From 776206eec88cc4070884982e0ed488fe363e9398 Mon Sep 17 00:00:00 2001
From: Quentin McGaw <quentin.mcgaw@gmail.com>
Date: Thu, 13 Jun 2024 19:29:56 +0000
Subject: [PATCH] feat(health): only run health server when running in Docker

---
 Dockerfile                  |  5 ++++-
 cmd/updater/main.go         | 18 ++++++++++++++----
 internal/health/isdocker.go |  8 ++++++++
 internal/noop/service.go    | 25 +++++++++++++++++++++++++
 4 files changed, 51 insertions(+), 5 deletions(-)
 create mode 100644 internal/health/isdocker.go
 create mode 100644 internal/noop/service.go

diff --git a/Dockerfile b/Dockerfile
index 99c59753..15c75105 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -50,7 +50,8 @@ RUN git init && \
     rm -rf .git/
 
 FROM --platform=$BUILDPLATFORM base AS build
-RUN mkdir -p /tmp/data
+RUN mkdir -p /tmp/data && \
+    touch /tmp/isdocker
 ARG VERSION=unknown
 ARG CREATED="an unknown date"
 ARG COMMIT=unknown
@@ -69,8 +70,10 @@ HEALTHCHECK --interval=60s --timeout=5s --start-period=10s --retries=2 CMD ["/up
 ARG UID=1000
 ARG GID=1000
 USER ${UID}:${GID}
+WORKDIR /updater
 ENTRYPOINT ["/updater/ddns-updater"]
 COPY --from=build --chown=${UID}:${GID} /tmp/data /updater/data
+COPY --from=build --chown=${UID}:${GID} /tmp/isdocker /updater/isdocker
 ENV \
     # Core
     CONFIG= \
diff --git a/cmd/updater/main.go b/cmd/updater/main.go
index a487e413..a3fa672c 100644
--- a/cmd/updater/main.go
+++ b/cmd/updater/main.go
@@ -19,6 +19,7 @@ import (
 	"github.com/qdm12/ddns-updater/internal/health"
 	"github.com/qdm12/ddns-updater/internal/healthchecksio"
 	"github.com/qdm12/ddns-updater/internal/models"
+	"github.com/qdm12/ddns-updater/internal/noop"
 	jsonparams "github.com/qdm12/ddns-updater/internal/params"
 	persistence "github.com/qdm12/ddns-updater/internal/persistence/json"
 	"github.com/qdm12/ddns-updater/internal/provider"
@@ -205,10 +206,7 @@ func _main(ctx context.Context, reader *reader.Reader, args []string, logger log
 	updaterService := update.NewService(db, updater, ipGetter, config.Update.Period,
 		config.Update.Cooldown, logger, resolver, timeNow, hioClient)
 
-	isHealthy := health.MakeIsHealthy(db, resolver)
-	healthLogger := logger.New(log.SetComponent("healthcheck server"))
-	healthServer, err := health.NewServer(*config.Health.ServerAddress,
-		healthLogger, isHealthy)
+	healthServer, err := createHealthServer(db, resolver, logger, *config.Health.ServerAddress)
 	if err != nil {
 		return fmt.Errorf("creating health server: %w", err)
 	}
@@ -348,3 +346,15 @@ func exitHealthchecksio(hioClient *healthchecksio.Client,
 		logger.Error(err.Error())
 	}
 }
+
+//nolint:ireturn
+func createHealthServer(db health.AllSelecter, resolver health.LookupIPer,
+	logger log.LoggerInterface, serverAddress string) (
+	healthServer goservices.Service, err error) {
+	if !health.IsDocker() {
+		return noop.New("healthcheck server"), nil
+	}
+	isHealthy := health.MakeIsHealthy(db, resolver)
+	healthLogger := logger.New(log.SetComponent("healthcheck server"))
+	return health.NewServer(serverAddress, healthLogger, isHealthy)
+}
diff --git a/internal/health/isdocker.go b/internal/health/isdocker.go
new file mode 100644
index 00000000..993be150
--- /dev/null
+++ b/internal/health/isdocker.go
@@ -0,0 +1,8 @@
+package health
+
+import "os"
+
+func IsDocker() (ok bool) {
+	_, err := os.Stat("isdocker")
+	return err == nil
+}
diff --git a/internal/noop/service.go b/internal/noop/service.go
new file mode 100644
index 00000000..e73b1891
--- /dev/null
+++ b/internal/noop/service.go
@@ -0,0 +1,25 @@
+package noop
+
+import "context"
+
+type Service struct {
+	name string
+}
+
+func New(name string) *Service {
+	return &Service{
+		name: name,
+	}
+}
+
+func (s *Service) String() string {
+	return s.name + " (no-op)"
+}
+
+func (s *Service) Start(_ context.Context) (_ <-chan error, _ error) {
+	return nil, nil //nolint:nilnil
+}
+
+func (s *Service) Stop() (stopErr error) {
+	return nil
+}