/
querytoheader.go
85 lines (69 loc) · 2.02 KB
/
querytoheader.go
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package builtin
import (
"fmt"
"github.com/zalando/skipper/filters"
)
type (
queryToHeaderSpec struct {
}
queryToHeaderFilter struct {
headerName string
queryParamName string
formatString string
}
)
// NewQueryToHeader creates a filter which converts query params
// from the incoming Request to headers
//
// queryToHeader("foo-query-param", "X-Foo-Header")
//
// The above filter will set the value of "X-Foo-Header" header to the
// value of "foo-query-param" query param , to the request and will
// not override the value if the header exists already
//
// The header value can be created by a formatstring with an optional third parameter
//
// queryToHeader("foo-query-param", "X-Foo-Header", "prefix %s postfix")
// queryToHeader("access_token", "Authorization", "Bearer %s")
func NewQueryToHeader() filters.Spec {
return &queryToHeaderSpec{}
}
func (*queryToHeaderSpec) Name() string {
return filters.QueryToHeaderName
}
// CreateFilter creates a `queryToHeader` filter instance with below signature
// s.CreateFilter("foo-query-param", "X-Foo-Header")
func (*queryToHeaderSpec) CreateFilter(args []interface{}) (filters.Filter, error) {
if l := len(args); l < 2 || l > 3 {
return nil, filters.ErrInvalidFilterParameters
}
q, ok := args[0].(string)
if !ok {
return nil, filters.ErrInvalidFilterParameters
}
h, ok := args[1].(string)
if !ok {
return nil, filters.ErrInvalidFilterParameters
}
formatString := "%s"
if len(args) == 3 {
formatString, ok = args[2].(string)
if !ok {
return nil, filters.ErrInvalidFilterParameters
}
}
return &queryToHeaderFilter{headerName: h, queryParamName: q, formatString: formatString}, nil
}
func (f *queryToHeaderFilter) Request(ctx filters.FilterContext) {
req := ctx.Request()
headerValue := req.Header.Get(f.headerName)
if headerValue != "" {
return
}
v := req.URL.Query().Get(f.queryParamName)
if v == "" {
return
}
req.Header.Set(f.headerName, fmt.Sprintf(f.formatString, v))
}
func (*queryToHeaderFilter) Response(ctx filters.FilterContext) {}