Quick Start
In this tutorial we will show you how you can create decentralized application over the iExec infrastructure.
Last updated
In this tutorial we will show you how you can create decentralized application over the iExec infrastructure.
Last updated
iExec enables decentralized docker app deployment and monetization on the blockchain.
In this guide, we will use the iExec SDK command-line interface to deploy an iExec app on a test blockchain.
Tutorial Steps :
On the blockchain, your identity is defined by your wallet, constisting of cryptochraphically encrypted private key and public address. What you own on the blockchain is associated with your address. The applications you deploy on iExec are associated with your wallet.
Let's set up your wallet.
Create a new Wallet file
You will be asked to choose a password to protect your wallet, don't forget it since there is no way to recover it. The SDK creates a wallet file that contains a randomly generated private key encrypted by the chosen password and the derived public address. Make sure to back up the wallet file in a safe place and write down your address.
Your wallet is stored in the ethereum keystore, the location depends on your OS:
On Linux: ~/.ethereum/keystore
On Mac : ~/Library/Ethereum/keystore
On Windows: ~/AppData/Roaming/Ethereum/keystore
Wallet file name follow the pattern UTC--<CREATION_DATE>--<ADDRESS>
iExec SDK uses standard Ethereum wallet, you can reuse or import existing Ethereum wallet. See iExec SDK documentation wallet command.
Create a new folder for your iExec project and initialize the project:
The iExec SDK creates the minimum configuration files:
iexec.json contains the project configuration
chain.json contains the blockchain connection configuration
we use --skip-wallet to skip wallet creation as we already created it
You can now connect to the blockchain. In the following steps, we will use the iExec sidechain (also called Bellecour).
You can now check your wallet content:
iExec enables decentralized deployment of dockerized applications. The applications deployed on iExec are Smart Contracts identified by their Ethereum address and referencing a public docker image. Each iExec application has an owner who can set the execution permissions on iExec platform.
Let's deploy an iExec app!
Initialize a new application
The iExec SDK writes the minimum app configuration in iexec.json
key
description
owner
app owner ethereum address (default your wallet address)
name
name of the application
type
type of application ("DOCKER" for docker container)
multiaddr
download URI of the application (a public docker registry)
checksum
checksum of the app ("0x" + docker image digest)
mrenclave
app fingerprint used for confidential computing use cases (default empty)
The default app is the public docker image iexechub/python-hello-world.
Given an input string, the application generates an ASCII art greeting.
You can deploy this application on iExec, it will run out of the box. When you are confident with iExec concept, you can read Your first app and learn how to setup your own app on iExec.
You will now deploy your app on iExec, this will be your first transaction on the blockchain:
While running iexec app deploy you sent your first transaction on the bellecour blockchain.
You can check your deployed apps with their index, let's check your last deployed app:
iExec allows you to run applications on a decentralized infrastructure with payment in RLC tokens (the native cryptocurrency of iExec).
To run an application you must have enough RLC staked on your iExec account to pay for the computing resources.
Your iExec account is managed by smart contracts (and not owned by iExec).
When you request an execution the price for the task is locked from your account's stake then transferred to accounts of the workers contributing to the task (read more about Proof of Contribution protocol).
At any time you can:
view your balance
deposit RLC from your wallet to your iExec Account
withdraw RLC from your iExec account to your wallet (only stake can be withdrawn)
Currently, iExec sponsors applications running on Bellecour, and you won't have to pay for the computation.
Everything is ready to run your application!
iexec app run allows to run an application on iExec at the market price.
Useful options:
--args <args> specify the app execution arguments
--watch watch execution status changes
--workerpool <address> specify the workerpool to use (eg: --workerpool prod-v8-learn.main.pools.iexec.eth)
Discover more option with iexec app run --help
Congratulation you requested the execution of iexechub/python-hello-world.
This will generate an ASCII art greeting with your name.
The execution of tasks on the iExec network is asynchronous by design.
Guaranties about completion times (fast/slow) are available in the category section:
maximum deal/task time
maximum computing time
Once the task is completed copy the taskid from iexec app run output (taskid is a 32Bytes hexadecimal string).
Download the result of your task
You can get your taskid with the command:
A task result is a zip file containing the output files of the application.
iexechub/python-hello-world produce an text file in result.txt.
Let's discover the result of the computation.
Congratulations! You successfully executed your application on iExec!
Your application is deployed on iExec and you completed an execution on iExec. For now, only you can request an execution of your application. The next step is to publish it on the iExec Marketplace, making it available for anyone to use.
As the owner of this application, you can define the conditions under which it can be used
iExec uses orders signed by the resource owner's wallet to ensure resources governance.
The conditions to use an app are defined in the apporder.
Publish a new apporder for your application.
iexec app publish options allows to define custom access rules to the app (run iexec app publish --help to discover all the possibilities).
You will learn more about orders management later, keep the apporder default values for now.
Your application is now available for everyone on iExec marketplace on the conditions defined in apporder.
You can check the published apporders for your app
Congratulation you just created a decentralized application! Anyone can now trigger an execution of your application on the iExec decentralized infrastructure.
With the iexec SDK CLI iexec app run <app address> --workerpool prod-v8-learn.main.pools.iexec.eth
On iExec marketplace
You are now familiar with the following key iExec concepts for developers:
Your wallet is your on-chain ID and blockchain account
You can deploy decentralized applications on iExec
Anyone can run tasks against payment in RLC on iExec
Payments are processed by the decentralized platform between users' iExec Accounts
Resource governance is managed by orders
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