Remove healthcheck script for Docker image (#8095)

There are multiple possibilities for running MinIO within
a container e.g. configurable address, non-root user etc.
This makes it difficult to identify actual IP / Port to
use to check healthcheck status from within a container.

It is simpler to use external healthcheck mechanisms
like healthcheck command in docker-compose to check
for MinIO health status. This is similar to how checks
work in Kubernetes as well.

This PR removes the healthcheck script used inside
Docker container and ad documentation on how to
use docker-compose based healthcheck mechanism.

.gitignore

@@ -22,4 +22,3 @@ prime/
 stage/
 .sia_temp/
 config.json
-dockerscripts/healthcheck

Dockerfile

@@ -9,8 +9,7 @@ ENV GO111MODULE on
 RUN  \
      apk add --no-cache git && \
      git clone https://github.com/minio/minio && cd minio && \
-     go install -v -ldflags "$(go run buildscripts/gen-ldflags.go)" && \
+     go install -v -ldflags "$(go run buildscripts/gen-ldflags.go)"
-     cd dockerscripts; go build -tags kqueue -ldflags "-s -w" -o /usr/bin/healthcheck healthcheck.go
 
 FROM alpine:3.9
 
@@ -22,7 +21,6 @@ ENV MINIO_ACCESS_KEY_FILE=access_key \
 EXPOSE 9000
 
 COPY --from=0 /go/bin/minio /usr/bin/minio
-COPY --from=0 /usr/bin/healthcheck /usr/bin/healthcheck
 COPY dockerscripts/docker-entrypoint.sh /usr/bin/
 
 RUN  \
@@ -33,6 +31,4 @@ ENTRYPOINT ["/usr/bin/docker-entrypoint.sh"]
 
 VOLUME ["/data"]
 
-HEALTHCHECK --interval=1m CMD healthcheck
-
 CMD ["minio"]

Dockerfile.dev

@@ -2,7 +2,7 @@ FROM alpine:3.9
 
 LABEL maintainer="MinIO Inc <dev@min.io>"
 
-COPY dockerscripts/docker-entrypoint.sh dockerscripts/healthcheck /usr/bin/
+COPY dockerscripts/docker-entrypoint.sh /usr/bin/
 COPY minio /usr/bin/
 
 ENV MINIO_UPDATE off
@@ -14,8 +14,7 @@ RUN \
      apk add --no-cache ca-certificates 'curl>7.61.0' 'su-exec>=0.2' && \
      echo 'hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4' >> /etc/nsswitch.conf && \
      chmod +x /usr/bin/minio  && \
-     chmod +x /usr/bin/docker-entrypoint.sh && \
+     chmod +x /usr/bin/docker-entrypoint.sh
-     chmod +x /usr/bin/healthcheck
 
 EXPOSE 9000
 
@@ -23,6 +22,4 @@ ENTRYPOINT ["/usr/bin/docker-entrypoint.sh"]
 
 VOLUME ["/data"]
 
-HEALTHCHECK --interval=1m CMD healthcheck
-
 CMD ["minio"]

Dockerfile.release

@@ -6,14 +6,12 @@ ENV GO111MODULE on
 
 RUN  \
      apk add --no-cache git && \
-     git clone https://github.com/minio/minio && cd minio/dockerscripts && \
+     git clone https://github.com/minio/minio
-     go build -tags kqueue -ldflags "-s -w" -o /usr/bin/healthcheck healthcheck.go
 
 FROM alpine:3.9
 
 LABEL maintainer="MinIO Inc <dev@min.io>"
 
-COPY --from=0 /usr/bin/healthcheck /usr/bin/healthcheck
 COPY dockerscripts/docker-entrypoint.sh /usr/bin/
 
 ENV MINIO_UPDATE off
@@ -26,8 +24,7 @@ RUN \
      echo 'hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4' >> /etc/nsswitch.conf && \
      curl https://dl.min.io/server/minio/release/linux-amd64/minio > /usr/bin/minio && \
      chmod +x /usr/bin/minio  && \
-     chmod +x /usr/bin/docker-entrypoint.sh && \
+     chmod +x /usr/bin/docker-entrypoint.sh
-     chmod +x /usr/bin/healthcheck
 
 EXPOSE 9000
 
@@ -35,6 +32,4 @@ ENTRYPOINT ["/usr/bin/docker-entrypoint.sh"]
 
 VOLUME ["/data"]
 
-HEALTHCHECK --interval=1m CMD healthcheck
-
 CMD ["minio"]

Makefile

@@ -72,7 +72,6 @@ coverage: build
 build: checks
 	@echo "Building minio binary to './minio'"
 	@GOPROXY=https://proxy.golang.org GO111MODULE=on GOFLAGS="" CGO_ENABLED=0 go build -tags kqueue --ldflags $(BUILD_LDFLAGS) -o $(PWD)/minio 1>/dev/null
-	@GOPROXY=https://proxy.golang.org GO111MODULE=on GOFLAGS="" CGO_ENABLED=0 go build -tags kqueue --ldflags $(BUILD_LDFLAGS) -o $(PWD)/dockerscripts/healthcheck $(PWD)/dockerscripts/healthcheck.go 1>/dev/null
 
 docker: build
 	@docker build -t $(TAG) . -f Dockerfile.dev

dockerscripts/healthcheck.go

@@ -1,181 +0,0 @@
-// +build ignore
-
-/*
- * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package main
-
-import (
-	"bufio"
-	"crypto/tls"
-	"errors"
-	"fmt"
-	"log"
-	"net/http"
-	"net/url"
-	"os"
-	"os/exec"
-	"strings"
-	"time"
-
-	xhttp "github.com/minio/minio/cmd/http"
-)
-
-const (
-	initGraceTime = 300
-	healthPath    = "/minio/health/live"
-	timeout       = time.Duration(30 * time.Second)
-	tcp           = "tcp"
-	anyIPv6		  = ":::"
-	anyIPv4		  = "0.0.0.0"
-)
-
-// returns container boot time by finding
-// modtime of /proc/1 directory
-func getStartTime() time.Time {
-	di, err := os.Stat("/proc/1")
-	if err != nil {
-		// Cant stat proc dir successfully, exit with error
-		log.Fatalln(err)
-	}
-	return di.ModTime()
-}
-
-// Returns the ip:port of the MinIO process
-// running in the container
-func findEndpoint() (string, error) {
-	cmd := exec.Command("netstat", "-ntlp")
-	stdout, err := cmd.StdoutPipe()
-	if err != nil {
-		// error getting stdout pipe
-		return "", err
-	}
-	if err = cmd.Start(); err != nil {
-		// error executing the command.
-		return "", err
-	}
-	// split netstat output in rows
-	scanner := bufio.NewScanner(stdout)
-	scanner.Split(bufio.ScanLines)
-	// MinIO works on TCP and it is supposed to be
-	// the only process listening on a port on any IP address 
-	// (on ::: or 0.0.0.0) inside container.
-	// Since MinIO may run as non-root user, we can
-	// not depend on the PID/Program name column
-	// of netstat output
-	for scanner.Scan() {
-		line := scanner.Text()
-		if strings.Contains(line, tcp) && (strings.Contains(line, anyIPv6) || strings.Contains(line, anyIPv4)) {
-			newLine := strings.Replace(line, anyIPv4, "127.0.0.1:", 1)
-			if strings.Contains(line, anyIPv6) {
-				newLine = strings.Replace(line, anyIPv6, "::1:", 1)
-			}
-			fields := strings.Fields(newLine)
-			// index 3 in the row has the Local address
-			// find the last index of ":" - address will
-			// have port number after this index
-			i := strings.LastIndex(fields[3], ":")
-			// split address and port
-			addr := fields[3][:i]
-			port := fields[3][i+1:]
-			// add surrounding [] for ip6 address
-			if strings.Count(addr, ":") > 0 {
-				addr = strings.Join([]string{"[", addr, "]"}, "")
-			}
-			// wait for cmd to complete before return
-			if err = cmd.Wait(); err != nil {
-				return "", err
-			}
-			// return joint address and port
-			return strings.Join([]string{addr, port}, ":"), nil
-		}
-	}
-	if err = scanner.Err(); err != nil {
-		return "", err
-	}
-	if err = cmd.Wait(); err != nil {
-		// command failed to run
-		return "", err
-	}
-	// minio process not found, exit with error
-	return "", errors.New("no minio process found")
-}
-
-func main() {
-	startTime := getStartTime()
-
-	//  In distributed environment like Swarm, traffic is routed
-	//  to a container only when it reports a `healthy` status. So, we exit
-	//  with 0 to ensure healthy status till distributed MinIO starts (120s).
-
-	//  Refer: https://github.com/moby/moby/pull/28938#issuecomment-301753272
-
-	if (time.Now().Sub(startTime) / time.Second) > initGraceTime {
-		endPoint, err := findEndpoint()
-		if err != nil {
-			log.Fatalln(err)
-		}
-		u, err := url.Parse(fmt.Sprintf("http://%s%s", endPoint, healthPath))
-		if err != nil {
-			// Could not parse URL successfully
-			log.Fatalln(err)
-		}
-		// MinIO server may be using self-signed or CA certificates. To avoid
-		// making Docker setup complicated, we skip verifying certificates here.
-		// This is because, following request tests for health status within
-		// containerized environment, i.e. requests are always made to the MinIO
-		// server running on the same host.
-		tr := &http.Transport{
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
-		}
-		client := &http.Client{Transport: tr, Timeout: timeout}
-		resp, err := client.Get(u.String())
-		if err != nil {
-			// GET failed exit
-			log.Fatalln(err)
-		}
-		if resp.StatusCode == http.StatusOK {
-			// Drain any response.
-			xhttp.DrainBody(resp.Body)
-			// exit with success
-			os.Exit(0)
-		}
-		// Drain any response.
-		xhttp.DrainBody(resp.Body)
-		// 400 response may mean sever is configured with https
-		if resp.StatusCode == http.StatusBadRequest {
-			// Try with https
-			u.Scheme = "https"
-			resp, err = client.Get(u.String())
-			if err != nil {
-				// GET failed exit
-				log.Fatalln(err)
-			}
-			if resp.StatusCode == http.StatusOK {
-				// Drain any response.
-				xhttp.DrainBody(resp.Body)
-				// exit with success
-				os.Exit(0)
-			}
-			// Drain any response.
-			xhttp.DrainBody(resp.Body)
-		}
-		// Execution reaching here means none of
-		// the success cases were satisfied
-		os.Exit(1)
-	}
-	os.Exit(0)
-}

docs/orchestration/docker-compose/docker-compose.yaml

@@ -1,4 +1,4 @@
-version: '2'
+version: '3.7'
 
 # starts 4 docker containers running minio server instances. Each
 # minio server's web interface will be accessible on the host at port
@@ -14,6 +14,13 @@ services:
       MINIO_ACCESS_KEY: minio
       MINIO_SECRET_KEY: minio123
     command: server http://minio1/data http://minio2/data http://minio3/data http://minio4/data 
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio1:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
+
   minio2:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
     volumes:
@@ -24,6 +31,13 @@ services:
       MINIO_ACCESS_KEY: minio
       MINIO_SECRET_KEY: minio123
     command: server http://minio1/data http://minio2/data http://minio3/data http://minio4/data 
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio2:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
+
   minio3:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
     volumes:
@@ -34,6 +48,13 @@ services:
       MINIO_ACCESS_KEY: minio
       MINIO_SECRET_KEY: minio123
     command: server http://minio1/data http://minio2/data http://minio3/data http://minio4/data 
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio3:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
+
   minio4:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
     volumes:
@@ -44,6 +65,12 @@ services:
       MINIO_ACCESS_KEY: minio
       MINIO_SECRET_KEY: minio123
     command: server http://minio1/data http://minio2/data http://minio3/data http://minio4/data 
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio4:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
 ## By default this config uses default local driver,
 ## For custom volumes replace with volume driver configuration.

docs/orchestration/docker-swarm/docker-compose-secrets.yaml

@@ -1,4 +1,4 @@
-version: '3.1'
+version: '3.7'
 
 services:
   minio1:
@@ -22,6 +22,12 @@ services:
     secrets:
       - secret_key
       - access_key
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio1:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio2:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -44,6 +50,12 @@ services:
     secrets:
       - secret_key
       - access_key
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio2:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio3:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -66,6 +78,12 @@ services:
     secrets:
       - secret_key
       - access_key
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio3:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio4:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -88,6 +106,12 @@ services:
     secrets:
       - secret_key
       - access_key
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio4:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
 volumes:
   minio1-data:

docs/orchestration/docker-swarm/docker-compose.yaml

@@ -26,6 +26,12 @@ services:
         constraints:
           - node.labels.minio1==true
     command: server http://minio1/export http://minio2/export http://minio3/export http://minio4/export
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio1:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio2:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -52,6 +58,12 @@ services:
         constraints:
           - node.labels.minio2==true
     command: server http://minio1/export http://minio2/export http://minio3/export http://minio4/export
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio2:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio3:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -78,6 +90,12 @@ services:
         constraints:
           - node.labels.minio3==true
     command: server http://minio1/export http://minio2/export http://minio3/export http://minio4/export
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio3:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
   minio4:
     image: minio/minio:RELEASE.2019-08-14T20-37-41Z
@@ -104,6 +122,12 @@ services:
         constraints:
           - node.labels.minio4==true
     command: server http://minio1/export http://minio2/export http://minio3/export http://minio4/export
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://minio4:9000/minio/health/live"]
+      interval: 1m30s
+      timeout: 20s
+      retries: 3
+      start_period: 3m
 
 volumes:
   minio1-data: