Using dev mode

Normally chaincodes are started and maintained by peer. However in “dev mode", chaincode is built and started by the user. This mode is useful during chaincode development phase for rapid code/build/run/debug cycle turnaround.

We start "dev mode" by leveraging pre-generated orderer and channel artifacts for a sample dev network. As such, the user can immediately jump into the process of compiling chaincode and driving calls.

Install Fabric Samples

If you haven't already done so, please install samples.

Navigate to the chaincode-docker-devmode directory of the fabric-samples clone:

cd chaincode-docker-devmode

Download docker images

We need four docker images in order for "dev mode" to run against the supplied docker compose script. If you installed the fabric-samples repo clone and followed the instructions to install samples, binaries and docker images, then you should have the necessary Docker images installed locally.

Note

If you choose to manually pull the images then you must retag them as latest.

Issue a docker images command to reveal your local Docker Registry. You should see something similar to following:

docker images
REPOSITORY                     TAG                                  IMAGE ID            CREATED             SIZE
hyperledger/fabric-tools       latest                c584c20ac82b        9 days ago         1.42 GB
hyperledger/fabric-tools       x86_64-1.1.0-preview  c584c20ac82b        9 days ago         1.42 GB
hyperledger/fabric-orderer     latest                2fccc91736df        9 days ago         159 MB
hyperledger/fabric-orderer     x86_64-1.1.0-preview  2fccc91736df        9 dyas ago         159 MB
hyperledger/fabric-peer        latest                337f3d90b452        9 days ago         165 MB
hyperledger/fabric-peer        x86_64-1.1.0-preview  337f3d90b452        9 days ago         165 MB
hyperledger/fabric-ccenv       latest                82489d1c11e8        9 days ago         1.35 GB
hyperledger/fabric-ccenv       x86_64-1.1.0-preview  82489d1c11e8        9 days ago         1.35 GB

Note

If you retrieved the images through the install samples, binaries and docker images, then you will see additional images listed. However, we are only concerned with these four.

Now open three terminals and navigate to your chaincode-docker-devmode directory in each.

Terminal 1 - Start the network

docker-compose -f docker-compose-simple.yaml up

The above starts the network with the SingleSampleMSPSolo orderer profile and launches the peer in "dev mode". It also launches two additional containers - one for the chaincode environment and a CLI to interact with the chaincode. The commands for create and join channel are embedded in the CLI container, so we can jump immediately to the chaincode calls.

Terminal 2 - Build & start the chaincode

docker exec -it chaincode sh

You should see the following:

/opt/gopath/src/chaincode $

Now, compile your chaincode:

cd chaincode_example02/go
go build -o chaincode_example02

Now run the chaincode:

CORE_PEER_ADDRESS=peer:7052 CORE_CHAINCODE_ID_NAME=mycc:0 ./chaincode_example02

The chaincode is started with peer and chaincode logs indicating successful registration with the peer. Note that at this stage the chaincode is not associated with any channel. This is done in subsequent steps using the instantiate command.

Terminal 3 - Use the chaincode

Even though you are in --peer-chaincodedev mode, you still have to install the chaincode so the life-cycle system chaincode can go through its checks normally. This requirement may be removed in future when in --peer-chaincodedev mode.

We'll leverage the CLI container to drive these calls.

docker exec -it cli bash

peer chaincode install -p chaincodedev/chaincode/chaincode_example02/go -n mycc -v 0
peer chaincode instantiate -n mycc -v 0 -c '{"Args":["init","a","100","b","200"]}' -C myc

Now issue an invoke to move 10 from a to b.

peer chaincode invoke -n mycc -c '{"Args":["invoke","a","b","10"]}' -C myc

Finally, query a. We should see a value of 90.

peer chaincode query -n mycc -c '{"Args":["query","a"]}' -C myc

Testing new chaincode

By default, we mount only chaincode_example02. However, you can easily test different chaincodes by adding them to the chaincode subdirectory and relaunching your network. At this point they will be accessible in your chaincode container.