Let’s explore the supply chain scenario using Hyperledger Fabric v1 framework components in terms of its role and relevance on the network. The core components are as follows:<\/p>\n
- \n
- Shared Permissioned Ledger<\/strong><\/em> contains the current state of all records right from the beginning of the network and the series of transaction invocations. As ledger is an append-only system of records and serves as a single source of all transactions and it is made available to all peers on the network.<\/li>\n
- All Peers<\/strong><\/em> commit blocks and maintain a copy of the ledger. Two types of peers: Endorsers<\/strong> and Committer<\/strong><\/em> peers.\u00a0Endorsers<\/strong>\u00a0<\/em>simulate and endorse transactions.\u00a0Committers<\/strong>\u00a0<\/em>verify endorsements and validate transaction results.<\/li>\n
- Channels<\/strong><\/em> establish\u00a0transaction visibility to all the members of the network. \u00a0Each channel maintains independent chain of transaction blocks containing only transactions specific to that channel.<\/li>\n
- Chaincode\u00a0<\/strong><\/em><\/em>\u00a0encapsulates the asset definitions and the business logic (or transactions) for creating and modifying (CRUD) which performs transaction invocations on those assets<\/span><\/li>\n
- Orderer<\/strong><\/em>\u00a0accepts endorsed transactions, orders them into a block, and delivers the blocks to the committing peers.<\/li>\n
- MSP<\/strong><\/em>\u00a0manage user IDs, and authenticate all the participants in the network.<\/li>\n<\/ul>\n
The demo application made available is written using Hyperledger Node.js SDK.<\/span><\/p>\n
Try it yourself:<\/p>\n
- \n
- \u00a0Have your Ubuntu instance (atleast\u00a08Gb memory and 16Gb storage) up and running. Make sure you installed the following:\n
- \n
- Docker.io and Docker Compose (docker.io and docker-compose)<\/li>\n<\/ul>\n<\/li>\n
- Download and install the latest Hyperledger Docker VMs binaries – refer to the following URL:<\/li>\n<\/ol>\n
https:\/\/hyperledger-fabric.readthedocs.io\/en\/latest\/samples.html#binaries<\/strong><\/pre>\n
I used the following URL (please note this changes upon new builds so make sure to download from the latest URL obtained from the link above:<\/p>\n
$ curl -sSL https:\/\/goo.gl\/Q3YRTi<\/a>\u00a0| bash<\/strong><\/pre>\n
3. \u00a0Verify install by running ‘$docker images’ <\/strong>(refer output, should look like this)<\/em><\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/Docker-VM1.png\")
<\/p>\n4. Download the Linux Foundation (Hyperledger Fabric v1 Education sample repository) and then change the directory to ‘tuna-app<\/em>‘.<\/p>\n
$ git clone https:\/\/github.com\/hyperledger\/education.git<\/strong>\r\n$ cd education\/LFS171x\/fabric-material\/tuna-app<\/strong><\/pre>\n
5. Start the Hyperledger Fabric network using the following command:<\/p>\n
$ .\/startFabric.sh<\/strong><\/pre>\n
A typical output would look like this:<\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/tunafsh1.png\")
<\/p>\n6.\u00a0As the application is written using Node.js SDK, it is critical to Node.js binaries installed and available for use. The application also has dependencies to Go SDK. \u00a0So let’s install beginning with Go language and Node.js binaries.<\/p>\n
$\u00a0apt install golang-go<\/strong>\r\n \r\n $ go version<\/strong>\r\n \r\n $\u00a0sudo bash -c \"cat >\/etc\/apt\/sources.list.d\/nodesource.list\" <<EOL<\/strong>\r\n > \u00a0deb https:\/\/deb.nodesource.com\/node_6.x xenial main<\/strong>\r\n > \u00a0deb-src https:\/\/deb.nodesource.com\/node_6.x xenial main<\/strong>\r\n > \u00a0EOL<\/strong>\r\n \r\n $ curl -s https:\/\/deb.nodesource.com\/gpgkey\/nodesource.gpg.key | sudo apt-key add -<\/strong>\r\n \r\n $ apt update<\/strong>\r\n \r\n $ apt install nodejs<\/strong>\r\n \r\n $ apt install npm<\/strong>\r\n \r\n $ node --version && npm --version<\/strong>\r\n \r\n $ npm install<\/strong>\r\n \r\n $ npm rebuild<\/strong><\/pre>\n
Discard warnings, not errors! If you encounter errors you may want to start from the beginning.<\/p>\n
- \n
- Finally, register the Admin<\/strong> and User<\/strong> components of our network, and then start the client application using the following commands:<\/li>\n<\/ol>\n
$ node registerAdmin.js<\/strong><\/pre>\n
You should be seeing similar output:<\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/tunafish_register.png\")
<\/p>\n$ node registerUser.js<\/strong><\/pre>\n
You should see the following output:<\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/tunafish_user.png\")
<\/p>\n8. Now, start the server (server.js) and then try accessing client at the servehost_address:8000. \u00a0Make sure port 8000 is accessible from the host. The\u00a0user can interact with the Web application that enables users to query and update a ledger. Under the hood, the<\/span>\u00a0application using the SDK sends\u00a0the endorsed proposal (automatically) to the Solo ordering service where the order is packaged into a block then broadcasted to all the peers on the network.<\/span><\/p>\n
$ <\/strong>nohup node server.js &<\/strong><\/pre>\n
Try accessing the Web application client using the browser (http:\/\/IPaddress:8000\/:<\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/tunafish_demo1.png\")
<\/span><\/p>\n2) Try “Query” All or “Query a Specific Tuna Catch”:<\/p>\n
![\"\"](\"http:\/\/websecuritypatterns.com\/blogs\/wp-content\/uploads\/2018\/01\/tunafish_demo2.png\")
<\/p>\nYou should able to “Create a Tuna Record”<\/strong><\/em> and also “Change Tuna Holder”<\/strong><\/em> and so on.<\/p>\n
THAT’S ALL FOLKS!<\/strong><\/span><\/p>\n
Further References:<\/p>\n
https:\/\/hyperledger-fabric.readthedocs.io\/en\/release\/<\/p>\n
https:\/\/courses.edx.org\/courses\/course-v1:LinuxFoundationX+LFS171x+3T2017\/course\/<\/p>\n","protected":false},"excerpt":{"rendered":"
Let’s begin with some fundamentals! Adopting Blockchain helps to establish a “System of Proof”, where we can verify the complete historical record of transactions right from the\u00a0genesis\u00a0of the blockchain – which is immutable, unbreakable meaning that it cannot be changed, moved, or deleted. The blockchain integrity is protected by Cryptographic hashing, key signature, and timestamping mechanisms.\u00a0\u00a0Every change scheduled and addressed… Read more »<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3,82,89,1],"tags":[83,102,104,101],"class_list":["post-2604","post","type-post","status-publish","format-standard","hentry","category-blockchain","category-hyperledger","category-permissioned-blockchain","category-uncategorized","tag-hyperledger","tag-hyperledger-fabric","tag-permssioned-blockchain","tag-private-blockchain"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/posts\/2604","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/comments?post=2604"}],"version-history":[{"count":49,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/posts\/2604\/revisions"}],"predecessor-version":[{"id":2659,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/posts\/2604\/revisions\/2659"}],"wp:attachment":[{"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/media?parent=2604"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/categories?post=2604"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/websecuritypatterns.com\/blogs\/wp-json\/wp\/v2\/tags?post=2604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Finally, register the Admin<\/strong> and User<\/strong> components of our network, and then start the client application using the following commands:<\/li>\n<\/ol>\n
- All Peers<\/strong><\/em> commit blocks and maintain a copy of the ledger. Two types of peers: Endorsers<\/strong> and Committer<\/strong><\/em> peers.\u00a0Endorsers<\/strong>\u00a0<\/em>simulate and endorse transactions.\u00a0Committers<\/strong>\u00a0<\/em>verify endorsements and validate transaction results.<\/li>\n