Add Splunk scaler (#5905)

Signed-off-by: circa10a <caleblemoine@gmail.com>
Signed-off-by: Caleb Lemoine <21261388+circa10a@users.noreply.github.com>

CHANGELOG.md

@@ -61,6 +61,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 - TODO ([#XXX](https://github.com/kedacore/keda/issues/XXX))
 - **General**: Add --ca-dir flag to KEDA operator to specify directories with CA certificates for scalers to authenticate TLS connections (defaults to /custom/ca) ([#5860](https://github.com/kedacore/keda/issues/5860))
 - **General**: Declarative parsing of scaler config ([#5037](https://github.com/kedacore/keda/issues/5037)|[#5797](https://github.com/kedacore/keda/issues/5797))
+- **General**: Introduce new Splunk Scaler ([#5904](https://github.com/kedacore/keda/issues/5904))
 - **General**: Remove deprecated Kustomize commonLabels ([#5888](https://github.com/kedacore/keda/pull/5888))
 - **General**: Support for Kubernetes v1.30 ([#5828](https://github.com/kedacore/keda/issues/5828))
 

pkg/scalers/splunk/splunk.go

@@ -0,0 +1,120 @@
+package splunk
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/kedacore/keda/v2/pkg/scalers/scalersconfig"
+	kedautil "github.com/kedacore/keda/v2/pkg/util"
+)
+
+const (
+	savedSearchPathTemplateStr = "/servicesNS/%s/search/search/jobs/export"
+)
+
+// Config contains the information required to authenticate with a Splunk instance.
+type Config struct {
+	Host        string
+	Username    string
+	Password    string
+	APIToken    string
+	HTTPTimeout time.Duration
+	UnsafeSsl   bool
+}
+
+// Client contains Splunk config information as well as an http client for requests.
+type Client struct {
+	*Config
+	*http.Client
+}
+
+// SearchResponse is used for unmarshalling search results.
+type SearchResponse struct {
+	Result map[string]string `json:"result"`
+}
+
+// NewClient returns a new Splunk client.
+func NewClient(c *Config, sc *scalersconfig.ScalerConfig) (*Client, error) {
+	if c.Username == "" {
+		return nil, errors.New("username was not set")
+	}
+
+	if c.APIToken != "" && c.Password != "" {
+		return nil, errors.New("API token and Password were all set. If APIToken is set, username and password must not be used")
+	}
+
+	httpClient := kedautil.CreateHTTPClient(sc.GlobalHTTPTimeout, c.UnsafeSsl)
+
+	client := &Client{
+		c,
+		httpClient,
+	}
+
+	return client, nil
+}
+
+// SavedSearch fetches the results of a saved search/report in Splunk.
+func (c *Client) SavedSearch(name string) (*SearchResponse, error) {
+	savedSearchAPIPath := fmt.Sprintf(savedSearchPathTemplateStr, c.Username)
+	endpoint := fmt.Sprintf("%s%s", c.Host, savedSearchAPIPath)
+
+	body := strings.NewReader(fmt.Sprintf("search=savedsearch %s", name))
+	req, err := http.NewRequest(http.MethodPost, endpoint, body)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	if c.APIToken != "" {
+		req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", c.APIToken))
+	} else {
+		req.SetBasicAuth(c.Username, c.Password)
+	}
+
+	req.URL.RawQuery = url.Values{
+		"output_mode": {"json"},
+	}.Encode()
+
+	resp, err := c.Client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+
+	if resp.StatusCode > 399 {
+		bodyText, err := io.ReadAll(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		return nil, errors.New(string(bodyText))
+	}
+
+	result := &SearchResponse{}
+
+	err = json.NewDecoder(resp.Body).Decode(&result)
+
+	return result, err
+}
+
+// ToMetric converts a search response to a consumable metric value.
+func (s *SearchResponse) ToMetric(valueField string) (float64, error) {
+	metricValueStr, ok := s.Result[valueField]
+	if !ok {
+		return 0, fmt.Errorf("field: %s not found in search results", valueField)
+	}
+
+	metricValueInt, err := strconv.ParseFloat(metricValueStr, 64)
+	if err != nil {
+		return 0, fmt.Errorf("value: %s is not a float value", valueField)
+	}
+
+	return metricValueInt, nil
+}