ossrules.md

railpack

Configure and troubleshoot Railpack builds, with emphasis on RAILPACK_* environment variables, railpack.json overlays, build-plan inspection, local CLI installation and usage, and local BuildKit containers. Use for Railpack provider configuration, custom install/build/start commands, Mise or Apt packages, build or runtime variables and secrets, generated-plan debugging, BUILDKIT_HOST errors, or running Railpack from a release or source checkout.

Install
npx skills add 'https://github.com/railwayapp/railpack/tree/main/.'
Incomplete bundle · no download
main · 21a254f ↗Scanned 2026-09-17

Contributors

GitHub-linked commit authors for this SKILL.md at the saved revision. Co-authors and history before file renames are not included.

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core/__snapshots__/TestGenerateBuildPlanForExamples_ruby-with-node_1.snap.json

core/__snapshots__/TestGenerateBuildPlanForExamples_ruby-with-node_1.snap.jsonBrowse 1970 files
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{ "caches": {  "apt": {   "directory": "/var/cache/apt",   "type": "locked"  },  "apt-lists": {   "directory": "/var/lib/apt/lists",   "type": "locked"  },  "node-modules": {   "directory": "/app/node_modules/.cache",   "type": "shared"  },  "npm-install": {   "directory": "/root/.npm",   "type": "shared"  } }, "deploy": {  "base": {   "step": "packages:apt:runtime"  },  "inputs": [   {    "include": [     "/mise/shims",     "/mise/installs",     "/usr/local/bin/mise",     "/etc/mise/config.toml",     "/root/.local/state/mise"    ],    "step": "packages:mise"   },   {    "include": [     "/usr/local/bundle"    ],    "step": "install"   },   {    "include": [     "/app"    ],    "step": "build"   },   {    "include": [     "/app/node_modules"    ],    "step": "prune:node"   },   {    "exclude": [     "node_modules",     ".yarn"    ],    "include": [     "."    ],    "step": "build:node"   }  ],  "startCommand": "ruby app.rb",  "variables": {   "BUNDLE_GEMFILE": "/app/Gemfile",   "GEM_HOME": "/usr/local/bundle",   "GEM_PATH": "/usr/local/bundle",   "LD_PRELOAD": "libjemalloc.so.2",   "MALLOC_ARENA_MAX": "2",   "RAILPACK_VERSION": "dev"  } }, "steps": [  {   "caches": [    "apt",    "apt-lists"   ],   "commands": [    {     "cmd": "sh -c 'apt-get update \u0026\u0026 apt-get install -y libjemalloc-dev libyaml-dev'",     "customName": "install apt packages: libjemalloc-dev libyaml-dev"    }   ],   "inputs": [    {     "image": "ghcr.io/railwayapp/railpack-builder:mise-2026.9.9"    }   ],   "name": "packages:apt:build"  },  {   "assets": {    "generated-mise-toml": "[generated-mise-toml]"   },   "commands": [    {     "path": "/mise/shims"    },    {     "dest": "Gemfile",     "src": "Gemfile"    },    {     "customName": "create mise config",     "name": "generated-mise-toml",     "path": "/etc/mise/config.toml"    },    {     "cmd": "mise install",     "customName": "install mise packages: node, ruby"    }   ],   "inputs": [    {     "step": "packages:apt:build"    }   ],   "name": "packages:mise",   "variables": {    "MISE_CACHE_DIR": "/mise/cache",    "MISE_CONFIG_DIR": "/mise",    "MISE_DATA_DIR": "/mise",    "MISE_INSTALLS_DIR": "/mise/installs",    "MISE_SHIMS_DIR": "/mise/shims",    "RUBY_CONFIGURE_OPTS": "--disable-install-doc"   }  },  {   "commands": [    {     "cmd": "gem install -N bundler:2.3.7"    },    {     "dest": "Gemfile",     "src": "Gemfile"    },    {     "dest": "Gemfile.lock",     "src": "Gemfile.lock"    },    {     "cmd": "bundle install"    },    {     "path": "/usr/local/bundle"    }   ],   "inputs": [    {     "step": "packages:mise"    }   ],   "name": "install",   "variables": {    "BUNDLE_GEMFILE": "/app/Gemfile",    "GEM_HOME": "/usr/local/bundle",    "GEM_PATH": "/usr/local/bundle",    "LD_PRELOAD": "libjemalloc.so.2",    "MALLOC_ARENA_MAX": "2"   }  },  {   "caches": [    "npm-install"   ],   "commands": [    {     "path": "/app/node_modules/.bin"    },    {     "cmd": "mkdir -p /app/node_modules/.cache"    },    {     "dest": "package-lock.json",     "src": "package-lock.json"    },    {     "dest": "package.json",     "src": "package.json"    },    {     "cmd": "npm install"    }   ],   "inputs": [    {     "step": "packages:mise"    }   ],   "name": "install:node",   "variables": {    "CI": "true",    "NODE_ENV": "production",    "NPM_CONFIG_FETCH_RETRIES": "5",    "NPM_CONFIG_FUND": "false",    "NPM_CONFIG_PRODUCTION": "false",    "NPM_CONFIG_UPDATE_NOTIFIER": "false"   }  },  {   "caches": [    "npm-install"   ],   "commands": [    {     "cmd": "npm prune --omit=dev --ignore-scripts"    }   ],   "inputs": [    {     "step": "install:node"    }   ],   "name": "prune:node",   "variables": {    "NPM_CONFIG_PRODUCTION": "true"   }  },  {   "caches": [    "node-modules"   ],   "inputs": [    {     "step": "install"    },    {     "include": [      ".",      "/mise/shims",      "/mise/installs",      "/usr/local/bin/mise",      "/etc/mise/config.toml",      "/root/.local/state/mise"     ],     "step": "install:node"    },    {     "include": [      "."     ],     "local": true    }   ],   "name": "build:node",   "secrets": [    "*"   ]  },  {   "inputs": [    {     "step": "install"    },    {     "include": [      "."     ],     "local": true    }   ],   "name": "build",   "variables": {    "BUNDLE_GEMFILE": "/app/Gemfile",    "GEM_HOME": "/usr/local/bundle",    "GEM_PATH": "/usr/local/bundle",    "LD_PRELOAD": "libjemalloc.so.2",    "MALLOC_ARENA_MAX": "2"   }  },  {   "caches": [    "apt",    "apt-lists"   ],   "commands": [    {     "cmd": "sh -c 'apt-get update \u0026\u0026 apt-get install -y libatomic1 libjemalloc2 libyaml-dev'",     "customName": "install apt packages: libatomic1 libjemalloc2 libyaml-dev"    }   ],   "inputs": [    {     "image": "ghcr.io/railwayapp/railpack-runtime:mise-2026.9.9"    }   ],   "name": "packages:apt:runtime"  } ]}
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