docker: for dev, separate standalone ClickHouse setup from cluster

This way, there is no need to start a whole cluster just to work on a
single ClickHouse. Also add some hints in CONTRIBUTING.md.

CONTRIBUTING.md

@@ -40,9 +40,12 @@ with `make test-go PKG=akvorado/orchestrator/clickhouse`. Using just `go test`
 would work, but `make test-go` also runs linting and formatting automatically.
 
 If possible, tests should not rely on external components, but when it becomes
-hard to do so, it is possible to spawns services through Docker. Locally, one
+hard to do so, it is possible to spawn services through Docker. Locally, one
-can spawns them through `docker compose -f docker/docker-compose-dev.yml`.
+can spawn them through `docker compose -f docker/docker-compose-dev.yml`:
-GitHub actions are using services to spawn them.
+
+- `... up clickhouse` to spawn a single ClickHouse
+- `... up clickhouse-\*` to spawn a ClickHouse cluster
+- `... up kafka` to spawn a Kafka broker
 
 For manual end-to-end tests, you can use `make docker-dev` to build a Docker
 container of Akvorado, then use `docker compose up` to run Docker compose.

common/clickhousedb/tests.go

@@ -22,11 +22,14 @@ import (
 func SetupClickHouse(t *testing.T, r *reporter.Reporter, cluster bool) *Component {
 	t.Helper()
 	config := DefaultConfiguration()
-	config.Servers = []string{
+	if !cluster {
-		helpers.CheckExternalService(t, "ClickHouse", []string{"clickhouse:9000", "127.0.0.1:9000"}),
+		config.Servers = []string{
-	}
+			helpers.CheckExternalService(t, "ClickHouse", []string{"clickhouse:9000", "127.0.0.1:9000"}),
-	if cluster {
+		}
-		helpers.CheckExternalService(t, "ClickHouse cluster", []string{"clickhouse-2:9000", "127.0.0.1:9001"})
+	} else {
+		config.Servers = []string{
+			helpers.CheckExternalService(t, "ClickHouse cluster", []string{"clickhouse-2:9000", "127.0.0.1:9002"}),
+		}
 		config.Cluster = "akvorado"
 	}
 	config.DialTimeout = 100 * time.Millisecond

docker/clickhouse/cluster.xml

@@ -7,7 +7,7 @@
       <shard>
         <internal_replication>true</internal_replication>
         <replica>
-          <host>clickhouse</host>
+          <host>clickhouse-1</host>
           <port>9000</port>
         </replica>
         <replica>

docker/clickhouse/standalone.xml

@@ -0,0 +1,4 @@
+<clickhouse>
+  <!-- For testing, ensure tables are dropped quickly -->
+  <database_atomic_delay_before_drop_table_sec>0</database_atomic_delay_before_drop_table_sec>
+</clickhouse>

docker/docker-compose-dev.yml

@@ -121,41 +121,47 @@ services:
     extends:
       file: versions.yml
       service: clickhouse
-    depends_on:
-      - clickhouse-keeper-1
     environment:
       - CLICKHOUSE_SKIP_USER_SETUP=1
       - CLICKHOUSE_ALWAYS_RUN_INITDB_SCRIPTS=1
     cap_add:
       - SYS_NICE
     volumes:
-      - ./clickhouse/cluster.xml:/etc/clickhouse-server/config.d/cluster.xml
+      - ./clickhouse/standalone.xml:/etc/clickhouse-server/config.d/standalone.xml
-      - ./clickhouse/cluster-1.xml:/etc/clickhouse-server/config.d/cluster-1.xml
       - ./clickhouse/test-db.sql:/docker-entrypoint-initdb.d/test-db.sql
     ports:
       - 127.0.0.1:8123:8123/tcp
       - 127.0.0.1:9000:9000/tcp
-  clickhouse-2:
+  clickhouse-1: &clickhouse-cluster
     <<: *clickhouse
+    depends_on:
+      - clickhouse-keeper-1
+    volumes:
+      - ./clickhouse/cluster.xml:/etc/clickhouse-server/config.d/cluster.xml
+      - ./clickhouse/cluster-1.xml:/etc/clickhouse-server/config.d/cluster-1.xml
+    ports:
+      - 127.0.0.1:9001:9000/tcp
+  clickhouse-2:
+    <<: *clickhouse-cluster
     volumes:
       - ./clickhouse/cluster.xml:/etc/clickhouse-server/config.d/cluster.xml
       - ./clickhouse/cluster-2.xml:/etc/clickhouse-server/config.d/cluster-2.xml
     ports:
-      - 127.0.0.1:9001:9000/tcp
+      - 127.0.0.1:9002:9000/tcp
   clickhouse-3:
-    <<: *clickhouse
+    <<: *clickhouse-cluster
     volumes:
       - ./clickhouse/cluster.xml:/etc/clickhouse-server/config.d/cluster.xml
       - ./clickhouse/cluster-3.xml:/etc/clickhouse-server/config.d/cluster-3.xml
     ports:
-      - 127.0.0.1:9002:9000/tcp
+      - 127.0.0.1:9003:9000/tcp
   clickhouse-4:
-    <<: *clickhouse
+    <<: *clickhouse-cluster
     volumes:
       - ./clickhouse/cluster.xml:/etc/clickhouse-server/config.d/cluster.xml
       - ./clickhouse/cluster-4.xml:/etc/clickhouse-server/config.d/cluster-4.xml
     ports:
-      - 127.0.0.1:9003:9000/tcp
+      - 127.0.0.1:9004:9000/tcp
   clickhouse-keeper-1:
     extends:
       file: versions.yml