Experimenting With Elixir in Docker

I am working on my book Elixir Function Guide. Having noticed that there are a lot of mix tasks that I did not know about (and some that my exercism.io students don’t) then I thought that I would add some details at the start of the book.

I started using mix help to list the available functions:

mix                   # Runs the default task (current: "mix run")
mix app.start         # Starts all registered apps
mix app.tree          # Prints the application tree
mix archive           # Lists installed archives
mix archive.build     # Archives this project into a .ez file
mix archive.install   # Installs an archive locally
mix archive.uninstall # Uninstalls archives
mix clean             # Deletes generated application files
mix cmd               # Executes the given command
mix compile           # Compiles source files
mix credo             # Run code analysis (use `--help` for options)
mix credo.gen.check   # Generate a new custom check for Credo
mix credo.gen.config  # Generate a new config for Credo
mix deps              # Lists dependencies and their status
mix deps.clean        # Deletes the given dependencies' files
mix deps.compile      # Compiles dependencies
mix deps.get          # Gets all out of date dependencies
mix deps.tree         # Prints the dependency tree
mix deps.unlock       # Unlocks the given dependencies
mix deps.update       # Updates the given dependencies
mix do                # Executes the tasks separated by comma
mix escript           # Lists installed escripts
mix escript.build     # Builds an escript for the project
mix escript.install   # Installs an escript locally
mix escript.uninstall # Uninstalls escripts
mix format            # Formats the given files/patterns
mix help              # Prints help information for tasks
mix hex               # Prints Hex help information
mix hex.audit         # Shows retired Hex deps for the current project
mix hex.build         # Builds a new package version locally
mix hex.config        # Reads, updates or deletes local Hex config
mix hex.docs          # Fetches or opens documentation of a package
mix hex.info          # Prints Hex information
mix hex.organization  # Manages Hex.pm organizations
mix hex.outdated      # Shows outdated Hex deps for the current project
mix hex.owner         # Manages Hex package ownership
mix hex.publish       # Publishes a new package version
mix hex.repo          # Manages Hex repositories
mix hex.retire        # Retires a package version
mix hex.search        # Searches for package names
mix hex.user          # Manages your Hex user account
mix loadconfig        # Loads and persists the given configuration
mix local             # Lists local tasks
mix local.hex         # Installs Hex locally
mix local.phx         # Updates the Phoenix project generator locally
mix local.public_keys # Manages public keys
mix local.rebar       # Installs Rebar locally
mix new               # Creates a new Elixir project
mix phx.new           # Creates a new Phoenix v1.4.0 application
mix phx.new.ecto      # Creates a new Ecto project within an umbrella project
mix phx.new.web       # Creates a new Phoenix web project within an umbrella project
mix profile.cprof     # Profiles the given file or expression with cprof
mix profile.eprof     # Profiles the given file or expression with eprof
mix profile.fprof     # Profiles the given file or expression with fprof
mix release           # Assembles a self-contained release
mix release.init      # Generates sample files for releases
mix run               # Starts and runs the current application
mix test              # Runs a project's tests
mix xref              # Prints cross reference information
iex -S mix            # Starts IEx and runs the default task

It was only then that I realised that I have a number of mix extensions installed.

I need to start with what comes out of the box.
At this point I have three choices:

  • Uninstall the extensions (these are usefull .)
  • Manually edit out the extensions (error prone)
  • Use docker

The docker option is appealing as it will allow me to test using different versions of Elixir.

Here is the simple option that allows the use of docker:

docker run -it elixir:1.10 /bin/bash

This downloads the image and runs up the container. Note that this starts with bash, rather than the default iex.

From this mix help gives the more useful list:

mix                   # Runs the default task (current: "mix run")
mix app.start         # Starts all registered apps
mix app.tree          # Prints the application tree
mix archive           # Lists installed archives
mix archive.build     # Archives this project into a .ez file
mix archive.install   # Installs an archive locally
mix archive.uninstall # Uninstalls archives
mix clean             # Deletes generated application files
mix cmd               # Executes the given command
mix compile           # Compiles source files
mix deps              # Lists dependencies and their status
mix deps.clean        # Deletes the given dependencies' files
mix deps.compile      # Compiles dependencies
mix deps.get          # Gets all out of date dependencies
mix deps.tree         # Prints the dependency tree
mix deps.unlock       # Unlocks the given dependencies
mix deps.update       # Updates the given dependencies
mix do                # Executes the tasks separated by comma
mix escript           # Lists installed escripts
mix escript.build     # Builds an escript for the project
mix escript.install   # Installs an escript locally
mix escript.uninstall # Uninstalls escripts
mix format            # Formats the given files/patterns
mix help              # Prints help information for tasks
mix loadconfig        # Loads and persists the given configuration
mix local             # Lists local tasks
mix local.hex         # Installs Hex locally
mix local.public_keys # Manages public keys
mix local.rebar       # Installs Rebar locally
mix new               # Creates a new Elixir project
mix profile.cprof     # Profiles the given file or expression with cprof
mix profile.eprof     # Profiles the given file or expression with eprof
mix profile.fprof     # Profiles the given file or expression with fprof
mix release           # Assembles a self-contained release
mix release.init      # Generates sample files for releases
mix run               # Starts and runs the current application
mix test              # Runs a project's tests
mix xref              # Prints cross reference information
iex -S mix            # Starts IEx and runs the default task

Installing Lumen

Lumen is an alternative BEAM Implementation.
Warning that this is still at a very early stage. It promises the ability to build WebAssembly

I am not currently interested in using Rust to build it from sources, but there are now images published here

https://github.com/lumen/lumen/releases

I used the following to install the tarball (I use a mac):

sudo tar xf lumen-0.1.0-nightly-x86_64-apple-darwin.tar.gz -C /opt

This deploys the bundle to: /opt/lumen

The compiler is now available at: /opt/lumen/bin/lumen

Here are more details on lumen: https://getlumen.org/