[Release-2.2 BP FAB-2643]

[kopaygorodsky]

This is a backport of pull request #2643

Because we can't upgrade viper to v1.1.1 in which the bug of shadowing a key is fixed and hooks are introduced, I had to find a workaround to simplify the backport as more as possible.

Also, I added a test and a short explanation for overriding the list of system chaincodes. The default approach with env var CORE_CHAINCODE_SYSTEM_XXX: enabled won't work due to a bug in viper in earlier versions. I agree that bumping it to v1.1.1 requires too many changes and might break the LTS release.

updated a few related tests to use strings as viper config values instead of variables.

[yacovm]

code looks fine, but seems like the test failed:

--- FAIL: TestPropagateEnvironment (0.00s)
    config_test.go:455: 
        	Error Trace:	config_test.go:455
        	Error:      	Not equal: 
        	            	expected: &peer.Config{LocalMSPID:"", ListenAddress:"", PeerID:"", PeerAddress:"localhost:8080", NetworkID:"", ChaincodeListenAddress:"", ChaincodeAddress:"", ValidatorPoolSize:2, DeliverClientKeepaliveOptions:comm.KeepaliveOptions{ClientInterval:60000000000, ClientTimeout:20000000000, ServerInterval:7200000000000, ServerTimeout:20000000000, ServerMinInterval:60000000000}, ProfileEnabled:false, ProfileListenAddress:"", DiscoveryEnabled:false, DiscoveryOrgMembersAllowed:false, DiscoveryAuthCacheEnabled:false, DiscoveryAuthCacheMaxSize:0, DiscoveryAuthCachePurgeRetentionRatio:0, LimitsConcurrencyEndorserService:0, LimitsConcurrencyDeliverService:0, PeerTLSEnabled:false, AuthenticationTimeWindow:900000000000, VMEndpoint:"", VMDockerTLSEnabled:false, VMDockerAttachStdout:false, VMNetworkMode:"host", ChaincodePull:false, ExternalBuilders:[]peer.ExternalBuilder{peer.ExternalBuilder{Environment:[]string{"KEY=VALUE"}, PropagateEnvironment:[]string{"KEY=VALUE"}, Name:"testName", Path:"/testPath"}, peer.ExternalBuilder{Environment:[]string(nil), PropagateEnvironment:[]string{"KEY=VALUE"}, Name:"testName", Path:"/testPath"}, peer.ExternalBuilder{Environment:[]string{"KEY=VALUE"}, PropagateEnvironment:[]string{"KEY=VALUE2"}, Name:"testName", Path:"/testPath"}}, OperationsListenAddress:"", OperationsTLSEnabled:false, OperationsTLSCertFile:"", OperationsTLSKeyFile:"", OperationsTLSClientAuthRequired:false, OperationsTLSClientRootCAs:[]string(nil), MetricsProvider:"", StatsdNetwork:"", StatsdAaddress:"", StatsdWriteInterval:0, StatsdPrefix:"", DockerCert:"", DockerKey:"", DockerCA:""}
        	            	actual  : &peer.Config{LocalMSPID:"", ListenAddress:"", PeerID:"", PeerAddress:"localhost:8080", NetworkID:"", ChaincodeListenAddress:"", ChaincodeAddress:"", ValidatorPoolSize:2, DeliverClientKeepaliveOptions:comm.KeepaliveOptions{ClientInterval:60000000000, ClientTimeout:20000000000, ServerInterval:7200000000000, ServerTimeout:20000000000, ServerMinInterval:60000000000}, ProfileEnabled:false, ProfileListenAddress:"", DiscoveryEnabled:false, DiscoveryOrgMembersAllowed:false, DiscoveryAuthCacheEnabled:false, DiscoveryAuthCacheMaxSize:0, DiscoveryAuthCachePurgeRetentionRatio:0, LimitsConcurrencyEndorserService:0, LimitsConcurrencyDeliverService:0, PeerTLSEnabled:false, AuthenticationTimeWindow:900000000000, VMEndpoint:"", VMDockerTLSEnabled:false, VMDockerAttachStdout:false, VMNetworkMode:"host", ChaincodePull:false, ExternalBuilders:[]peer.ExternalBuilder(nil), OperationsListenAddress:"", OperationsTLSEnabled:false, OperationsTLSCertFile:"", OperationsTLSKeyFile:"", OperationsTLSClientAuthRequired:false, OperationsTLSClientRootCAs:[]string(nil), MetricsProvider:"", StatsdNetwork:"", StatsdAaddress:"", StatsdWriteInterval:0, StatsdPrefix:"", DockerCert:"", DockerKey:"", DockerCA:""}
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -32,32 +32,3 @@
```

[kopaygorodsky]

I just realized that the master branch has also a potential issue with PropagateEnvorinment field.
A different implementation/version of the unmarshaller might set builder.PropagateEnvironment to nil or empty slice. In the last case PropagateEnvironment won't have a correct value. The fix is to use a bulletproof check builder.PropagateEnvironment == nil => len(builder.PropagateEnvironment) == 0 as I did in this PR.

fabric/core/peer/config.go

Line 292 in b80b615

if builder.Environment != nil && len(builder.PropagateEnvironment) == 0 {