fix(dns): fix slow dns resolution of localhost for grpc health probe

see: golang/go#35305

Author: ecordell

Dockerfile

@@ -28,6 +28,7 @@ FROM openshift/origin-base
 RUN mkdir /registry
 WORKDIR /registry
 
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 COPY --from=builder /src/bin/initializer /bin/initializer
 COPY --from=builder /src/bin/registry-server /bin/registry-server
 COPY --from=builder /src/bin/configmap-server /bin/configmap-server

appr-registry.Dockerfile

@@ -13,6 +13,7 @@ RUN make static
 FROM golang:1.13-alpine as probe-builder
 
 RUN apk update && apk add build-base git
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 ENV ORG github.com/grpc-ecosystem
 ENV PROJECT $ORG/grpc_health_probe
 WORKDIR /go/src/$PROJECT
@@ -24,5 +25,6 @@ RUN CGO_ENABLED=0 go install -a -tags netgo -ldflags "-w"
 FROM scratch
 COPY --from=builder /go/src/github.com/operator-framework/operator-registry/bin/appregistry-server /bin/appregistry-server
 COPY --from=probe-builder /go/bin/grpc-health-probe /bin/grpc_health_probe
+COPY --from=probe-builder /etc/nsswitch.conf /etc/nsswitch.conf
 EXPOSE 50051
 ENTRYPOINT ["/bin/appregistry-server"]

configmap-registry.Dockerfile

@@ -1,10 +1,12 @@
 FROM quay.io/operator-framework/upstream-registry-builder:latest as builder
 FROM busybox as userspace
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
 FROM scratch
 COPY --from=builder /build/bin/configmap-server /bin/configmap-server
 COPY --from=builder /build/bin/opm /bin/opm
 COPY --from=userspace /bin/cp /bin/cp
+COPY --from=userspace /etc/nsswitch.conf /etc/nsswitch.conf
 COPY --from=builder /bin/grpc_health_probe /bin/grpc_health_probe
 EXPOSE 50051
 ENTRYPOINT ["/bin/configmap-server"]

opm-example.Dockerfile

@@ -1,10 +1,12 @@
 FROM quay.io/operator-framework/upstream-registry-builder AS builder
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
 FROM scratch
 LABEL operators.operatorframework.io.index.database.v1=./index.db
 COPY database ./
 COPY --from=builder /build/bin/opm /opm
 COPY --from=builder /bin/grpc_health_probe /bin/grpc_health_probe
+COPY --from=builder /etc/nsswitch.conf /etc/nsswitch.conf
 EXPOSE 50051
 ENTRYPOINT ["/opm"]
 CMD ["registry", "serve", "--database", "index.db"]

registry.Dockerfile

@@ -12,10 +12,12 @@ RUN make static
 RUN GRPC_HEALTH_PROBE_VERSION=v0.2.1 && \
     wget -qO/bin/grpc_health_probe https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/${GRPC_HEALTH_PROBE_VERSION}/grpc_health_probe-linux-$(go env GOARCH) && \
     chmod +x /bin/grpc_health_probe
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
 FROM scratch
 COPY --from=builder /build/bin/registry-server /registry-server
 COPY --from=builder /bin/grpc_health_probe /bin/grpc_health_probe
+COPY --from=builder /etc/nsswitch.conf /etc/nsswitch.conf
 EXPOSE 50051
 ENTRYPOINT ["/registry-server"]
 CMD ["--database", "/bundles.db"]

upstream-builder.Dockerfile

@@ -12,6 +12,7 @@ RUN make static
 RUN GRPC_HEALTH_PROBE_VERSION=v0.2.1 && \
     wget -qO/bin/grpc_health_probe https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/${GRPC_HEALTH_PROBE_VERSION}/grpc_health_probe-linux-$(go env GOARCH) && \
     chmod +x /bin/grpc_health_probe
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 RUN cp /build/bin/opm /bin/opm && \
     cp /build/bin/initializer /bin/initializer && \
     cp /build/bin/appregistry-server /bin/appregistry-server && \

upstream-example.Dockerfile

@@ -2,11 +2,13 @@ FROM quay.io/operator-framework/upstream-registry-builder as builder
 
 COPY manifests manifests
 RUN /bin/initializer -o ./bundles.db
+RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
 FROM scratch
 COPY --from=builder /build/bundles.db /bundles.db
 COPY --from=builder /bin/registry-server /registry-server
 COPY --from=builder /bin/grpc_health_probe /bin/grpc_health_probe
+COPY --from=builder /etc/nsswitch.conf /etc/nsswitch.conf
 EXPOSE 50051
 ENTRYPOINT ["/registry-server"]
 CMD ["--database", "bundles.db"]