1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
% podman-generate-systemd(1)
## NAME
podman\-generate\-systemd - Generate systemd unit file(s) for a container or pod. Not supported for the remote client
## SYNOPSIS
**podman generate systemd** [*options*] *container|pod*
## DESCRIPTION
**podman generate systemd** will create a systemd unit file that can be used to control a container or pod.
By default, the command will print the content of the unit files to stdout.
Note that this command is not supported for the remote client.
## OPTIONS:
**--files**, **-f**
Generate files instead of printing to stdout. The generated files are named {container,pod}-{ID,name}.service and will be placed in the current working directory.
Note: On a system with SELinux enabled, the generated files will inherit contexts from the current working directory. Depending on the SELinux setup, changes to the generated files using `restorecon`, `chcon`, or `semanage` may be required to allow systemd to access these files. Alternatively, use the `-Z` option when running `mv` or `cp`.
**--name**, **-n**
Use the name of the container for the start, stop, and description in the unit file
**--new**
Create a new container via podman-run instead of starting an existing one. This option relies on container configuration files, which may not map directly to podman CLI flags; please review the generated output carefully before placing in production.
Since we use systemd `Type=forking` service, using this option will force the container run with the detached param `-d`.
Note: Generating systemd unit files with `--new` flag is not yet supported for pods.
**--time**, **-t**=*value*
Override the default stop timeout for the container with the given value.
**--restart-policy**=*policy*
Set the systemd restart policy. The restart-policy must be one of: "no", "on-success", "on-failure", "on-abnormal",
"on-watchdog", "on-abort", or "always". The default policy is *on-failure*.
## Examples
### Generate and print a systemd unit file for a container
Generate a systemd unit file for a container running nginx with an *always* restart policy and 1-second timeout to stdout.
```
$ podman create --name nginx nginx:latest
$ podman generate systemd --restart-policy=always -t 1 nginx
# container-de1e3223b1b888bc02d0962dd6cb5855eb00734061013ffdd3479d225abacdc6.service
# autogenerated by Podman 1.8.0
# Wed Mar 09 09:46:45 CEST 2020
[Unit]
Description=Podman container-de1e3223b1b888bc02d0962dd6cb5855eb00734061013ffdd3479d225abacdc6.service
Documentation=man:podman-generate-systemd(1)
[Service]
Restart=always
ExecStart=/usr/bin/podman start de1e3223b1b888bc02d0962dd6cb5855eb00734061013ffdd3479d225abacdc6
ExecStop=/usr/bin/podman stop -t 1 de1e3223b1b888bc02d0962dd6cb5855eb00734061013ffdd3479d225abacdc6
KillMode=none
Type=forking
PIDFile=/run/user/1000/overlay-containers/de1e3223b1b888bc02d0962dd6cb5855eb00734061013ffdd3479d225abacdc6/userdata/conmon.pid
[Install]
WantedBy=multi-user.target default.target
```
### Generate systemd unit file for a container with `--new` flag
The `--new` flag generates systemd unit files that create and remove containers at service start and stop commands (see ExecStartPre and ExecStopPost service actions). Such unit files are not tied to a single machine and can easily be shared and used on other machines.
```
$ sudo podman generate systemd --new --files --name bb310a0780ae
# container-busy_moser.service
# autogenerated by Podman 1.8.3
# Fri Apr 3 09:40:47 EDT 2020
[Unit]
Description=Podman container-busy_moser.service
Documentation=man:podman-generate-systemd(1)
Wants=network.target
After=network-online.target
[Service]
Environment=PODMAN_SYSTEMD_UNIT=%n
Restart=on-failure
ExecStartPre=/usr/bin/rm -f %t/%n-pid %t/%n-cid
ExecStart=/usr/local/bin/podman run --conmon-pidfile %t/%n-pid --cidfile %t/%n-cid --cgroups=no-conmon -d -dit alpine
ExecStop=/usr/local/bin/podman stop --ignore --cidfile %t/%n-cid -t 10
ExecStopPost=/usr/local/bin/podman rm --ignore -f --cidfile %t/%n-cid
PIDFile=%t/%n-pid
KillMode=none
Type=forking
[Install]
WantedBy=multi-user.target default.target
```
### Generate systemd unit files for a pod with two simple alpine containers
Note `systemctl` should only be used on the pod unit and one should not start or stop containers individually via `systemctl`, as they are managed by the pod service along with the internal infra-container.
You can still use `systemctl status` or `journalctl` to examine container or pod unit files.
```
$ podman pod create --name systemd-pod
$ podman create --pod systemd-pod alpine top
$ podman create --pod systemd-pod alpine top
$ podman generate systemd --files --name systemd-pod
/home/user/pod-systemd-pod.service
/home/user/container-amazing_chandrasekhar.service
/home/user/container-jolly_shtern.service
$ cat pod-systemd-pod.service
# pod-systemd-pod.service
# autogenerated by Podman 1.8.0
# Wed Mar 09 09:52:37 CEST 2020
[Unit]
Description=Podman pod-systemd-pod.service
Documentation=man:podman-generate-systemd(1)
Requires=container-amazing_chandrasekhar.service container-jolly_shtern.service
Before=container-amazing_chandrasekhar.service container-jolly_shtern.service
[Service]
Restart=on-failure
ExecStart=/usr/bin/podman start 77a818221650-infra
ExecStop=/usr/bin/podman stop -t 10 77a818221650-infra
KillMode=none
Type=forking
PIDFile=/run/user/1000/overlay-containers/ccfd5c71a088768774ca7bd05888d55cc287698dde06f475c8b02f696a25adcd/userdata/conmon.pid
[Install]
WantedBy=multi-user.target default.target
```
### Installation of generated systemd unit files.
Podman-generated unit files include an `[Install]` section, which carries installation information for the unit. It is used by the enable and disable commands of systemctl(1) during installation.
Once you have generated the systemd unit file, you can copy the generated systemd file to ```/usr/lib/systemd/system``` for installing as a root user and to ```$HOME/.config/systemd/user ``` for installing it as a non-root user. Enable the copied unit file or files using `systemctl enable`.
Note: Coping unit files to ```/usr/lib/systemd/system``` and enabling it marks the unit file to be automatically started at boot. And smillarly, coping a unit file to ```$HOME/.config/systemd/user ``` and enabling it marks the unit file to be automatically started on user login.
```
# Generated systemd files.
$ podman pod create --name systemd-pod
$ podman create --pod systemd-pod alpine top
$ podman generate systemd --files --name systemd-pod
# Copy all the generated files.
$ sudo cp pod-systemd-pod.service container-great_payne.service /usr/lib/systemd/system
$ systemctl enable pod-systemd-po.service
Created symlink /etc/systemd/system/multi-user.target.wants/pod-systemd-po.service → /usr/lib/systemd/system/pod-systemd-po.service.
Created symlink /etc/systemd/system/default.target.wants/pod-systemd-po.service → /usr/lib/systemd/system/pod-systemd-po.service.
$ systemctl is-enabled pod-systemd-po.service
enabled
```
To run the user services placed in `$HOME/.config/systemd/user/` on first login of that user, enable the service with --user flag.
```
$ systemctl --user enable <.service>
```
The systemd user instance is killed after the last session for the user is closed. The systemd user instance can be kept running ever after the user logs out by enabling `lingering` using
```
$ loginctl enable-linger <username>
```
### Use `systemctl` to perform operations on generated installed unit files.
Create and enable systemd unit files for a pod using the above examples as reference and use `systemctl` to perform operations.
Since systemctl defaults to using the root user, all the changes using the systemctl can be seen by appending sudo to the podman cli commands. To perform `systemctl` actions as a non-root user use the `--user` flag when interacting with `systemctl`.
```
$ systemctl --user start pod-systemd-pod.service
$ podman pod ps
POD ID NAME STATUS CREATED # OF CONTAINERS INFRA ID
0815c7b8e7f5 systemd-pod Running 29 minutes ago 2 6c5d116f4bbe
$ sudo podman ps # 0 Number of pods on root.
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
$ systemctl stop pod-systemd-pod.service
$ podman pod ps
POD ID NAME STATUS CREATED # OF CONTAINERS INFRA ID
272d2813c798 systemd-pod Exited 29 minutes ago 2 6c5d116f4bbe
```
Create a simple alpine container and generate the systemd unit file with `--new` flag.
Enable the service and control operations using the systemctl commands.
Note: When starting the container using `systemctl start` rather than altering the already running container it spins up a "new" container with similar configuration.
```
# Enable the service.
$ sudo podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
bb310a0780ae docker.io/library/alpine:latest /bin/sh 2 minutes ago Created busy_moser
$ sudo systemctl start container-busy_moser.service
$ sudo podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
772df2f8cf3b docker.io/library/alpine:latest /bin/sh 1 second ago Up 1 second ago distracted_albattani
bb310a0780ae docker.io/library/alpine:latest /bin/sh 3 minutes ago Created busy_moser
```
## SEE ALSO
[podman(1)](podman.1.md), [podman-container(1)](podman-container.1.md), systemctl(1), systemd.unit(5), systemd.service(5)
## HISTORY
April 2020, Updated details and added usecase to use generated .service files as root and non-root, by Sujil Shah (sushah at redhat dot com)
August 2019, Updated with pod support by Valentin Rothberg (rothberg at redhat dot com)
April 2019, Originally compiled by Brent Baude (bbaude at redhat dot com)
|
