refactor(git): use go-git instead of shelled out commands (#14)

conform.yaml

@@ -61,24 +61,23 @@ scripts:
 templates:
   build: |
     FROM golang:1.8.3 as build
-    WORKDIR /go/src/github.com/autonomy/conform
+    WORKDIR $GOPATH/src/github.com/autonomy/conform
     COPY ./ ./
-    RUN GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o /conform -a -ldflags "-X \"github.com/autonomy/conform/conform.Tag={{ trimAll "v" .GitInfo.Tag }}\" -X \"github.com/autonomy/conform/conform.SHA={{ .GitInfo.SHA }}\" -X \"github.com/autonomy/conform/conform.Built={{ .Built }}\""
+    RUN GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o /conform -ldflags "-X \"github.com/autonomy/conform/cmd.Tag={{ trimAll "v" .GitInfo.Tag }}\" -X \"github.com/autonomy/conform/conform.Tag={{ trimAll "v" .GitInfo.Tag }}\" -X \"github.com/autonomy/conform/conform.SHA={{ .GitInfo.SHA }}\" -X \"github.com/autonomy/conform/conform.Built={{ .Built }}\""
   test: |
     FROM golang:1.8.3 as test
-    WORKDIR /go/src/github.com/autonomy/conform
+    WORKDIR $GOPATH/src/github.com/autonomy/conform
     RUN go get -u gopkg.in/alecthomas/gometalinter.v1
     RUN gometalinter.v1 --install
-    COPY --from=build /go/src/github.com/autonomy/conform .
+    COPY --from=build $GOPATH/src/github.com/autonomy/conform .
     RUN chmod +x ./scripts/test.sh; sync; ./scripts/test.sh
   image: |
     FROM alpine:3.6 as image
     MAINTAINER Andrew Rynhard <andrew.rynhard@autonomy.io>
     RUN apk --update add bash \
         && rm -rf /var/cache/apk/*
-    WORKDIR /app
-    COPY --from=build /conform .
-    ENTRYPOINT ["./conform"]
+    COPY --from=build /conform /bin
+    ENTRYPOINT ["conform"]
 
 rules:
   build:

conform/enforce.go

@@ -4,9 +4,9 @@ import (
 	"bytes"
 	"fmt"
 	"io/ioutil"
-	"log"
 	"os"
 	"os/exec"
+	"strconv"
 	"strings"
 	"text/template"
 
@@ -30,6 +30,10 @@ func NewEnforcer(rule string) (enforcer *Enforcer, err error) {
 	if err != nil {
 		return
 	}
+	err = exportAll(gitInfo)
+	if err != nil {
+		return
+	}
 	date := []byte{}
 	if gitInfo.IsTag {
 		date, err = exec.Command("/bin/date").Output()
@@ -129,7 +133,7 @@ func (e *Enforcer) ExtractArtifact(artifact string) error {
 // ExecuteScript executes a script for a rule.
 func (e *Enforcer) ExecuteScript(script string) error {
 	if s, ok := e.config.Scripts[script]; ok {
-		log.Printf("Running %q script", script)
+		fmt.Printf("Running %q script\n", script)
 
 		command := exec.Command("bash", "-c", s)
 		command.Stdout = os.Stdout
@@ -152,7 +156,7 @@ func (e *Enforcer) ExecuteScript(script string) error {
 // ExecuteRule performs all the relevant actions specified in its' declaration.
 func (e *Enforcer) ExecuteRule() error {
 	if t, ok := e.config.Rules[e.rule]; ok {
-		log.Printf("Enforcing %q", e.rule)
+		fmt.Printf("Enforcing %q\n", e.rule)
 		for _, s := range t.Before {
 			err := e.ExecuteScript(s)
 			if err != nil {
@@ -180,6 +184,59 @@ func (e *Enforcer) ExecuteRule() error {
 	return fmt.Errorf("Rule %q is not defined in conform.yaml", e.rule)
 }
 
+func exportAll(gitInfo *git.Info) (err error) {
+	fmt.Printf("Branch: %s\n", gitInfo.Branch)
+	err = ExportConformVar("branch", gitInfo.Branch)
+	if err != nil {
+		return
+	}
+	fmt.Printf("SHA: %s\n", gitInfo.SHA)
+	err = ExportConformVar("sha", gitInfo.SHA)
+	if err != nil {
+		return
+	}
+	fmt.Printf("Tag: %s\n", gitInfo.Tag)
+	err = ExportConformVar("tag", gitInfo.Tag)
+	if err != nil {
+		return
+	}
+	fmt.Printf("IsTag: %s\n", strconv.FormatBool(gitInfo.IsTag))
+	err = ExportConformVar("is_tag", strconv.FormatBool(gitInfo.IsTag))
+	if err != nil {
+		return
+	}
+	fmt.Printf("Prerelease: %s\n", gitInfo.Prerelease)
+	err = ExportConformVar("prerelease", gitInfo.Prerelease)
+	if err != nil {
+		return
+	}
+	fmt.Printf("IsPrerelease: %s\n", strconv.FormatBool(gitInfo.IsPrerelease))
+	err = ExportConformVar("is_prerelease", strconv.FormatBool(gitInfo.IsPrerelease))
+	if err != nil {
+		return
+	}
+	fmt.Printf("Status: \n%s\n", strings.TrimRight(gitInfo.Status, "\n"))
+	err = ExportConformVar("status", strconv.FormatBool(gitInfo.IsDirty))
+	if err != nil {
+		return
+	}
+	fmt.Printf("IsDirty: %s\n", strconv.FormatBool(gitInfo.IsDirty))
+	err = ExportConformVar("is_dirty", strconv.FormatBool(gitInfo.IsDirty))
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// ExportConformVar exports variable prefixed with CONFORM_
+func ExportConformVar(name, value string) (err error) {
+	variable := fmt.Sprintf("CONFORM_%s", strings.ToUpper(name))
+	err = os.Setenv(variable, value)
+
+	return
+}
+
 // FormatImageNameDirty formats the image name.
 func (e *Enforcer) FormatImageNameDirty() string {
 	return fmt.Sprintf("%s:%s", *e.config.Metadata.Repository, "dirty")