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feat: Override default HARVEST_TSDB_URL on a per-request basis for Harvest MCP #4042

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Merged
cgrinds merged 2 commits into from
Nov 26, 2025
Merged

feat: Override default HARVEST_TSDB_URL on a per-request basis for Harvest MCP #4042

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c630b3f
feat: Override default HARVEST_TSDB_URL on a per-request basis for Ha…
rahulguptajss Nov 26, 2025
12cbdae
feat: Override default HARVEST_TSDB_URL on a per-request basis for Ha…
rahulguptajss Nov 26, 2025
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118 changes: 75 additions & 43 deletions mcp/cmd/server/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,8 @@ import (
"mcp-server/cmd/descriptions"
"mcp-server/cmd/loader"
"mcp-server/cmd/version"
"mcp-server/pkg/auth"
"mcp-server/pkg/helper"
"mcp-server/pkg/mcptypes"
"mcp-server/pkg/rules"
"net/http"
Expand All @@ -21,12 +23,8 @@ import (
"strings"
"time"

"mcp-server/pkg/auth"
"mcp-server/pkg/helper"

"github.com/netapp/harvest/v2/pkg/slogx"

"github.com/modelcontextprotocol/go-sdk/mcp"
"github.com/netapp/harvest/v2/pkg/slogx"
"github.com/spf13/cobra"
)

Expand Down Expand Up @@ -167,12 +165,12 @@ func handleValidationError(message string) *mcp.CallToolResult {
}
}

func makePrometheusAPICall(endpoint string) ([]byte, error) {
fullURL := tsdbConfig.URL + endpoint
func makePrometheusAPICall(config auth.TSDBConfig, endpoint string) ([]byte, error) {
fullURL := config.URL + endpoint

logger.Debug("Making Prometheus API call", slog.String("url", fullURL))

resp, err := auth.MakeRequest(tsdbConfig, fullURL)
resp, err := auth.MakeRequest(config, fullURL)
if err != nil {
return nil, fmt.Errorf("request failed: %w", err)
}
Expand All @@ -198,16 +196,46 @@ func formatDataResponse(data any) (*mcp.CallToolResult, any, error) {
return &mcp.CallToolResult{Content: content}, nil, nil
}

// resolveTSDBConfig returns the appropriate TSDBConfig to use for a request
// If override parameters are provided, creates a new config otherwise uses default
func resolveTSDBConfig(override *mcptypes.TSDBOverride) auth.TSDBConfig {
if override == nil || override.URL == "" {
return tsdbConfig
}

logger.Debug("using per-request TSDB URL override",
slog.String("url", override.URL),
slog.Bool("custom_auth", override.Username != ""))

config := auth.TSDBConfig{
URL: override.URL,
Timeout: tsdbConfig.Timeout,
RulesPath: tsdbConfig.RulesPath,
Auth: auth.Config{
Type: auth.None,
InsecureSkipTLS: tsdbConfig.Auth.InsecureSkipTLS,
},
}

if override.Username != "" && override.Password != "" {
config.Auth.Type = auth.Basic
config.Auth.Username = override.Username
config.Auth.Password = override.Password
}

return config
}

func addTool[T any](server *mcp.Server, name, description string, handler func(context.Context, *mcp.CallToolRequest, T) (*mcp.CallToolResult, any, error)) {
mcp.AddTool(server, &mcp.Tool{
Name: name,
Description: description,
}, handler)
}

func executeTSDBQuery(queryURL string, params url.Values) (*mcptypes.MetricsResponse, error) {
func executeTSDBQuery(config auth.TSDBConfig, queryURL string, params url.Values) (*mcptypes.MetricsResponse, error) {
fullURL := fmt.Sprintf("%s?%s", queryURL, params.Encode())
resp, err := auth.MakeRequest(tsdbConfig, fullURL)
resp, err := auth.MakeRequest(config, fullURL)
if err != nil {
return nil, fmt.Errorf("request failed: %w", err)
}
Expand Down Expand Up @@ -245,20 +273,22 @@ func formatJSONResponse(data any) ([]mcp.Content, error) {
}

// MetricsQuery executes a time series database instant query
func MetricsQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.QueryArgs) (*mcp.CallToolResult, any, error) {
func MetricsQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.QueryRequest) (*mcp.CallToolResult, any, error) {
if err := helper.ValidateQueryArgs(args.Query); err != nil {
return handleValidationError(err.Error()), nil, err
}

queryURL := tsdbConfig.URL + "/api/v1/query"
config := resolveTSDBConfig(args.TSDBOverride)

queryURL := config.URL + "/api/v1/query"
urlValues := url.Values{}
urlValues.Set("query", args.Query)

logger.Debug("Executing Prometheus instant query",
slog.String("query", args.Query),
slog.String("url", queryURL))

promResp, err := executeTSDBQuery(queryURL, urlValues)
promResp, err := executeTSDBQuery(config, queryURL, urlValues)
if err != nil {
logger.Error("Prometheus query failed", slogx.Err(err), slog.String("query", helper.TruncateString(args.Query, 100)))
return handlePrometheusError(err, "Prometheus query"), nil, nil
Expand All @@ -268,12 +298,14 @@ func MetricsQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.Query
}

// MetricsRangeQuery executes a time series database range query
func MetricsRangeQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.RangeQueryArgs) (*mcp.CallToolResult, any, error) {
func MetricsRangeQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.RangeQueryRequest) (*mcp.CallToolResult, any, error) {
if err := helper.ValidateRangeQueryArgs(args.Query, args.Start, args.End, args.Step); err != nil {
return handleValidationError(err.Error()), nil, err
}

queryURL := tsdbConfig.URL + "/api/v1/query_range"
config := resolveTSDBConfig(args.TSDBOverride)

queryURL := config.URL + "/api/v1/query_range"
urlValues := url.Values{}
urlValues.Set("query", args.Query)
urlValues.Set("start", args.Start)
Expand All @@ -287,7 +319,7 @@ func MetricsRangeQuery(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.
slog.String("step", args.Step),
slog.String("url", queryURL))

promResp, err := executeTSDBQuery(queryURL, urlValues)
promResp, err := executeTSDBQuery(config, queryURL, urlValues)
if err != nil {
logger.Error("Prometheus range query failed", slogx.Err(err), slog.String("query", helper.TruncateString(args.Query, 100)))
return handlePrometheusError(err, "Prometheus range query"), nil, nil
Expand Down Expand Up @@ -325,24 +357,24 @@ func filterStrings(items []string, pattern string) []string {
}

// makePrometheusAPICallWithMatches performs API call with optional label matchers
func makePrometheusAPICallWithMatches(endpoint string, matches []string) ([]byte, error) {
func makePrometheusAPICallWithMatches(config auth.TSDBConfig, endpoint string, matches []string) ([]byte, error) {
var fullURL string
if len(matches) > 0 {
// Build URL with matches parameter
params := url.Values{}
for _, match := range matches {
params.Add("match[]", match)
}
fullURL = tsdbConfig.URL + endpoint + "?" + params.Encode()
fullURL = config.URL + endpoint + "?" + params.Encode()
} else {
fullURL = tsdbConfig.URL + endpoint
fullURL = config.URL + endpoint
}

logger.Debug("Making Prometheus API call with matches",
slog.String("url", fullURL),
slog.Any("matches", matches))

resp, err := auth.MakeRequest(tsdbConfig, fullURL)
resp, err := auth.MakeRequest(config, fullURL)
if err != nil {
return nil, fmt.Errorf("request failed: %w", err)
}
Expand All @@ -354,15 +386,17 @@ func makePrometheusAPICallWithMatches(endpoint string, matches []string) ([]byte
}

// ListMetrics lists available metrics from time series database
func ListMetrics(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListMetricsArgs) (*mcp.CallToolResult, any, error) {
func ListMetrics(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListMetricsRequest) (*mcp.CallToolResult, any, error) {
var body []byte
var err error

config := resolveTSDBConfig(args.TSDBOverride)

if len(args.Matches) > 0 {
logger.Debug("Using server-side filtering with matches", slog.Any("matches", args.Matches))
body, err = makePrometheusAPICallWithMatches("/api/v1/label/__name__/values", args.Matches)
body, err = makePrometheusAPICallWithMatches(config, "/api/v1/label/__name__/values", args.Matches)
} else {
body, err = makePrometheusAPICall("/api/v1/label/__name__/values")
body, err = makePrometheusAPICall(config, "/api/v1/label/__name__/values")
}

if err != nil {
Expand Down Expand Up @@ -416,12 +450,14 @@ func ListMetrics(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListMe
}

// ListLabelValues lists available values for a specific label from Prometheus
func ListLabelValues(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListLabelValuesArgs) (*mcp.CallToolResult, any, error) {
func ListLabelValues(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListLabelValuesRequest) (*mcp.CallToolResult, any, error) {
if args.Label == "" {
return handleValidationError("label parameter is required"), nil, errors.New("label parameter is required")
}

body, err := makePrometheusAPICall("/api/v1/label/" + args.Label + "/values")
config := resolveTSDBConfig(args.TSDBOverride)

body, err := makePrometheusAPICall(config, "/api/v1/label/"+args.Label+"/values")
if err != nil {
logger.Error("Failed to query Prometheus label values", slogx.Err(err), slog.String("label", args.Label))
return handlePrometheusError(err, fmt.Sprintf("query label values for '%s'", args.Label)), nil, nil
Expand Down Expand Up @@ -454,8 +490,9 @@ func ListLabelValues(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.Li
}

// ListAllLabelNames lists all available label names (dimensions) from Prometheus
func ListAllLabelNames(_ context.Context, _ *mcp.CallToolRequest, _ any) (*mcp.CallToolResult, any, error) {
body, err := makePrometheusAPICall("/api/v1/labels")
func ListAllLabelNames(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.ListAllLabelNamesRequest) (*mcp.CallToolResult, any, error) {
config := resolveTSDBConfig(args.TSDBOverride)
body, err := makePrometheusAPICall(config, "/api/v1/labels")
if err != nil {
return handlePrometheusError(err, "query Prometheus label names"), nil, nil
}
Expand All @@ -480,10 +517,11 @@ func ListAllLabelNames(_ context.Context, _ *mcp.CallToolRequest, _ any) (*mcp.C
return formatDataResponse(response)
}

func GetActiveAlerts(_ context.Context, _ *mcp.CallToolRequest, _ any) (*mcp.CallToolResult, any, error) {
queryURL := tsdbConfig.URL + "/api/v1/alerts"
func GetActiveAlerts(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.GetActiveAlertsRequest) (*mcp.CallToolResult, any, error) {
config := resolveTSDBConfig(args.TSDBOverride)
queryURL := config.URL + "/api/v1/alerts"

resp, err := auth.MakeRequest(tsdbConfig, queryURL)
resp, err := auth.MakeRequest(config, queryURL)
if err != nil {
logger.Error("Failed to query Prometheus alerts", slogx.Err(err))
return &mcp.CallToolResult{
Expand Down Expand Up @@ -578,7 +616,7 @@ func countAlertsBySeverity(alerts []any) (int, int, int) {
return critical, warning, info
}

func InfrastructureHealth(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.InfrastructureHealthArgs) (*mcp.CallToolResult, any, error) {
func InfrastructureHealth(_ context.Context, _ *mcp.CallToolRequest, args mcptypes.InfrastructureHealthRequest) (*mcp.CallToolResult, any, error) {
healthReport := strings.Builder{}
var report string
healthReport.WriteString("## ONTAP Infrastructure Health Report\n\n")
Expand All @@ -601,8 +639,10 @@ func InfrastructureHealth(_ context.Context, _ *mcp.CallToolRequest, args mcptyp
{"Health Alerts", "{__name__=~\"health_.*\"}", "Active health alerts", true},
}

config := resolveTSDBConfig(args.TSDBOverride)

for _, check := range healthChecks {
queryURL := tsdbConfig.URL + "/api/v1/query"
queryURL := config.URL + "/api/v1/query"
urlValues := url.Values{}
urlValues.Set("query", check.query)

Expand All @@ -612,7 +652,7 @@ func InfrastructureHealth(_ context.Context, _ *mcp.CallToolRequest, args mcptyp
slog.String("query", check.query),
slog.String("url", queryURL))

promResp, err := executeTSDBQuery(queryURL, urlValues)
promResp, err := executeTSDBQuery(config, queryURL, urlValues)
if err != nil {
healthReport.WriteString(fmt.Sprintf("❌ **%s**: Error querying - %v\n", check.name, err))
continue
Expand Down Expand Up @@ -941,15 +981,7 @@ func runHTTPServer(server *mcp.Server) {
logger.Info("mcp server shutdown gracefully")
}

type GetMetricDescriptionRequest struct {
MetricName string `json:"metricName"`
}

type SearchMetricsRequest struct {
Pattern string `json:"pattern"`
}

func GetMetricDescription(_ context.Context, _ *mcp.CallToolRequest, params GetMetricDescriptionRequest) (*mcp.CallToolResult, any, error) {
func GetMetricDescription(_ context.Context, _ *mcp.CallToolRequest, params mcptypes.GetMetricDescriptionRequest) (*mcp.CallToolResult, any, error) {
if len(metricDescriptions) == 0 {
return &mcp.CallToolResult{
Content: []mcp.Content{
Expand Down Expand Up @@ -986,7 +1018,7 @@ func GetMetricDescription(_ context.Context, _ *mcp.CallToolRequest, params GetM
}, nil, nil
}

func SearchMetrics(_ context.Context, _ *mcp.CallToolRequest, params SearchMetricsRequest) (*mcp.CallToolResult, any, error) {
func SearchMetrics(_ context.Context, _ *mcp.CallToolRequest, params mcptypes.SearchMetricsRequest) (*mcp.CallToolResult, any, error) {
if len(metricDescriptions) == 0 {
return &mcp.CallToolResult{
Content: []mcp.Content{
Expand Down
61 changes: 46 additions & 15 deletions mcp/pkg/mcptypes/types.go
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -26,27 +26,58 @@ type LabelsResponse struct {
ErrorType string `json:"errorType,omitempty"`
}

type QueryArgs struct {
Query string `json:"query" jsonschema:"PromQL query string"`
// TSDBOverride allows per-request override of the Prometheus/VictoriaMetrics URL and credentials
// This is useful when a single MCP server needs to query multiple TSDB instances
type TSDBOverride struct {
URL string `json:"tsdb_url,omitempty" jsonschema:"Optional override for Prometheus/VictoriaMetrics URL. If not provided, uses the default HARVEST_TSDB_URL from server configuration. Example: http://prometheus-prod:9090"`
Username string `json:"tsdb_username,omitempty" jsonschema:"Optional basic auth username. Only used if tsdb_url is provided. Overrides default authentication."`
Password string `json:"tsdb_password,omitempty" jsonschema:"Optional basic auth password. Only used if tsdb_url is provided. Overrides default authentication."`
}

type RangeQueryArgs struct {
Query string `json:"query" jsonschema:"PromQL query string"`
Start string `json:"start" jsonschema:"Start timestamp (RFC3339 or Unix timestamp)"`
End string `json:"end" jsonschema:"End timestamp (RFC3339 or Unix timestamp)"`
Step string `json:"step" jsonschema:"Query resolution step width (e.g., '15s', '1m', '1h')"`
type QueryRequest struct {
Query string `json:"query" jsonschema:"PromQL query string"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type ListMetricsArgs struct {
Match string `json:"match,omitempty" jsonschema:"Optional metric name pattern to filter results. Supports: 1) Simple string matching (e.g., 'volume'), 2) Regex patterns (e.g., '.*volume.*space.*'), 3) PromQL label matchers (e.g., '{__name__=~\".*volume.*\"}')"`
Matches []string `json:"matches,omitempty" jsonschema:"Array of PromQL label matchers for server-side filtering (e.g., ['{__name__=~\".*volume.*space.*\"}']). More efficient than 'match' for complex patterns."`
type RangeQueryRequest struct {
Query string `json:"query" jsonschema:"PromQL query string"`
Start string `json:"start" jsonschema:"Start timestamp (RFC3339 or Unix timestamp)"`
End string `json:"end" jsonschema:"End timestamp (RFC3339 or Unix timestamp)"`
Step string `json:"step" jsonschema:"Query resolution step width (e.g., '15s', '1m', '1h')"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type InfrastructureHealthArgs struct {
IncludeDetails bool `json:"includeDetails,omitempty" jsonschema:"Include detailed metrics in the response"`
type ListMetricsRequest struct {
Match string `json:"match,omitempty" jsonschema:"Optional metric name pattern to filter results. Supports: 1) Simple string matching (e.g., 'volume'), 2) Regex patterns (e.g., '.*volume.*space.*'), 3) PromQL label matchers (e.g., '{__name__=~\".*volume.*\"}')"`
Matches []string `json:"matches,omitempty" jsonschema:"Array of PromQL label matchers for server-side filtering (e.g., ['{__name__=~\".*volume.*space.*\"}']). More efficient than 'match' for complex patterns."`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type ListLabelValuesArgs struct {
Label string `json:"label" jsonschema:"Label name to get values for (e.g., 'cluster', 'node', 'volume')"`
Match string `json:"match,omitempty" jsonschema:"Optional pattern to filter label values. Supports simple string matching or regex patterns (e.g., '.*prod.*', '^cluster_[0-9]+$')"`
type InfrastructureHealthRequest struct {
IncludeDetails bool `json:"includeDetails,omitempty" jsonschema:"Include detailed metrics in the response"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type ListLabelValuesRequest struct {
Label string `json:"label" jsonschema:"Label name to get values for (e.g., 'cluster', 'node', 'volume')"`
Match string `json:"match,omitempty" jsonschema:"Optional pattern to filter label values. Supports simple string matching or regex patterns (e.g., '.*prod.*', '^cluster_[0-9]+$')"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type GetMetricDescriptionRequest struct {
MetricName string `json:"metricName" jsonschema:"The name of the metric to get description for"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type SearchMetricsRequest struct {
Pattern string `json:"pattern" jsonschema:"Search pattern to match against metric names and descriptions"`
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type GetActiveAlertsRequest struct {
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}

type ListAllLabelNamesRequest struct {
TSDBOverride *TSDBOverride `json:"tsdb_override,omitempty" jsonschema:"Optional override for TSDB connection"`
}
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