generate: add pids limit support

Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>

Backported to v1.0.0.rc1 from beb6478 #206 (cherry-pick applied
cleanly).

Signed-off-by: W. Trevor King <wking@tremily.us>

Author: Ma Shimiao

cmd/oci-runtime-tool/generate.go

@@ -72,6 +72,7 @@ var generateFlags = []cli.Flag{
 	cli.Uint64Flag{Name: "linux-mem-kernel-limit", Usage: "kernel memory limit (in bytes)"},
 	cli.Uint64Flag{Name: "linux-mem-kernel-tcp", Usage: "kernel memory limit for tcp (in bytes)"},
 	cli.Uint64Flag{Name: "linux-mem-swappiness", Usage: "how aggressive the kernel will swap memory pages (Range from 0 to 100)"},
+	cli.Int64Flag{Name: "linux-pids-limit", Usage: "maximum number of PIDs"},
 }
 
 var generateCommand = cli.Command{
@@ -389,6 +390,10 @@ func setupSpec(g *generate.Generator, context *cli.Context) error {
 		g.SetLinuxResourcesMemorySwappiness(context.Uint64("linux-mem-swappiness"))
 	}
 
+	if context.IsSet("linux-pids-limit") {
+		g.SetLinuxResourcesPidsLimit(context.Int64("linux-pids-limit"))
+	}
+
 	var sd string
 	var sa, ss []string
 

completions/bash/oci-runtime-tool

@@ -285,6 +285,7 @@ _oci-runtime-tool_generate() {
 	      --help
 	      --ipc
 	      --label
+	      --linux-pids-limit
 	      --mount
 	      --mount-cgroups
 	      --mount-label

generate/generate.go

@@ -442,6 +442,12 @@ func (g *Generator) SetLinuxResourcesMemorySwappiness(swappiness uint64) {
 	g.spec.Linux.Resources.Memory.Swappiness = &swappiness
 }
 
+// SetLinuxResourcesPidsLimit sets g.spec.Linux.Resources.Pids.Limit.
+func (g *Generator) SetLinuxResourcesPidsLimit(limit int64) {
+	g.initSpecLinuxResourcesPids()
+	g.spec.Linux.Resources.Pids.Limit = &limit
+}
+
 // ClearLinuxSysctl clears g.spec.Linux.Sysctl.
 func (g *Generator) ClearLinuxSysctl() {
 	if g.spec == nil {

generate/spec.go

@@ -55,3 +55,10 @@ func (g *Generator) initSpecLinuxResourcesMemory() {
 		g.spec.Linux.Resources.Memory = &rspec.Memory{}
 	}
 }
+
+func (g *Generator) initSpecLinuxResourcesPids() {
+	g.initSpecLinuxResources()
+	if g.spec.Linux.Resources.Pids == nil {
+		g.spec.Linux.Resources.Pids = &rspec.Pids{}
+	}
+}

man/oci-runtime-tool-generate.1.md

@@ -126,6 +126,9 @@ read the configuration from `config.json`.
 **--linux-mem-swappiness**=MEMSWAPPINESS
   Sets the swappiness of how the kernel will swap memory pages (Range from 0 to 100).
 
+**--linux-pids-limit**=PIDSLIMIT
+  Set maximum number of PIDs.
+
 **--mount**=*PATH*
   Use a mount namespace where *PATH* is an existing mount namespace file
   to join. The special *PATH*  empty-string  creates a new namespace.