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• Everyone is welcome to actively participate in editing and record how they filled the pits they encountered. Many hands make light work

I. Golang Basics

1. Program throws an exception, but the program crashes directly and is not automatically captured by the framework

Using the GoFrame framework is rigorous and safe. If a program throws an exception, it will be captured by the framework by default. If it is not automatically captured, it may be due to the program logic opening new goroutines independently, causing an exception in the new goroutine. So there are two options for you to choose from:

• It is not recommended to open goroutine in a request to handle the request, as this may cause goroutine to expand rapidly. When there are too many goroutines, it will also affect the overall scheduling of the program at the Go engine level.
• If it is really necessary to start a new goroutine, consider using grpool.AddWithRecover to create a new goroutine, which captures exceptions automatically. For more detailed information, please refer to: Goroutine.

2. Shield some fields in json output

You can achieve this through structure nesting using *struct{} type with no space usage and the omitempty feature, which does not output fields if they are empty.

type User struct {
    Pwd string `json:"pwd"`
    Age int    `json:"age"`
}
type UserOut struct {
    User
    Pwd *struct{} `json:"pwd,omitempty"` // The json name of this field must match the nested field json name, or it will be invalid
}
func TestJson(t *testing.T) {
    u := User{Pwd: "123", Age: 1}
    bb := UserOut{User: u}
    b, _ := json.MarshalIndent(bb, "", "    ")
    t.Log(string(b))
}

II. Compatibility Issues

1. client_tracing.go:73:3: undefined: attribute.Any

The following error:

D:\Program Files\Go\bin\pkg\mod\github.com\gogf\gf@v1.16.6\net\ghttp\internal\client\client_tracing.go:73:3: undefined: attribute.Any
D:\Program Files\Go\bin\pkg\mod\github.com\gogf\gf@v1.16.6\net\ghttp\internal\client\client_tracing_tracer.go:150:3: undefined: attribute.Any
D:\Program Files\Go\bin\pkg\mod\github.com\gogf\gf@v1.16.6\net\ghttp\internal\client\client_tracing_tracer.go:151:3: undefined: attribute.Any

This error is caused by the otel package that goframe depends on having too low a version (the otel package is a third-party package used by OpenTelemetry implemented in Golang, commonly used, with many third-party basic components relying on it), while other third-party dependencies in the project have higher versions of the otel package. According to the Golang module management strategy, the project will use the latest otel package, which leads to version incompatibility.

The root cause is the otel package having made incompatible upgrades during its iteration. However, the otel package has now stabilized, reducing the likelihood of incompatibilities.

The solution is to upgrade the goframe version. The latest version of goframe has updated to use a stable otel package. If you are already using the latest version of v1 ( v1.16), then upgrade to v2 to resolve this.

2. go mod tidy failure while using gf dependency v1.16.2

found (v0.36.0), but does not contain package go.opentelemetry.io/otel/metric/registry

Solution, upgrade gf dependency to v1.16.9 then go mod tidy

III. Database Issues

Please refer to the section: ORM - FAQ

IV. Usage Issues

1. How to load different configuration files for different environments?

Different environments refer to: Development environment / Testing environment / Pre-production environment / Production environment, etc.

• First of all, in some internet projects, especially under distributed or microservice architecture, a configuration management center is often used, corresponding to different environments, so such a problem will not arise.
• Secondly, if it is under the traditional project management method, the configuration files may be managed together in the code repository, which is not recommended. If you still want to do this, you can let the program automatically select the configuration file or specify the configuration directory through system environment variables or command-line startup parameters, reference Configuration section. For example: ./app --gf.gcfg.file config-prod.toml then the default configuration file is modified to config-prod.toml file by command-line startup parameters.

We do not recommend distinguishing and reading different environment configuration files through code logic in the program.

2. glog with "ERROR: logging before flag.Parse"

There is a simple logging library package from Golang also called glog, check the package name at the top of your file import, change github.com/golang/glog to the framework’s logging component, please refer to: Logging

3. How to use gcron and http at the same time?

func main() {
    // Scheduled task 1
    gcron.AddSingleton("*/5 * * * * *", func() {
        task.Test()
        glog.Debug("gcron1")
    })
    // Scheduled task 2
    gcron.AddSingleton("*/10 * * * * *", func() {
        glog.Debug("gcron2")
    })
    // Receive http requests
    g.Server().Run()
}

Note, gcron must be before g.Server().Run.

4. What struct tags does GoFrame have?

Parameter requests, data validation, OpenAPIv3, command management, database ORM.

Others:

• Command-line structured management parameters: Command - Structure
• Framework commonly used tag labels are centrally managed under the gtag component: https://github.com/gogf/gf/blob/master/util/gtag/gtag.go
• In the interface documentation section, as the label form is used to generate the OpenAPI documentation, there are many tags, please refer to the section: API Document

5. HTTP Server throws context cancel error

From version v2.5 of the framework, the Request object of the framework’s HTTP Server will directly inherit from the standard library’s http.Request object, which includes the context object. When the client, such as a browser or HTTP Client, cancels the request, the server will receive a context cancel operation (context.Done), but the server will not directly report a context cancel error. This error often occurs when business logic calls underlying components such as databases or messaging, where these components recognize the context cancel operation, stop execution, and pass the context cancel error up to notify the upper layer that execution has already terminated.

This behavior is in line with the standard library design. There is no need for the server to continue execution after the client terminates the request.

Frequent server context cancel errors

V. Environment Related

1. go build main.go on Linux hints connection time out connection timed out

go: github.com/gogf/gf@v1.14.6-0.20201214132204-c685876e6f67: Get "https://proxy.golang.org/github.com/gogf/gf/@v/v1.14.6-0.20201214132204-c685876e6f67.mod":
dial tcp 172.217.160.113:443:
connect: connection timed out

Solution:

export GO111MODULE=on
export GOPROXY=https://goproxy.cn

Please refer to:

• Go Module
• https://goproxy.cn

2. gf command not found on Linux

./gf install
After installation
execute gf -v
gf: command not found
and there is no gf file in the /usr/bin directory
Solution:
Copy the sh file to the /usr/bin directory
cp gf /usr/bin
Then execute
gf -v
You will see
GoFrame CLI Tool v1.15.4, https://goframe.org
Install Path: /bin/gf
Build Detail:
Go Version: go1.16.2
GF Version: v1.15.3
Git Commit: 22011e76dc3e14006936164cc89e2d4c9190a36d
Build Time: 2021-03-30 15:43:22

3. gf command not found on Win10

Solution: Install gf.exe Refer to: CLI Tool