init

.gitignore

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+.idea
+.pyc

README.md

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+# Blue/Green deployment wih Docker compose, Nginx, Consul and Registrator
+
+* Run `docker network create consul` to create a new network;
+* Run `docker-compose -f docker-compose-consul.yml up -d` to start Consul and Registrator;
+* Open in browser `http://localhost:8500/` to check;
+* Run `./deploy.sh` to first run;
+* Open in browser `http://localhost/` to check;
+* Run `./deploy.sh` to imitate deploying of a new app;
+* Open in browser `http://localhost/` to check a new version;
+* Run `./rollback.sh` to imitate a rollback;
+* Open in browser `http://localhost/` to check an old version;
+* Use `python2.7 test.py` in a new terminal to be sure that an app is always online during a deploy/rollback.

app/Dockerfile

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+FROM nginx:1.11.12
+
+RUN rm /etc/nginx/conf.d/default.conf
+
+ADD app.conf /etc/nginx/conf.d/app.conf
+
+RUN mkdir /app
+
+ADD index.html /app

app/app.conf

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+server {
+    listen 80 default_server;
+    server_name localhost;
+
+    location / {
+        root /app;
+    }
+}

app/index.html

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+Thu Oct 12 19:46:09 MSK 2017

deploy.sh

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+#!/usr/bin/env bash
+
+set -e
+
+kv=http://localhost:8500/v1/kv/deploy/backend
+
+if [[ "$(docker images -q app:latest 2> /dev/null)" == "" ]]
+then
+    echo 'Build new app:latest image'
+    cd app
+    docker build . -t app:latest
+    cd ..
+fi
+if [[ "$(docker images -q app:new 2> /dev/null)" == "" ]]
+then
+    echo 'Build new app:new image'
+    cd app
+    docker build . -t app:new
+    cd ..
+fi
+docker exec nginx true 2>/dev/null || docker-compose up -d
+
+date > app/index.html
+
+echo 'Build new image'
+cd app
+docker build . -t app:new
+cd ..
+
+echo 'Update green container'
+docker-compose up -d green
+
+echo 'Set green container as working'
+curl -X PUT -d 'green' ${kv}
+
+echo 'Check new app'
+status=$(curl http://localhost -o /dev/null -Isw '%{http_code}\n')
+if [[ ${status} != "200" ]]
+then
+    echo 'Bad HTTP response:';
+    echo ${status};
+
+    echo 'Set blue container as working'
+    curl -X PUT -d 'blue' ${kv}
+
+    echo 'Remove new container'
+    docker tag app:latest app:new
+
+    exit 1;
+fi
+
+echo 'Set old container as previous'
+docker tag app:latest app:previous
+
+echo 'Set new container as latest'
+docker tag app:new app:latest
+
+echo 'Update blue container'
+docker-compose up -d blue
+
+echo 'Set blue container as working'
+curl -X PUT -d 'blue' ${kv}
+
+echo 'Stop green container'
+docker-compose stop green

docker-compose-consul.yml

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+version: '3.1'
+
+# https://www.consul.io/intro/index.html
+# http://gliderlabs.github.io/registrator/latest/
+
+services:
+  consul:
+    hostname: consul
+    container_name: consul
+    image: consul:latest
+    environment:
+      - CONSUL_LOCAL_CONFIG={"disable_update_check":true}
+    entrypoint:
+      - consul
+      - agent
+      - -server
+      - -bootstrap
+      - -data-dir=/data
+      - -bind={{ GetInterfaceIP "eth0" }}
+      - -client=0.0.0.0
+      - -ui
+    volumes:
+      - consul:/data
+    networks:
+      - consul
+    ports:
+      - 8500:8500
+
+  registrator:
+    container_name: registrator
+    command: -internal consul://consul:8500
+    privileged: true
+    image: gliderlabs/registrator:latest
+    links:
+      - consul
+    volumes:
+      - /var/run/docker.sock:/tmp/docker.sock
+    networks:
+      - consul
+
+networks:
+  consul:
+    external:
+      name: consul
+
+volumes:
+  consul:

docker-compose.yml

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+version: '3.1'
+
+services:
+  blue:
+    container_name: blue
+    image: app:latest
+    environment:
+      - SERVICE_80_NAME=blue
+      - SERVICE_80_TAGS=backends
+    networks:
+      - app
+      - consul
+
+  green:
+    container_name: green
+    image: app:new
+    environment:
+      - SERVICE_80_NAME=green
+      - SERVICE_80_TAGS=backends
+    networks:
+      - app
+      - consul
+
+  nginx:
+    container_name: nginx
+    build: ./nginx/
+    environment:
+      - SERVICE_NAME=nginx
+      - SERVICE_TAGS=nginx
+    external_links:
+      - consul
+    links:
+      - blue
+      - green
+    networks:
+      - app
+      - consul
+    ports:
+      - 80:80
+
+networks:
+  app:
+  consul:
+    external:
+      name: consul

nginx/Dockerfile

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+FROM nginx:1.11.12
+
+RUN apt-get update -qqy && apt-get -qqy install curl runit wget unzip && \
+    rm -rf /var/lib/apt/lists/* /var/cache/apt/*
+
+RUN wget https://releases.hashicorp.com/consul-template/0.19.3/consul-template_0.19.3_linux_amd64.zip && \
+    unzip -d /usr/local/bin consul-template_0.19.3_linux_amd64.zip && \
+    rm -rf consul-template_0.19.3_linux_amd64.zip
+
+ADD nginx.service /etc/service/nginx/run
+ADD consul-template.service /etc/service/consul-template/run
+RUN mkdir /etc/consul-templates
+ADD nginx.conf.ctmpl /etc/consul-templates
+RUN chmod +x /etc/service/nginx/run && chmod +x /etc/service/consul-template/run
+RUN rm /etc/nginx/conf.d/default.conf
+
+CMD ["/usr/bin/runsvdir", "/etc/service"]

nginx/consul-template.service

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+#!/bin/sh
+
+exec consul-template \
+     -consul-addr consul:8500 \
+     -template "/etc/consul-templates/nginx.conf.ctmpl:/etc/nginx/conf.d/nginx.conf:sv hup nginx"

nginx/nginx.conf.ctmpl

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+upstream blue {
+    {{ range service "backends.blue" }}
+        server {{ .Name }}:{{ .Port }};
+    {{ else }}
+        {{ range service "backends.green" }}
+            server {{ .Name }}:{{ .Port }};
+        {{ else }}
+            server 127.0.0.1:12345;
+        {{ end }}
+    {{ end }}
+}
+
+upstream green {
+    {{ range service "backends.green" }}
+        server {{ .Name }}:{{ .Port }};
+    {{ else }}
+        {{ range service "backends.blue" }}
+            server {{ .Name }}:{{ .Port }};
+        {{ else }}
+            server 127.0.0.1:12345;
+        {{ end }}
+    {{ end }}
+}
+
+server {
+    listen 80 default_server;
+    server_name localhost;
+
+    location / {
+        add_header Pragma no-cache;
+        add_header Cache-Control no-cache;
+        {{ with $key_value := keyOrDefault "deploy/backend" "blue" }}
+            {{ if or (eq $key_value "blue") (eq $key_value "green") }}
+                proxy_pass http://{{ $key_value }};
+            {{ else }}
+                proxy_pass http://blue;
+            {{ end }}
+        {{ end }}
+        proxy_set_header Host $host;
+        proxy_set_header X-Scheme $scheme;
+        proxy_set_header X-Forwarded-Protocol $scheme;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_http_version 1.1;
+    }
+}

nginx/nginx.service

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+#!/bin/sh
+
+/usr/sbin/nginx -t && exec /usr/sbin/nginx -g "daemon off;"

rollback.sh

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+#!/usr/bin/env bash
+
+set -e
+
+kv=http://localhost:8500/v1/kv/deploy/backend
+
+docker exec nginx true 2>/dev/null || docker-compose up -d
+
+echo 'Set previous container as latest'
+docker tag app:previous app:latest
+docker tag app:previous app:new
+
+echo 'Update green container'
+docker-compose up -d green
+
+echo 'Set green container as working'
+curl -X PUT -d 'green' ${kv}
+
+echo 'Update blue container'
+docker-compose up -d blue
+
+echo 'Set blue container as working'
+curl -X PUT -d 'blue' ${kv}
+
+echo 'Stop green container'
+docker-compose stop green

test.py

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+import httplib
+
+
+def get_status_code(host, path="/"):
+    try:
+        conn = httplib.HTTPConnection(host)
+        conn.request("HEAD", path)
+        return conn.getresponse().status
+    except StandardError:
+        return None
+
+
+while True:
+    print get_status_code('localhost')