Use conmon pidfile in generated systemd unit as PIDFile.

By default, podman points PIDFile in generated unit file to non-existent
location. As a result, the unit file, generated by podman, is broken:
an attempt to start this unit without prior modification results in a crash,
because systemd can not find the pidfile of service's main process.

Fix the value of "PIDFile" and add a system test for this case.

Signed-off-by: Danila Kiver <danila.kiver@mail.ru>

docs/podman-generate-systemd.1.md

@@ -39,7 +39,7 @@ ExecStart=/usr/bin/podman start c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f14
 ExecStop=/usr/bin/podman stop -t 10 c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc
 KillMode=none
 Type=forking
-PIDFile=/var/lib/containers/storage/overlay-containers/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc/userdata/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc.pid
+PIDFile=/var/run/containers/storage/overlay-containers/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc/userdata/conmon.pid
 [Install]
 WantedBy=multi-user.target
 ```
@@ -55,7 +55,7 @@ ExecStart=/usr/bin/podman start c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f14
 ExecStop=/usr/bin/podman stop -t 1 c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc
 KillMode=none
 Type=forking
-PIDFile=/var/lib/containers/storage/overlay-containers/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc/userdata/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc.pid
+PIDFile=/var/run/containers/storage/overlay-containers/c21da63c4783be2ac2cd3487ef8d2ec15ee2a28f63dd8f145e3b05607f31cffc/userdata/conmon.pid
 [Install]
 WantedBy=multi-user.target
 ```

pkg/adapter/containers.go

@@ -1058,7 +1058,14 @@ func (r *LocalRuntime) GenerateSystemd(c *cliconfig.GenerateSystemdValues) (stri
 	if c.Name {
 		name = ctr.Name()
 	}
-	return systemdgen.CreateSystemdUnitAsString(name, ctr.ID(), c.RestartPolicy, ctr.Config().StaticDir, timeout)
+
+	config := ctr.Config()
+	conmonPidFile := config.ConmonPidFile
+	if conmonPidFile == "" {
+		return "", errors.Errorf("conmon PID file path is empty, try to recreate the container with --conmon-pidfile flag")
+	}
+
+	return systemdgen.CreateSystemdUnitAsString(name, ctr.ID(), c.RestartPolicy, conmonPidFile, timeout)
 }
 
 // GetNamespaces returns namespace information about a container for PS

pkg/systemdgen/systemdgen.go

@@ -2,7 +2,6 @@ package systemdgen
 
 import (
 	"fmt"
-	"path/filepath"
 
 	"github.com/pkg/errors"
 )
@@ -33,11 +32,11 @@ func ValidateRestartPolicy(restart string) error {
 
 // CreateSystemdUnitAsString takes variables to create a systemd unit file used to control
 // a libpod container
-func CreateSystemdUnitAsString(name, cid, restart, pidPath string, stopTimeout int) (string, error) {
+func CreateSystemdUnitAsString(name, cid, restart, pidFile string, stopTimeout int) (string, error) {
 	if err := ValidateRestartPolicy(restart); err != nil {
 		return "", err
 	}
-	pidFile := filepath.Join(pidPath, fmt.Sprintf("%s.pid", cid))
+
 	unit := fmt.Sprintf(template, name, restart, name, stopTimeout, name, pidFile)
 	return unit, nil
 }

pkg/systemdgen/systemdgen_test.go

@@ -41,7 +41,7 @@ ExecStart=/usr/bin/podman start 639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4
 ExecStop=/usr/bin/podman stop -t 10 639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401
 KillMode=none
 Type=forking
-PIDFile=/var/lib/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401.pid
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
 [Install]
 WantedBy=multi-user.target`
 
@@ -53,7 +53,7 @@ ExecStart=/usr/bin/podman start foobar
 ExecStop=/usr/bin/podman stop -t 10 foobar
 KillMode=none
 Type=forking
-PIDFile=/var/lib/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401.pid
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
 [Install]
 WantedBy=multi-user.target`
 
@@ -61,7 +61,7 @@ WantedBy=multi-user.target`
 		name        string
 		cid         string
 		restart     string
-		pidPath     string
+		pidFile     string
 		stopTimeout int
 	}
 	tests := []struct {
@@ -76,7 +76,7 @@ WantedBy=multi-user.target`
 				"639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401",
 				"639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401",
 				"always",
-				"/var/lib/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/",
+				"/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid",
 				10,
 			},
 			goodID,
@@ -87,7 +87,7 @@ WantedBy=multi-user.target`
 				"foobar",
 				"639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401",
 				"always",
-				"/var/lib/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/",
+				"/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid",
 				10,
 			},
 			goodName,
@@ -98,7 +98,7 @@ WantedBy=multi-user.target`
 				"639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401",
 				"639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401",
 				"never",
-				"/var/lib/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/",
+				"/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid",
 				10,
 			},
 			"",
@@ -107,7 +107,7 @@ WantedBy=multi-user.target`
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := CreateSystemdUnitAsString(tt.args.name, tt.args.cid, tt.args.restart, tt.args.pidPath, tt.args.stopTimeout)
+			got, err := CreateSystemdUnitAsString(tt.args.name, tt.args.cid, tt.args.restart, tt.args.pidFile, tt.args.stopTimeout)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("CreateSystemdUnitAsString() error = %v, wantErr %v", err, tt.wantErr)
 				return

test/system/250-generate-systemd.bats

@@ -0,0 +1,42 @@
+#!/usr/bin/env bats   -*- bats -*-
+#
+# Tests generated configurations for systemd.
+#
+
+load helpers
+
+# Be extra paranoid in naming to avoid collisions.
+SERVICE_NAME="podman_test_$(random_string)"
+UNIT_DIR="$HOME/.config/systemd/user"
+UNIT_FILE="$UNIT_DIR/$SERVICE_NAME.service"
+
+function setup() {
+    basic_setup
+    mkdir -p "$UNIT_DIR"
+}
+
+function teardown() {
+    rm -f "$UNIT_FILE"
+    systemctl --user stop "$SERVICE_NAME"
+    basic_teardown
+}
+
+@test "podman generate - systemd - basic" {
+    skip_if_not_systemd
+    skip_if_remote
+
+    run_podman create $IMAGE echo "I'm alive!"
+    cid="$output"
+
+    run_podman generate systemd $cid > "$UNIT_FILE"
+
+    run systemctl --user start "$SERVICE_NAME"
+    if [ $status -ne 0 ]; then
+        die "The systemd service $SERVICE_NAME did not start correctly!"
+    fi
+
+    run_podman logs $cid
+    is "$output" "I'm alive!" "Container output"
+}
+
+# vim: filetype=sh

test/system/helpers.bash

@@ -236,6 +236,17 @@ function skip_if_remote() {
     skip "${1:-test does not work with podman-remote}"
 }
 
+#########################
+#  skip_if_not_systemd  #  ...with an optional message
+#########################
+function skip_if_not_systemd() {
+    if systemctl --user >/dev/null 2>&1; then
+        return
+    fi
+
+    skip "${1:-no systemd or daemon does not respond}"
+}
+
 #########
 #  die  #  Abort with helpful message
 #########