Merge pull request #58 from ekimekim/mike/nginx-dns-hack

Fix nginx when some services are disabled

docker-compose.jsonnet

@@ -208,9 +208,25 @@
     },
 
     [if $.enabled.nginx then "nginx"]: {
+      # mapping of services to internal ports for nginx to forward
+      local forward_ports = {
+        restreamer: 8000,
+        downloader: 8001,
+        backfiller: 8002,
+        cutter: 8003,
+        thrimshim: 8004,
+        sheetsync: 8005,
+      },
       image: "quay.io/ekimekim/wubloader-nginx:%s" % $.image_tag,
       restart: "on-failure",
       [if "nginx" in $.ports then "ports"]: ["%s:80" % $.ports.nginx],
+      environment: {
+        SERVICES: std.join("\n", [
+          "%s %s" % [service, forward_ports[service]]
+          for service in std.objectFields(forward_ports)
+          if service in $.enabled && $.enabled[service]
+        ]),
+      },
     },
 
     [if $.enabled.postgres then "postgres"]: {

nginx/Dockerfile

@@ -1,3 +1,4 @@
 # nginx container contains config that exposes all the various services metrics
 FROM nginx:latest
-ADD nginx/nginx.conf /etc/nginx/nginx.conf
+ADD nginx/generate-config /
+ENTRYPOINT ["/bin/sh", "-c", "/generate-config && nginx -g \"daemon off;\""]

nginx/generate-config

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+# This script expects a mapping of services and ports in the SERVICES env var,
+# with one line per service containing "NAME PORT".
+
+generate_location() {
+	# generate_location PATH URL
+	echo -e "\t\tlocation $1 { proxy_pass $2; }"
+}
+
+LOCATIONS=$(
+	echo "$SERVICES" | while read name port; do
+		# restreamer is the catch-all
+		[ "$name" == "restreamer" ] && generate_location / "http://restreamer:$port"
+		# thrimshim takes any calls to thrimshim/
+		[ "$name" == "thrimshim" ] && generate_location /thrimshim "http://thrimshim:$port"
+		# all services have metrics under /metrics/SERVICE
+		generate_location "/metrics/$name" "http://$name:$port/metrics"
+	done
+)
+
+cat > /etc/nginx/nginx.conf <<EOF
+worker_processes 1;
+
+events {
+	worker_connections 1024;
+}
+
+http {
+	server {
+		listen 80;
+$LOCATIONS
+	}
+}
+EOF

nginx/nginx.conf

@@ -1,37 +0,0 @@
-
-worker_processes 1;
-
-events {
-	worker_connections 1024;
-}
-
-http {
-	server {
-		listen 80;
-		location / {
-			proxy_pass http://restreamer:8000;
-		}
-		location /thrimshim {
-			proxy_pass http://thrimshim:8004;
-		}
-		# Restreamer metrics would be available regardless, this is just for consistency
-		location /metrics/restreamer {
-			proxy_pass http://restreamer:8000/metrics;
-		}
-		location /metrics/downloader {
-			proxy_pass http://downloader:8001/metrics;
-		}
-		location /metrics/backfiller {
-			proxy_pass http://backfiller:8002/metrics;
-		}
-		location /metrics/cutter {
-			proxy_pass http://cutter:8003/metrics;
-		}
-		location /metrics/thrimshim {
-			proxy_pass http://thrimshim:8004/metrics;
-		}
-		location /metrics/sheetsync {
-			proxy_pass http://sheetsync:8005/metrics;
-		}
-	}
-}