From db30464aef69addb479b8ccd01d6cfaf5a440ad6 Mon Sep 17 00:00:00 2001
From: rasmus <rasmus@k-space.ee>
Date: Wed, 9 Nov 2022 21:09:15 +0200
Subject: [PATCH] implement filters

---
 pkg/watcher/watcher.go | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/pkg/watcher/watcher.go b/pkg/watcher/watcher.go
index d628290..9544d33 100644
--- a/pkg/watcher/watcher.go
+++ b/pkg/watcher/watcher.go
@@ -5,6 +5,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 
 	"git.k-space.ee/k-space/logmower-shipper/pkg/file"
@@ -31,8 +32,8 @@ var App = &cli.App{
 		//TODO: &cli.BoolFlag{Name: "normalize-log-level", Usage: "Normalize log.level values to Syslog defined keywords"},
 		//TODO: &cli.BoolFlag{Name: "parse-json"},
 		//
-		// &cli.StringFlag{Category: "k8s metadata", Name: "pod-namespace", EnvVars: []string{"KUBE_POD_NAMESPACE"}},
-		// &cli.StringFlag{Category: "k8s metadata", Name: "node-name", EnvVars: []string{"KUBE_NODE_NAME"}, Required: true},
+		&cli.StringSliceFlag{Category: "selectors", Name: "pod-namespace", EnvVars: []string{"KUBE_POD_NAMESPACE"}},
+		&cli.StringSliceFlag{Category: "selectors", Name: "pod-prefix", EnvVars: []string{"KUBE_NODE_NAME"}},
 		//
 		&cli.StringFlag{Category: "secrets", Name: "mongo-uri", EnvVars: []string{"MONGO_URI"}, Usage: "mongodb://foo:bar@host:27017/database", Required: true},
 	},
@@ -48,6 +49,7 @@ var App = &cli.App{
 	},
 
 	Action: func(ctx *cli.Context) error {
+		filterNamespace, filterPodPrefixes := sliceToMap(ctx.StringSlice("pod-namespace")), ctx.StringSlice("pod-prefix")
 		var wg sync.WaitGroup
 
 		log.Printf("%s %s starting", ctx.App.Name, ctx.App.Version)
@@ -94,6 +96,14 @@ var App = &cli.App{
 						continue
 					}
 
+					if _, ok := filterNamespace[kubeInfo.Namespace]; !ok {
+						continue
+					}
+
+					if ok := hasSlicePrefix(kubeInfo.Pod, filterPodPrefixes); !ok {
+						continue
+					}
+
 					promWatcherFilesStarted.Add(1)
 
 					wg.Add(1)
@@ -156,3 +166,22 @@ func simulateInitialCreates(dirName string, eventChan chan<- fsnotify.Event) err
 
 	return nil
 }
+
+func sliceToMap[T comparable](sl []T) map[T]interface{} {
+	m := make(map[T]interface{})
+
+	for _, k := range sl {
+		m[k] = nil
+	}
+
+	return m
+}
+
+func hasSlicePrefix(s string, sl []string) bool {
+	for _, prefix := range sl {
+		if strings.HasPrefix(s, prefix) {
+			return true
+		}
+	}
+	return false
+}