add script for easier setup of mailserver

Signed-off-by: Jakub Sokołowski <jakub@status.im>

.gitignore

@@ -68,5 +68,4 @@ Session.vim
 /cmd/*/.ethereum/
 
 # created for running container
-_assets/compose/mailserver/config.json
 _assets/compose/bootnode/keys

MAILSERVER.md

@@ -0,0 +1,26 @@
+# Description
+
+This document describes the two easiest ways to start a Status Mailserver:
+
+* [Docker Compose](https://docs.docker.com/compose/) - More self-contained and portable
+* [Systemd Service](https://www.freedesktop.org/wiki/Software/systemd/) - More local and configurable
+
+## Docker Compose
+
+The simplest way is to just use:
+```
+make run-mailserver-docker
+```
+This will generate the necessary config, compose and then start the container.
+
+For more details read the [README](_assets/compose/mailserver/README.md).
+
+## Systemd Service
+
+The other way is to run the `mailserver` under `systemd`:
+```
+make run-mailserver-systemd
+```
+This will generate the necessary config, define and then start the service.
+
+For more details read the [README](_assets/systemd/README.md).

Makefile

@@ -278,7 +278,7 @@ ci: lint canary-test test-unit test-e2e ##@tests Run all linters and tests at on
 ci-race: lint canary-test test-unit test-e2e-race ##@tests Run all linters and tests at once + race
 
 clean: ##@other Cleanup
-	rm -fr build/bin/*
+	rm -fr build/bin/* mailserver-config.json
 
 deep-clean: clean
 	rm -Rdf .ethereumtest/StatusChain
@@ -298,8 +298,11 @@ update-fleet-config: ##@other Update fleets configuration from fleets.status.im
 	@go generate ./static
 	@echo "Done"
 
-run-bootnode: ##@Easy way to run a bootnode locally with Docker Compose
+run-bootnode-docker: ##@Easy way to run a bootnode locally with Docker Compose
 	cd _assets/compose/bootnode/ && $(MAKE)
 
-run-mailserver: ##@Easy way to run a mailserver locally with Docker Compose
+run-mailserver-systemd: ##@Easy way to run a mailserver locally with systemd
-	cd _assets/compose/mailserver/ && $(MAKE)
+	@_assets/systemd/start.sh
+
+run-mailserver-docker: ##@Easy way to run a mailserver locally with Docker Compose
+	@cd _assets/compose/mailserver/ && $(MAKE)

README.md

@@ -9,7 +9,7 @@
 - [How to Contribute](CONTRIBUTING.md)
 - [How to Release](RELEASING.md)
 - [How to run a Bootnode](_assets/compose/bootnode)
-- [How to run a Mailserver](_assets/compose/mailserver)
+- [How to run a Mailserver](MAILSERVER.md)
 - [How to configure status-go](/config)
 
 # License

_assets/compose/mailserver/Makefile

@@ -1,4 +1,4 @@
-GIT_ROOT = $(shell git rev-parse --show-toplevel)
+export GIT_ROOT = $(shell git rev-parse --show-toplevel)
 
 RED    := $(shell tput -Txterm setaf 1)
 GREEN  := $(shell tput -Txterm setaf 2)
@@ -45,12 +45,10 @@ logs:
 	docker-compose logs -f -t --tail=100
 
 enode:
-	@curl -s -XPOST http://localhost:$(RPC_PORT)/ \
+	@$(GIT_ROOT)/_assets/scripts/get_enode.sh
-		-H 'Content-type: application/json' \
-		-d '{"jsonrpc":"2.0","method":"admin_nodeInfo","params":[],"id":1}' \
-		| jq -r '.result.enode' \
-		| grep -oP '\Kenode://[^?]+'
 
+config:
+	@$(GIT_ROOT)/_assets/scripts/gen_config.sh
 
 info:
 	@echo "$(GREEN)Your mailserver is listening on:$(RESET) $(BOLD)$(PUBLIC_IP):$(LISTEN_PORT)$(RESET)"
@@ -58,22 +56,9 @@ info:
 	@echo "$(GREEN)Your enode address is:$(RESET)"
 
 show:
-	@docker ps --filter='name=$(CONTAINER_NAME)' --format="table {{.ID}}\t{{.Names}}\t{{.Status}}\t{{.Ports}}"
+	@docker ps \
-
+		--filter='name=$(CONTAINER_NAME)' \
-config: ##@ Generate config for mailserver with current public IP.
+		--format="table {{.ID}}\t{{.Names}}\t{{.Status}}\t{{.Ports}}"
-	@cat $(GIT_ROOT)/config/cli/fleet-$(FLEET_NAME).json \
-		| jq '.AdvertiseAddr = "$(PUBLIC_IP)"' \
-		| jq '.HTTPEnabled = true' \
-		| jq '.HTTPHost = "0.0.0.0"' \
-		| jq '.HTTPPort= $(RPC_PORT)' \
-		| jq '.APIModules = "$(API_MODULES)"' \
-		| jq '.RegisterTopics = ["$(REGISTER_TOPIC)"]' \
-		| jq '.WhisperConfig.Enabled = true' \
-		| jq '.WhisperConfig.EnableMailServer = true' \
-		| jq '.WhisperConfig.LightClient = false' \
-		| jq '.WhisperConfig.MailServerPassword = "$(MAIL_PASSWORD)"' \
-		> config.json
 
 clean:
-	rm -f config.json
 	docker-compose rm -s -f

_assets/compose/mailserver/README.md

@@ -18,7 +18,7 @@ To simply start a container run `make`, other commands include:
 * `make stop` - Stops the container.
 * `make show` - Shows you current status of the container.
 * `make logs` - Shows you logs of the container.
-* `make config` - Creates `config.json` with your Public IP.
+* `make config` - Creates `${DATA_PATH}/config.json` with your Public IP.
 * `make enode` - Shows `enode://` address of the container.
 
 # Settings
@@ -35,6 +35,8 @@ All settings are passed through environment variables:
 * `MAIL_PASSWORD` - Basic HTTP auth password for mailserver. (Default: `status-offline-inbox`)
 * `LOG_LEVEL` - Set level of log messages to show. (`ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`)
 
+The generated configuration file end up under `${DATA_PATH}/config.json`.
+
 # Known Issues
 
 If the discovery of your Public IP does not work please simply export the `PUBLIC_IP` env variable.
@@ -50,7 +52,7 @@ bee56564926d        status-go-mailserver   Up 6 minutes        8080/tcp, 127.0.0
 Your mailserver is listening on: 1.2.3.4:443
 Make sure that address and port are available from the internet!
 Your enode address is:
-enode://dccd2f3c1df42c23af6672df28f287893ab70a5d45668637576a759b6db10b83e83fc02598f36c80ac094fbf8621419153cfe539f56d278ab099da21800f880c@127.0.0.1:30303
+enode://dccd2f3c1df42c23af6672df28f287893ab70a5d45668637576a759b6db10b83e83fc02598f36c80ac094fbf8621419153cfe539f56d278ab099da21800f880c@1.2.3.4:30303
 ```
 
 # F.A.Q.

_assets/compose/mailserver/docker-compose.yml

@@ -11,5 +11,5 @@ services:
       - '0.0.0.0:${LISTEN_PORT}:30303/tcp'
       - '0.0.0.0:${LISTEN_PORT}:30303/udp'
     volumes:
-      - '${PWD}/config.json:/config.json'
+      - '${DATA_PATH}/config.json:/config.json'
       - '${DATA_PATH}:/data'

_assets/scripts/gen_config.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+GIT_ROOT=$(cd "${BASH_SOURCE%/*}" && git rev-parse --show-toplevel)
+
+# Settings & defaults
+RPC_PORT="${RPC_PORT:-8545}"
+API_MODULES="${API_MODULES:-eth,net,web3,admin}"
+FLEET_NAME="${FLEET_NAME:-eth.beta}"
+REGISTER_TOPIC="${REGISTER_TOPIC:-whispermail}"
+MAIL_PASSWORD="${MAIL_PASSWORD:-status-offline-inbox}"
+DATA_PATH="${DATA_PATH:-/var/tmp/status-go-mail}"
+CONFIG_PATH="${CONFIG_PATH:-${DATA_PATH}/config.json}"
+
+if [[ -e "${CONFIG_PATH}" ]]; then
+  echo "Config already exits. Remove it to generate a new one."
+  exit 0
+fi
+
+# Necessary to make mailserver available publicly
+export PUBLIC_IP=$(curl -s https://ipecho.net/plain)
+
+# Assemble the filter for changing the config JSON
+JQ_FILTER_ARRAY=(
+  ".AdvertiseAddr = \"${PUBLIC_IP}\""
+  ".HTTPEnabled = true"
+  ".HTTPHost = \"0.0.0.0\""
+  ".HTTPPort= ${RPC_PORT}"
+  ".APIModules = \"${API_MODULES}\""
+  ".RegisterTopics = [\"${REGISTER_TOPIC}\"]"
+  ".WhisperConfig.Enabled = true"
+  ".WhisperConfig.EnableMailServer = true"
+  ".WhisperConfig.LightClient = false"
+  ".WhisperConfig.MailServerPassword = \"${MAIL_PASSWORD}\""
+)
+
+JQ_FILTER=$(printf " | %s" "${JQ_FILTER_ARRAY[@]}")
+
+echo "Generating config at: ${CONFIG_PATH}"
+
+cat "${GIT_ROOT}/config/cli/fleet-${FLEET_NAME}.json" \
+    | jq "${JQ_FILTER:3}" > "${CONFIG_PATH}"

_assets/scripts/get_enode.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+RPC_ADDR="${RPC_ADDR:-localhost}"
+RPC_PORT="${RPC_PORT:-8545}"
+# might be provided by parent
+if [[ -z "${PUBLIC_IP}" ]]; then
+    PUBLIC_IP=$(curl -s https://ipecho.net/plain)
+fi
+
+# query local 
+RESP_JSON=$(
+    curl -s -XPOST http://${RPC_ADDR}:${RPC_PORT}/ \
+        -H 'Content-type: application/json' \
+        -d '{"jsonrpc":"2.0","method":"admin_nodeInfo","params":[],"id":1}'
+)
+if [[ "$?" -ne 0 ]]; then
+    echo "RPC port not up, unable to query enode address!" 1>&2
+    exit 1
+fi
+
+# extract enode from JSON response
+ENODE_RAW=$(echo "${RESP_JSON}" | jq -r '.result.enode')
+# drop arguments at the end of enode address
+ENODE_CLEAN=$(echo "${ENODE_RAW}" | grep -oP '\Kenode://[^?]+')
+
+# replace localhost with public IP
+echo "${ENODE_CLEAN}" | sed s/127.0.0.1/${PUBLIC_IP}/

_assets/systemd/README.md

@@ -0,0 +1,52 @@
+# Status Mailserver
+
+This folder contains setup for running your own Status Mailserver.
+It uses [Systemd](https://www.freedesktop.org/wiki/Software/systemd/) for managing the Status Mailserver service.
+
+The steps it takes are:
+
+* Builds statusd
+* Generates `statusd` config
+* Generates `systemd` service
+* Starts the service
+
+# Usage
+
+To simply configure and start the service run `./start.sh`.
+
+In order to manage the new `statusd` service you use `systemctl` command:
+
+* `systemctl --user start statusd` - Start the service
+* `systemctl --user stop statusd` - Stop the service
+* `systemctl --user status statusd` - Check service status
+* `systemctl --user disable statusd` - Disable the service
+* `journalctl --user-unit statusd` - Read the service logs
+
+If you want to remove the service you can just remove its definition:
+```
+systemctl --user stop statusd
+rm ~/.config/systemd/user/statusd.service
+systemctl --user daemon-reload
+```
+
+# Settings
+
+All settings are passed through environment variables:
+
+* `SERVICE_NAME` - Name of the `systemd` service to be created. (Default: `statusd`)
+* `PUBLIC_IP` - Your IP visible from the internet and advertised by the Mailserver.
+* `LISTEN_PORT` - Mailserver TCP & UDP port, by default it's `30303` but you might want to use `443`.
+* `RPC_PORT` - Control port making it possible to use the [JSON-RPC API](https://github.com/ethereum/wiki/wiki/JSON-RPC).
+* `API_MODULES` - API modules to be made available via the `RPC_PORT`.
+* `DATA_PATH` - Location of Mailserver storage and keys. (Default: `/var/tmp/status-go-mail`)
+* `REGISTER_TOPIC` - Mynamic mailserver discovery topic. (Default: `whispermail`)
+* `MAIL_PASSWORD` - Basic HTTP auth password for mailserver. (Default: `status-offline-inbox`)
+* `LOG_LEVEL` - Set level of log messages to show. (`ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`)
+
+The generated configuration file end up under `${DATA_PATH}/config.json`.
+
+# Known Issues
+
+* `No journal files were opened due to insufficient permissions.` from `systemctl`
+  - To see logs of a user systemd service you need to be a member of `systemd-journal` group.
+  - Use: `bash usermod -a -G systemd-journal ${USER}`

_assets/systemd/gen_service.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+GIT_ROOT=$(cd "${BASH_SOURCE%/*}" && git rev-parse --show-toplevel)
+
+mkdir -p "${HOME}/.config/systemd/user"
+
+cat >"${HOME}/.config/systemd/user/${SERVICE_NAME}.service" << EOF
+[Unit]
+Description=Status.im Mailserver Service
+
+[Service]
+Type=notify
+Restart=on-failure
+WatchdogSec=60s
+WorkingDirectory=${DATA_PATH}
+ExecStart=${GIT_ROOT}/build/bin/statusd \\
+    -log "${LOG_LEVEL}" \\
+    -log-without-color \\
+    -dir "${DATA_PATH}" \\
+    -c "./config.json"
+
+[Install]
+WantedBy=default.target
+EOF

_assets/systemd/start.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+RED=$(tput -Txterm setaf 1)
+GRN=$(tput -Txterm setaf 2)
+YLW=$(tput -Txterm setaf 3)
+RST=$(tput -Txterm sgr0)
+BLD=$(tput bold)
+
+GIT_ROOT=$(cd "${BASH_SOURCE%/*}" && git rev-parse --show-toplevel)
+
+# Settings & defaults
+export SERVICE_NAME="${SERVICE_NAME:-statusd}"
+export LOG_LEVEL="${LOG_LEVEL:-INFO}"
+export LISTEN_PORT="${LISTEN_PORT:-30303}"
+export DATA_PATH="${DATA_PATH:-/var/tmp/status-go-mail}"
+# Necessary to make mailserver available publicly
+export PUBLIC_IP=$(curl -s https://ipecho.net/plain)
+
+function show_info() {
+  systemctl --user status --no-pager ${SERVICE_NAME}
+  echo
+  # just nice to show at the end
+  ENODE=$("${GIT_ROOT}/_assets/scripts/get_enode.sh")
+
+  echo "* ${GRN}Your mailserver is listening on:${RST} ${BLD}${PUBLIC_IP}:${LISTEN_PORT}${RST}"
+  echo "* ${YLW}Make sure that IP and TCP port are available from the internet!${RST}"
+  echo -e "${GRN}Your enode address is:${RST}\n${ENODE}"
+  exit 0
+}
+
+if ! [[ -x "$(command -v systemctl)" ]]; then
+  echo "${RED}Your system does not have systemd!${RST}"
+  exit 1
+fi
+
+# if the service is already up just show some info
+if systemctl --user is-active --quiet ${SERVICE_NAME}; then
+  echo "${YLW}Service already started!${RST}"
+  show_info
+fi
+
+# if the service has failed just show the status
+if systemctl --user is-failed --quiet ${SERVICE_NAME}; then
+  echo "${RED}Service has failed!${RST}"
+  systemctl --user status --no-pager ${SERVICE_NAME}
+  exit 1
+fi
+
+# Build the statusd binary
+# TODO possibly download it in the future
+if [[ ! -x "${GIT_ROOT}/build/bin/statusd" ]]; then
+    echo "* ${BLD}Building mailserver binary...${RST}"
+    cd "${GIT_ROOT}" && make statusgo
+fi
+
+echo "* ${BLD}Generating '${SERVICE_NAME}' config...${RST}"
+"${GIT_ROOT}/_assets/scripts/gen_config.sh"
+
+echo "* ${BLD}Generating '${SERVICE_NAME}' service...${RST}"
+"${GIT_ROOT}/_assets/systemd/gen_service.sh"
+
+echo "* ${BLD}Enabling '${SERVICE_NAME}' service...${RST}"
+systemctl --user enable ${SERVICE_NAME}
+
+echo "* ${BLD}Starting '${SERVICE_NAME}' service...${RST}"
+systemctl --user restart ${SERVICE_NAME}
+
+show_info

cmd/statusd/main.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/log"
 	gethmetrics "github.com/ethereum/go-ethereum/metrics"
+	"github.com/okzk/sdnotify"
 	"github.com/status-im/status-go/api"
 	"github.com/status-im/status-go/logutils"
 	nodemetrics "github.com/status-im/status-go/metrics/node"
@@ -134,6 +135,16 @@ func main() {
 		return
 	}
 
+	err = sdnotify.Ready()
+	if err == sdnotify.ErrSdNotifyNoSocket {
+		logger.Debug("sd_notify socket not available")
+	} else if err != nil {
+		logger.Warn("sd_notify READY call failed", "error", err)
+	} else {
+		// systemd aliveness notifications, affects only Linux
+		go startSystemDWatchdog()
+	}
+
 	// handle interrupt signals
 	interruptCh := haltOnInterruptSignal(backend.StatusNode())
 
@@ -168,6 +179,9 @@ func main() {
 	if gethNode != nil {
 		// wait till node has been stopped
 		gethNode.Wait()
+		if err := sdnotify.Stopping(); err != nil {
+			logger.Warn("sd_notify STOPPING call failed", "error", err)
+		}
 	}
 }
 
@@ -189,6 +203,15 @@ func setupLogging(config *params.NodeConfig) {
 	}
 }
 
+// loop for notifying systemd about process being alive
+func startSystemDWatchdog() {
+	for range time.Tick(30 * time.Second) {
+		if err := sdnotify.Watchdog(); err != nil {
+			logger.Warn("sd_notify WATCHDOG call failed", "error", err)
+		}
+	}
+}
+
 // startCollectingStats collects various stats about the node and other protocols like Whisper.
 func startCollectingNodeMetrics(interruptCh <-chan struct{}, statusNode *node.StatusNode) {
 	logger.Info("Starting collecting node metrics")

go.mod

@@ -25,6 +25,7 @@ require (
 	github.com/mutecomm/go-sqlcipher v0.0.0-20190227152316-55dbde17881f
 	github.com/pborman/uuid v1.2.0
 	github.com/prometheus/tsdb v0.10.0 // indirect
+	github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd
 	github.com/russolsen/transit v0.0.0-20180705123435-0794b4c4505a
 	github.com/status-im/doubleratchet v2.0.0+incompatible
 	github.com/status-im/keycard-go v0.0.0-20190424133014-d95853db0f48 // indirect

go.sum

@@ -457,6 +457,8 @@ github.com/naoina/toml v0.0.0-20170918210437-9fafd6967416/go.mod h1:NBIhNtsFMo3G
 github.com/nsf/termbox-go v0.0.0-20170211012700-3540b76b9c77/go.mod h1:IuKpRQcYE1Tfu+oAQqaLisqDeXgjyyltCfsaoYN18NQ=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/olekukonko/tablewriter v0.0.0-20170128050532-febf2d34b54a h1:m6hB6GkmZ/suOSKZM7yx3Yt+7iZ9HNfzacCykJqgXA8=
+github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd h1:+iAPaTbi1gZpcpDwe/BW1fx7Xoesv69hLNGPheoyhBs=
+github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd/go.mod h1:4soZNh0zW0LtYGdQ416i0jO0EIqMGcbtaspRS4BDvRQ=
 github.com/olekukonko/tablewriter v0.0.0-20170128050532-febf2d34b54a/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=

vendor/github.com/okzk/sdnotify/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 okzk
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/okzk/sdnotify/README.md

@@ -0,0 +1,15 @@
+# sdnotify
+
+sd_notify utility for golang.
+
+## Installation
+
+    go get github.com/okzk/sdnotify
+
+## Example
+
+see [sample/main.go](sample/main.go)
+
+## License
+
+MIT

vendor/github.com/okzk/sdnotify/notify.go

@@ -0,0 +1,9 @@
+// +build !linux
+
+package sdnotify
+
+// SdNotify sends a specified string to the systemd notification socket.
+func SdNotify(state string) error {
+	// do nothing
+	return nil
+}

vendor/github.com/okzk/sdnotify/notify_linux.go

@@ -0,0 +1,23 @@
+package sdnotify
+
+import (
+	"net"
+	"os"
+)
+
+// SdNotify sends a specified string to the systemd notification socket.
+func SdNotify(state string) error {
+	name := os.Getenv("NOTIFY_SOCKET")
+	if name == "" {
+		return ErrSdNotifyNoSocket
+	}
+
+	conn, err := net.DialUnix("unixgram", nil, &net.UnixAddr{Name: name, Net: "unixgram"})
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	_, err = conn.Write([]byte(state))
+	return err
+}

vendor/github.com/okzk/sdnotify/util.go

@@ -0,0 +1,39 @@
+package sdnotify
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrSdNotifyNoSocket is the error returned when the NOTIFY_SOCKET does not exist.
+var ErrSdNotifyNoSocket = errors.New("No socket")
+
+// Ready sends READY=1 to the systemd notify socket.
+func Ready() error {
+	return SdNotify("READY=1")
+}
+
+// Stopping sends STOPPING=1 to the systemd notify socket.
+func Stopping() error {
+	return SdNotify("STOPPING=1")
+}
+
+// Reloading sends RELOADING=1 to the systemd notify socket.
+func Reloading() error {
+	return SdNotify("RELOADING=1")
+}
+
+// Errno sends ERRNO=? to the systemd notify socket.
+func Errno(errno int) error {
+	return SdNotify(fmt.Sprintf("ERRNO=%d", errno))
+}
+
+// Status sends STATUS=? to the systemd notify socket.
+func Status(status string) error {
+	return SdNotify("STATUS=" + status)
+}
+
+// Watchdog sends WATCHDOG=1 to the systemd notify socket.
+func Watchdog() error {
+	return SdNotify("WATCHDOG=1")
+}

vendor/modules.txt

@@ -307,6 +307,8 @@ github.com/multiformats/go-multistream
 github.com/mutecomm/go-sqlcipher
 # github.com/olekukonko/tablewriter v0.0.0-20170128050532-febf2d34b54a
 github.com/olekukonko/tablewriter
+# github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd
+github.com/okzk/sdnotify
 # github.com/opentracing/opentracing-go v1.0.2
 github.com/opentracing/opentracing-go
 github.com/opentracing/opentracing-go/ext