How to wait on another container using docker-compose

docker-compose.yml

version: "3.7"
services:
  fupisha:
    build:
      context: .
    container_name: fupisha-backend
    depends_on:
      - postgres
      - redis
    command:
      [
        "./wait-for-it.sh",
        "postgres:5432",
        "redis:6379",
        "--strict",
        "--timeout=300",
        "--",
        "./fupisha",
        "-t",
        "./templates/email",
      ]
    ports:
      - 8888:8888
      - 53:53/udp
      - 80:80
      - 2345:2345
      - 443:443
    volumes:
      - ./fupisha:/fupisha
    tty: true
    networks:
      - backend

  postgres:
    image: postgres:12.2
    container_name: postgres
    ports:
      - 5432:5432
    environment:
      POSTGRES_DB: "fupisha"
      POSTGRES_USER: "fupisha"
      POSTGRES_PASSWORD: "fupisha"
    volumes:
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
      - pgdata:/var/lib/postgresql/data
    networks:
      - backend

  redis:
    image: redis:5.0.7
    container_name: cache
    ports:
      - 6379:6379
    command: redis-server --appendonly yes --requirepass Fup1sha
    volumes:
      - redisdata:/data
    networks:
      - backend

volumes:
  pgdata:
  redisdata:
  fupisha:

networks:
  backend:
    driver: "bridge"

Dockerfile

# Start from the latest golang base image
FROM golang:1.14-alpine as builder

# Add Maintainer Info
LABEL maintainer="The Basebandit <@the_basebandit>"

# Set the Current Working Directory inside the container
WORKDIR /backend

# Copy everything from the current directory to the Working Directory inside the container
COPY . .

# Build the Go app
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o mvuvi .

FROM aquasec/trivy:0.4.4 as trivy

# RUN executes commands on top of the current image as a new layer and commits the results
# Scan the golang alpine image before production use
RUN trivy --debug --timeout 4m golang:1.14-alpine && \
  echo "No image vulnerabilities" > result


######## Start a new stage from scratch #######
FROM alpine:3.12  

ENV FUPISHA_USER fupisha
ENV FUPISHA_HOME /go/src/fupisha
ENV FUPISHA_JWT_SECRET Ic@nk33py0uR53cr3tf0rAsL0nga5Y0uW@nt!
ENV FUPISHA_JWT_EXPIRATION_DELTA 6
ENV FUPISHA_JWT_REFRESH_EXPIRATION_DELTA 60
ENV FUPISHA_REDIS_PWD Fupisha
ENV FUPISHA_PG_USER fupisha
ENV FUPISHA_PG_PWD fupisha
ENV FUPISHA_PG_DB fupisha
# postgres is the name of the postgres container in docker-compose file
ENV FUPISHA_PG_HOST postgres 
ENV FUPISHA_PG_PORT 5432
ENV FUPISHA_PG_SSL disable
ENV FUPISHA_EMAIL_SMTP_HOST smtp.gmail.com
ENV FUPISHA_EMAIL_SMTP_PORT 587
ENV FUPISHA_EMAIL_SMTP_USER yourgmailemail
ENV FUPISHA_EMAIL_SMTP_PASSWORD yourappsecret
ENV FUPISHA_EMAIL_FROM_ADDRESS support@fupisha.io
ENV FUPISHA_EMAIL_FROM_NAME Fupisha
ENV FUPISHA_LOGIN_URL https://fupisha.io/auth/login
ENV FUPISHA_TEXT_LOGGING true
ENV FUPISHA_LOG_LEVEL info



RUN apk update && apk --no-cache add ca-certificates
RUN apk --no-cache add  bash

WORKDIR /root/


COPY templates/ /root/templates/
# Copy the Pre-built binary file from the previous stage
COPY --from=builder /backend/fupisha.

#Copy the wait script file from the previous stage
COPY --from=builder /backend/wait-for-it.sh .


# Give permission to run script
RUN chmod +x ./wait-for-it.sh


# Expose ports to the outside world
# port 80 - http server
# port 443 - https server
# port 53/udp - name server
# port 8888 - api server
EXPOSE 8888 443 80 53/udp

# Command to run the executable
CMD ["./fupisha","-t","./templates/email"] 

wait-for-it.sh

#!/usr/bin/env bash
# Use this script to test if a given TCP host/port are available

WAITFORIT_cmdname=${0##*/}

echoerr() { if [[ $WAITFORIT_QUIET -ne 1 ]]; then echo "$@" 1>&2; fi }

usage()
{
    cat << USAGE >&2
Usage:
    $WAITFORIT_cmdname host:port [-s] [-t timeout] [-- command args]
    -h HOST | --host=HOST       Host or IP under test
    -p PORT | --port=PORT       TCP port under test
                                Alternatively, you specify the host and port as host:port
    -s | --strict               Only execute subcommand if the test succeeds
    -q | --quiet                Don't output any status messages
    -t TIMEOUT | --timeout=TIMEOUT
                                Timeout in seconds, zero for no timeout
    -- COMMAND ARGS             Execute command with args after the test finishes
USAGE
    exit 1
}

wait_for()
{
    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
        echoerr "$WAITFORIT_cmdname: waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
    else
        echoerr "$WAITFORIT_cmdname: waiting for $WAITFORIT_HOST:$WAITFORIT_PORT without a timeout"
    fi
    WAITFORIT_start_ts=$(date +%s)
    while :
    do
        if [[ $WAITFORIT_ISBUSY -eq 1 ]]; then
            nc -z $WAITFORIT_HOST $WAITFORIT_PORT
            WAITFORIT_result=$?
        else
            (echo > /dev/tcp/$WAITFORIT_HOST/$WAITFORIT_PORT) >/dev/null 2>&1
            WAITFORIT_result=$?
        fi
        if [[ $WAITFORIT_result -eq 0 ]]; then
            WAITFORIT_end_ts=$(date +%s)
            echoerr "$WAITFORIT_cmdname: $WAITFORIT_HOST:$WAITFORIT_PORT is available after $((WAITFORIT_end_ts - WAITFORIT_start_ts)) seconds"
            break
        fi
        sleep 1
    done
    return $WAITFORIT_result
}

wait_for_wrapper()
{
    # In order to support SIGINT during timeout: http://unix.stackexchange.com/a/57692
    if [[ $WAITFORIT_QUIET -eq 1 ]]; then
        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --quiet --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
    else
        timeout $WAITFORIT_BUSYTIMEFLAG $WAITFORIT_TIMEOUT $0 --child --host=$WAITFORIT_HOST --port=$WAITFORIT_PORT --timeout=$WAITFORIT_TIMEOUT &
    fi
    WAITFORIT_PID=$!
    trap "kill -INT -$WAITFORIT_PID" INT
    wait $WAITFORIT_PID
    WAITFORIT_RESULT=$?
    if [[ $WAITFORIT_RESULT -ne 0 ]]; then
        echoerr "$WAITFORIT_cmdname: timeout occurred after waiting $WAITFORIT_TIMEOUT seconds for $WAITFORIT_HOST:$WAITFORIT_PORT"
    fi
    return $WAITFORIT_RESULT
}

# process arguments
while [[ $# -gt 0 ]]
do
    case "$1" in
        *:* )
        WAITFORIT_hostport=(${1//:/ })
        WAITFORIT_HOST=${WAITFORIT_hostport[0]}
        WAITFORIT_PORT=${WAITFORIT_hostport[1]}
        shift 1
        ;;
        --child)
        WAITFORIT_CHILD=1
        shift 1
        ;;
        -q | --quiet)
        WAITFORIT_QUIET=1
        shift 1
        ;;
        -s | --strict)
        WAITFORIT_STRICT=1
        shift 1
        ;;
        -h)
        WAITFORIT_HOST="$2"
        if [[ $WAITFORIT_HOST == "" ]]; then break; fi
        shift 2
        ;;
        --host=*)
        WAITFORIT_HOST="${1#*=}"
        shift 1
        ;;
        -p)
        WAITFORIT_PORT="$2"
        if [[ $WAITFORIT_PORT == "" ]]; then break; fi
        shift 2
        ;;
        --port=*)
        WAITFORIT_PORT="${1#*=}"
        shift 1
        ;;
        -t)
        WAITFORIT_TIMEOUT="$2"
        if [[ $WAITFORIT_TIMEOUT == "" ]]; then break; fi
        shift 2
        ;;
        --timeout=*)
        WAITFORIT_TIMEOUT="${1#*=}"
        shift 1
        ;;
        --)
        shift
        WAITFORIT_CLI=("$@")
        break
        ;;
        --help)
        usage
        ;;
        *)
        echoerr "Unknown argument: $1"
        usage
        ;;
    esac
done

if [[ "$WAITFORIT_HOST" == "" || "$WAITFORIT_PORT" == "" ]]; then
    echoerr "Error: you need to provide a host and port to test."
    usage
fi

WAITFORIT_TIMEOUT=${WAITFORIT_TIMEOUT:-15}
WAITFORIT_STRICT=${WAITFORIT_STRICT:-0}
WAITFORIT_CHILD=${WAITFORIT_CHILD:-0}
WAITFORIT_QUIET=${WAITFORIT_QUIET:-0}

# Check to see if timeout is from busybox?
WAITFORIT_TIMEOUT_PATH=$(type -p timeout)
WAITFORIT_TIMEOUT_PATH=$(realpath $WAITFORIT_TIMEOUT_PATH 2>/dev/null || readlink -f $WAITFORIT_TIMEOUT_PATH)

WAITFORIT_BUSYTIMEFLAG=""
if [[ $WAITFORIT_TIMEOUT_PATH =~ "busybox" ]]; then
    WAITFORIT_ISBUSY=1
    # Check if busybox timeout uses -t flag
    # (recent Alpine versions don't support -t anymore)
    if timeout &>/dev/stdout | grep -q -e '-t '; then
        WAITFORIT_BUSYTIMEFLAG="-t"
    fi
else
    WAITFORIT_ISBUSY=0
fi

if [[ $WAITFORIT_CHILD -gt 0 ]]; then
    wait_for
    WAITFORIT_RESULT=$?
    exit $WAITFORIT_RESULT
else
    if [[ $WAITFORIT_TIMEOUT -gt 0 ]]; then
        wait_for_wrapper
        WAITFORIT_RESULT=$?
    else
        wait_for
        WAITFORIT_RESULT=$?
    fi
fi

if [[ $WAITFORIT_CLI != "" ]]; then
    if [[ $WAITFORIT_RESULT -ne 0 && $WAITFORIT_STRICT -eq 1 ]]; then
        echoerr "$WAITFORIT_cmdname: strict mode, refusing to execute subprocess"
        exit $WAITFORIT_RESULT
    fi
    exec "${WAITFORIT_CLI[@]}"
else
    exit $WAITFORIT_RESULT
fi

There are some good libraries out there for retry policies. I also wrote a post a while back on doing this without a library: https://upgear.io/blog/simple-golang-retry-function/

If you were deploying to something like kubernetes I would not even worry about adding a retry policy into my code. I would let kubernetes restart my containers for me. Thinking about production, this would give me quick feedback that my app is failing. It has been a while since I messed with docker-compose, but it looks like you might be able to specify a restart policy for your app: https://docs.docker.com/compose/compose-file/#restart_policy