JMESPath custom functions (#1772)

* JMESPath: Support regex expressions

Signed-off-by: Max Goncharenko <kacejot@fex.net>

* JMESPath: Add string functions

Signed-off-by: Max Goncharenko <kacejot@fex.net>

* Removed {{$}} variable handling logic

Signed-off-by: Max Goncharenko <kacejot@fex.net>

* Name all functions in snake case; Update error message; Fix {{@}} behavior

Signed-off-by: Max Goncharenko <kacejot@fex.net>

go.mod

@@ -25,7 +25,6 @@ require (
 	github.com/onsi/ginkgo v1.14.1
 	github.com/onsi/gomega v1.10.2
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.0.1 // indirect
 	github.com/orcaman/concurrent-map v0.0.0-20190826125027-8c72a8bb44f6
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/pkg/errors v0.9.1
@@ -51,6 +50,7 @@ require (
 // Added for go1.13 migration https://github.com/golang/go/issues/32805
 replace (
 	github.com/gorilla/rpc v1.2.0+incompatible => github.com/gorilla/rpc v1.2.0
+	github.com/jmespath/go-jmespath => github.com/kyverno/go-jmespath v0.4.1-0.20210302163943-f30eab0a3ed6
 	k8s.io/code-generator => k8s.io/code-generator v0.0.0-20200306081859-6a048a382944
 	k8s.io/component-base => k8s.io/component-base v0.0.0-20190612130303-4062e14deebe
 )

go.sum

@@ -476,8 +476,8 @@ github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOl
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 github.com/jcmturner/gofork v0.0.0-20190328161633-dc7c13fece03/go.mod h1:MK8+TM0La+2rjBD4jE12Kj1pCCxK7d2LK/UM3ncEo0o=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
-github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af h1:pmfjZENx5imkbgOkpRUYLnmbU7UEFbjtDA2hxJ1ichM=
-github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1 h1:shLQSRRSCCPj3f2gpwzGwWFoC7ycTf1rcQZHOlsJ6N8=
+github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/json-iterator/go v0.0.0-20180612202835-f2b4162afba3/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v0.0.0-20180701071628-ab8a2e0c74be/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
@@ -523,6 +523,8 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/kurin/blazer v0.5.4-0.20190613185654-cf2f27cc0be3/go.mod h1:4FCXMUWo9DllR2Do4TtBd377ezyAJ51vB5uTBjt0pGU=
+github.com/kyverno/go-jmespath v0.4.1-0.20210302163943-f30eab0a3ed6 h1:9rJUAc/XxL6wV4i+3X56wcRM8tDhoo0l7DIieuXPGfk=
+github.com/kyverno/go-jmespath v0.4.1-0.20210302163943-f30eab0a3ed6/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
 github.com/lensesio/tableprinter v0.0.0-20201125135848-89e81fc956e7 h1:k/1ku0yehLCPqERCHkIHMDqDg1R02AcCScRuHbamU3s=
 github.com/lensesio/tableprinter v0.0.0-20201125135848-89e81fc956e7/go.mod h1:YR/zYthNdWfO8+0IOyHDcIDBBBS2JMnYUIwSsnwmRqU=
 github.com/lib/pq v1.1.1/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
@@ -652,8 +654,6 @@ github.com/onsi/gomega v1.10.2 h1:aY/nuoWlKJud2J6U0E3NWsjlg+0GtwXxgEqthRdzlcs=
 github.com/onsi/gomega v1.10.2/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
-github.com/opencontainers/image-spec v1.0.1 h1:JMemWkRwHx4Zj+fVxWoMCFm/8sYGGrUVojFA6h/TRcI=
-github.com/opencontainers/image-spec v1.0.1/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
 github.com/orcaman/concurrent-map v0.0.0-20190826125027-8c72a8bb44f6 h1:lNCW6THrCKBiJBpz8kbVGjC7MgdCGKwuvBgc7LoD6sw=
 github.com/orcaman/concurrent-map v0.0.0-20190826125027-8c72a8bb44f6/go.mod h1:Lu3tH6HLW3feq74c2GC+jIMS/K2CFcDWnWD9XkenwhI=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=

pkg/engine/context/evaluate.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"strings"
 
-	jmespath "github.com/jmespath/go-jmespath"
+	jmespath "github.com/kyverno/kyverno/pkg/engine/jmespath"
 )
 
 //Query the JSON context with JMESPATH search path
@@ -25,7 +25,7 @@ func (ctx *Context) Query(query string) (interface{}, error) {
 	}
 
 	// compile the query
-	queryPath, err := jmespath.Compile(query)
+	queryPath, err := jmespath.New(query)
 	if err != nil {
 		ctx.log.Error(err, "incorrect query", "query", query)
 		return emptyResult, fmt.Errorf("incorrect query %s: %v", query, err)