README.md

Scripting remote services with Ammonite

This repo showcases how to script remote services with Ammonite based on a Northwind-like database. [Insert link to blog post when it's published]

Sample interaction with the repository (note that scripts handle environment setup/teardown by themselves):

> git clone $REPO && cd $REPONAME
> # we will now bring up a Docker container with a DB and insert data into it
> cmd/setup.sc
Docker container is up and running
Inserted:
	10 employees
	92 customers
	101 orders
> # Check the last order in the database
> cmd/order.sc last
Last order: Order(10348,5,FAMIA,Familia Arquibaldo,Sao Paulo)
> # Add a new one and see if it was inserted
> cmd/order.sc place --employee 2 --customer ANTON --shipName Boat --shipCity London
> cmd/order.sc compare
Last local order (10348) is 2 order(s) behind
> cmd/order.sc last
Last order: Order(10349,2,ANTON,Boat,London)
> # Finally, check the status of the Docker container and bring it down
> cmd/docker.sc status
Docker container is up and running
> cmd/docker.sc down

cmd/repl can be used to start an Ammonite REPL with all scripts imported:

> cmd/repl
Welcome to the Ammonite Repl 1.1.2
(Scala 2.12.6 Java 1.8.0_144)
If you like Ammonite, please support our development at www.patreon.com/lihaoyi
@ order.place(
    employee = 2, customer = "ANTON", shipName = "Boat", shipCity = "London"
  )

@ order.compare()
Last local order (10347) is 1 order(s) behind

@ order.last()
Last order: Order(10348,2,ANTON,Boat,London)

bin/try-auth.sc shows how to add custom repositories with the help of coursier+auth:

> bin/try-auth.sc
bash-4.4$ bin/is-prime.sc 5
true
bash-4.4$ cat bin/is-prime.sc
#!/usr/bin/env amm
import $ivy.`org.apache.commons:commons-math3:3.4.1.redhat-3`

@main def check(n: Int) =
  org.apache.commons.math3.primes.Primes.isPrime(n)
bash-4.4$ ^D

Notable points

1. All scripts are executable

   They begin with #!/usr/bin/env amm shebang. This makes running them simple and also makes bin/try-auth.sh possible.

2. Every script has at least one @main entrypoint

   The alternative would be to keep the main script code as top-level code. This would make it impossible to re-run the scripts inside REPL or to use the scripts from other scripts, so instead @main is used everywhere.

3. All dependencies are kept in a single file

   cmd/modules/dependencies.sc contains all the dependencies. This makes resolving dependency conflicts work exactly the same between all scripts and prevents including the same library twice in a different version.

    Also, since the dependencies are kept in a variable, they can be used
    from scripts to, for example, generate a POM file.