy: resource_name
+```
+
+The resulting database on the server is named `some_database`.
+
+!!! warning Strategy resource_name can lead to conflicts
+
+    Using the `resource_name` strategy can lead to conflicts. If you define
+    `PostgresDatabase` resources with the same name in different namespaces,
+    both resources would control the same database on the server. Therefore the
+    default strategy is `prefix_namespace`
+
 ## Deletion Policy - Abandoning Underlying Resources
 
 When using Kompost on a live environment, you might want to protect the
@@ -103,7 +122,7 @@ metadata:
     kompost.chuge.li/deletion-policy: abandon # <-- underlying resources are abandoned (not deleted) when this resource gets deleted
 spec:
   instanceRef:
-    name: staging-server  
+    name: staging-server
 ```
 
 ## Database Creation Parameters
@@ -113,7 +132,7 @@ parameters](https://www.postgresql.org/docs/current/sql-createdatabase.html)
 when creating a database. Some of these parameters are supported by Kompost and
 can be passed in `spec.params`.
 
-!!! note Creation params cannot be changed 
+!!! note Creation params cannot be changed
 
     These parameters are only used when the database is created. Kompost therefore denies requests to change them on an existing resource.
 

lib/kompost/kompo/postgres/controller/database_controller.ex

@@ -37,10 +37,11 @@ defmodule Kompost.Kompo.Postgres.Controller.DatabaseController do
     resource = axn.resource
     namespace = resource["metadata"]["namespace"]
 
-    using_prefix_strategy? =
-      resource["spec"]["usingPrefixNamingStrategy"] != "true"
+    db_name =
+      Database.name(resource,
+        strategy: resource["spec"]["databaseNamingStrategy"] || "prefix_namespace"
+      )
 
-    db_name = Database.name(resource, prefix_namespace: using_prefix_strategy?)
     db_params = Params.new!(resource["spec"]["params"] || %{})
     instance = resource |> instance_id() |> Instance.lookup()
 
@@ -136,8 +137,12 @@ defmodule Kompost.Kompo.Postgres.Controller.DatabaseController do
   @spec delete_resources(Bonny.Axn.t()) :: {:ok, Bonny.Axn.t()} | {:error, Bonny.Axn.t()}
   def delete_resources(axn) do
     resource = axn.resource
-    using_prefix_strategy? = resource["spec"]["usingPrefixNamingStrategy"] != "true"
-    db_name = Database.name(resource, prefix_namespace: using_prefix_strategy?)
+
+    db_name =
+      Database.name(resource,
+        strategy: resource["spec"]["databaseNamingStrategy"] || "prefix_namespace"
+      )
+
     users = resource["status"]["users"]
     instance = resource |> instance_id() |> Instance.lookup()
 

lib/kompost/kompo/postgres/database.ex

@@ -15,25 +15,23 @@ defmodule Kompost.Kompo.Postgres.Database do
       "default_foo_bar"
 
       iex> resource = %{"metadata" => %{"namespace" => "default", "name" => "foo-bar"}}
-      ...> Kompost.Kompo.Postgres.Database.name(resource, prefix_namespace:  false)
+      ...> Kompost.Kompo.Postgres.Database.name(resource, strategy: "resource_name")
       "foo_bar"
   """
   @spec name(map(), Keyword.t()) :: binary()
   def name(resource, opts \\ [])
 
   def name(resource, opts) do
-    prefix_namespace = Keyword.get(opts, :prefix_namespace, true)
-
-    case prefix_namespace do
-      true ->
+    case Keyword.get(opts, :strategy, "prefix_namespace") do
+      "resource_name" ->
         Slugger.slugify_downcase(
-          "#{resource["metadata"]["namespace"]}_#{resource["metadata"]["name"]}",
+          "#{resource["metadata"]["name"]}",
           ?_
         )
 
-      _ ->
+      "prefix_namespace" ->
         Slugger.slugify_downcase(
-          "#{resource["metadata"]["name"]}",
+          "#{resource["metadata"]["namespace"]}_#{resource["metadata"]["name"]}",
           ?_
         )
     end

lib/kompost/kompo/postgres/v1alpha1/postgres_database.ex

@@ -24,8 +24,6 @@ defmodule Kompost.Kompo.Postgres.V1Alpha1.PostgresDatabase do
               - required: ["instanceRef"]
               - required: ["clusterInstanceRef"]
             properties:
-              usingPrefixNamingStrategy:
-                type: boolean
               instanceRef:
                 type: object
                 properties:
@@ -36,6 +34,10 @@ defmodule Kompost.Kompo.Postgres.V1Alpha1.PostgresDatabase do
                 properties:
                   name:
                     type: string
+              databaseNamingStrategy:
+                type: string
+                enum: ["resource_name", "prefix_namespace"]
+                description: "(Optional) Strategy to derive the name of the `database` on the server. resource_name uses the resource name as DB name. `prefix_namespace` prefixes the resource name with the namespace. Defaults to `prefix_namespace`"
               params:
                 description: "Parameters passed to CREATE TEMPLATE."
                 type: object

priv/manifest/postgresdatabase.crd.yaml

@@ -40,6 +40,10 @@ spec:
                     name:
                       type: string
                   type: object
+                databaseNamingStrategy:
+                  type: string
+                  enum: ["resource_name", "prefix_namespace"]
+                  description: "(Optional) Strategy to derive the name of the `database` on the server. resource_name uses the resource name as DB name. `prefix_namespace` prefixes the resource name with the namespace. Defaults to `prefix_namespace`"
                 params:
                   description: Parameters passed to CREATE TEMPLATE.
                   properties:
@@ -84,8 +88,8 @@ spec:
                         type: string
                       status:
                         enum:
-                          - 'True'
-                          - 'False'
+                          - "True"
+                          - "False"
                         type: string
                       type:
                         type: string