OpenAPI: Fix API calls pointing to subpath

Closes #1137
Currently, the test suite is pointing to a subpath BUT Grafana redirects from the root to the subpath
The provider is badly configured but the tests still pass because of the redirect

To fix the test suite, I add a nginx proxy in this PR, so that calling the host directly fails and you have to go through the subpath

GNUmakefile

@@ -41,10 +41,10 @@ testacc-enterprise-docker:
 
 testacc-tls-docker:
 	make -C testdata generate
-	GRAFANA_VERSION=$(GRAFANA_VERSION) docker compose --profile tls up --force-recreate --detach --remove-orphans --wait
+	TEST_PORT=3001 GRAFANA_VERSION=$(GRAFANA_VERSION) docker compose --profile tls up --force-recreate --detach --remove-orphans --wait
 
 	GRAFANA_VERSION=$(GRAFANA_VERSION) \
-	GRAFANA_URL="http://0.0.0.0:3000" \
+	GRAFANA_URL="https://0.0.0.0:3001" \
 	GRAFANA_AUTH="admin:admin" \
 	GRAFANA_TLS_KEY=$$(pwd)/testdata/client.key \
     GRAFANA_TLS_CERT=$$(pwd)/testdata/client.crt \
@@ -54,14 +54,14 @@ testacc-tls-docker:
 	docker compose --profile tls down
 
 testacc-subpath-docker:
-	GRAFANA_VERSION=$(GRAFANA_VERSION) GRAFANA_SUBPATH=/grafana/ GF_SERVER_SERVE_FROM_SUB_PATH=true docker compose up --force-recreate --detach --remove-orphans --wait
+	TEST_PORT=3001 GRAFANA_VERSION=$(GRAFANA_VERSION) GRAFANA_SUBPATH=/grafana/ GF_SERVER_SERVE_FROM_SUB_PATH=true docker compose --profile proxy up --force-recreate --detach --remove-orphans --wait
 
 	GRAFANA_VERSION=$(GRAFANA_VERSION) \
-	GRAFANA_URL="http://0.0.0.0:3000/grafana" \
+	GRAFANA_URL="http://0.0.0.0:3001/grafana" \
 	GRAFANA_AUTH="admin:admin" \
 	make testacc-oss
 
-	docker compose down
+	docker compose --profile proxy down
 
 release:
 	@test $${RELEASE_VERSION?Please set environment variable RELEASE_VERSION}

docker-compose.yml

@@ -5,7 +5,7 @@ services:
       - 3000:3000
     image: ${GRAFANA_IMAGE:-grafana/grafana}:${GRAFANA_VERSION}
     environment:
-      - GF_SERVER_ROOT_URL=http://0.0.0.0:3000${GRAFANA_SUBPATH:-}
+      - GF_SERVER_ROOT_URL=http://0.0.0.0:${TEST_PORT:-3000}${GRAFANA_SUBPATH:-}
       - GF_ENTERPRISE_LICENSE_TEXT=${GF_ENTERPRISE_LICENSE_TEXT:-}
       - GF_SERVER_SERVE_FROM_SUB_PATH=${GF_SERVER_SERVE_FROM_SUB_PATH:-}
     healthcheck:
@@ -32,3 +32,13 @@ services:
       - ./testdata:/certs
     ports:
       - 3001:3001
+  nginx:
+    profiles:
+      - "proxy"
+    depends_on:
+      - grafana
+    image: nginx:latest
+    ports:
+      - 3001:3001
+    volumes:
+      - ./testdata/nginx.conf:/etc/nginx/nginx.conf

internal/provider/provider.go

@@ -430,6 +430,10 @@ func createGrafanaOAPIClient(apiURL string, d *schema.ResourceData) (*goapi.Graf
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse API url: %v", err.Error())
 	}
+	apiPath, err := url.JoinPath(u.Path, "api")
+	if err != nil {
+		return nil, fmt.Errorf("failed to join API path: %v", err.Error())
+	}
 
 	userInfo, orgID, APIKey, err := parseAuth(d)
 	if err != nil {
@@ -438,7 +442,7 @@ func createGrafanaOAPIClient(apiURL string, d *schema.ResourceData) (*goapi.Graf
 
 	cfg := goapi.TransportConfig{
 		Host:         u.Host,
-		BasePath:     "/api",
+		BasePath:     apiPath,
 		Schemes:      []string{u.Scheme},
 		NumRetries:   d.Get("retries").(int),
 		RetryTimeout: time.Second * time.Duration(d.Get("retry_wait").(int)),

testdata/nginx.conf

@@ -0,0 +1,34 @@
+events{}
+
+http {
+    # this is required to proxy Grafana Live WebSocket connections.
+    map $http_upgrade $connection_upgrade {
+        default upgrade;
+        '' close;
+    }
+
+    upstream grafana {
+        server grafana:3000;
+    }
+
+    server {
+        listen 3001;
+        root /usr/share/nginx/html;
+        index index.html index.htm;
+        server_name  0.0.0.0;
+
+        location /grafana/ {
+            proxy_set_header Host $host;
+            proxy_pass http://grafana;
+        }
+
+        # Proxy Grafana Live WebSocket connections.
+        location /api/live/ {
+            proxy_http_version 1.1;
+            proxy_set_header Upgrade $http_upgrade;
+            proxy_set_header Connection $connection_upgrade;
+            proxy_set_header Host $host;
+            proxy_pass http://grafana;
+        }
+    }
+}