What Is the Go Workspace Mode

Transcript

1. What Is the Go Workspace Mode
   Yuki Ito (@mrno110)
   Go 1.18 Release Party
   

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2. Merpay / Mercoin
   
   
   Architect
   
   
   Mercari
   
   
   Microservices Platform CI/CD
   Yuki Ito
   
   
   @mrno110
   

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3. Disclaimer
   $ go version
   
   
   go version go1.18rc1 linux/amd64
   As of this writing...
   

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4. Agenda
   ɾBackground
   
   
   ɾWorkspace Mode
   
   
   ɾUse cases
   

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5. Background
   ɾgithub.com/110y/gwdemo1
   
   
   ɾgithub.com/110y/gwdemo2
   
   
   ɾgithub.com/110y/gwdemo3
   Let's assume we develop 3 modules
   

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6. Background
   gwdemo3
   gwdemo2
   gwdemo1
   Let's assume we develop 3 modules
   

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7. Background
   gwdemo3
   package gwdemo3
   
   
   import "fmt"
   
   
   func Hello(s string) string {
   
   
   return fmt.Sprintf("Hello, %s!", s)
   
   
   }
   

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8. Background
   gwdemo1 gwdemo2
   package main
   
   
   import (
   
   
   "fmt"
   
   
   "github.com/110y/gwdemo3"
   
   
   )
   
   
   func main() {
   
   
   fmt.Println(gwdemo3.Hello("Workspace"))
   
   
   }
   package main
   
   
   import (
   
   
   "fmt"
   
   
   "github.com/110y/gwdemo3"
   
   
   )
   
   
   func main() {
   
   
   fmt.Println(gwdemo3.Hello("Generics"))
   
   
   }
   

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9. Background
   When we add a new feature to gwdemo3...
   package gwdemo3
   
   
   import "fmt"
   
   
   func Hello(s string) string {
   
   
   return fmt.Sprintf("Hello, %s!", s)
   
   
   }
   
   
   func Bye(s string) string {
   
   
   return fmt.Sprintf("Bye, %s!", s)
   
   
   }
   

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10. Background
    And want to use it on gwdemo1 and gwdemo2 locally...
    package main
    
    
    import (
    
    
    "fmt"
    
    
    "github.com/110y/gwdemo3"
    
    
    )
    
    
    func main() {
    
    
    fmt.Println(gwdemo3.Hello("Workspace"))
    
    
    fmt.Println(gwdemo3.Bye("Workspace"))
    
    
    }
    

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11. Background
    We have to add a replace directive to the go.mod
    fi
    le
    module github.com/110y/gwdemo1
    
    
    go 1.18
    
    
    require github.com/110y/gwdemo3 v0.0.0-20220218011518-502c64a9beed
    
    
    replace github.com/110y/gwdemo3 => ../gwdemo3
    

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12. Background
    Problem
    ɾHave to add replace directive to each module's go.mod
    fi
    le.
    
    
    ɾHave to remove replace directive before submitting the code.
    

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13. Background
    But working with the replace directive can
    often be awkward: each module
    developer might have working versions at
    di
    ff
    erent location on disk, so having the
    directive in a
    fi
    le that needs to be
    distributed with the module isn't a good
    fi
    t for all use cases.
    https://go.googlesource.com/proposal/+/master/design/45713-workspace.md
    Proposal: Multi-Module Workspaces in cmd/go
    

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14. Agenda
    ɾBackground
    
    
    ɾWorkspace Mode
    
    
    ɾUse cases
    

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15. Workspace Mode
    gwdemo3
    gwdemo2
    gwdemo1
    

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16. Workspace Mode
    Workspace
    gwdemo3
    gwdemo2
    gwdemo1
    

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17. Workspace Mode
    $ mkdir gwdemo-workspace
    
    
    $ cd gwdemo-workspace
    
    
    $ git clone https://github.com/110y/gwdemo1.git
    
    
    $ git clone https://github.com/110y/gwdemo2.git
    
    
    $ git clone https://github.com/110y/gwdemo3.git
    Workspace
    

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18. Workspace Mode
    Workspace
    $ go work init ./gwdemo1 ./gwdemo2 ./gwdemo3
    

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19. Workspace Mode
    go work init creates go.work
    fi
    le
    go 1.18
    
    
    use (
    
    
    ./gwdemo1
    
    
    ./gwdemo2
    
    
    ./gwdemo3
    
    
    )
    go.work
    

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20. Workspace Mode
    $ tree .
    
    
    .
    
    
    ├── go.work
    
    
    ├── gwdemo1
    
    
    │ ├── go.mod
    
    
    │ ├── go.sum
    
    
    │ └── main.go
    
    
    ├── gwdemo2
    
    
    │ ├── go.mod
    
    
    │ ├── go.sum
    
    
    │ └── main.go
    
    
    └── gwdemo3
    
    
    ├── go.mod
    
    
    └── gwdemo3.go
    

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21. Workspace Mode
    $ cd gwdemo1
    
    
    $ go env GOWORK
    
    
    /path/to/gwdemo-workspace/go.work
    Workspace
    

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22. Workspace Mode
    $ go help work
    
    
    ...
    
    
    To determine whether the go command is operating
    in workspace mode, use the "go env GOWORK"
    command. This will specify the workspace file
    being used.
    
    
    ...
    Workspace
    

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23. Workspace Mode
    package gwdemo3
    
    
    import "fmt"
    
    
    func Hello(s string) string {
    
    
    return fmt.Sprintf("Hello, %s!", s)
    
    
    }
    
    
    func Bye(s string) string {
    
    
    return fmt.Sprintf("Bye, %s!", s)
    
    
    }
    gwdemo3
    

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24. Workspace Mode
    package main
    
    
    import (
    
    
    "fmt"
    
    
    "github.com/110y/gwdemo3"
    
    
    )
    
    
    func main() {
    
    
    fmt.Println(gwdemo3.Hello("Workspace"))
    
    
    fmt.Println(gwdemo3.Bye("Workspace"))
    
    
    }
    gwdemo1
    

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25. Workspace Mode
    $ cd gwdemo1
    
    
    $ go env GOWORK
    
    
    /path/to/gwdemo-workspace/go.work
    
    
    $ go run .
    
    
    Hello, Workspace!
    
    
    Bye, Workspace!
    Workspace
    

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26. Problem
    ✅ Have to add replace directive to each module's go.mod
    fi
    le.
    
    
    ✅ Have to remove replace directive before submitting the code.
    Workspace Mode
    

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27. Workspace Mode
    $ cd gwdemo1
    
    
    $ go env GOWORK
    
    
    /path/to/gwdemo-workspace/go.work
    
    
    $ GOWORK=off go run .
    
    
    # github.com/110y/gwdemo1
    
    
    ./main.go:12:22: undefined: gwdemo3.Bye
    Check the actual behavior with GOWORK=o
    f
    

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28. Workspace Mode
    -work
    fi
    le
    fl
    ag...?
    https://go-review.googlesource.com/c/go/+/385995/
    

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29. Agenda
    ɾBackground
    
    
    ɾWorkspace Mode
    
    
    ɾUse cases
    

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30. Use cases
    Microservice Chassis Pattern
    https://microservices.io/patterns/microservice-chassis.html
    

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31. Use cases
    chassis
    application
    template
    

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32. Use cases
    chassis
    application
    template
    Workspace
    

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33. Use cases
    Multi Modules Monorepo
    ├── cmd
    
    
    │ ├── app1
    
    
    │ │ ├── go.mod
    
    
    │ │ └── main.go
    
    
    │ ├── app2
    
    
    │ │ ├── go.mod
    
    
    │ │ └── main.go
    
    
    │ └── app3
    
    
    │ ├── go.mod
    
    
    │ └── main.go
    
    
    ├── go.work
    
    
    └── pkg
    
    
    ├── echo
    
    
    │ ├── echo.go
    
    
    │ └── go.mod
    
    
    └── hello
    
    
    ├── go.mod
    
    
    └── hello.go
    

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34. Workspace Mode
    Workspace
    gwdemo3
    gwdemo2
    gwdemo1
    

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