Integration of osbuild composer with systemd

osbuild-composer now uses socket activation instead of hardcoded paths
in the code. osbuild-worker is an http client therefore it uses only
service unit. osbuild-worker must be started after the socket is
created. osbuild-composer service requires osbuild-worker to run, because without
it no jobs can be started.

osbuild-composer is executed as a regular user (newly created
_osbuild-composer user) as opposed to the worker which must run as root
in order to execute osbuild itself

Makefile

@@ -0,0 +1,12 @@
+build:
+	go build -o osbuild-composer ./cmd/osbuild-composer/
+	go build -o osbuild-worker ./cmd/osbuild-worker/
+
+install:
+	- mkdir -p /usr/lib/osbuild-composer
+	cp osbuild-composer /usr/lib/osbuild-composer/
+	cp osbuild-worker /usr/lib/osbuild-composer/
+	cp dnf-json /usr/lib/osbuild-composer/
+
+run-socket:
+	systemd-socket-activate -l /run/weldr/api.socket -l /run/osbuild-composer/job.socket ./osbuild-composer

cmd/osbuild-composer/main.go

@@ -4,7 +4,6 @@ import (
 	"flag"
 	"io/ioutil"
 	"log"
-	"net"
 	"os"
 	"path/filepath"
 
@@ -12,6 +11,8 @@ import (
 	"osbuild-composer/internal/jobqueue"
 	"osbuild-composer/internal/rpmmd"
 	"osbuild-composer/internal/weldr"
+
+	"github.com/coreos/go-systemd/activation"
 )
 
 const StateFile = "/var/lib/osbuild-composer/weldr-state.json"
@@ -21,35 +22,17 @@ func main() {
 	flag.BoolVar(&verbose, "v", false, "Print access log")
 	flag.Parse()
 
-	err := os.Remove("/run/weldr/api.socket")
-	if err != nil && !os.IsNotExist(err) {
-		panic(err)
-	}
-
-	err = os.Mkdir("/run/weldr", 0755)
-	if err != nil && !os.IsExist(err) {
-		panic(err)
-	}
-
-	weldrListener, err := net.Listen("unix", "/run/weldr/api.socket")
+	listeners, err := activation.Listeners()
 	if err != nil {
 		panic(err)
 	}
 
-	err = os.Remove("/run/osbuild-composer/job.socket")
-	if err != nil && !os.IsNotExist(err) {
-		panic(err)
+	if len(listeners) != 2 {
+		panic("Unexpected number of sockets. Composer require 2 of them.")
 	}
 
-	err = os.Mkdir("/run/osbuild-composer", 0755)
-	if err != nil && !os.IsExist(err) {
-		panic(err)
-	}
-
-	jobListener, err := net.Listen("unix", "/run/osbuild-composer/job.socket")
-	if err != nil {
-		panic(err)
-	}
+	weldrListener := listeners[0]
+	jobListener := listeners[1]
 
 	repo := rpmmd.RepoConfig{
 		Id:       "fedora-30",

distribution/Makefile

@@ -0,0 +1,23 @@
+sd-install:
+	cp *.service /etc/systemd/system/
+	cp *.socket /etc/systemd/system/
+	systemctl daemon-reload
+	
+sd-start:
+	systemctl start osbuild-composer.socket
+	systemctl start osbuild-worker.service
+
+sd-enable:
+	systemctl enable osbuild-composer.socket
+	systemctl enable osbuild-worker.service
+
+sd-stop:
+	systemctl disable osbuild-composer.socket
+	systemctl stop osbuild-composer.socket
+	systemctl stop osbuild-composer.service
+	systemctl disable osbuild-worker.service
+	systemctl stop osbuild-worker.service
+
+user-install:
+	- mkdir -p /etc/sysusers.d/
+	cp osbuild-composer.conf /etc/sysusers.d/

distribution/osbuild-composer.conf

@@ -0,0 +1 @@
+u   _osbuild-composer   -   "OSBuild Composer user"

distribution/osbuild-composer.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=OSBuild Composer
+After=multi-user.target
+Requires=osbuild-composer.socket
+
+[Service]
+Type=simple
+ExecStart=/usr/lib/osbuild-composer/osbuild-composer
+RuntimeDirectory=osbuild-composer weldr
+StateDirectory=osbuild-composer
+WorkingDirectory=/usr/lib/osbuild-composer/
+User=_osbuild-composer
+Restart=on-failure
+
+[Install]
+WantedBy=multi-user.target

distribution/osbuild-composer.socket

@@ -0,0 +1,9 @@
+[Unit]
+PartOf=osbuild-composer.service
+
+[Socket]
+ListenStream=/run/weldr/api.socket
+ListenStream=/run/osbuild-composer/job.socket
+
+[Install]
+WantedBy=sockets.target

distribution/osbuild-worker.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=OSBuild Composer Worker (%i)
+After=multi-user.target osbuild-composer.socket
+
+[Service]
+Type=simple
+PrivateTmp=true
+ExecStart=/usr/lib/osbuild-composer/osbuild-worker -C /var/lib/osbuild
+CacheDirectory=osbuild-composer
+Restart=on-failure
+RestartSec=10s
+
+[Install]
+DefaultInstance=1
+WantedBy=multi-user.target

go.mod

@@ -3,6 +3,7 @@ module osbuild-composer
 go 1.12
 
 require (
+	github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f
 	github.com/google/uuid v1.1.1
 	github.com/julienschmidt/httprouter v1.2.0
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f h1:JOrtw2xFKzlg+cbHpyrpLDmnN1HqhBfnX7WDiW7eG2c=
+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/julienschmidt/httprouter v1.2.0 h1:TDTW5Yz1mjftljbcKqRcrYhd4XeOoI98t+9HbQbYf7g=

init/osbuild-composer-worker@.service

@@ -1,10 +0,0 @@
-[Unit]
-Description=OSBuild Composer Worker (%i)
-
-[Service]
-PrivateTmp=true
-ExecStart=/usr/local/lib/osbuild-composer/osbuild-composer-worker -C /var/lib/osbuild
-
-[Install]
-DefaultInstance=1
-WantedBy=default.target

internal/rpmmd/repository.go

@@ -2,6 +2,7 @@ package rpmmd
 
 import (
 	"encoding/json"
+	"log"
 	"os/exec"
 	"sort"
 	"time"
@@ -44,6 +45,7 @@ func runDNF(command string, arguments []string, result interface{}) error {
 	cmd := exec.Command("python3", argv...)
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
+		log.Fatalf("Could not execute dnf-json")
 		return err
 	}