github.com/dannyzhou2015/migrate/v4@v4.15.2/source/httpfs/README.md (about)

     1  # httpfs
     2  
     3  ## Usage
     4  
     5  This package could be used to create new migration source drivers that uses
     6  `http.FileSystem` to read migration files.
     7  
     8  Struct `httpfs.PartialDriver` partly implements the `source.Driver` interface. It has all
     9  the methods except for `Open()`. Embedding this struct and adding `Open()` method
    10  allows users of this package to create new migration sources. Example:
    11  
    12  ```go
    13  struct mydriver {
    14          httpfs.PartialDriver
    15  }
    16  
    17  func (d *mydriver) Open(url string) (source.Driver, error) {
    18  	var fs http.FileSystem
    19  	var path string
    20  	var ds mydriver
    21  
    22  	// acquire fs and path from url
    23  	// set-up ds if necessary
    24  
    25  	if err := ds.Init(fs, path); err != nil {
    26  		return nil, err
    27  	}
    28  	return &ds, nil
    29  }
    30  ```
    31  
    32  This package also provides a simple `source.Driver` implementation that works
    33  with `http.FileSystem` provided by the user of this package. It is created with
    34  `httpfs.New()` call.
    35  
    36  Example of using `http.Dir()` to read migrations from `sql` directory:
    37  
    38  ```go
    39  	src, err := httpfs.New(http.Dir("sql"))
    40  	if err != nil {
    41  		// do something
    42  	}
    43  	m, err := migrate.NewWithSourceInstance("httpfs", src, "database://url")
    44  	if err != nil {
    45  		// do something
    46  	}
    47          err = m.Up()
    48  	...
    49  ```