无法使用NodePort服务连接到kubernetes中的redis pod

Question

我是kubernetes的新手，我正试图在我的MacBook上使用minikube来编排我的rails应用程序。我的应用程序包括MySQL、Redis和Sidekiq。我正在孤立的pod中运行webapp、sidekiq、redis和数据库。Sidekiq吊舱未连接到redis吊舱。

sidekiq pod的kubectl日志显示：

2020-09-15T14:01:16.978Z 1 TID-gnaz4yzs0 INFO: Booting Sidekiq 4.2.10 with redis options {:url=>"redis://redis:6379/0"}
2020-09-15T14:01:18.475Z 1 TID-gnaz4yzs0 INFO: Running in ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-linux]
2020-09-15T14:01:18.475Z 1 TID-gnaz4yzs0 INFO: See LICENSE and the LGPL-3.0 for licensing details.
2020-09-15T14:01:18.475Z 1 TID-gnaz4yzs0 INFO: Upgrade to Sidekiq Pro for more features and support: http://sidekiq.org
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:459: warning: constant ::Fixnum is deprecated
Error connecting to Redis on redis:6379 (Errno::ECONNREFUSED)
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:345:in `rescue in establish_connection'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:330:in `establish_connection'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:101:in `block in connect'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:293:in `with_reconnect'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:100:in `connect'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:364:in `ensure_connected'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:221:in `block in process'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:306:in `logging'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:220:in `process'
/usr/local/bundle/gems/redis-3.3.1/lib/redis/client.rb:120:in `call'
/usr/local/bundle/gems/redis-3.3.1/lib/redis.rb:251:in `block in info'
/usr/local/bundle/gems/redis-3.3.1/lib/redis.rb:58:in `block in synchronize'
/usr/local/lib/ruby/2.6.0/monitor.rb:230:in `mon_synchronize'
/usr/local/bundle/gems/redis-3.3.1/lib/redis.rb:58:in `synchronize'
/usr/local/bundle/gems/redis-3.3.1/lib/redis.rb:250:in `info'
/usr/local/bundle/gems/sidekiq-4.2.10/lib/sidekiq.rb:113:in `block in redis_info'
/usr/local/bundle/gems/sidekiq-4.2.10/lib/sidekiq.rb:95:in `block in redis'
/usr/local/bundle/gems/connection_pool-2.2.3/lib/connection_pool.rb:63:in `block (2 levels) in with'
/usr/local/bundle/gems/connection_pool-2.2.3/lib/connection_pool.rb:62:in `handle_interrupt'
/usr/local/bundle/gems/connection_pool-2.2.3/lib/connection_pool.rb:62:in `block in with'
/usr/local/bundle/gems/connection_pool-2.2.3/lib/connection_pool.rb:59:in `handle_interrupt'
/usr/local/bundle/gems/connection_pool-2.2.3/lib/connection_pool.rb:59:in `with'
/usr/local/bundle/gems/sidekiq-4.2.10/lib/sidekiq.rb:92:in `redis'
/usr/local/bundle/gems/sidekiq-4.2.10/lib/sidekiq.rb:106:in `redis_info'
/usr/local/bundle/gems/sidekiq-4.2.10/lib/sidekiq/cli.rb:71:in `run'
/usr/local/bundle/gems/sidekiq-4.2.10/bin/sidekiq:12:in `<top (required)>'
/usr/local/bundle/bin/sidekiq:29:in `load'
/usr/local/bundle/bin/sidekiq:29:in `<main>'

我的webapp.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
name: checklist-deployment
spec:
replicas: 2
template:
metadata:
labels:
app: railsapp
spec:
containers:
- name: webapp
image: masettyabhishek/checklist:latest
command: ["rails", "s", "-p", "3001", "-b", "0.0.0.0", "-e", "PRODUCTION"]
ports:
- name: checklist-port
containerPort: 3001
env:
- name: MYSQL_HOST
value: database-service
- name: MYSQL_USER
value: root
- name: MYSQL_PASSWORD
value: Mission2019
- name: MYSQL_DATABASE
value: checklist
- name: MYSQL_ROOT_PASSWORD
value: Mission2019
- name: REDIS_URL
value: redis
- name: REDIS_PORT
value: "6379"
selector:
matchLabels:
app: railsapp

webapps-service.yaml

apiVersion: v1
kind: Service
metadata:
name: webapp-service
spec:
ports:
- port: 3001
protocol: TCP
type: NodePort
selector:
app: railsapp

sidekiq.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
name: sidekiq-deployment
spec:
replicas: 1
template:
metadata:
labels:
instance: sidekiq
spec:
containers:
- name: sidekiq
image: masettyabhishek/checklist:latest
command: ["sidekiq", "-C", "config/sidekiq.yml"]
env:
- name: MYSQL_HOST
value: database-service
- name: MYSQL_USER
value: root
- name: MYSQL_PASSWORD
value: Mission2019
- name: MYSQL_DATABASE
value: checklist
- name: MYSQL_ROOT_PASSWORD
value: Mission2019
- name: REDIS_URL
value: redis
- name: REDIS_PORT
value: "6379"
ports:
- name: redis-port
containerPort: 6379
selector:
matchLabels:
instance: sidekiq

redis.yaml

apiVersion: v1
kind: Pod
metadata:
name: redis-pod
spec:
containers:
- name: redis
image: redis:alpine
command: ["redis-server"]
ports:
- containerPort: 6379
---
apiVersion: v1
kind: Service
metadata:
name: redis
spec:
selector:
name: redis-pod
instance: sidekiq
app: railsapp
type: NodePort
ports:
- port: 6379

这是sidekiq.yml在我的轨道应用

Sidekiq.configure_server do |config|
config.redis = { url: "redis://#{ENV['REDIS_URL']}:#{ENV['REDIS_PORT']}/0"}
end
Sidekiq.configure_client do |config|
config.redis = { url: "redis://#{ENV['REDIS_URL']}:#{ENV['REDIS_PORT']}/0"}
end

这是Dockerfile，如果这有助于回答这个问题的话。

FROM ubuntu:16.04
ENV RUBY_MAJOR="2.6" 
RUBY_VERSION="2.6.3" 
RUBYGEMS_VERSION="3.0.8" 
BUNDLER_VERSION="1.17.3" 
RAILS_VERSION="5.2.1" 
RAILS_ENV="production" 
GEM_HOME="/usr/local/bundle"
ENV BUNDLE_PATH="$GEM_HOME" 
BUNDLE_BIN="$GEM_HOME/bin" 
BUNDLE_SILENCE_ROOT_WARNING=1 
BUNDLE_APP_CONFIG="$GEM_HOME"
ENV PATH="$BUNDLE_BIN:$GEM_HOME/bin:$GEM_HOME/gems/bin:$PATH"
USER root
RUN apt-get update && 
apt-get -y install sudo
RUN echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers && 
addgroup --gid 1024 stars && 
useradd -G stars,sudo -d /home/user --shell /bin/bash -m user
RUN mkdir -p /usr/local/etc 
&& echo 'install: --no-document' >> /usr/local/etc/gemrc 
&& echo 'update: --no-document' >> /usr/local/etc/gemrc
USER user
RUN sudo apt-get -y install --no-install-recommends vim make gcc zlib1g-dev autoconf build-essential libssl-dev libsqlite3-dev 
curl htop unzip mc openssh-server openssl bison libgdbm-dev ruby git libmysqlclient-dev tzdata mysql-client

RUN sudo rm -rf /var/lib/apt/lists/* 
&& sudo curl -fSL -o ruby.tar.gz "http://cache.ruby-lang.org/pub/ruby/$RUBY_MAJOR/ruby-$RUBY_VERSION.tar.gz" 
&& sudo mkdir -p /usr/src/ruby 
&& sudo tar -xzf ruby.tar.gz -C /usr/src/ruby --strip-components=1 
&& sudo rm ruby.tar.gz
USER root
RUN cd /usr/src/ruby 
&& { sudo echo '#define ENABLE_PATH_CHECK 0'; echo; cat file.c; } > file.c.new && mv file.c.new file.c 
&& autoconf 
&& ./configure --disable-install-doc
USER user
RUN cd /usr/src/ruby 
&& sudo make -j"$(nproc)" 
&& sudo make install 
&& sudo gem update --system $RUBYGEMS_VERSION 
&& sudo rm -r /usr/src/ruby
RUN sudo gem install bundler --version "$BUNDLER_VERSION"
RUN sudo mkdir -p "$GEM_HOME" "$BUNDLE_BIN" 
&& sudo chmod 777 "$GEM_HOME" "$BUNDLE_BIN" 
&& sudo gem install rails --version "$RAILS_VERSION"
RUN mkdir -p ~/.ssh && 
chmod 0700 ~/.ssh && 
ssh-keyscan github.com > ~/.ssh/known_hosts
ARG ssh_pub_key
ARG ssh_prv_key
RUN echo "$ssh_pub_key" > ~/.ssh/id_rsa.pub && 
echo "$ssh_prv_key" > ~/.ssh/id_rsa && 
chmod 600 ~/.ssh/id_rsa.pub && 
chmod 600 ~/.ssh/id_rsa
USER root
RUN curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
RUN apt-get install -y nodejs
USER user
WORKDIR /data
RUN sudo mkdir /data/checklist
WORKDIR /data/checklist
ADD Gemfile Gemfile.lock ./
RUN sudo chown -R user /data/checklist
RUN bundle install
ADD . .
RUN sudo chown -R user /data/checklist
EXPOSE 3001
ENV RAILS_SERVE_STATIC_FILES true
ENV RAILS_LOG_TO_STDOUT true
RUN chmod +x ./config/docker/prepare-db.sh && sh ./config/docker/prepare-db.sh
ENTRYPOINT ["bundle", "exec"]
CMD ["sh", "./config/docker/startup.sh"]

kubectl描述svc-reis

➜  checklist kubectl describe svc redis
Name:                     redis
Namespace:                default
Labels:                   <none>
Annotations:              <none>
Selector:                 app=railsapp,instance=sidekiq,name=redis-pod
Type:                     NodePort
IP:                       10.103.6.43
Port:                     <unset>  6379/TCP
TargetPort:               6379/TCP
NodePort:                 <unset>  31886/TCP
Endpoints:                <none>
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

Answer 1

如您所见，redis服务的Endpoints部分没有pod IP，这是Connection refused错误的原因。Pod需要有与服务选择器匹配的标签。用下面的标签更新redis pod应该可以解决这个问题。

apiVersion: v1
kind: Pod
metadata:
name: redis-pod
labels:
instance: sidekiq
app: ailsapp
name: redis-pod
spec:
containers:
- name: redis
image: redis:alpine
command: ["redis-server"]
ports:
- containerPort: 6379