Cheatrebar3 Erlang build tool
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Start here
rebar3 new app <name>
Create an OTP app
rebar3 compileFetch deps and build
rebar3 shellErlang shell with the project
rebar3 eunitRun unit tests
rebar3 ctRun Common Test suites
rebar3 dialyzerType analysis
rebar3 as prod tar
Release tarball
rebar3 help <task>
Help for a task
Concepts
- rebar.config deps, profiles
- rebar.lock pinned deps
- _build/<profile> beams, deps, rel
- Release relx, start script
Projects
rebar3 new app <name>
OTP application with supervisor
rebar3 new lib <name>
Library without a supervisor
rebar3 new release <name>
Umbrella project for releases
umbrella is an alias of the release template; apps go under
apps/.
rebar3 new escript <name>
Command-line escript project
rebar3 new plugin <name>
Start a rebar3 plugin
rebar3 new helpList available templates
rebar3 new <template> <name> --force
Overwrite existing files
Build & run
rebar3 compileFetch deps and compile all apps
rebar3 compile -d
Compile dependencies only
rebar3 cleanRemove compiled beams
rebar3 clean --all
Clean deps and all profiles too
rebar3 shellShell with apps and deps loaded
Starts the apps in the shell; use --start-clean to load code
without starting them.
rebar3 shell --sname <name>
Shell as a named node
rebar3 shell --apps <a>,<b>
Start only these apps
rebar3 shell --config <file>
Use a sys.config file
rebar3 shell --eval "<expr>."
Run Erlang code on start
rebar3 shell --setcookie <cookie>
Set the distribution cookie
rebar3 do <task>,<task>
Run several tasks in a row
rebar3 path --lib
Print library paths of the build
rebar3 escriptize
Package an escript executable
rebar3 versionShow rebar3 and Erlang versions
Test
rebar3 eunitRun all EUnit tests
rebar3 eunit --module=<mod>
Tests of one module
rebar3 eunit --test=<mod>:<fun>
Run one test function
rebar3 eunit --application=<app>
Tests of one app
rebar3 eunit --file=<path>
Tests from a source file
rebar3 eunit -vVerbose output
rebar3 ctRun all Common Test suites
Suites are *_SUITE.erl files in each app's test/
directory.
rebar3 ct --suite=<path>
Run one suite
Comma-separate several suites; the path has no .erl extension.
rebar3 ct --suite=<path> --group=<g>
Run one test group
rebar3 ct --suite=<path> --case=<c>
Run one test case
rebar3 ct --repeat <n>
Repeat the run n times
rebar3 ct --sys_config=<file>
Use a sys.config for tests
rebar3 ct --verbose
Print more output
rebar3 eunit --cover
Collect coverage data
rebar3 ct --cover
Collect coverage data
rebar3 cover --verbose
Coverage report in the console
rebar3 cover --min_coverage <pct>
Fail below a percentage
rebar3 do eunit,ct
Run both test types
Dependencies
rebar3 depsList deps and lock status
rebar3 treeShow the dependency tree
rebar3 upgradeUpgrade all dependencies
rebar3 upgrade <dep>
Upgrade one dependency
Also upgrades the subtree of that dependency.
rebar3 unlock <dep>
Drop a dependency from the lock
rebar3 updateRefresh the Hex package index
rebar3 get-depsFetch deps without compiling
rebar3 lockFetch unbuilt deps into the lock
{deps, [ cowboy, {jsx, "~> 3.1"}, {mylib, {git, "<url>", {tag, "1.0.0"}}}, {other, {git, "<url>", {branch, "main"}}}]}.Profiles
rebar3 as <profile> <task>
Run a task in a profile
rebar3 as <p1>,<p2> <task>
Combine profiles
REBAR_PROFILE=<profile> rebar3 <task>
Set the base profile by env
rebar3 as test compile
Build with test profile deps
{profiles, [ {test, [{deps, [meck]}]}, {prod, [{erl_opts, [no_debug_info]}]}]}.Quality
rebar3 dialyzerBuild the PLT and check types
The first run builds a PLT and is slow; later runs reuse it.
rebar3 dialyzer --update-plt
Rebuild the PLT after changes
rebar3 xrefCross-reference check
rebar3 edocGenerate API docs
rebar3 report "<task>"
Collect info for a bug report
{dialyzer, [{warnings, [no_return]}]}.{xref_checks, [undefined_function_calls, exports_not_used]}.{cover_enabled, true}.Releases
rebar3 releaseBuild a dev release
rebar3 as prod release
Release with ERTS, no symlinks
rebar3 as prod tar
Release as a .tar.gz
rebar3 relupBuild a release upgrade
_build/<profile>/rel/<name>/bin/<name>
console
Start a release in a shell
bin/<name> foreground
Run in foreground (systemd, Docker)
bin/<name> daemon
Run as a background node
bin/<name> remote_console
Attach to a running node
bin/<name> ping / stop / restart
Control a running node
bin/<name> eval "<expr>"
Evaluate code on a node
{relx, [ {release, {<name>, "0.1.0"}, [<name>, sasl]}, {dev_mode, true}, {include_erts, false}, {extended_start_script, true}]}.Config & plugins
{erl_opts, [debug_info, warnings_as_errors]}.{minimum_otp_vsn, "26"}.{alias, [{check, [xref, dialyzer, eunit, ct]}]}.{provider_hooks, [{pre, [{compile, clean}]}]}.rebar3 aliasList aliases from rebar.config
{plugins, [rebar3_auto]}.{project_plugins, [erlfmt]}.rebar3 plugins upgrade <plugin>
Upgrade a plugin
rebar3 completion
Generate shell completion
Hex
rebar3 hex user auth
Log in to hex.pm
rebar3 hex search <term>
Search packages
rebar3 hex publish
Publish package and docs
rebar3 hex build
Build tarballs without publishing
rebar3 hex cutBump version, tag and publish
rebar3 hex retire <pkg> <vsn>
<reason>
Retire a version
Recipes
rebar3 new app myapp && cd myapprebar3 eunitrebar3 shell# 1> observer:start().rebar3 do xref, dialyzer, eunit, ct# or define an alias and run: rebar3 checkrebar3 as prod tartar xzf _build/prod/rel/<name>/<name>-*.tar.gz -C /opt/<name>/opt/<name>/bin/<name> foregroundrebar3 ct --suite=test/<name>_SUITE --case=<case>rebar3 shell --eval "<mod>:<fun>()."
