Backport FAB-18482 into 2.2. Ability to specify chaincode's external …

…builders via env var. Added example on how to override the list of system chaincodes using env var due to bugs in viper.

Signed-off-by: Vladyslav Kopaihorodskyi <vlad.kopaygorodsky@gmail.com>

core/chaincode/config_test.go

@@ -36,6 +36,7 @@ var _ = Describe("Config", func() {
 			viper.Set("chaincode.logging.format", "test-chaincode-logging-format")
 			viper.Set("chaincode.logging.level", "warning")
 			viper.Set("chaincode.logging.shim", "warning")
+			viper.Set("chaincode.system", `{"lscc": "true", "escc": "true", "vscc": "true", "cscc": "true", "somecc": "enabled"}`)
 
 			config := chaincode.GlobalConfig()
 			Expect(config.TLSEnabled).To(BeTrue())
@@ -46,6 +47,13 @@ var _ = Describe("Config", func() {
 			Expect(config.LogFormat).To(Equal("test-chaincode-logging-format"))
 			Expect(config.LogLevel).To(Equal("warn"))
 			Expect(config.ShimLogLevel).To(Equal("warn"))
+			Expect(config.SCCAllowlist).To(Equal(map[string]bool{
+				"somecc": true,
+				"lscc":   true,
+				"escc":   true,
+				"vscc":   true,
+				"cscc":   true,
+			}))
 		})
 
 		Context("when an invalid keepalive is configured", func() {

core/peer/config.go

@@ -22,6 +22,7 @@ package peer
 import (
 	"crypto/tls"
 	"fmt"
+	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	"net"
 	"path/filepath"
@@ -276,10 +277,11 @@ func (c *Config) load() error {
 
 	c.ChaincodePull = viper.GetBool("chaincode.pull")
 	var externalBuilders []ExternalBuilder
-	err = viper.UnmarshalKey("chaincode.externalBuilders", &externalBuilders)
-	if err != nil {
-		return err
+
+	if err := yaml.UnmarshalStrict([]byte(viper.GetString("chaincode.externalBuilders")), &externalBuilders); err != nil {
+		return errors.Wrap(err, "unmarshalling 'chaincode.externalBuilders' into yaml")
 	}
+
 	c.ExternalBuilders = externalBuilders
 	for builderIndex, builder := range c.ExternalBuilders {
 		if builder.Path == "" {

core/peer/config_test.go

@@ -455,6 +455,26 @@ func TestPropagateEnvironment(t *testing.T) {
 	assert.Equal(t, expectedConfig, coreConfig)
 }
 
+func TestExternalBuilderConfigAsEnvVar(t *testing.T) {
+	defer viper.Reset()
+	viper.Set("peer.address", "localhost:8080")
+	viper.Set("chaincode.externalBuilders", "[{name: relative, path: relative/plugin_dir, propagateEnvironment: [ENVVAR_NAME_TO_PROPAGATE_FROM_PEER, GOPROXY]}, {name: absolute, path: /absolute/plugin_dir}]")
+	coreConfig, err := GlobalConfig()
+	require.NoError(t, err)
+
+	require.Equal(t, []ExternalBuilder{
+		{
+			Path:                 "relative/plugin_dir",
+			Name:                 "relative",
+			PropagateEnvironment: []string{"ENVVAR_NAME_TO_PROPAGATE_FROM_PEER", "GOPROXY"},
+		},
+		{
+			Path: "/absolute/plugin_dir",
+			Name: "absolute",
+		},
+	}, coreConfig.ExternalBuilders)
+}
+
 func TestMissingExternalBuilderPath(t *testing.T) {
 	defer viper.Reset()
 	viper.Set("peer.address", "localhost:8080")

sampleconfig/core.yaml

@@ -602,6 +602,7 @@ chaincode:
     keepalive: 0
 
     # enabled system chaincodes
+    # To override this property via env variable use CORE_CHAINCODE_SYSTEM: {"xxx:": "enable"}
     system:
         _lifecycle: enable
         cscc: enable