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authorValentin Rothberg <rothberg@redhat.com>2020-01-09 12:27:24 +0100
committerValentin Rothberg <rothberg@redhat.com>2020-01-09 16:12:12 +0100
commit816e50ba02837946afade83e3cad06dd44d213ec (patch)
tree67834eb73ab890cb4c9fba8d37f68e3fdec9dcd6 /pkg/systemdgen
parentf3fc10feb42930def6922fc050096ea38bafed7a (diff)
downloadpodman-816e50ba02837946afade83e3cad06dd44d213ec.tar.gz
podman-816e50ba02837946afade83e3cad06dd44d213ec.tar.bz2
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podman-generate-systemd --new
Add a --new flag to podman-generate-systemd to create a new container via podman-run instead of starting an existing container. Creating a new container presents the challenge to find a reverse mapping from a container to the CLI flags it can be created with. We are doing this via `(Container).Config.CreateCommand` field, which includes a copy of the process' command from procFS at creating time. This field may not be useful when the container was not created via the Podman CLI (e.g., via a Python script). Hence, we do not guarantee the correctness of the generated files. Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'pkg/systemdgen')
-rw-r--r--pkg/systemdgen/systemdgen.go63
-rw-r--r--pkg/systemdgen/systemdgen_test.go51
2 files changed, 105 insertions, 9 deletions
diff --git a/pkg/systemdgen/systemdgen.go b/pkg/systemdgen/systemdgen.go
index 09d3c6fd5..b6167a23e 100644
--- a/pkg/systemdgen/systemdgen.go
+++ b/pkg/systemdgen/systemdgen.go
@@ -7,6 +7,7 @@ import (
"os"
"path/filepath"
"sort"
+ "strings"
"text/template"
"time"
@@ -48,6 +49,14 @@ type ContainerInfo struct {
Executable string
// TimeStamp at the time of creating the unit file. Will be set internally.
TimeStamp string
+ // New controls if a new container is created or if an existing one is started.
+ New bool
+ // CreateCommand is the full command plus arguments of the process the
+ // container has been created with.
+ CreateCommand []string
+ // RunCommand is a post-processed variant of CreateCommand and used for
+ // the ExecStart field in generic unit files.
+ RunCommand string
}
var restartPolicies = []string{"no", "on-success", "on-failure", "on-abnormal", "on-watchdog", "on-abort", "always"}
@@ -84,17 +93,35 @@ Before={{- range $index, $value := .RequiredServices -}}{{if $index}} {{end}}{{
[Service]
Restart={{.RestartPolicy}}
+{{- if .New}}
+ExecStartPre=/usr/bin/rm -f /%t/%n-pid /%t/%n-cid
+ExecStart={{.RunCommand}}
+ExecStop={{.Executable}} stop --cidfile /%t/%n-cid {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}}
+ExecStopPost={{.Executable}} rm -f --cidfile /%t/%n-cid
+PIDFile=/%t/%n-pid
+{{- else}}
ExecStart={{.Executable}} start {{.ContainerName}}
ExecStop={{.Executable}} stop {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}} {{.ContainerName}}
+PIDFile={{.PIDFile}}
+{{- end}}
KillMode=none
Type=forking
-PIDFile={{.PIDFile}}
[Install]
WantedBy=multi-user.target`
+// Options include different options to control the unit file generation.
+type Options struct {
+ // When set, generate service files in the current working directory and
+ // return the paths to these files instead of returning all contents in one
+ // big string.
+ Files bool
+ // New controls if a new container is created or if an existing one is started.
+ New bool
+}
+
// CreateContainerSystemdUnit creates a systemd unit file for a container.
-func CreateContainerSystemdUnit(info *ContainerInfo, generateFiles bool) (string, error) {
+func CreateContainerSystemdUnit(info *ContainerInfo, opts Options) (string, error) {
if err := validateRestartPolicy(info.RestartPolicy); err != nil {
return "", err
}
@@ -109,6 +136,36 @@ func CreateContainerSystemdUnit(info *ContainerInfo, generateFiles bool) (string
info.Executable = executable
}
+ // Assemble the ExecStart command when creating a new container.
+ //
+ // Note that we cannot catch all corner cases here such that users
+ // *must* manually check the generated files. A container might have
+ // been created via a Python script, which would certainly yield an
+ // invalid `info.CreateCommand`. Hence, we're doing a best effort unit
+ // generation and don't try aiming at completeness.
+ if opts.New {
+ // The create command must at least have three arguments:
+ // /usr/bin/podman run $IMAGE
+ index := 2
+ if info.CreateCommand[1] == "container" {
+ index = 3
+ }
+ if len(info.CreateCommand) < index+1 {
+ return "", errors.Errorf("container's create command is too short or invalid: %v", info.CreateCommand)
+ }
+ // We're hard-coding the first four arguments and append the
+ // CreatCommand with a stripped command and subcomand.
+ command := []string{
+ info.Executable,
+ "run",
+ "--conmon-pidfile", "/%t/%n-pid",
+ "--cidfile", "/%t/%n-cid",
+ }
+ command = append(command, info.CreateCommand[index:]...)
+ info.RunCommand = strings.Join(command, " ")
+ info.New = true
+ }
+
if info.PodmanVersion == "" {
info.PodmanVersion = version.Version
}
@@ -131,7 +188,7 @@ func CreateContainerSystemdUnit(info *ContainerInfo, generateFiles bool) (string
return "", err
}
- if !generateFiles {
+ if !opts.Files {
return buf.String(), nil
}
diff --git a/pkg/systemdgen/systemdgen_test.go b/pkg/systemdgen/systemdgen_test.go
index 1ddb0c514..e1da7e8e0 100644
--- a/pkg/systemdgen/systemdgen_test.go
+++ b/pkg/systemdgen/systemdgen_test.go
@@ -44,9 +44,9 @@ Documentation=man:podman-generate-systemd(1)
Restart=always
ExecStart=/usr/bin/podman start 639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401
ExecStop=/usr/bin/podman stop -t 10 639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
KillMode=none
Type=forking
-PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
[Install]
WantedBy=multi-user.target`
@@ -62,9 +62,9 @@ Documentation=man:podman-generate-systemd(1)
Restart=always
ExecStart=/usr/bin/podman start foobar
ExecStop=/usr/bin/podman stop -t 10 foobar
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
KillMode=none
Type=forking
-PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
[Install]
WantedBy=multi-user.target`
@@ -84,9 +84,9 @@ After=a.service b.service c.service pod.service
Restart=always
ExecStart=/usr/bin/podman start foobar
ExecStop=/usr/bin/podman stop -t 10 foobar
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
KillMode=none
Type=forking
-PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
[Install]
WantedBy=multi-user.target`
@@ -104,9 +104,29 @@ Before=container-1.service container-2.service
Restart=always
ExecStart=/usr/bin/podman start jadda-jadda-infra
ExecStop=/usr/bin/podman stop -t 10 jadda-jadda-infra
+PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
+KillMode=none
+Type=forking
+
+[Install]
+WantedBy=multi-user.target`
+
+ goodNameNew := `# jadda-jadda.service
+# autogenerated by Podman CI
+
+[Unit]
+Description=Podman jadda-jadda.service
+Documentation=man:podman-generate-systemd(1)
+
+[Service]
+Restart=always
+ExecStartPre=/usr/bin/rm -f /%t/%n-pid /%t/%n-cid
+ExecStart=/usr/bin/podman run --conmon-pidfile /%t/%n-pid --cidfile /%t/%n-cid --name jadda-jadda --hostname hello-world awesome-image:latest command arg1 ... argN
+ExecStop=/usr/bin/podman stop --cidfile /%t/%n-cid -t 42
+ExecStopPost=/usr/bin/podman rm -f --cidfile /%t/%n-cid
+PIDFile=/%t/%n-pid
KillMode=none
Type=forking
-PIDFile=/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid
[Install]
WantedBy=multi-user.target`
@@ -184,16 +204,35 @@ WantedBy=multi-user.target`
"",
true,
},
+ {"good with name and generic",
+ ContainerInfo{
+ Executable: "/usr/bin/podman",
+ ServiceName: "jadda-jadda",
+ ContainerName: "jadda-jadda",
+ RestartPolicy: "always",
+ PIDFile: "/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid",
+ StopTimeout: 42,
+ PodmanVersion: "CI",
+ New: true,
+ CreateCommand: []string{"I'll get stripped", "container", "run", "--name", "jadda-jadda", "--hostname", "hello-world", "awesome-image:latest", "command", "arg1", "...", "argN"},
+ },
+ goodNameNew,
+ false,
+ },
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
- got, err := CreateContainerSystemdUnit(&tt.info, false)
+ opts := Options{
+ Files: false,
+ New: tt.info.New,
+ }
+ got, err := CreateContainerSystemdUnit(&tt.info, opts)
if (err != nil) != tt.wantErr {
t.Errorf("CreateContainerSystemdUnit() error = \n%v, wantErr \n%v", err, tt.wantErr)
return
}
if got != tt.want {
- t.Errorf("CreateContainerSystemdUnit() = \n%v, want \n%v", got, tt.want)
+ t.Errorf("CreateContainerSystemdUnit() = \n%v\n---------> want\n%v", got, tt.want)
}
})
}