Build flow for alpine from scratch

.travis.yml

@@ -1,4 +1,6 @@
-sudo: false
+sudo: true
+services:
+  - docker
 language: node_js
 node_js:
   - 'stable'

Makefile

@@ -1,6 +1,7 @@
 FLOW_VERSION ?= $(shell node -p 'require("./package.json").version')
 FLOW_BINS = \
 	flow-linux64-v$(FLOW_VERSION)/flow \
+	flow-linux64-musl-v$(FLOW_VERSION)/flow \
 	flow-osx-v$(FLOW_VERSION)/flow \
 	flow-win64-v$(FLOW_VERSION)/flow.exe
 
@@ -32,6 +33,12 @@ get-flow = \
 flow-linux64-v%/flow:
 	$(get-flow)
 
+flow-linux64-musl-v%/flow:
+	mkdir -p $(@D) && \
+	cd flow-linux64-musl-build && \
+	docker build --build-arg FLOW_TAG=v$(*F) -t flow-musl-build . && \
+	docker run -v $(PWD)/$(@D):/out --rm -ti flow-musl-build cp /tmp/flow/bin/flow /out/ \
+
 flow-osx-v%/flow:
 	$(get-flow)
 

SHASUM256.txt

@@ -1,3 +1,4 @@
 ca40e98614074a5358f17733b2b06885977bb6a03f55e3488e366d5dd0861497  flow-linux64-v0.43.0/flow
+73a717da991b24ff12fa1809f31286d49ee35a0a16489d16acde403125ae1e9d  flow-linux64-musl-v0.43.0/flow
 deb3b619c60abb16676679c2c4df265bc0f42278a631ab88a1777f10a6779475  flow-osx-v0.43.0/flow
 9ab57b8c731454d23e337255aa675da6333e46ca59c035f78c732ab9039d5361  flow-win64-v0.43.0/flow.exe

flow-linux64-musl-build/Dockerfile

@@ -0,0 +1,24 @@
+FROM node:6.9.4-alpine
+
+ARG FLOW_TAG
+
+RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories \
+  && echo "http://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories \
+  && apk --no-cache add \
+     alpine-sdk \
+     ocaml \
+     ocamlbuild \
+     libelf \
+     libelf-dev \
+     ncurses \
+     inotify-tools \
+     linux-headers \
+     git \
+     bash \
+     diffutils
+
+RUN npm install -g yarn
+RUN git clone --depth 1 https://github.com/facebook/flow.git /tmp/flow \
+  && cd /tmp/flow \
+  && yarn
+RUN cd /tmp/flow && make

index.js

@@ -11,10 +11,30 @@
 var VERSION = require('./package.json').version;
 
 var path = require('path');
+var fs = require('fs');
+
+function isLibcMusl() {
+  try {
+    var contents = fs.readFileSync(process.execPath);
+
+    // Buffer.indexOf was added in v1.5.0 so cast to string for old node
+    // Delay contents.toStrings because it's expensive
+    if (!contents.indexOf) {
+      contents = contents.toString();
+    }
+
+    if (contents.indexOf('libc.musl-x86_64.so.1') !== -1) {
+      return true;
+    }
+  } catch (err) { } // eslint-disable-line no-empty
+  return false;
+}
 
 module.exports =
   process.platform === 'darwin'
     ? path.join(__dirname, 'flow-osx-v' + VERSION, 'flow') :
+  process.platform === 'linux' && isLibcMusl() && process.arch === 'x64'
+    ? path.join(__dirname, 'flow-linux64-musl-v' + VERSION, 'flow') :
   process.platform === 'linux' && process.arch === 'x64'
     ? path.join(__dirname, 'flow-linux64-v' + VERSION, 'flow') :
   process.platform === 'win32' &&  process.arch === 'x64'