[Elastic Agent] Add support for EQL based conditions (elastic#20994)

* Refactor Boolexp to Eql.

* Connect new Eql to specs and input emitter.

* Fix compare with null.

* Fix notice and go.mod.

NOTICE.txt

@@ -2182,36 +2182,6 @@ Contents of probable licence file $GOMODCACHE/github.com/!azure/go-autorest/auto
    limitations under the License.
 
 
---------------------------------------------------------------------------------
-Dependency : github.com/Masterminds/semver
-Version: v1.4.2
-Licence type (autodetected): MIT
---------------------------------------------------------------------------------
-
-Contents of probable licence file $GOMODCACHE/github.com/!masterminds/semver@v1.4.2/LICENSE.txt:
-
-The Masterminds
-Copyright (C) 2014-2015, Matt Butcher and Matt Farina
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
-
-
 --------------------------------------------------------------------------------
 Dependency : github.com/Microsoft/go-winio
 Version: v0.4.15-0.20190919025122-fc70bd9a86b5
@@ -2555,11 +2525,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 --------------------------------------------------------------------------------
 Dependency : github.com/antlr/antlr4
-Version: v0.0.0-20200225173536-225249fdaef5
+Version: v0.0.0-20200820155224-be881fa6b91d
 Licence type (autodetected): MIT
 --------------------------------------------------------------------------------
 
-Contents of probable licence file $GOMODCACHE/github.com/antlr/antlr4@v0.0.0-20200225173536-225249fdaef5/LICENSE.txt:
+Contents of probable licence file $GOMODCACHE/github.com/antlr/antlr4@v0.0.0-20200820155224-be881fa6b91d/LICENSE.txt:
 
 [The "BSD 3-clause license"]
 Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
@@ -19451,6 +19421,36 @@ Contents of probable licence file $GOMODCACHE/github.com/!burnt!sushi/xgb@v0.0.0
 // such litigation is filed.
 
 
+--------------------------------------------------------------------------------
+Dependency : github.com/Masterminds/semver
+Version: v1.4.2
+Licence type (autodetected): MIT
+--------------------------------------------------------------------------------
+
+Contents of probable licence file $GOMODCACHE/github.com/!masterminds/semver@v1.4.2/LICENSE.txt:
+
+The Masterminds
+Copyright (C) 2014-2015, Matt Butcher and Matt Farina
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+
 --------------------------------------------------------------------------------
 Dependency : github.com/Microsoft/hcsshim
 Version: v0.8.7

go.mod

@@ -19,14 +19,13 @@ require (
 	github.com/Azure/go-autorest/autorest/adal v0.8.1
 	github.com/Azure/go-autorest/autorest/azure/auth v0.4.2
 	github.com/Azure/go-autorest/autorest/date v0.2.0
-	github.com/Masterminds/semver v1.4.2
 	github.com/Microsoft/go-winio v0.4.15-0.20190919025122-fc70bd9a86b5
 	github.com/Shopify/sarama v1.27.0
 	github.com/StackExchange/wmi v0.0.0-20170221213301-9f32b5905fd6
 	github.com/aerospike/aerospike-client-go v1.27.1-0.20170612174108-0f3b54da6bdc
 	github.com/akavel/rsrc v0.8.0 // indirect
 	github.com/andrewkroh/sys v0.0.0-20151128191922-287798fe3e43
-	github.com/antlr/antlr4 v0.0.0-20200225173536-225249fdaef5
+	github.com/antlr/antlr4 v0.0.0-20200820155224-be881fa6b91d
 	github.com/apoydence/eachers v0.0.0-20181020210610-23942921fe77 // indirect
 	github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5
 	github.com/aws/aws-lambda-go v1.6.0

go.sum

@@ -108,8 +108,8 @@ github.com/andrewkroh/goja v0.0.0-20190128172624-dd2ac4456e20/go.mod h1:cI59GRkC
 github.com/andrewkroh/sys v0.0.0-20151128191922-287798fe3e43 h1:WFwa9pqou0Nb4DdfBOyaBTH0GqLE74Qwdf61E7ITHwQ=
 github.com/andrewkroh/sys v0.0.0-20151128191922-287798fe3e43/go.mod h1:tJPYQG4mnMeUtQvQKNkbsFrnmZOg59Qnf8CcctFv5v4=
 github.com/antihax/optional v0.0.0-20180407024304-ca021399b1a6/go.mod h1:V8iCPQYkqmusNa815XgQio277wI47sdRh1dUOLdyC6Q=
-github.com/antlr/antlr4 v0.0.0-20200225173536-225249fdaef5 h1:nkZ9axP+MvUFCu8JRN/MCY+DmTfs6lY7hE0QnJbxSdI=
-github.com/antlr/antlr4 v0.0.0-20200225173536-225249fdaef5/go.mod h1:T7PbCXFs94rrTttyxjbyT5+/1V8T2TYDejxUfHJjw1Y=
+github.com/antlr/antlr4 v0.0.0-20200820155224-be881fa6b91d h1:OE3kzLBpy7pOJEzE55j9sdgrSilUPzzj++FWvp1cmIs=
+github.com/antlr/antlr4 v0.0.0-20200820155224-be881fa6b91d/go.mod h1:T7PbCXFs94rrTttyxjbyT5+/1V8T2TYDejxUfHJjw1Y=
 github.com/apoydence/eachers v0.0.0-20181020210610-23942921fe77 h1:afT88tB6u9JCKQZVAAaa9ICz/uGn5Uw9ekn6P22mYKM=
 github.com/apoydence/eachers v0.0.0-20181020210610-23942921fe77/go.mod h1:bXvGk6IkT1Agy7qzJ+DjIw/SJ1AaB3AvAuMDVV+Vkoo=
 github.com/armon/go-radix v1.0.0 h1:F4z6KzEeeQIMeLFa97iZU6vupzoecKdU5TX24SNppXI=

x-pack/elastic-agent/pkg/agent/application/emitter.go

@@ -45,7 +45,7 @@ type emitterController struct {
 	lock   sync.RWMutex
 	config *config.Config
 	ast    *transpiler.AST
-	vars   []transpiler.Vars
+	vars   []*transpiler.Vars
 }
 
 func (e *emitterController) Update(c *config.Config) error {
@@ -68,38 +68,6 @@ func (e *emitterController) Update(c *config.Config) error {
 		}
 	}
 
-	// sanitary check that nothing in the config is wrong when it comes to variable syntax
-	ast := rawAst.Clone()
-	inputs, ok := transpiler.Lookup(ast, "inputs")
-	if ok {
-		renderedInputs, err := renderInputs(inputs, []transpiler.Vars{
-			{
-				Mapping: map[string]interface{}{},
-			},
-		})
-		if err != nil {
-			return err
-		}
-		err = transpiler.Insert(ast, renderedInputs, "inputs")
-		if err != nil {
-			return err
-		}
-	}
-
-	programsToRun, err := program.Programs(ast)
-	if err != nil {
-		return err
-	}
-
-	for _, decorator := range e.modifiers.Decorators {
-		for outputType, ptr := range programsToRun {
-			programsToRun[outputType], err = decorator(outputType, ast, ptr)
-			if err != nil {
-				return err
-			}
-		}
-	}
-
 	e.lock.Lock()
 	e.config = c
 	e.ast = rawAst
@@ -108,7 +76,7 @@ func (e *emitterController) Update(c *config.Config) error {
 	return e.update()
 }
 
-func (e *emitterController) Set(vars []transpiler.Vars) {
+func (e *emitterController) Set(vars []*transpiler.Vars) {
 	e.lock.Lock()
 	ast := e.ast
 	e.vars = vars
@@ -170,19 +138,16 @@ func (e *emitterController) update() error {
 func emitter(ctx context.Context, log *logger.Logger, controller composable.Controller, router programsDispatcher, modifiers *configModifiers, reloadables ...reloadable) (emitterFunc, error) {
 	log.Debugf("Supported programs: %s", strings.Join(program.KnownProgramNames(), ", "))
 
+	init, _ := transpiler.NewVars(map[string]interface{}{})
 	ctrl := &emitterController{
 		logger:      log,
 		controller:  controller,
 		router:      router,
 		modifiers:   modifiers,
 		reloadables: reloadables,
-		vars: []transpiler.Vars{
-			{
-				Mapping: map[string]interface{}{},
-			},
-		},
+		vars:        []*transpiler.Vars{init},
 	}
-	err := controller.Run(ctx, func(vars []transpiler.Vars) {
+	err := controller.Run(ctx, func(vars []*transpiler.Vars) {
 		ctrl.Set(vars)
 	})
 	if err != nil {
@@ -202,7 +167,7 @@ func readfiles(files []string, emitter emitterFunc) error {
 	return emitter(c)
 }
 
-func renderInputs(inputs transpiler.Node, varsArray []transpiler.Vars) (transpiler.Node, error) {
+func renderInputs(inputs transpiler.Node, varsArray []*transpiler.Vars) (transpiler.Node, error) {
 	l, ok := inputs.Value().(*transpiler.List)
 	if !ok {
 		return nil, fmt.Errorf("inputs must be an array")
@@ -224,6 +189,10 @@ func renderInputs(inputs transpiler.Node, varsArray []transpiler.Vars) (transpil
 				// another error that needs to be reported
 				return nil, err
 			}
+			if n == nil {
+				// condition removed it
+				continue
+			}
 			dict = n.(*transpiler.Dict)
 			dict = promoteProcessors(dict)
 			hash := string(dict.Hash())