feat(api): Add key/value store with namespace emulation

For storing pipeline settings and variable and make them
a bit more stateful we need reliable key/value store.

Signed-off-by: Denys Fedoryshchenko <[email protected]>

api/db.py

@@ -10,7 +10,8 @@
 from beanie import init_beanie
 from fastapi_pagination.ext.motor import paginate
 from motor import motor_asyncio
-from kernelci.api.models import Hierarchy, Node, parse_node_obj, EventHistory
+from redis import asyncio as aioredis
+from kernelci.api.models import EventHistory, Hierarchy, Node, parse_node_obj
 from .models import User, UserGroup
 
 
@@ -45,6 +46,8 @@ class Database:
 
     def __init__(self, service='mongodb://db:27017', db_name='kernelci'):
         self._motor = motor_asyncio.AsyncIOMotorClient(service)
+        # TBD: Make redis host configurable
+        self._redis = aioredis.from_url('redis://redis:6379')
         self._db = self._motor[db_name]
 
     async def initialize_beanie(self):
@@ -60,6 +63,38 @@ def _get_collection(self, model):
         col = self.COLLECTIONS[model]
         return self._db[col]
 
+    async def get_kv(self, namespace, key):
+        """
+        Get value from redis key-value store
+        Create a keyname by concatenating namespace and key
+        """
+        keyname = f"{namespace}:{key}"
+        return await self._redis.get(keyname)
+
+    async def set_kv(self, namespace, key, value):
+        """
+        Set value in redis key-value store
+        Create a keyname by concatenating namespace and key
+        """
+        keyname = f"{namespace}:{key}"
+        return await self._redis.set(keyname, value)
+
+    async def del_kv(self, namespace, key):
+        """
+        Delete key from redis key-value store
+        Create a keyname by concatenating namespace and key
+        """
+        keyname = f"{namespace}:{key}"
+        return await self._redis.delete(keyname)
+
+    async def exists_kv(self, namespace, key):
+        """
+        Check if key exists in redis key-value store
+        Create a keyname by concatenating namespace and key
+        """
+        keyname = f"{namespace}:{key}"
+        return await self._redis.exists(keyname)
+
     async def create_indexes(self):
         """Create indexes for models"""
         for model in self.COLLECTIONS:

api/main.py

@@ -21,7 +21,8 @@
     Request,
     Form,
     Header,
-    Query
+    Query,
+    Body,
 )
 from fastapi.responses import JSONResponse, PlainTextResponse, FileResponse
 from fastapi.security import OAuth2PasswordRequestForm
@@ -780,6 +781,47 @@ async def put_nodes(
     return obj_list
 
 
+# -----------------------------------------------------------------------------
+# Key/Value namespace enabled store
+@app.get('/kv/{namespace}/{key}', response_model=Union[str, None])
+async def get_kv(namespace: str, key: str,
+                 user: User = Depends(get_current_user)):
+
+    """Get a key value pair from the store"""
+    metrics.add('http_requests_total', 1)
+    return await db.get_kv(namespace, key)
+
+
+@app.post('/kv/{namespace}/{key}', response_model=Optional[str])
+async def post_kv(namespace: str, key: str,
+                  value: Optional[str] = Body(default=None),
+                  user: User = Depends(get_current_user)):
+    """Set a key-value pair in the store
+    namespace and key are part of the URL
+    value is part of the request body.
+    If value is not provided, we need to call delete_kv to remove the key.
+    """
+    metrics.add('http_requests_total', 1)
+    if not value:
+        await db.del_kv(namespace, key)
+        return "OK"
+    ret = await db.set_kv(namespace, key, value)
+    if ret:
+        return "OK"
+    raise HTTPException(status_code=500, detail="Failed to set key-value pair")
+
+
+# Delete a key-value pair from the store
+@app.delete('/kv/{namespace}/{key}', response_model=Optional[str])
+async def delete_kv(namespace: str, key: str,
+                    user: User = Depends(get_current_user)):
+    """Delete a key-value pair from the store"""
+    metrics.add('http_requests_total', 1)
+    await db.del_kv(namespace, key)
+    response = "Key-value pair deleted successfully"
+    return response
+
+
 # -----------------------------------------------------------------------------
 # Pub/Sub