This article is Part 1 in a 5-Part Series.
- Part 1 - This Article
- Part 2 - Eris CLI Services Walkabout: IPFS
- Part 3 - Eris CLI Services Walkabout: BTCD
- Part 4 - Eris CLI Walkabout: Docker & Execution
- Part 5 - Eris CLI Chains Walkabout: New
##Services as a Service
Services are what you, as a developer, stitch together to build an application. They are the glue that holds everything together, run in docker containers, and can be built on top of other services.
Let’s say you want a blockchain to manage and automate an army of 3d printers. Your service, call it three-dee-printing, might index CAD files as IPFS objects, each with a bitcoin address and price. A tendermint chain listening for (valid - i.e., paid in full) transactions to those bitcoin addresses could initiate printing by pulling the CAD image from IPFS and adding the print job to the queue. Users could upload any CAD file to your service to get a quote, after which it would be added to the index. There isn’t much left for you to do other than ensure your printers are running smoothly.
The service definition file for three-dee-printing would have this extra line:
[services]
dependencies = ["ipfs", "btcd", "chainName"]
where chainName is itself a chain running as a service. Yeah, it’s that easy. Of course, the bulk of the work goes into making contracts for your chain to manage the process.
Perhaps Alice operates an army of delivery drones in the warehouse next door. She could have a service that has three-dee-printing as a dependency and listens for transactions where the user has requested and paid for drone delivery. From order to delivery, services can do it all.
That’s a neat example. What’s your service?
##Getting Started
Install Eris CLI
Read the README
Run
eris init
to grab some default service definition files.
Find out which services are available
eris services known
Launch a service
eris services start [name]
Docker will do its thing and voila! Your service is running.
Confirm this is the case
eris services ls
Run a Bitcoin node: btcd, or an ethereum node eth
Learn more about IPFS as a service here
Starting a service can also spawn a data container if data_container = true
See here for more information about eris data.
Protip: Running too many services at once might crash you operating system: kill a service
eris services stop [name]
Add the -x and -r flags to get rid of the data containers and containers, respectively. When things really get bloated, run
docker rm -v -f $(docker ps -a -q)
but be careful with this command.
Note to OSX users - save yourself a lot of headache by working on a remote box or use Kitematic.