Set the app version

So that 'trust --version' will show a meaningful value instead
of always 0.10.

Signed-off-by: Serge Hallyn <serge@hallyn.com>

.github/workflows/build.yml

@@ -56,6 +56,7 @@ jobs:
               sbsigntool
             pip install virt-firmware
           run: |
+              git describe --always --dirty
               go version
               make
               make test

Makefile

@@ -1,7 +1,13 @@
 all: trust
 
+MAIN_VERSION ?= $(shell git describe --always --dirty || echo no-git)
+ifeq ($(MAIN_VERSION),$(filter $(MAIN_VERSION), "", no-git))
+$(error "Bad value for MAIN_VERSION: '$(MAIN_VERSION)'")
+endif
+
+VERSION_LDFLAGS=-X github.com/project-machine/trust/pkg/trust.Version=$(MAIN_VERSION)
 trust: cmd/trust/*.go pkg/trust/*.go pkg/printdirtree/*.go
-	go build -buildvcs=false -o trust ./cmd/trust/
+	go build -buildvcs=false -ldflags "$(VERSION_LDFLAGS)" -o trust ./cmd/trust/
 
 clean:
 	rm -f trust

cmd/trust/main.go

@@ -4,22 +4,19 @@ import (
 	"os"
 
 	"github.com/apex/log"
+	"github.com/project-machine/trust/pkg/trust"
 	"github.com/urfave/cli"
 )
 
 //   provision - dangerous
 //   boot - read data from tpm, extend pcr7
 //   intrd-setup - create new luks key, extend pcr7
 
-
-// Version of trust
-const Version = "0.01"
-
 func main() {
 	app := cli.NewApp()
 	app.Name = "trust"
 	app.Usage = "Manage the trustroot"
-	app.Version = Version
+	app.Version = trust.Version
 	app.Commands = []cli.Command{
 		initrdSetupCmd,
 		preInstallCmd,

pkg/trust/const.go

@@ -55,3 +55,5 @@ var SBFPartitionTypeID = [16]byte{
 	0x9f, 0xe1, 0xa3, 0x01, 0xea, 0x9f, 0x47, 0xed, 0x92, 0xc2, 0xe7, 0x56, 0x39, 0xff, 0x56, 0x02}
 
 const MiB, GiB = uint64(1024 * 1024), uint64(1024 * 1024 * 1024)
+
+var Version string