diff options
| -rw-r--r-- | g3doc/user_guide/quick_start/oci.md | 10 | ||||
| -rw-r--r-- | g3doc/user_guide/tutorials/cni.md | 14 | ||||
| -rw-r--r-- | runsc/cmd/spec.go | 220 |
3 files changed, 129 insertions, 115 deletions
diff --git a/g3doc/user_guide/quick_start/oci.md b/g3doc/user_guide/quick_start/oci.md index 877169145..e7768946b 100644 --- a/g3doc/user_guide/quick_start/oci.md +++ b/g3doc/user_guide/quick_start/oci.md @@ -15,8 +15,8 @@ mkdir bundle cd bundle ``` -Create a root file system for the container. We will use the Docker hello-world -image as the basis for our container. +Create a root file system for the container. We will use the Docker +`hello-world` image as the basis for our container. ```bash mkdir rootfs @@ -24,12 +24,10 @@ docker export $(docker create hello-world) | tar -xf - -C rootfs ``` Next, create an specification file called `config.json` that contains our -container specification. We will update the default command it runs to `/hello` -in the `hello-world` container. +container specification. We tell the container to run the `/hello` program. ```bash -runsc spec -sed -i 's;"sh";"/hello";' config.json +runsc spec -- /hello ``` Finally run the container. diff --git a/g3doc/user_guide/tutorials/cni.md b/g3doc/user_guide/tutorials/cni.md index ad6c9fa59..ce2fd09a8 100644 --- a/g3doc/user_guide/tutorials/cni.md +++ b/g3doc/user_guide/tutorials/cni.md @@ -128,12 +128,14 @@ sudo mkdir -p rootfs/var/www/html sudo sh -c 'echo "Hello World!" > rootfs/var/www/html/index.html' ``` -Next create the `config.json` specifying the network namespace. `sudo -/usr/local/bin/runsc spec sudo sed -i 's;"sh";"python", "-m", "http.server";' -config.json sudo sed -i "s;\"cwd\": \"/\";\"cwd\": \"/var/www/html\";" -config.json sudo sed -i "s;\"type\": \"network\";\"type\": -\"network\",\n\t\t\t\t\"path\": \"/var/run/netns/${CNI_CONTAINERID}\";" -config.json` +Next create the `config.json` specifying the network namespace. + +``` +sudo /usr/local/bin/runsc spec \ + --cwd /var/www/html \ + --netns /var/run/netns/${CNI_CONTAINERID} \ + -- python -m http.server +``` ## Run the Container diff --git a/runsc/cmd/spec.go b/runsc/cmd/spec.go index a2b0a4b14..55194e641 100644 --- a/runsc/cmd/spec.go +++ b/runsc/cmd/spec.go @@ -16,124 +16,122 @@ package cmd import ( "context" - "fmt" - "io/ioutil" + "encoding/json" + "io" "os" "path/filepath" "github.com/google/subcommands" + specs "github.com/opencontainers/runtime-spec/specs-go" "gvisor.dev/gvisor/runsc/flag" ) -func genSpec(cwd string) []byte { - var template = fmt.Sprintf(`{ - "ociVersion": "1.0.0", - "process": { - "terminal": true, - "user": { - "uid": 0, - "gid": 0 - }, - "args": [ - "sh" - ], - "env": [ - "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", - "TERM=xterm" - ], - "cwd": "%s", - "capabilities": { - "bounding": [ - "CAP_AUDIT_WRITE", - "CAP_KILL", - "CAP_NET_BIND_SERVICE" - ], - "effective": [ - "CAP_AUDIT_WRITE", - "CAP_KILL", - "CAP_NET_BIND_SERVICE" - ], - "inheritable": [ - "CAP_AUDIT_WRITE", - "CAP_KILL", - "CAP_NET_BIND_SERVICE" - ], - "permitted": [ - "CAP_AUDIT_WRITE", - "CAP_KILL", - "CAP_NET_BIND_SERVICE" - ], - "ambient": [ - "CAP_AUDIT_WRITE", - "CAP_KILL", - "CAP_NET_BIND_SERVICE" - ] - }, - "rlimits": [ - { - "type": "RLIMIT_NOFILE", - "hard": 1024, - "soft": 1024 - } - ] - }, - "root": { - "path": "rootfs", - "readonly": true - }, - "hostname": "runsc", - "mounts": [ - { - "destination": "/proc", - "type": "proc", - "source": "proc" +func writeSpec(w io.Writer, cwd string, netns string, args []string) error { + spec := &specs.Spec{ + Version: "1.0.0", + Process: &specs.Process{ + Terminal: true, + User: specs.User{ + UID: 0, + GID: 0, + }, + Args: args, + Env: []string{ + "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", + "TERM=xterm", + }, + Cwd: cwd, + Capabilities: &specs.LinuxCapabilities{ + Bounding: []string{ + "CAP_AUDIT_WRITE", + "CAP_KILL", + "CAP_NET_BIND_SERVICE", + }, + Effective: []string{ + "CAP_AUDIT_WRITE", + "CAP_KILL", + "CAP_NET_BIND_SERVICE", + }, + Inheritable: []string{ + "CAP_AUDIT_WRITE", + "CAP_KILL", + "CAP_NET_BIND_SERVICE", + }, + Permitted: []string{ + "CAP_AUDIT_WRITE", + "CAP_KILL", + "CAP_NET_BIND_SERVICE", + }, + // TODO(gvisor.dev/issue/3166): support ambient capabilities + }, + Rlimits: []specs.POSIXRlimit{ + { + Type: "RLIMIT_NOFILE", + Hard: 1024, + Soft: 1024, + }, + }, }, - { - "destination": "/dev", - "type": "tmpfs", - "source": "tmpfs", - "options": [] + Root: &specs.Root{ + Path: "rootfs", + Readonly: true, }, - { - "destination": "/sys", - "type": "sysfs", - "source": "sysfs", - "options": [ - "nosuid", - "noexec", - "nodev", - "ro" - ] - } - ], - "linux": { - "namespaces": [ + Hostname: "runsc", + Mounts: []specs.Mount{ { - "type": "pid" + Destination: "/proc", + Type: "proc", + Source: "proc", }, { - "type": "network" + Destination: "/dev", + Type: "tmpfs", + Source: "tmpfs", }, { - "type": "ipc" + Destination: "/sys", + Type: "sysfs", + Source: "sysfs", + Options: []string{ + "nosuid", + "noexec", + "nodev", + "ro", + }, }, - { - "type": "uts" + }, + Linux: &specs.Linux{ + Namespaces: []specs.LinuxNamespace{ + { + Type: "pid", + }, + { + Type: "network", + Path: netns, + }, + { + Type: "ipc", + }, + { + Type: "uts", + }, + { + Type: "mount", + }, }, - { - "type": "mount" - } - ] + }, } -}`, cwd) - return []byte(template) + e := json.NewEncoder(w) + e.SetIndent("", " ") + return e.Encode(spec) } // Spec implements subcommands.Command for the "spec" command. type Spec struct { bundle string cwd string + netns string } // Name implements subcommands.Command.Name. @@ -148,21 +146,26 @@ func (*Spec) Synopsis() string { // Usage implements subcommands.Command.Usage. func (*Spec) Usage() string { - return `spec [options] - create a new OCI bundle specification file. + return `spec [options] [-- args...] - create a new OCI bundle specification file. + +The spec command creates a new specification file (config.json) for a new OCI +bundle. -The spec command creates a new specification file (config.json) for a new OCI bundle. +The specification file is a starter file that runs the command specified by +'args' in the container. If 'args' is not specified the default is to run the +'sh' program. -The specification file is a starter file that runs the "sh" command in the container. You -should edit the file to suit your needs. You can find out more about the format of the -specification file by visiting the OCI runtime spec repository: +While a number of flags are provided to change values in the specification, you +can examine the file and edit it to suit your needs after this command runs. +You can find out more about the format of the specification file by visiting +the OCI runtime spec repository: https://github.com/opencontainers/runtime-spec/ EXAMPLE: $ mkdir -p bundle/rootfs $ cd bundle - $ runsc spec + $ runsc spec -- /hello $ docker export $(docker create hello-world) | tar -xf - -C rootfs - $ sed -i 's;"sh";"/hello";' config.json $ sudo runsc run hello ` @@ -173,18 +176,29 @@ func (s *Spec) SetFlags(f *flag.FlagSet) { f.StringVar(&s.bundle, "bundle", ".", "path to the root of the OCI bundle") f.StringVar(&s.cwd, "cwd", "/", "working directory that will be set for the executable, "+ "this value MUST be an absolute path") + f.StringVar(&s.netns, "netns", "", "network namespace path") } // Execute implements subcommands.Command.Execute. func (s *Spec) Execute(_ context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus { + // Grab the arguments. + containerArgs := f.Args() + if len(containerArgs) == 0 { + containerArgs = []string{"sh"} + } + confPath := filepath.Join(s.bundle, "config.json") if _, err := os.Stat(confPath); !os.IsNotExist(err) { Fatalf("file %q already exists", confPath) } - var spec = genSpec(s.cwd) + configFile, err := os.OpenFile(confPath, os.O_WRONLY|os.O_CREATE, 0664) + if err != nil { + Fatalf("opening file %q: %v", confPath, err) + } - if err := ioutil.WriteFile(confPath, spec, 0664); err != nil { + err = writeSpec(configFile, s.cwd, s.netns, containerArgs) + if err != nil { Fatalf("writing to %q: %v", confPath, err) } |