Initial sponsored transaction enabled auction

.gitignore

@@ -18,7 +18,7 @@ node_modules
 .env.development.local
 .env.test.local
 .env.production.local
-.yarn/*
+/**/.yarn/*
 
 npm-debug.log*
 yarn-debug.log*
@@ -27,4 +27,4 @@ yarn-error.log*
 target
 dist
 gallery/public
-.eslintcache
+.eslintcache

README.md

@@ -16,7 +16,9 @@ The following examples are available.
 
 - [gallery](./gallery/) demonstrates a gallery which requires the user to authorize using ID proofs from the browser wallet.
 
-- [sponsoredTransactions](./sponsoredTransactions/) demonstrates how a user (without holding CCD in the wallet) can sign a message with the browser wallet or mobile wallet through wallet connect and submit the signature to a backend. The backend pays for the transaction fee and submits the sponsored transaction on behalf of the user to the chain.
+- [sponsoredTransactionsBasic](./sponsoredTransactionsBasic/) demonstrates how a user (without holding CCD in the wallet) can sign a message with the browser wallet or mobile wallet through wallet connect and submit the signature to a backend. The backend pays for the transaction fee and submits the sponsored transaction on behalf of the user to the chain.
+
+- [sponsoredTransactionsAuction](./sponsoredTransactionsAuction/) demonstrates how to use a sponsored-transaction-enabled token as a payment method in an auction contract so that the user does not have to hold CCD in their wallet. The user signs a bidding message with the browser wallet or mobile wallet through wallet connect and submit the signature to a backend. The backend pays for the transaction fee and submits the sponsored transaction on behalf of the user to the chain.
 
 - [simple age verification](./simpleAgeVerification/) demonstrates in a simple use case of verifiying the users age with the browser wallet.
 

sponsoredTransactionsAuction/Dockerfile

@@ -0,0 +1,35 @@
+ARG node_base_image=node:16-slim
+ARG rust_base_image=rust:1.65
+
+FROM ${node_base_image} AS frontend
+
+WORKDIR /app
+COPY ./sponsoredTransactions/frontend ./
+
+RUN yarn && yarn cache clean
+RUN yarn build
+
+FROM ${rust_base_image} AS backend
+
+WORKDIR /backend
+COPY ./deps/concordium-rust-sdk /deps/concordium-rust-sdk
+COPY ./sponsoredTransactions/backend ./
+
+RUN cargo build --release
+
+FROM ubuntu:22.04
+WORKDIR /build
+
+ENV PORT=8080
+ENV NODE=http://node.testnet.concordium.com:20000
+ENV LOG_LEVEL=info
+ENV SMART_CONTRACT_INDEX=6372
+
+ENV ACCOUNT_KEY_FILE=/KEY_FILE
+
+COPY --from=backend ./backend/target/release/sponsored-transaction-backend ./main
+COPY --from=frontend ./app/dist ./public
+
+RUN chmod +x ./main
+
+CMD ./main --node "${NODE}" --port "${PORT}" --account "${ACCOUNT_KEY_FILE}" --smart-contract-index "${SMART_CONTRACT_INDEX}" --log-level "${LOG_LEVEL}" --public-folder public

sponsoredTransactionsAuction/README.md

@@ -0,0 +1,55 @@
+# Sponsored Transactions Auction Web Application
+
+This repository includes a dApp example of an auction. Users can bid for the items in the auction contract by using a sponsored-transaction-enabled token as a payment method (no CCD required in the user's wallet). The project has a front end and a back end.
+
+Clone the root repo with the following command:
+
+```shell
+git clone --recurse-submodules git@github.com:Concordium/concordium-dapp-examples.git
+```
+
+or
+```shell
+git clone --recurse-submodules https://github.com/Concordium/concordium-dapp-examples.git
+```
+
+To set up the project locally, complete the steps in the `README.md` file in the `sponsoredTransactions/frontend` folder and then complete the steps in the `README.md` file in the `sponsoredTransactions/backend` folder.
+
+Alternatively, follow the steps to deploy the docker container below. This docker container will set up the frontend as well as the backend.
+
+## Run as docker
+
+Add your `ACCOUNT_KEY_FILE` to the repository's root folder and run the dockerfile from the repository's root folder with the command:
+```shell
+docker build -t sponsored_transactions -f sponsoredTransactions/Dockerfile .
+```
+
+
+The image can then be run with:
+```shell
+docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/<ACCOUNT_KEY_FILE>,target=/KEY_FILE,readonly sponsored_transactions
+```
+
+e.g.
+
+```shell
+docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/3PXwJYYPf6fyVb4GJquxSZU8puxrHfzc4XogdMVot8MUQK53tW.export,target=/KEY_FILE,readonly sponsored_transactions
+```
+
+Note: To get your `ACCOUNT_KEY_FILE` (the `3PXwJYYPf6fyVb4GJquxSZU8puxrHfzc4XogdMVot8MUQK53tW.export` file), export it from the Concordium Browser Wallet for Web.
+
+<img src="./backend/pic/pic1.png"  width="200" />
+<img src="./backend/pic/pic2.png"  width="200" />
+<img src="./backend/pic/pic3.png"  width="200" />
+
+See the [docker file](./Dockerfile) to explore the environment variables that can set.
+
+Note: Use the same smart contract index for the frontend and backend. In other words, use the smart contract index from the `./frontend/package.json` file in the dockerfile.
+
+
+
+## Explore the tutorial
+
+You can find an associated tutorial on the [developer documentation](./https://developer.concordium.software/en/mainnet/smart-contracts/tutorials/index.html).
+
+

sponsoredTransactionsAuction/backend/CHANGELOG.md

@@ -0,0 +1,9 @@
+## Unreleased changes
+
+## 2.0.0
+
+- Use `AccountSignatures` type for the input parameter to the `permit` function. The sponsored transaction smart contract uses the `check_account_signature` host function with the `AccountSignatures` type as input parameter to verify signatures in the smart contract now.
+
+## 1.0.0
+
+- Initial sponsored transaction back end.