adopt shellcheck

CONTRIBUTING.md

@@ -12,6 +12,7 @@
         - [Docker](#docker)
         - [Testing](#testing)
             - [`godo` mocks](#godo-mocks)
+        - [Build Scripts](#build-scripts)
     - [Releasing](#releasing)
         - [Setup](#setup)
         - [Cutting a release](#cutting-a-release)
@@ -90,6 +91,10 @@ When you upgrade `godo` you have to re-generate the mocks.
     make mocks
     ```
 
+### Build Scripts
+
+If you modify the build scripts, use `make shellcheck` to check your changes.
+
 ## Releasing
 
 ### Setup

Makefile

@@ -42,6 +42,11 @@ mocks:
 	@echo "update mocks"
 	scripts/regenmocks.sh
 
+.PHONY: shellcheck
+shellcheck:
+	@echo "analyze shell scripts"
+	scripts/shell_check.sh
+
 # These builds are for convenience. This logic isn't used in the build-release process
 my_d = $(shell pwd)
 OUT_D = $(shell echo $${OUT_D:-$(my_d)/builds})

scripts/build.sh

@@ -1,14 +1,14 @@
 #!/bin/bash
 
-set -eo pipefail
+set -eou pipefail
 
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 OUT_DIR="$DIR/../out"
-mkdir -p $OUT_DIR
+mkdir -p "$OUT_DIR"
 
 go build \
-  -o $OUT_DIR/doctl \
-  -ldflags "-X github.com/digitalocean/doctl/Build=`git rev-parse --short HEAD`" \
+  -o "$OUT_DIR/doctl" \
+  -ldflags "-X github.com/digitalocean/doctl/Build=$(git rev-parse --short HEAD)" \
   github.com/digitalocean/doctl/cmd/doctl
 
-chmod +x $OUT_DIR/doctl
+chmod +x "$OUT_DIR/doctl"