build: improve debian packaging

This commit tweaks the debian packaging tool:

* All build environment metadata can now be overriden on the command
  line. This allows testing the CI build behaviour locally.
* -unstable packages now actually contain the binaries (oops)
* packages use Go 1.7 to build
* archiving is skipped for PR builds

2 files changed, 120 insertions, 8 deletions

diff --git a/internal/build/env.go b/internal/build/env.go
new file mode 100644
index 000000000..87b4c57ac
--- /dev/null
+++ b/internal/build/env.go
@@ -0,0 +1,114 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package build
+
+import (
+	"flag"
+	"fmt"
+	"os"
+)
+
+var (
+	// These flags override values in build env.
+	GitCommitFlag   = flag.String("git-commit", "", `Overrides git commit hash embedded into executables`)
+	GitBranchFlag   = flag.String("git-branch", "", `Overrides git branch being built`)
+	GitTagFlag      = flag.String("git-tag", "", `Overrides git tag being built`)
+	BuildnumFlag    = flag.String("buildnum", "", `Overrides CI build number`)
+	PullRequestFlag = flag.Bool("pull-request", false, `Overrides pull request status of the build`)
+)
+
+// Environment contains metadata provided by the build environment.
+type Environment struct {
+	Name                string // name of the environment
+	Repo                string // name of GitHub repo
+	Commit, Branch, Tag string // Git info
+	Buildnum            string
+	IsPullRequest       bool
+}
+
+func (env Environment) String() string {
+	return fmt.Sprintf("%s env (commit:%s branch:%s tag:%s buildnum:%s pr:%t)",
+		env.Name, env.Commit, env.Branch, env.Tag, env.Buildnum, env.IsPullRequest)
+}
+
+// Env returns metadata about the current CI environment, falling back to LocalEnv
+// if not running on CI.
+func Env() Environment {
+	switch {
+	case os.Getenv("CI") == "true" && os.Getenv("TRAVIS") == "true":
+		return Environment{
+			Name:          "travis",
+			Repo:          os.Getenv("TRAVIS_REPO_SLUG"),
+			Commit:        os.Getenv("TRAVIS_COMMIT"),
+			Branch:        os.Getenv("TRAVIS_BRANCH"),
+			Tag:           os.Getenv("TRAVIS_TAG"),
+			Buildnum:      os.Getenv("TRAVIS_BUILD_NUMBER"),
+			IsPullRequest: os.Getenv("TRAVIS_PULL_REQUEST") != "false",
+		}
+	case os.Getenv("CI") == "True" && os.Getenv("APPVEYOR") == "True":
+		return Environment{
+			Name:          "appveyor",
+			Repo:          os.Getenv("APPVEYOR_REPO_NAME"),
+			Commit:        os.Getenv("APPVEYOR_REPO_COMMIT"),
+			Branch:        os.Getenv("APPVEYOR_REPO_BRANCH"),
+			Tag:           os.Getenv("APPVEYOR_REPO_TAG"),
+			Buildnum:      os.Getenv("APPVEYOR_BUILD_NUMBER"),
+			IsPullRequest: os.Getenv("APPVEYOR_PULL_REQUEST_NUMBER") != "",
+		}
+	default:
+		return LocalEnv()
+	}
+}
+
+// LocalEnv returns build environment metadata gathered from git.
+func LocalEnv() Environment {
+	env := applyEnvFlags(Environment{Name: "local", Repo: "ethereum/go-ethereum"})
+	if _, err := os.Stat(".git"); err != nil {
+		return env
+	}
+	if env.Commit == "" {
+		env.Commit = RunGit("rev-parse", "HEAD")
+	}
+	if env.Branch == "" {
+		env.Branch = RunGit("symbolic-ref", "-q", "--short", "HEAD")
+	}
+	// Note that we don't get the current git tag. It would slow down
+	// builds and isn't used by anything.
+	return env
+}
+
+func applyEnvFlags(env Environment) Environment {
+	if !flag.Parsed() {
+		panic("you need to call flag.Parse before Env or LocalEnv")
+	}
+	if *GitCommitFlag != "" {
+		env.Commit = *GitCommitFlag
+	}
+	if *GitBranchFlag != "" {
+		env.Branch = *GitBranchFlag
+	}
+	if *GitTagFlag != "" {
+		env.Tag = *GitTagFlag
+	}
+	if *BuildnumFlag != "" {
+		env.Buildnum = *BuildnumFlag
+	}
+	if *PullRequestFlag {
+		env.IsPullRequest = true
+	}
+	return env
+}
diff --git a/internal/build/util.go b/internal/build/util.go
index eead824b2..be41efed7 100644
--- a/internal/build/util.go
+++ b/internal/build/util.go
@@ -29,9 +29,7 @@ import (
 	"text/template"
 )
 
-var (
-	DryRunFlag = flag.Bool("n", false, "dry run, don't execute commands")
-)
+var DryRunFlag = flag.Bool("n", false, "dry run, don't execute commands")
 
 // MustRun executes the given command and exits the host process for
 // any error.
@@ -69,6 +67,7 @@ func GOPATH() string {
 	return strings.Join(newpath, string(filepath.ListSeparator))
 }
 
+// VERSION returns the content of the VERSION file.
 func VERSION() string {
 	version, err := ioutil.ReadFile("VERSION")
 	if err != nil {
@@ -77,10 +76,8 @@ func VERSION() string {
 	return string(bytes.TrimSpace(version))
 }
 
-func GitCommit() string {
-	return RunGit("rev-parse", "HEAD")
-}
-
+// RunGit runs a git subcommand and returns its output.
+// The command must complete successfully.
 func RunGit(args ...string) string {
 	cmd := exec.Command("git", args...)
 	var stdout, stderr bytes.Buffer
@@ -94,12 +91,13 @@ func RunGit(args ...string) string {
 	return strings.TrimSpace(stdout.String())
 }
 
-// Render renders the given template file.
+// Render renders the given template file into outputFile.
 func Render(templateFile, outputFile string, outputPerm os.FileMode, x interface{}) {
 	tpl := template.Must(template.ParseFiles(templateFile))
 	render(tpl, outputFile, outputPerm, x)
 }
 
+// RenderString renders the given template string into outputFile.
 func RenderString(templateContent, outputFile string, outputPerm os.FileMode, x interface{}) {
 	tpl := template.Must(template.New("").Parse(templateContent))
 	render(tpl, outputFile, outputPerm, x)