diff --git a/caddytest/integration/caddyfile_adapt/log_filters.txt b/caddytest/integration/caddyfile_adapt/log_filters.txt index 2693e9c6..1bef4c21 100644 --- a/caddytest/integration/caddyfile_adapt/log_filters.txt +++ b/caddytest/integration/caddyfile_adapt/log_filters.txt @@ -19,6 +19,7 @@ log { ipv4 24 ipv6 32 } + request>headers>Regexp regexp secret REDACTED } } } @@ -55,6 +56,11 @@ log { ], "filter": "cookie" }, + "request\u003eheaders\u003eRegexp": { + "filter": "regexp", + "regexp": "secret", + "value": "REDACTED" + }, "request\u003eheaders\u003eServer": { "filter": "delete" }, diff --git a/modules/logging/filters.go b/modules/logging/filters.go index cf3b5cc1..ded08acb 100644 --- a/modules/logging/filters.go +++ b/modules/logging/filters.go @@ -19,6 +19,7 @@ import ( "net" "net/http" "net/url" + "regexp" "strconv" "github.com/caddyserver/caddy/v2" @@ -32,6 +33,7 @@ func init() { caddy.RegisterModule(IPMaskFilter{}) caddy.RegisterModule(QueryFilter{}) caddy.RegisterModule(CookieFilter{}) + caddy.RegisterModule(RegexpFilter{}) } // LogFieldFilter can filter (or manipulate) @@ -426,6 +428,58 @@ OUTER: return in } +// RegexpFilter is a Caddy log field filter that +// replaces the field matching the provided regexp with the indicated string. +type RegexpFilter struct { + // The regular expression pattern defining what to replace. + RawRegexp string `json:"regexp,omitempty"` + + // The value to use as replacement + Value string `json:"value,omitempty"` + + regexp *regexp.Regexp +} + +// CaddyModule returns the Caddy module information. +func (RegexpFilter) CaddyModule() caddy.ModuleInfo { + return caddy.ModuleInfo{ + ID: "caddy.logging.encoders.filter.regexp", + New: func() caddy.Module { return new(RegexpFilter) }, + } +} + +// UnmarshalCaddyfile sets up the module from Caddyfile tokens. +func (f *RegexpFilter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error { + for d.Next() { + if d.NextArg() { + f.RawRegexp = d.Val() + } + if d.NextArg() { + f.Value = d.Val() + } + } + return nil +} + +// Provision compiles m's regexp. +func (m *RegexpFilter) Provision(ctx caddy.Context) error { + r, err := regexp.Compile(m.RawRegexp) + if err != nil { + return err + } + + m.regexp = r + + return nil +} + +// Filter filters the input field with the replacement value if it matches the regexp. +func (f *RegexpFilter) Filter(in zapcore.Field) zapcore.Field { + in.String = f.regexp.ReplaceAllString(in.String, f.Value) + + return in +} + // Interface guards var ( _ LogFieldFilter = (*DeleteFilter)(nil) @@ -433,14 +487,17 @@ var ( _ LogFieldFilter = (*IPMaskFilter)(nil) _ LogFieldFilter = (*QueryFilter)(nil) _ LogFieldFilter = (*CookieFilter)(nil) + _ LogFieldFilter = (*RegexpFilter)(nil) _ caddyfile.Unmarshaler = (*DeleteFilter)(nil) _ caddyfile.Unmarshaler = (*ReplaceFilter)(nil) _ caddyfile.Unmarshaler = (*IPMaskFilter)(nil) _ caddyfile.Unmarshaler = (*QueryFilter)(nil) _ caddyfile.Unmarshaler = (*CookieFilter)(nil) + _ caddyfile.Unmarshaler = (*RegexpFilter)(nil) _ caddy.Provisioner = (*IPMaskFilter)(nil) + _ caddy.Provisioner = (*RegexpFilter)(nil) _ caddy.Validator = (*QueryFilter)(nil) ) diff --git a/modules/logging/filters_test.go b/modules/logging/filters_test.go index 6871bea0..99289c3e 100644 --- a/modules/logging/filters_test.go +++ b/modules/logging/filters_test.go @@ -3,6 +3,7 @@ package logging import ( "testing" + "github.com/caddyserver/caddy/v2" "go.uber.org/zap/zapcore" ) @@ -67,3 +68,13 @@ func TestValidateCookieFilter(t *testing.T) { t.Fatalf("unknown action type must be invalid") } } + +func TestRegexpFilter(t *testing.T) { + f := RegexpFilter{RawRegexp: `secret`, Value: "REDACTED"} + f.Provision(caddy.Context{}) + + out := f.Filter(zapcore.Field{String: "foo-secret-bar"}) + if out.String != "foo-REDACTED-bar" { + t.Fatalf("field has not been filtered: %s", out.String) + } +}