Category: IT邦幫忙鐵人賽

參考官方文件的教學如下:
https://prometheus.io/docs/prometheus/latest/configuration/configuration/

Prometheus can reload its configuration at runtime. If the new configuration is not well-formed, the changes will not be applied. A configuration reload is triggered by sending a SIGHUP to the Prometheus process or sending a HTTP POST request to the /-/reload endpoint (when the –web.enable-lifecycle flag is enabled). This will also reload any configured rule files.

而實際的應用方式則是:

• 第一種，向prometheus進行發信號
  kill -HUP pid
• 第二種，向prometheus發送HTTP請求
  curl -XPOST http://127.0.0.1:9090/-/reload
  但是會需要先設定--web.enable-lifecycle參數

   template:
      metadata:
        labels:
          ...
          prometheus: rancher-monitoring-prometheus
      spec:
        containers:
        - args:
          - --web.enable-lifecycle
          image: rancher/mirrored-prometheus-prometheus:v2.27.1
          imagePullPolicy: IfNotPresent
          name: prometheus
          ....

如何製作docker image

1. 到docker hub尋找適合的基礎容器或官方提供的映像檔
2. 自行撰寫需要客製化的部分
3. 撰寫Dockerfile內容
4. 執行command line，指向專案資料夾

docker build –tag NAME .

5. 上傳映像檔至儲存庫

Dockerfile的指令介紹

範例:

1. FROM: 從某個別人建好的容器開始製作自己的容器。如centos:6.7
2. ENV: 定義一些變數後面可使用
3. ARG: 在BUILD IMAGE時可帶入參數
   docker build –build-arg SCRIPT=tmp.js .
4. WORKDIR: 指定下指令的位置
5. RUN: 於CONTAINER下指令
6. COPY: 複製檔案進去
7. CMD: 最後要開始主程式的指令
8. ENTRYPOINT:與CMD相同，差在不會被docker run時帶的指令蓋掉，而是相加

YAML範本：redis-master-controller.yaml

apiVersion: v1
kind: ReplicationController
metadata:
 name: redis-master
 labels:
  name: redis-master
spec:
 replicas: 1
 selector:
  name: redis-master
 template:
  metadata:
   labels:
    name: redis-master
  spec:
   containers:
   - name: master
     image: kubeguide/redis-master
     ports:
     - containerPort: 6379

建立這個Pod

kubectl create -f redis-master-controller.yaml

查看這個ReplicationController

kubectl get rc

查看現有的Pod

kubectl get pods

查看現有ReplicationController的狀態

 kubectl describe rc frontend

這個指令可以列出所有未被tag的image

docker images -q -a | xargs docker inspect --format='{{.Id}}{{range $rt := .RepoTags}} {{$rt}} {{end}}'|grep -v ':'

這個指令可以列出所有被tag為None的image

docker rmi $(docker images --filter "dangling=true" -q --no-trunc)

參考：https://stackoverflow.com/questions/33913020/docker-remove-none-tag-images

必備模組

• openssl
• zlib
• pcre

安裝步驟

cd /tmp
# 下載並安裝pcre
wget https://ftp.pcre.org/pub/pcre/pcre-8.42.zip
unzip pcre-8.42.zip
tar -zxf pcre-8.41.tar.gz
cd pcre-8.41
./configure
make && make install
# 下載並安裝zlib
cd /tmp
wget https://www.zlib.net/zlib-1.2.11.tar.gz
tar -xzvf zlib-1.2.11.tar.gz
tar -zxf zlib-1.2.11.tar.gz
cd zlib-1.2.11
./configure
make && make install
# 下載並安裝openssl
cd /tmp
wget https://www.openssl.org/source/openssl-1.1.0h.tar.gz
tar -xzvf openssl-1.1.0h.tar.gz
tar -zxf openssl-1.0.2k.tar.gz
cd openssl-1.0.2k
./config -fPIC --prefix=/usr
make && make install
# 下載所需的rtmp安裝包
cd /tmp
git clone https://github.com/sergey-dryabzhinsky/nginx-rtmp-module.git
# 下載並安裝nginx
tar -xzvf nginx-1.14.0.tar.gz
useradd nginx # 建立系統使用者
tar zxf nginx-1.12.2.tar.gz
cd nginx-1.12.2
wget https://nginx.org/download/nginx-1.14.0.tar.gz
./configure --user=nginx --add-module=nginx-rtmp-module
make && make install
cd /tmp
rm -f *.tar.gz *.zip

參考資料

• How to Install Nginx with RTMP Module on CentOS 7
• How to Install Nginx with RTMP Module on CentOS 7