stop using GB, convert to dep/gox/GOPATH model

GB seems semi-abandoned, and currently doesn't cross compile with
either go-1.9.4 or go-1.10 ([bug][1]). Possibly due to the new cgo flag
whitelisting (see: [go issue: 23739][2])?

Instead:
*   require devs to put into GOPATH, as this seems unfortunately to be
    the convention the go community arrived at :(
*   use dep for vendoring
*   use gox for easy cross compilation

[1]: constabulary/gb#733
[2]: golang/go#23739

.circleci/config.yml

@@ -5,4 +5,4 @@ jobs:
             - image: circleci/golang:1
         steps:
           - checkout
-          - run: make build-setup test
+          - run: make test

.gitignore

@@ -1,8 +1,5 @@
+/build
 /config.json
-/bin
-/pkg
-/tar
-/man/*.[1-9]
 /prox.exe
 /server.pem
 /server.key

.travis.yml

@@ -1,6 +1,6 @@
 language: go
-script: make build-setup test
+script: make test
 sudo: false
 go:
-    - 1.8
-    - 1.9
+    - "1.9.x"
+    - "1.10"

DEPS.md

@@ -6,11 +6,8 @@ Portions of this software utilize third party libraries:
 
 *   Runtime dependencies:
     ├── https://github.com/cactus/mlog              (MIT License)
-    ├── https://github.com/cactus/tai64             (MIT License)
     └── https://github.com/jessevdk/go-flags        (BSD License)
 
 *   Test only dependencies:
     └── https://github.com/stretchr/testify/assert  (MIT License)
-        ├── https://github.com/davecgh/go-spew      (ISC License)
-        └── https://github.com/pmezard/go-difflib   (BSD License)
 ~~~

Gopkg.toml

@@ -0,0 +1,33 @@
+# Gopkg.toml example
+#
+# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#  name = "github.com/x/y"
+#  version = "2.4.0"
+
+
+[[constraint]]
+  name = "github.com/cactus/mlog"
+  version = "1.0.0"
+
+[[constraint]]
+  name = "github.com/jessevdk/go-flags"
+  version = "1.3.0"
+
+[[constraint]]
+  name = "github.com/stretchr/testify"
+  version = "1.2.1"

Makefile

@@ -1,17 +1,28 @@
-
-BUILDDIR          := ${CURDIR}
+# environment
+BUILDDIR          := ${CURDIR}/build
 TARBUILDDIR       := ${BUILDDIR}/tar
 ARCH              := $(shell go env GOHOSTARCH)
 OS                := $(shell go env GOHOSTOS)
 GOVER             := $(shell go version | awk '{print $$3}' | tr -d '.')
+
+# app specific info
 APP_NAME          := go-camo
 APP_VER           := $(shell git describe --always --dirty --tags|sed 's/^v//')
 VERSION_VAR       := main.ServerVersion
+
+# flags and build configuration
 GOTEST_FLAGS      := -cpu=1,2
 GOBUILD_DEPFLAGS  := -tags netgo
 GOBUILD_LDFLAGS   ?= -s -w
 GOBUILD_FLAGS     := ${GOBUILD_DEPFLAGS} -ldflags "${GOBUILD_LDFLAGS} -X ${VERSION_VAR}=${APP_VER}"
-GB                := gb
+
+# cross compile defs
+CC_BUILD_ARCHES    = darwin/amd64 freebsd/amd64 linux/amd64
+CC_OUTPUT_TPL     := ${BUILDDIR}/bin/{{.Dir}}.{{.OS}}-{{.Arch}}
+
+# error messages
+GOX_ERR_MSG        = 'gox' command not found.
+GOX_INSTALL_MSG    = try 'go get github.com/mitchellh/gox'
 
 define HELP_OUTPUT
 Available targets:
@@ -20,7 +31,6 @@ Available targets:
   all                 build binaries and man pages
   test                run tests
   cover               run tests with cover output
-  build-setup         fetch dependencies
   build               build all binaries
   man                 build all man pages
   tar                 build release tarball
@@ -34,31 +44,31 @@ help:
 	@echo "$$HELP_OUTPUT"
 
 clean:
-	@rm -rf "${BUILDDIR}/bin"
-	@rm -rf "${BUILDDIR}/pkg"
-	@rm -rf "${BUILDDIR}/tar"
-	@rm -rf "${BUILDDIR}/man/"*.[1-9]
-
-build-setup:
-	@go get github.com/constabulary/gb/...
+	@rm -rf "${BUILDDIR}"
 
 build:
+	@[ -d "${BUILDDIR}/bin" ] || mkdir -p "${BUILDDIR}/bin"
 	@echo "Building..."
-	@${GB} build ${GOBUILD_FLAGS} ...
+	@echo "...go-camo..."
+	@env CGO_ENABLED=0 go build ${GOBUILD_FLAGS} -o "${BUILDDIR}/bin/go-camo" .
+	@echo "...url-tool..."
+	@env CGO_ENABLED=0 go build ${GOBUILD_FLAGS} -o "${BUILDDIR}/bin/url-tool" ./url-tool
+	@echo "done!"
 
 test:
 	@echo "Running tests..."
-	@${GB} test ${GOTEST_FLAGS} ...
+	@go test ${GOTEST_FLAGS} ./...
 
 generate:
 	@echo "Running generate..."
-	@${GB} generate
+	@go generate
 
 cover:
 	@echo "Running tests with coverage..."
-	@${GB} test -cover ${GOTEST_FLAGS} ...
+	@go test -cover ${GOTEST_FLAGS} ./...
 
 ${BUILDDIR}/man/%: man/%.mdoc
+	@[ -d "${BUILDDIR}/man" ] || mkdir -p "${BUILDDIR}/man"
 	@cat $< | sed -E "s#.Os (.*) VERSION#.Os \1 ${APP_VER}#" > $@
 
 man: $(patsubst man/%.mdoc,${BUILDDIR}/man/%,$(wildcard man/*.1.mdoc))
@@ -67,28 +77,41 @@ tar: all
 	@echo "Building tar..."
 	@mkdir -p ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/bin
 	@mkdir -p ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/man
-	@cp ${BUILDDIR}/bin/${APP_NAME}-netgo ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/bin/${APP_NAME}
-	@cp ${BUILDDIR}/bin/url-tool-netgo ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/bin/url-tool
+	@cp ${BUILDDIR}/bin/${APP_NAME} ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/bin/${APP_NAME}
+	@cp ${BUILDDIR}/bin/url-tool ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/bin/url-tool
 	@cp ${BUILDDIR}/man/*.[1-9] ${TARBUILDDIR}/${APP_NAME}-${APP_VER}/man/
 	@tar -C ${TARBUILDDIR} -czf ${TARBUILDDIR}/${APP_NAME}-${APP_VER}.${GOVER}.${OS}-${ARCH}.tar.gz ${APP_NAME}-${APP_VER}
+	@rm -rf "${TARBUILDDIR}/${APP_NAME}-${APP_VER}"
 
 cross-tar: man
-	@echo "Making tar for ${APP_NAME}:darwin.amd64"
-	@env GOOS=darwin  GOARCH=amd64 ${GB} build ${GOBUILD_FLAGS} ...
-	@env GOOS=freebsd GOARCH=amd64 ${GB} build ${GOBUILD_FLAGS} ...
-	@env GOOS=linux   GOARCH=amd64 ${GB} build ${GOBUILD_FLAGS} ...
-
-	@(for x in darwin-amd64 freebsd-amd64 linux-amd64; do \
-		echo "Making tar for ${APP_NAME}.$${x}"; \
+	$(if $(shell type -p gox),,$(error ${GOX_ERR_MSG} ${GOX_INSTALL_MSG}))
+
+	@echo "Building (cross-compile: ${CC_BUILD_ARCHES})..."
+	@echo "...go-camo..."
+	@env gox -output="${CC_OUTPUT_TPL}" -osarch="${CC_BUILD_ARCHES}" \
+		${GOBUILD_FLAGS} .
+	@echo
+
+	@echo "...url-tool..."
+	@env gox -output="${CC_OUTPUT_TPL}" -osarch="${CC_BUILD_ARCHES}" \
+		${GOBUILD_FLAGS} ./url-tool
+	@echo
+
+	@echo "...creating tar files..."
+	@(for x in $(subst /,-,${CC_BUILD_ARCHES}); do \
+		echo "making tar for ${APP_NAME}.$${x}"; \
 		XDIR="${GOVER}.$${x}"; \
-		mkdir -p ${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}/bin/; \
-		mkdir -p ${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}/man/; \
-		cp bin/${APP_NAME}-$${x}-netgo ${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}/bin/${APP_NAME}; \
-		cp bin/url-tool-$${x}-netgo ${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}/bin/url-tool; \
-		cp ${BUILDDIR}/man/*.[1-9] ${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}/man/; \
+		ODIR="${TARBUILDDIR}/$${XDIR}/${APP_NAME}-${APP_VER}"; \
+		mkdir -p $${ODIR}/{bin,man}/; \
+		cp ${BUILDDIR}/bin/${APP_NAME}.$${x} $${ODIR}/bin/${APP_NAME}; \
+		cp ${BUILDDIR}/bin/url-tool.$${x} $${ODIR}/bin/url-tool; \
+		cp ${BUILDDIR}/man/*.[1-9] $${ODIR}/man/; \
 		tar -C ${TARBUILDDIR}/$${XDIR} -czf ${TARBUILDDIR}/${APP_NAME}-${APP_VER}.$${XDIR}.tar.gz ${APP_NAME}-${APP_VER}; \
+		rm -rf "${TARBUILDDIR}/$${XDIR}/"; \
 	done)
 
+	@echo "done!"
+
 release-sign:
 	@echo "signing release tarballs"
 	@(cd tar; shasum -a 256 go-camo-*.tar.gz > SHA256; \

README.md

@@ -118,12 +118,27 @@ Extract, and copy files to desired locations.
 
 Building requires:
 
-*   git
 *   make
-*   go (version 1.8 recommended)
+*   git
+*   go (latest version recommended. At least version >= 1.9)
+
+Additionally required, if cross compiling:
+
+*   [gox](https://github.com/mitchellh/gox)
 
 Building:
 
+First, make sure you check out the repository into the proper location
+in your GOPATH. This can be done manually, or with `go get`.
+
+```
+$ export GOPATH=/tmp/go
+$ go get -d github.com/cactus/go-camo
+$ cd $GOPATH/src/github.com/cactus/go-camo
+```
+
+Once that is done, you are ready to build! 
+
 ```text
 # show make targets
 $ make
@@ -133,15 +148,11 @@ Available targets:
   all                 build binaries and man pages
   test                run tests
   cover               run tests with cover output
-  build-setup         fetch dependencies
   build               build all
   man                 build all man pages
   tar                 build release tarball
   cross-tar           cross compile and build release tarballs
 
-# fetch vendor dependencies
-$ make build-setup
-
 # build all binaries and man pages
 # strips debug symbols by default
 $ make all
@@ -150,12 +161,6 @@ $ make all
 $ make all GOBUILD_LDFLAGS=""
 ```
 
-By default, Go-Camo builds with `-tags netgo`. However, for Go versions
-older than 1.5, this may not result in Go-Camo using the netgo resolver unless
-your Go stdlib is also compiled with `-tags netgo`. For this reason, it is
-required to build with at least go-1.5. Building with the latest Go version is
-recommended.
-
 ## Running
 
 ```text

src/go-camo/camo/example_proxymetrics_test.go → camo/example_proxymetrics_test.go

@@ -8,8 +8,8 @@ import (
 	"fmt"
 	"os"
 
-	"go-camo/camo"
-	"go-camo/stats"
+	"github.com/cactus/go-camo/camo"
+	"github.com/cactus/go-camo/stats"
 )
 
 func ExampleProxyMetrics() {

src/go-camo/camo/proxy.go → camo/proxy.go

@@ -16,7 +16,7 @@ import (
 	"strings"
 	"time"
 
-	"go-camo/camo/encoding"
+	"github.com/cactus/go-camo/camo/encoding"
 
 	"github.com/cactus/mlog"
 )

src/go-camo/camo/proxy_test.go → camo/proxy_test.go

@@ -11,8 +11,8 @@ import (
 	"testing"
 	"time"
 
-	"go-camo/camo/encoding"
-	"go-camo/router"
+	"github.com/cactus/go-camo/camo/encoding"
+	"github.com/cactus/go-camo/router"
 
 	"github.com/stretchr/testify/assert"
 )

diagrams/diagram.txt

@@ -0,0 +1,17 @@
++----------+          request             +-------------+                 
+|          |----------------------------->|             |                 
+|          |                              |             |                 
+|          |                              |   web-app   |                 
+|          | img src=https://go-camo/url  |             |                 
+|          |<-----------------------------|             |                 
+|          |                              +-------------+                 
+|  client  |                                                              
+|          |     https://go-camo/url      +-------------+ http://some/img 
+|          |----------------------------->|             |---------------> 
+|          |                              |             |                 
+|          |                              |   go-camo   |                 
+|          |           img data           |             |  img data       
+|          |<-----------------------------|             |<--------------- 
+|          |                              +-------------+                 
++----------+                                                              
+

src/go-camo/main.go → main.go

@@ -5,7 +5,7 @@
 // go-camo daemon (go-camod)
 package main
 
-//go:generate go run ../../tools/genversion.go -pkg $GOPACKAGE -input ../../DEPS.md -output version_info_generated.go
+//go:generate go run tools/genversion.go -pkg $GOPACKAGE -input DEPS.md -output main_vers_gen.go
 
 import (
 	"fmt"
@@ -17,9 +17,9 @@ import (
 	"strings"
 	"time"
 
-	"go-camo/camo"
-	"go-camo/router"
-	"go-camo/stats"
+	"github.com/cactus/go-camo/camo"
+	"github.com/cactus/go-camo/router"
+	"github.com/cactus/go-camo/stats"
 
 	"github.com/cactus/mlog"
 	flags "github.com/jessevdk/go-flags"

src/go-camo/version_info_generated.go → main_vers_gen.go

@@ -14,11 +14,8 @@ Portions of this software utilize third party libraries:
 
 *   Runtime dependencies:
     ├── https://github.com/cactus/mlog              (MIT License)
-    ├── https://github.com/cactus/tai64             (MIT License)
     └── https://github.com/jessevdk/go-flags        (BSD License)
 
 *   Test only dependencies:
     └── https://github.com/stretchr/testify/assert  (MIT License)
-        ├── https://github.com/davecgh/go-spew      (ISC License)
-        └── https://github.com/pmezard/go-difflib   (BSD License)
 `