Get into the habit of writing together! This is the 13th day of my participation in the "Nuggets Daily New Plan · April Update Challenge", click to view the event details .
After going around, we came back and continued to read
podman api. We reviewed it about two days agoshell, and we decided to useshellit to encapsulatepodman apithe interface. This time we encapsulated three interfacesinfo,_ping, ,/_images/json
Why do you need podman api
Because podmanthe wheel is built, it is convenient for operation and maintenance/developers to call the interface. In short, the interface is provided to avoid us from building the wheel. For this, we can use the apicall directly podman.
Why do we need apiit? Suppose we are doing an automated deployment, during which we want to start a container. If not api, how should we do it? We will call podmanthe command directly, right, and then judge whether it is successful or not based on the output, which is cumbersome and troublesome to migrate (for example, the machine executes the command path is inconsistent), so if necessary api, let's take a look at the specific usage
Start the podman api service
podmanCan socket listen unixandtcp
Use command: podman system serviceopenpodman api
parameter
- --time: session timeout, in seconds, the default is 5 seconds
- --log-level: set
Logthe level, this ispodmanthe syntax, notapithe - --cors: Set CORS Headers (mainly used across domains)
open unix socket
Order:podman --log-level=debug system service -t0 unix:///tmp/podman.sock
The meaning of this command is, open debugon interrupt display, and unixsocket file in/tmp/podman.sock
Open TCP socket
Order:podman --log-level=debug system service -t0 tcp:127.0.0.1:8888
Similar to the above, note that we unixwill replace thetcp
如上，我们启动了podman api unix套接字 和 tcp套接字
请求方法
假设我们使用curl请求获取版本信息
TCP方式请求版本信息
格式: /版本/libpod/info 其中版本信息只要是v开头
命令: curl -s http://127.0.0.1:8881/v3.0.0/libpod/info | jq '.version'
jq是linux格式化json工具
unix套接字方式请求版本信息
格式: d/版本/libpod/info 其中版本信息只要是v开头 ，只不过需要指定unix套接字文件
命令: curl -s --unix-socket /tmp/podman.sock http://d/v3.0.0/libpod/info | jq '.version'
podman 常规请求
请求方法
/info: 获取podman api信息/_ping: 检测podman api状态/_images/json: 获取podman images信息
检测podman状态
使用路由_ping可以检测podman状态，
例如
返回OK则代表podman正常的
获取podman api信息
使用理由/info可以获取podman api信息
例如
使用jq格式化为json
例如使用命令: curl -s http://127.0.0.1:8881/v3.0.0/info | jq
获取images信息
使用理由images/json可以获取podman images信息
例如
使用命令: curl -s http://127.0.0.1:8881/v3.0.0/images/json | jq
使用shell封装podman api
脚本运行之后效果
我们通过bash shell的方式，封装了podman api之后运行的效果
我们再来查看下podman images看看是否和上面对得上
脚本列表
我们将脚本按照模块给分开了，以方便解释脚本含义
main.sh脚本有有个函数为main是该程序的入口podmanEvn.sh该脚本的一些配置变量checkHealth.sh检查podman api是否存活showVersion.sh显示出podman版本信息images.sh镜像操作，目前仅编写了列出镜像
配置变量
我们来看podmanEvn.sh的内容
All are defined as read-only variables, the wrong podmanversion information (this is not important), whether to use tcpor socketto connect podman api, and podman apithe routing information provided
Check if podman api is alive
The function is as follows, if the request result is empty, or the string is not "OK", it will return 2 (abnormal), otherwise it will return 0 (normal)
Display podman version information
This can be used directly with the curlrequest
Display image information
To query imagesinformation, we first calculate podman apihow many records are returned, and then loop to get the information of each part, including name, id, creation time, and size
main function
Because we want to use the functions of other files, we need to introduce them. We generally execute shellin the following ways:
sh xxx.sh./ xxx.sh. xxx.shsource xxx.sh
In fact, the above implementation plans can be summarized into two types, 1. sh xxx.sh2.source xxx.sh
So what's the difference? Why do we use sourceinsteadsh
Because, shwhen we go to execute, we open one 子shell. When the sub- 子shellexecution is completed, the data will not be imported into 父shellit, but sourceit will be executed in it 父shell. This is why we modify the environment variables. re-executed~/.bashrc.source
comprehension
Although shellwriting a script itself is not difficult, and its core is only a few lines of code, but for the robustness of the script, it is not so easy to collapse, we need to write a large number of auxiliary statements to judge whether the statement is successfully executed and so on. What to do after failure, etc. We will add others later api.