metrics: include the name of the server

all MCP servers will have the same metrics, so let's add a label for the name of the server (here: `argocd-mcp-server`) to help with our PromQL queries

Signed-off-by: Xavier Coulon <xcoulon@redhat.com>

Author: xcoulon

internal/metrics/metrics.go

@@ -13,7 +13,7 @@ var (
 			Name: "mcp_calls_total",
 			Help: "Total number of MCP calls",
 		},
-		[]string{"method", "name", "success"},
+		[]string{"server", "method", "name", "success"},
 	)
 
 	// MCPCallDuration measures the duration of MCP calls by method, name (for `tools/call`) and success
@@ -23,6 +23,6 @@ var (
 			Help:    "Duration of MCP calls in seconds",
 			Buckets: prometheus.DefBuckets,
 		},
-		[]string{"method", "name", "success"},
+		[]string{"server", "method", "name", "success"},
 	)
 )

internal/server/middleware.go

@@ -10,6 +10,8 @@ import (
 	"github.com/modelcontextprotocol/go-sdk/mcp"
 )
 
+const serverName = "argocd-mcp-server"
+
 func NewMetricsMiddleware(logger *slog.Logger) mcp.Middleware {
 	return func(next mcp.MethodHandler) mcp.MethodHandler {
 		return func(ctx context.Context, method string, req mcp.Request) (mcp.Result, error) {
@@ -30,8 +32,8 @@ func NewMetricsMiddleware(logger *slog.Logger) mcp.Middleware {
 				success = success && !r.IsError
 			}
 			// increment/update the metrics
-			metrics.MCPCallsTotal.WithLabelValues(method, tool, strconv.FormatBool(success)).Inc()
-			metrics.MCPCallDuration.WithLabelValues(method, tool, strconv.FormatBool(success)).Observe(float64(duration.Seconds()))
+			metrics.MCPCallsTotal.WithLabelValues(serverName, method, tool, strconv.FormatBool(success)).Inc()
+			metrics.MCPCallDuration.WithLabelValues(serverName, method, tool, strconv.FormatBool(success)).Observe(float64(duration.Seconds()))
 			return result, err
 		}
 	}

taskfile.yaml

@@ -24,7 +24,8 @@ tasks:
 
   podman-compose-up:
     cmds:
-      - podman-compose up -d
+      # --build is used to build the images if they are not already built
+      - podman-compose up -d --build 
 
   podman-compose-down:
     cmds:

test/e2e/server_test.go

@@ -63,6 +63,7 @@ func TestStatefulServer(t *testing.T) {
 				var mcpCallsDurationSecondsInfBucketBefore int64
 				if td.name == "http" {
 					mcpCallsTotalMetricBefore, mcpCallsDurationSecondsInfBucketBefore = getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplications",
 						"success": "true",
@@ -99,6 +100,7 @@ func TestStatefulServer(t *testing.T) {
 				if td.name == "http" {
 					// get the metrics after the call
 					mcpCallsTotalMetricAfter, mcpCallsDurationSecondsInfBucketAfter := getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplications",
 						"success": "true",
@@ -114,6 +116,7 @@ func TestStatefulServer(t *testing.T) {
 				var mcpCallsDurationSecondsInfBucketBefore int64
 				if td.name == "http" {
 					mcpCallsTotalMetricBefore, mcpCallsDurationSecondsInfBucketBefore = getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplicationResources",
 						"success": "true",
@@ -181,6 +184,7 @@ func TestStatefulServer(t *testing.T) {
 				if td.name == "http" {
 					// get the metrics after the call
 					mcpCallsTotalMetricAfter, mcpCallsDurationSecondsInfBucketAfter := getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplicationResources",
 						"success": "true",
@@ -195,6 +199,7 @@ func TestStatefulServer(t *testing.T) {
 				var mcpCallsDurationSecondsInfBucketBefore int64
 				if td.name == "http" {
 					mcpCallsTotalMetricBefore, mcpCallsDurationSecondsInfBucketBefore = getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplicationResources",
 						"success": "false",
@@ -215,6 +220,7 @@ func TestStatefulServer(t *testing.T) {
 				if td.name == "http" {
 					// get the metrics after the call
 					mcpCallsTotalMetricAfter, mcpCallsDurationSecondsInfBucketAfter := getMetrics(t, "http://localhost:50081", map[string]string{
+						"server":  "argocd-mcp-server",
 						"method":  "tools/call",
 						"name":    "unhealthyApplicationResources",
 						"success": "false",