caddyhttp: CEL matcher checks return type; slight refactor

As per https://github.com/caddyserver/caddy/issues/3051#issuecomment-611200414
This commit is contained in:
Matthew Holt
2020-04-08 15:39:23 -06:00
parent 7dfd69cdc5
commit e5dc76b054
3 changed files with 10 additions and 7 deletions

View File

@ -24,6 +24,7 @@ import (
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
"github.com/gogo/protobuf/proto"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/checker/decls"
"github.com/google/cel-go/common/types"
@ -99,16 +100,16 @@ func (m *MatchExpression) Provision(_ caddy.Context) error {
return fmt.Errorf("setting up CEL environment: %v", err)
}
// parse the expression
parsed, issues := env.Parse(m.expandedExpr)
// parse and type-check the expression
checked, issues := env.Compile(m.expandedExpr)
if issues != nil && issues.Err() != nil {
return fmt.Errorf("parsing CEL program: %s", issues.Err())
return fmt.Errorf("compiling CEL program: %s", issues.Err())
}
// type-check it
checked, issues := env.Check(parsed)
if issues != nil && issues.Err() != nil {
return fmt.Errorf("type-checking CEL program: %s", issues.Err())
// request matching is a boolean operation, so we don't really know
// what to do if the expression returns a non-boolean type
if !proto.Equal(checked.ResultType(), decls.Bool) {
return fmt.Errorf("CEL request matcher expects return type of bool, not %s", checked.ResultType())
}
// compile the "program"