https://habr.com/ru/post/516230/

deploy.sh

#!/bin/bash

usage_msg="Usage: $0 ssh_address local_image_tag"
ssh_address=${1?$usage_msg}
image_name=${2?$usage_msg}

echo "Sending gzipped image '$image_name' to '$ssh_address' via ssh..."
docker image save $image_name | gzip | ssh $ssh_address 'zcat | docker image load'

echo "Connecting to '$ssh_address' via ssh to seamlessly deploy '$image_name'..."
( sed "\$a deploy $image_name" | ssh -T $ssh_address ) << 'END_OF_SCRIPT'
if [ "$SHELL" != "/bin/bash" ]
then
	echo "The '$SHELL' shell is not supported by 'deploy.sh'. Set a '/bin/bash' shell for '$USER@$HOSTNAME'."
	exit 1
fi
deploy() {
	local image_name=${1?"Usage: ${FUNCNAME[0]} image_name"}

	ensure-reverse-proxy || return 2
	if get-active-slot $image_name
	then
		local OLD=${image_name}_BLUE
		local new_slot=GREEN
	else
		local OLD=${image_name}_GREEN
		local new_slot=BLUE
	fi
	local NEW=${image_name}_${new_slot}
	echo "Ensuring the '$NEW' container from previous deploy is removed..."
	docker rm -f $NEW || :
	echo "Deploying '$NEW' in place of '$OLD'..."
	docker run \
		--detach \
		--restart always \
		--log-driver journald \
		--name $NEW \
		--network web-gateway \
		$image_name || return 3
	echo "Container started. Checking health..."
	for i in {1..20}
	do
		sleep 1
		if get-service-status $image_name $new_slot
		then
			echo "New '$NEW' service seems OK. Switching heads..."
			sleep 2  # Ensure service is ready
			set-active-slot $image_name $new_slot || return 4
			echo "The '$NEW' service is live!"
			sleep 2  # Ensure all requests were processed
			echo "Stopping '$OLD'..."
			docker stop $OLD
			docker image prune -f
			echo "Deployment successful!"
			return 0
		fi
		echo "New '$NEW' service is not ready yet. Waiting ($i)..."
	done
	echo "New '$NEW' service did not raise, killing it. Failed to deploy T_T"
	docker rm -f $NEW
	return 5
}

ensure-reverse-proxy() {
	is-container-up reverse-proxy && return 0
	echo "Deploying reverse-proxy..."
	docker network create web-gateway
	docker run \
		--detach \
		--restart always \
		--log-driver journald \
		--name reverse-proxy \
		--network web-gateway \
		--publish 80:80 \
		nginx:alpine || return 1
	docker exec reverse-proxy sh -c "> /etc/nginx/conf.d/default.conf"
	docker exec reverse-proxy nginx -s reload
}

is-container-up() {
	local container=${1?"Usage: ${FUNCNAME[0]} container_name"}

	[ -n "$(docker ps -f name=${container} -q)" ]
	return $?
}

get-active-slot() {
	local image=${1?"Usage: ${FUNCNAME[0]} image_name"}

	if is-container-up ${image}_BLUE && is-container-up ${image}_GREEN; then
		echo "Collision detected! Stopping ${image}_GREEN..."
		docker rm -f ${image}_GREEN
		return 0  # BLUE
	fi
	if is-container-up ${image}_BLUE && ! is-container-up ${image}_GREEN; then
		return 0  # BLUE
	fi
	if ! is-container-up ${image}_BLUE; then
		return 1  # GREEN
	fi
}

get-service-status() {
	local usage_msg="Usage: ${FUNCNAME[0]} image_name deployment_slot"
	local image=${1?usage_msg}
	local slot=${2?$usage_msg}

	case $image in
		# Add specific healthcheck paths for your services here
		*) local health_check_port_path=":8080/" ;;
	esac
	local health_check_address="http://${image}_${slot}${health_check_port_path}"
	echo "Requesting '$health_check_address' within the 'web-gateway' docker network:"
	docker run --rm --network web-gateway alpine \
		wget --timeout=1 --quiet --output-document=/dev/null --server-response $health_check_address
	return $?
}

set-active-slot() {
	local usage_msg="Usage: ${FUNCNAME[0]} service_name deployment_slot"
	local service=${1?$usage_msg}
	local slot=${2?$usage_msg}
	[ "$slot" == BLUE ] || [ "$slot" == GREEN ] || return 1
	
	get-nginx-config $service $slot | docker exec --interactive reverse-proxy sh -c "cat > /etc/nginx/conf.d/$service.conf"
	docker exec reverse-proxy nginx -t || return 2
	docker exec reverse-proxy nginx -s reload
}

get-nginx-config() {
	local usage_msg="Usage: ${FUNCNAME[0]} image_name deployment_slot"
	local image=${1?$usage_msg}
	local slot=${2?$usage_msg}
	[ "$slot" == BLUE ] || [ "$slot" == GREEN ] || return 1
	
	local container_name=${image}_${slot}
	case $image in
		# Add specific nginx configs for your services here
		*) nginx-config-simple-service $container_name:8080 ;;
	esac
}

nginx-config-simple-service() {
	local usage_msg="Usage: ${FUNCNAME[0]} proxy_pass"
	local proxy_pass=${1?$usage_msg}

	# WARNING: Mixed tabs and spaces below
	cat <<- EOF
		server {
		    listen 80;
		    location / {
		        proxy_pass http://$proxy_pass;
		    }
		}
	EOF
}

rollback() {
	local image_name=${1?"Usage: ${FUNCNAME[0]} image_name"}

	if get-active-slot $image_name
	then
		local previous_slot=GREEN
		local current_slot=BLUE
	else
		local previous_slot=BLUE
		local current_slot=GREEN
	fi
	docker start ${image_name}_${previous_slot}
	set-active-slot $image_name $previous_slot
	docker stop ${image_name}_${current_slot}
}
END_OF_SCRIPT