ping redis hosts on startup, add build files

.drone.yml

@@ -0,0 +1,18 @@
+---
+kind: pipeline
+name: default
+steps:
+- name: docker
+  image: plugins/docker
+  settings:
+    registry: atdr-writer.meo.ws
+    username:
+      from_secret: atdr_user
+    password:
+      from_secret: atdr_pass
+    repo: atdr-writer.meo.ws/archiveteam/backfeed
+    dockerfile: Dockerfile
+    purge: true
+    auto_tag: false
+    tags:
+    - latest

Dockerfile

@@ -0,0 +1,9 @@
+FROM golang:1.17-alpine AS build
+WORKDIR /app
+COPY . ./
+RUN go mod download
+RUN CGO_ENABLED=0 go build -installsuffix 'static' -o /backfeed .
+FROM gcr.io/distroless/static
+WORKDIR /
+COPY --from=build /backfeed /backfeed
+ENTRYPOINT ["/backfeed"]

main.go

@@ -471,14 +471,14 @@ func main() {
 
 	trackerRedisOptions, err := redis.ParseURL(os.Getenv("REDIS_TRACKER"))
 	if err != nil {
-		log.Panicf("%s", err)
+		log.Panicf("invalid REDIS_TRACKER url: %s", err)
 	}
 	trackerRedisOptions.ReadTimeout = 15 * time.Minute
 	trackerRedisClient := redis.NewClient(trackerRedisOptions)
 
 	legacyRedisOptions, err := redis.ParseURL(os.Getenv("REDIS_LEGACY"))
 	if err != nil {
-		log.Panicf("%s", err)
+		log.Panicf("invalid REDIS_LEGACY url: %s", err)
 	}
 	legacyRedisOptions.ReadTimeout = 15 * time.Minute
 	legacyRedisClient := redis.NewClient(legacyRedisOptions)
@@ -490,6 +490,16 @@ func main() {
 		ReadTimeout: 15 * time.Minute,
 	})
 
+	if err := trackerRedisClient.Ping(context.Background()).Err(); err != nil {
+		log.Panicf("unable to ping tracker redis: %s", err)
+	}
+	if err := backfeedRedisClient.Ping(context.Background()).Err(); err != nil {
+		log.Panicf("unable to ping backfeed redis: %s", err)
+	}
+	if err := legacyRedisClient.Ping(context.Background()).Err(); err != nil {
+		log.Panicf("unable to ping legacy redis: %s", err)
+	}
+
 	globalBackfeedManager := &GlobalBackfeedManager{
 		ActiveFeeds:   map[string]*ProjectBackfeedManager{},
 		ActiveSlugs:   map[string]string{},