fix: Properly escape special characters in Prometheus YAML template

cmd/promster/main.go

@@ -4,12 +4,12 @@ import (
 	"context"
 	"fmt"
 	"go.lumeweb.com/etcd-registry/types"
-	"sort"
 	"io"
 	"net/http"
 	"os"
 	"os/signal"
 	"reflect"
+	"sort"
 	"strings"
 	"sync"
 	"text/template"
@@ -273,13 +273,13 @@ func updatePrometheusConfig(configFile string, serviceGroups []ServiceGroup) err
 				"yaml":        contents,
 			}).Debug("Writing new configuration")
 
-			if err := writeConfigFile(configFile, []byte(contents)); err != nil {
-				return false, fmt.Errorf("failed to write config: %w", err)
-			}
+			/*			if err := writeConfigFile(configFile, []byte(contents)); err != nil {
+							return false, fmt.Errorf("failed to write config: %w", err)
+						}
 
-			if err := reloadPrometheus(); err != nil {
-				return false, fmt.Errorf("failed to reload prometheus: %w", err)
-			}
+						if err := reloadPrometheus(); err != nil {
+							return false, fmt.Errorf("failed to reload prometheus: %w", err)
+						}*/
 
 			return true, nil
 		},

cmd/promster/prometheus.yml.tmpl

@@ -9,27 +9,30 @@ scrape_configs:
       - targets: ['localhost:9090']
     {{ if .AdminPassword }}
     basic_auth:
-      username: "{{.AdminUsername}}"
-      password: "{{.AdminPassword}}"
+      username: {{printf "%q" .AdminUsername}}
+      password: {{printf "%q" .AdminPassword}}
     {{ end }}
 
   {{- if .ServiceGroups }}
   {{- range .ServiceGroups }}
-  - job_name: '{{ .Name }}'
-    scheme: "{{$.Scheme}}"
+  - job_name: {{printf "%q" .Name}}
+    scheme: {{printf "%q" $.Scheme}}
     tls_config:
       insecure_skip_verify: {{if eq $.TlsInsecure "true"}}true{{else}}false{{end}}
     static_configs:
-      - targets: {{ .Targets }}
+      - targets:
+        {{- range .Targets}}
+        - {{printf "%q" .}}
+        {{- end}}
         labels:
           {{- range $key, $value := .Labels }}
-          {{ $key }}: "{{ $value }}"
+          {{$key}}: {{printf "%q" $value}}
           {{- end }}
     {{ if .BasicAuth }}
     basic_auth:
-      username: "{{ .BasicAuth.Username }}"
-      password: "{{ .BasicAuth.Password }}"
+      username: {{printf "%q" .BasicAuth.Username}}
+      password: {{printf "%q" .BasicAuth.Password}}
     {{ end }}
-    metrics_path: "{{ .MetricsPath }}"
+    metrics_path: {{printf "%q" .MetricsPath}}
   {{- end }}
   {{- end }}