Docker healthcheck

Dockerfile

@@ -2,11 +2,14 @@ ARG VERSION
 FROM hunterlong/statup:base-v${VERSION}
 MAINTAINER "Hunter Long (https://github.com/hunterlong)"
 
-# Locked version of Statup for 'latest' Docker tag
+RUN apk --no-cache add curl jq
 ENV IS_DOCKER=true
 ENV STATUP_DIR=/app
 
 WORKDIR /app
 VOLUME /app
 EXPOSE 8080
+
+HEALTHCHECK --interval=5s --timeout=5s --retries=5 CMD curl -s "http://localhost:8080/health" | jq -r -e ".online==true"
+
 CMD ["statup"]

dev/Dockerfile-dev

@@ -4,7 +4,7 @@ MAINTAINER "Hunter Long (https://github.com/hunterlong)"
 # Statup 'test' image for running a full test using the production environment
 
 ENV DEP_VERSION=v0.5.0
-RUN apk add --no-cache libstdc++ gcc g++ make git ca-certificates linux-headers wget curl
+RUN apk add --no-cache libstdc++ gcc g++ make git ca-certificates linux-headers wget curl jq
 
 RUN curl -L -s https://github.com/golang/dep/releases/download/$DEP_VERSION/dep-linux-amd64 -o /go/bin/dep && \
     chmod +x /go/bin/dep
@@ -25,4 +25,7 @@ RUN make install
 WORKDIR /app
 VOLUME /app
 EXPOSE 8080
+
+HEALTHCHECK --interval=5s --timeout=5s --retries=5 CMD curl -s "http://localhost:8080/health" | jq -r -e ".online==true"
+
 ENTRYPOINT statup

handlers/index.go

@@ -16,6 +16,7 @@
 package handlers
 
 import (
+	"encoding/json"
 	"github.com/hunterlong/statup/core"
 	"github.com/hunterlong/statup/types"
 	"github.com/hunterlong/statup/utils"
@@ -30,6 +31,15 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
 	executeResponse(w, r, "index.html", core.CoreApp, nil)
 }
 
+func healthCheckHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	health := map[string]interface{}{
+		"services": len(core.Services()),
+		"online":   core.Configs != nil,
+	}
+	json.NewEncoder(w).Encode(health)
+}
+
 func trayHandler(w http.ResponseWriter, r *http.Request) {
 	executeResponse(w, r, "tray.html", core.CoreApp, nil)
 }

handlers/routes.go

@@ -119,6 +119,7 @@ func Router() *mux.Router {
 	r.Handle("/api/notifier/{notifier}", http.HandlerFunc(apiNotifierGetHandler)).Methods("POST")
 
 	r.Handle("/metrics", http.HandlerFunc(prometheusHandler))
+	r.Handle("/health", http.HandlerFunc(healthCheckHandler))
 	r.Handle("/tray", http.HandlerFunc(trayHandler))
 	r.NotFoundHandler = http.HandlerFunc(error404Handler)
 	return r