CryptoCoinsInfoClub.com

Dockerhub Ethereum Client Go

Dockerfile - Denied: Requested Access To The Resource Is Denied : Docker - Stack Overflow

Dockerfile - Denied: Requested Access To The Resource Is Denied : Docker - Stack Overflow

denied: requested access to the resource is denied : docker I am following this link to create my first docker Image and it went successfully and now I am trying to push this Image into my docker repository from this link . But whenever I am trying to push this Image into repository , I got this type of error. denied: requested access to the resource is denied Could anyone give me some hint towards this problem ? Any help would appreciated. Note: I have successfully login into docker Did the accepted answer really work for u? Charlie Parker Oct 7 '17 at 18:48 this is much better: docs.docker.com/docker-cloud/builds/push-images Charlie Parker Oct 7 '17 at 18:49 @CharlieParker following the docs did the trick. David J Eddy Nov 17 '17 at 21:03 You need to include the namespace for Docker Hub to associate it with your account.The namespace is the same as your Docker Hub account name.You need to rename the image to YOUR_DOCKERHUB_NAME/docker-whale. So, this means you have to tag your image before pushing: docker tag firstimage YOUR_DOCKERHUB_NAME/firstimage docker push YOUR_DOCKERHUB_NAME/firstimage Update: see also the answer from provided by Dean Wu .Before pushing, remember to log in from the command line to your docker hub account Not for me. I've tried all combinations of [host]/[namespace]/[repo] and still the same error (meaning, i have organizations and my account as the namespace). Even tried docker login .... I can't push :-| nicerobot Feb 2 '17 at 23:38 hii i follow your command got Error ---Error response from daemon: No such image: ubuntu-nodejs:latest Yash Apr 12 '17 at 11:04 This answer should not have been marked as accepted! The solution provided clearly does not work as others have indicated. SamDevx Apr 30 '17 at 3:11 This actually fixed my problem so thi Continue reading >>

Setting Up Docker Client Within A Docker Image

Setting Up Docker Client Within A Docker Image

Setting up Docker client within a Docker image Sometimes, life is not easy. And DevOps can be a pain. Strangely, it was Docker that was causing it. Recently, I set up Jenkins for continuous integration on DigitalOcean. There are so many ways to do the same thing. And if something does not work, you try to tweak some settings to get it to work. Thankfully, there is a standard way to do things. And I found out how to do it with the help of Edward Viaene in an Udemy course. So, I set up Jenkins based on an Udemy course! It all works fine. I have an Express API. Whenever there is a push to the repo, Jenkins packages it as a Docker image and publishes it to Docker Hub. All set, right? No, not really. Who is going to deploy the Docker image to all my servers? I was hoping Jenkins will do it for me. Unfortunately, it wont. DeployDocker image to DigitalOcean servers We know the manual way of creating new containers using command-line. docker container rm -f api-serverdocker container run --name api-server --detach --publish 3000:3000--link mysql-server:mysqlvijayst/myapi:$1 The shell script removes a container by name of api-server.Then, it recreates a new one of the same name. While recreating the container, we use a different tag (image tag) as indicated by the $1 argument. Whenever an image is pushed to the public repository, I want to call the script. DockerHub allows setting a webhook (API). DockerHub calls the POST method of the API with the relevant details. Webhook is any API. For our example, we create a simple Express API. The Express API receives the event from DockerHub. It retrieves the image tag. And executes the shell script. const express = require('express');const app = express();const bodyParser = require('body-parser');const { exec } = require('child_process Continue reading >>

Deploying An Ethereum Viper Smart Contract

Deploying An Ethereum Viper Smart Contract

Deploying an Ethereum Viper Smart Contract Viper is missing a lot of documentation(though it has gotten better). It took a lot of trial and error to finally figure out how to deploy a contract to an Ethereum blockchain. This information may not be very useful for people who have deployed compiled smart contracts before. This is more geared towards people who are using Viper as their first language to create Ethereum smart contracts but are familiar with common Python development practices, and their local system. I'd recommend using this docker container . I updated it slightly from the original and doesn't match what's in Docker Hub. Alternatively, testrpc is easier to setup, but has on occasion had me chasing bugs for too long(YMMV). Either way, it's a lot better to test things out before real money is at stake on the main net. Alternatively, you could setup a full node on a test network, but the test networks are not always completely functional, so probably not the best choice for quick dev. In this article, I'm going to be deploying the contract using geth( go-ethereum ), but the geth commands should be loosely similar to any web3 interface or library. I may add information on how to use Mist and other Web3 browsers/wallets to deploy contracts later, but for now I haven't needed or wanted it. First and foremost, read the documentation they have . It's the only authoritative information about the language there is, so it's a good(only) goto for reference. For people familiar with some of the newer concepts of Python 3, it should be mostly straight forward. It utilizes type hinting a lot. Though of course there are some significant differences. I won't be going into that in depth here but I will point out some differences that were important when writing my first co Continue reading >>

Building An Ethereum Playground With Docker (part 2dockerimage)

Building An Ethereum Playground With Docker (part 2dockerimage)

@vertigobr Founder & CTIO, disrupting things for fun. Building an Ethereum playground with Docker (part 2 DockerImage) I have updated this article on December/2017. I no longer create a custom Docker image, because Ethereum official image already brings an all-tools version that includes bootnode and other treats. This is the second article in an ongoing series Building an Ethereum Playground with Docker. The articles already published are: We will cover using the official ethereum/go-ethereum Docker image, playing with Ethereum Wallet, provisioning the ethereum nodes on public clouds and deployment of a sample app. This article uses " ethereum/client-go " Docker image to run several Ethereum nodes locally (and safely). It also assumes you have a Docker engine available to you (and know a bit about it), probably after installing Docker for Mac or Docker for Windows on your notebook. All sources are located in . There is a public official image "docker pull ethereum/client-go" that will serve as the base of this work. We will create scripts with some functionality and configuration options to make it generally useful for our evil machinations. This original public base image is a nice piece of work: you can use it to participate on the main public Ethereum network with a simple command: The starting point is the creation of a "genesis.json" file that defines the genesis block of the blockchain. The "genesis.sh" script does that for you, and it can be edited to provide custom values for some variables Some variables on the top of this script can be modified to define your very own genesis block, the main point being that all containers will mount the same genesis.json file when launched with the helper scripts. Nodes that share the same genesis block and are capable of f Continue reading >>

Introduction To Docker Tutorial | Toptal

Introduction To Docker Tutorial | Toptal

#DevOps #Docker #Sandboxing #SystemIsolation If you like whales, or are simply interested in quick and painless continuous delivery of your software to production, then I invite you to read this introductory Docker Tutorial. Everything seems to indicate that software containers are the future of IT, so lets go for a quick dip with the container whales Moby Dock and Molly . Docker, represented by a logo with a friendly looking whale, is an open source project that facilitates deployment of applications inside of software containers. Its basic functionality is enabled by resource isolation features of the Linux kernel, but it provides a user-friendly API on top of it. The first version was released in 2013, and it has since become extremely popular and is being widely used by many big players such as eBay, Spotify, Baidu, and more . In the last funding round, Docker has landed a huge $95 million . The philosophy behind Docker could be illustrated with a following simple analogy. In the international transportation industry, goods have to be transported by different means like forklifts, trucks, trains, cranes, and ships. These goods come in different shapes and sizes and have different storing requirements: sacks of sugar, milk cans, plants etc. Historically, it was a painful process depending on manual intervention at every transit point for loading and unloading. It has all changed with the uptake of intermodal containers. As they come in standard sizes and are manufactured with transportation in mind, all the relevant machineries can be designed to handle these with minimal human intervention. The additional benefit of sealed containers is that they can preserve the internal environment like temperature and humidity for sensitive goods. As a result, the transportation Continue reading >>

Getting Started With Containers

Getting Started With Containers

Troubleshooting an issue? Try Solution Engine our new support tool. If you are a new customer, register now for access to product evaluations and purchasing capabilities. If your company has an existing Red Hat account, your organization administrator can grant you access. Increase visibility into IT operations to detect and resolve technical issues before they impact your business. Engage with our Red Hat Product Security team, access security updates, and ensure your environments are not exposed to any known security vulnerabilities. Chapter1.Get Started with Docker Formatted Container Images The Docker project was responsible for popularizing container development in Linux systems. The original project defined a command and service (both named docker) and a format in which containers are structured. This chapter provides a hands-on approach to using the docker command and service to begin working with containers in Red Hat Enterprise Linux 7 and RHEL Atomic Host by getting and using container images and working with running containers. Containers provide a means of packaging applications in lightweight, portable entities. Running applications within containers offers the following advantages: Smaller than Virtual Machines: Because container images include only the content needed to run an application, saving and sharing is much more efficient with containers than it is with virtual machines (which include entire operating systems) Improved performance: Likewise, since you are not running an entirely separate operating system, a container will typically run faster than an application that carries with it the overhead of a whole new virtual machine. Secure: Because a container typically has its own network interfaces, file system, and memory, the application running i Continue reading >>

Docker Ethereum Homestead 0.1 Documentation

Docker Ethereum Homestead 0.1 Documentation

We are hosting latest development snapshots (and in the future alsoreleases) at docker hub. You can run these images as follows: Before running the image, you should pull the latest version and preparethe data directories: # get the lastest version from dockerhub (redo for updates).docker pull ethereum/client-cpp# create mountable datadirs; blockchain/account data will be stored theremkdir -p ~/.ethereum ~/.web3 These steps need to be done only once. For upgrading to a new version dothe docker pull ... again. docker run --rm -it \ -p 127.0.0.1:8545:8545 \ -p 0.0.0.0:30303:30303 \ -v ~/.ethereum:/.ethereum \ -v ~/.web3:/.web3 \ -e HOME=/ \ --user $(id -u):$(id -g) \ ethereum/client-cpp This will write data to ~/.ethereum and ~/.web3/ on your host and runthe client with your users permissions. For most cases this should besufficient and the client should behave exactly as if run from a local build. If you want the rpc port reachable from the network (not recommended, never do thisif you have valuable data or private keys on your machine), replace-p 127.0.0.1:8545:8545 by -p 0.0.0.0:8545:8545. For convenience, you can create the file /usr/local/bin/docker-eth with thefollowing content: #!/usr/bin/env shmkdir -p ~/.ethereum ~/.web3if ! id -nG $(whoami)|grep -qw "docker"; then SUDO='sudo'; else SUDO=''; fi$SUDO docker run --rm -it \ -p 127.0.0.1:8545:8545 \ -p 0.0.0.0:30303:30303 \ -v ~/.ethereum:/.ethereum \ -v ~/.web3:/.web3 \ -e HOME=/ \ --user $(id -u):$(id -g) \ ethereum/client-cpp [email protected] And make it executable with chmod +x /usr/local/bin/docker-eth. Now you canstart the client with: Note: The docker-eth command will accept the same flags as the raw ethcommand. If you want to attach to the node, you can either just use mist (it willdetect the node automatically), use geth Continue reading >>

Hyperledgers Monthly Technical Update

Hyperledgers Monthly Technical Update

As our incubated projects continue to mature, wed like to update the community monthly on the progress we make. Below are June updates on Hyperledger projects. Implementation of dynamic memory on the Ethereum Virtual Machine New type-safe Application Binary Interface package for translating data to Ethereum contracts into packed Ethereum bytes for transaction formulation (logical requirement for Ethereum chain; but all package implementations thus far have been GPLv3 licensed, as such in tooling code not included in Burrow; this new package will be able to go into Hyperledger Burrow under Apache license) Alpha of batching client for new API with high transaction throughput (> 400 tx/s) First prototype of Burrow EVM to run as transaction processor on Hyperledger Sawtooth Ledger A user dashboard was added to support seeing blockchain status and chaincodes. The k8s support features was started with intern students; Upgrade swarm support to latest version (17.04). Refine the installation scripts to support multi-os-distributions. Fabric 1.0-* supported scripts was added. We completed all rebranding activities as part of the move to Hyperledger we moved to the Hyperledger Docker Hub organization, and renamed the Yeoman generator module. We added support for modelling and publishing events from a transaction processor function, allowing client applications and existing systems to respond to events from a deployed business network. We made extensive changes to our new user and getting started documentation, including reworked installation guides and tutorials which are available in the docs: We delivered a set of nodes for Node-RED which allow developers to easily build outbound and inbound integration between a deployed business network and external system using IoT/MQTT, We Continue reading >>

Building Private Ethereum Networks With Docker Compose

Building Private Ethereum Networks With Docker Compose

In my previous article about building a blockchain application , I shared some of the tools, tips and techniques I used to create an end-to-end blockchain web application. Lets hone in on a specific part of that and explain in more depth how I built an underlying Ethereum private blockchain for testing purposes. I mentioned that I predominantly used testrpc to stand up a simple, single-node Ethereum instance which had the APIs exposed and some accounts pre-filled with Ether for testing. Testrpc is a great tool, super simple and fast to get started, which makes it ideal for development and if you are new to the tech. However there are some situations where you might want some extra flexibility or you need to test different scenarios where you require a more production like setup. These include - Testing the effects of a network of nodes (e.g. a multi-node Ethereum cluster with each node in sync with other nodes via the P2P protocol) Access to other Ethereum APIs, for example the management API Access to the Ethereum JavaScript Console The confidence of developing against a full Geth node Easier integration with or ability to test alongside other tools or technology such as IPFS If you find yourself having to set up a private Ethereum cluster (as I did) youll find that its not actually a straightforward process. While there are one or two pretty clear tutorials out there as well as some scripts both for me had some problems. The scripts prefer that you are running Ubuntu, the preferred/recommended platform for Ethereum and the tutorials contain anywhere between 5-20 steps. I wanted a simple, repeatable and cross platform way to bring up and tear down my clusters. Enter Docker and Docker Compose . Today Im announcing our open-sourced ethereum-docker which contains a bunch Continue reading >>

Askmike.org

Askmike.org

I am Mike van Rossum. Here you'll find tech tutorials and tips for a lot of tools I've discovered since I started learning. Run Ethereum in a docker container on your Raspberry Pi For a project I need to run geth 1.6 in a docker container on my Raspberry Pi that has raspbian jessie installed. I was looking online for such a docker image, but after some searching I gave up and just created my own dockerimage. I am using this image as a basis for other docker images that set a geth node up for a private ethereum blockchain. There are a dozen of Ethereum docker images already, but none (that I could find) played nice with the ARM architecture of therpi. You can find the prebuild image on dockerhub/askmike/ethereum-raspbian . Running ethereum in docker on your rpi is as easyas: docker pull askmike/ethereum-raspbian:latestdocker run -t askmike/ethereum-raspbian:latest Note that if you are going to use this for anything serious (or if money is involved) always compile from source! The Dockerfile can be found on github/askmike/ethereum-raspbian-docker . It builds on top of an image that installs golang (so geth can be compiled), you can get that from dockerhub/askmike/golang-raspbian (dockerfile on github/askmike/golang-raspbian ). If the images dont work for you, please post an issue on github:) Posted at May 01, 2017, under devops sysadmin . Now weve set up Prometheus we can very easily start logging interesting metrics from our nodejsapp. The idea is that we will include an external node module in our app, that module will provide easy functions for the by Prometheus supported metric types . In this post we will use the metric types Counter and Gauge. The module will then expose the statistics using a lightweight express server, which Prometheus willscrape. Prometheus is a Continue reading >>

Released: Geth 1.4 Rc2 - Ethereum

Released: Geth 1.4 Rc2 - Ethereum

Among others, this second release candidate also contains the Geth release oracle , which is a multi-sig Ethereum contract tracking the latest Geth releases. Its goal is to allow Geth clients to periodically check for new releases on-chain, without any centralized server. New releases need to be signed off by 2 out of 3 current signers (Jeff/@obscuren, Felix/@fjl and Peter/@karalabe) to be accepted by the oracle and users be notified of it. Note, that we do not do any automatic upgrades, only display a small CLI notification to the user every once in a while. The verified contract is live at 0xFA7B9770Ca4cb04296Cac84F37736d4041251CDF . The full contract ABI is available here , but you can also use a reduced ABI that just contains the list of signers and the current release version. This is great stuff. You might want to give a head's up to the Mist team (if you haven't already), they were looking into something like this with a feature suggestion I made awhile back: Actually we've discussed it and decided against it. The reason is that Go builds aren't AFAIK binary reproducible (meaning that a rebuild produces a different hash, in part because Go uses random iterated maps). This could cause confusion with people who aren't aware of this, and also interesting corner cases where downloading from an Ubuntu PPA will have a different hash than the distributed binary from GitHub, and even different between PPA builds and Ubuntu versions. In general, we just wanted an easy way to notify people that they are running stale software and wanted to keep clear of any auto-update mechanisms that could have unforeseen vulnerabilities. In the future we can most definitely consider polishes, further updates, etc to the version oracle, but we wanted to start out small and grow as need b Continue reading >>

Monero Mining On Linux Made Easy With Docker

Monero Mining On Linux Made Easy With Docker

Monero Mining on Linux made easy with Docker Monero Mining on Linux made easy with Docker One week ago we published our Monero Mining Benchmarks: CPU Mining With Select Dual Intel Xeon E5 Systems article. At the end of that article, and in the STH forums we posted a quick how-to instruction guide for using Docker on Ubuntu Linux, CentOS or any other Linux operating system and mining Monero. In the past week since we published that article, we have now had over 50,000 pulls from our Docker hub repository which is an amazing response. Today we are going to have our formal guide on running the Docker-basedCPU miner. At the turn of 2017, and for the past several years, Bitcoin has been the largest cryptocurrency by far. Monero is a cryptocurrency that put an emphasis on privacy and is considered significantly more anonymous than Bitcoin. As a result, Monero has moved from a $0.50 / 1 XMR currency a year ago to $12.50/ 1 XMR as of today. That movement, and the privacy focus, has made Monero a top 5 cryptocurrency and pushed it into the mainstream with even a recent WIRED article on the currency. The advantage of this has been that Monero is now very easy to exchange and has tools that are more mature than several other cryptocurrencies. For STH readers there is a larger implication. Unlike Bitcoin mining which is dominated by ASICs, Monero is currently best mined on GPUs. CPU mining can be profitable as well. That means STH readers have theinfrastructure able to mine Monero. There are hundreds of questions out there on how to mine Monero with CPUs andvarious Linux distributions. Docker and our pre-made container makes that ridiculously simple. There is no more dependency hunting, build troubleshooting, or other work. Just a simple command to run the popular Wolfs CPU miner. Continue reading >>

License

License

enumerated a few common parameter combos to get you up to speed quickly on how you can run your By far the most common scenario is people wanting to simply interact with the Ethereum network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn't care about years-old historical data, so we can fast-sync quickly to the current Start geth in fast sync mode (--fast), causing it to download more data in exchange for avoiding processing the entire history of the Ethereum network, which is very CPU intensive. Bump the memory allowance of the database to 512MB (--cache=512), which can help significantly in sync times especially for HDD users. This flag is optional and you can set it as high or as low as you'd like, though we'd recommend the 512MB - 2GB range. Start up Geth's built-in interactive JavaScript console , (via the trailing console subcommand) through which you can invoke all official web3 methods This too is optional and if you leave it out you can always attach to an already running Geth instance Transitioning towards developers, if you'd like to play around with creating Ethereum contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the test network with your node, which is fully equivalent to the main network, but with play-Ether only. $ geth --testnet --fast --cache=512 console The --fast, --cache flags and console subcommand have the exact same meaning as above and they are equally useful on the testnet too. Please see above for their explanations if you've skipped to Specifying the --testnet flag however will reconfigure your Geth instance a bit: Inst Continue reading >>

Docker Meet Cassandra. Cassandra Meet Docker.

Docker Meet Cassandra. Cassandra Meet Docker.

Docker Meet Cassandra. Cassandra Meet Docker. After having spent quite a bit of time learning Docker and after hearing strong community interest for the technology even though few have played with it, I figured itd be be best to share what Ive learned. Hopefully the knowledge transfer helps newcomers get up and running with Cassandra in a concise, yet deeply informed manner. A few years ago I finally started playing with Docker by way of Vagrant. That entire experience was weird. Dont do it. Later Docker Compose was released and all the roadblocks I previously encountered immediately melted away and the power of Docker was made very aware to me. Since then Ive been like my cat, but instead of Tuna Tuna Tuna Tuna its more like: Docker Docker Docker Docker. But the more I spoke about Docker and asked around about Docker, the sadder I became since: Everyone was worried about how Docker performance would be in production. Some were waiting for the Mesos and Kubernetes war to play out. Kubernetes won by the way. Read any news around Docker-Kubernetes and AWS-Kubernetes to make your own judgements. Within The Last Pickle, I advocate for Docker as best I can. Development project? Why not use Docker? Quick test? cough Docker cough. Learn everything you can about Grafana, Graphite, and monitoring dashboards you ask? Okay, Docker it is! About a year later, were here and guess what? Now you get to be here with me as well! :tada: In October, Nick Bailey invited me to present at the local Austin Cassandra Users Meetup and I figured this was the time to consolidate my recent knowledge and learnings into a simplified project. I figured if I had already spent time on such an intricate project I could save others time and give them a clean environment they could play with, develop on, Continue reading >>

Ethereum Research Weekly Calls - Hackmd

Ethereum Research Weekly Calls - Hackmd

# Ethereum Research Weekly Calls## 4.6.18#### Attendees:#### Group Agenda:#### Individual Updates:* Nate: * Work on CBC class cirriculum outline + HWs: * CBC codebase redesign PR in-progress (working, needs to be cleaned up :D). See details here: Danny: * Continuing to support Runtime Verification team * compiling draft of hybrid casper EIP * hashing out fork specifics * discussing design decisions * Meeting with client devs to get people working on casper testnet * Chih-Cheng: * update pyethereum & pyethapp for upcomming change for Casper * working on pyevm p2p* Katherine: * Validator dashboard* Nicholas: * Reorganize/Clean up SMC and SMC handlers * Move SMC and handlers to sharding repo* Kevin: * Rewrited `guess_head` code, to make it simpler(but still complicated and not so readable, modifying based on the reviews) * Changed to the alternative `fetch_candidate_head`, it's still under review * Currently rebasing the code## 3.30.18#### Individual Updates:* Danny Ryan (Sorry can't make it today!) - PR for delayed logoff. Somewhat significant change so any review is welcome. - Upgrade casper contract to Vyper v0.0.4 - Working with Runtime Verification team as the casper liaison. They are making quick progress at formally verifying the contract. They have identified a couple of small bugs already. - Beginning work on hybrid casper EIP* Chih-Cheng * reorg casper, pyeth repo tests [casper#61]([pyethereum#17](* dive into behavior of [`deposit_scale_factor`](* code review for casper repo* Katherine * working on support decimal10 for web3.js. Used in dashboard of history of validators login, total deposits, and votes.* Kevin - prepared for the talk in FOSSASIA SG - document for SMC related things - guess_head tests, currently restructured to make it more readable* Nicholas * Continue reading >>

More in ethereum

  • What Is Mining In Ethereum?

    What is Ethereum? What is Ethereum Mining? Jordan Tuwiner Last updated July 13, 2017 Ethereum is more than a cryptocurr...

    ethereum Nov 17, 2019
  • Berlin Bitcoin Atm

    In the whole world Germany is celebrated for its technological and organisational power. Everything seems to work perfe...

    ethereum Mar 16, 2020
  • Beli Bitcoin

    Paxful adalah pasar bitcoin Peer to Peer yang menghubungkan pembeli dengan penjual. Pilih metode pembayaran yang Anda s...

    ethereum May 10, 2018
  • Maker Taker Bitcoin

    Bitcoin Trading At Lowest Or Even No Fees! The table above shows the best bitcoin trading platforms which don't charge ...

    ethereum Nov 17, 2019
  • Cara Membaca Chart Trading Bitcoin

    Setelah berdiskusi dengan para ahli di bidang perdagangan mata uang digital, Coin Pursuitmerangkum beberapa aturan dasa...

    ethereum Jan 24, 2020
  • Ethereum Price Prediction 2030

    ETHEREUM COFOUNDER: There is 'a ticking time bomb' in cryptocurrencies Ethereum is up about 1,700% over the last year.M...

    ethereum Mar 26, 2020
  • Contoh Blockchain

    Mempelajari blockchain pada awalnya akan mengakibatkan sedikit kebingungan. Sama seperti awal saya mempelajari blockcha...

    ethereum May 10, 2018
  • Kenaikan Harga Bitcoin

    Baca juga: Morgan Stanley: Harga Bitcoin Bakal Hanya 0 Sejumlah tokoh telah melontarkan kritik dan beberapa pemerintaha...

    ethereum Dec 17, 2019
  • Blockchain Log In

    Log into Blockchain and more than 10000 other apps quickly and securely with a one password. Bitium's easy-to-use Singl...

    ethereum Mar 19, 2020