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authorValentin Rothberg <rothberg@redhat.com>2019-10-21 19:48:23 +0200
committerValentin Rothberg <rothberg@redhat.com>2019-10-31 17:42:37 +0100
commit11c282ab02e5e7daca0b13a3ddc9bbc4468e7a31 (patch)
treee2fb684e0d1ec9c81534f2e8daeedf5ec9835b5e /libpod/config/config.go
parentfb5367f29510d2f82ffb834dcf5a422495d5b99b (diff)
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add libpod/config
Refactor the `RuntimeConfig` along with related code from libpod into libpod/config. Note that this is a first step of consolidating code into more coherent packages to make the code more maintainable and less prone to regressions on the long runs. Some libpod definitions were moved to `libpod/define` to resolve circular dependencies. Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'libpod/config/config.go')
-rw-r--r--libpod/config/config.go549
1 files changed, 549 insertions, 0 deletions
diff --git a/libpod/config/config.go b/libpod/config/config.go
new file mode 100644
index 000000000..5b4b57f3a
--- /dev/null
+++ b/libpod/config/config.go
@@ -0,0 +1,549 @@
+package config
+
+import (
+ "bytes"
+ "io/ioutil"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "regexp"
+ "strconv"
+ "strings"
+
+ "github.com/BurntSushi/toml"
+ "github.com/containers/libpod/libpod/define"
+ "github.com/containers/libpod/pkg/rootless"
+ "github.com/containers/libpod/pkg/util"
+ "github.com/containers/storage"
+ "github.com/pkg/errors"
+ "github.com/sirupsen/logrus"
+)
+
+const (
+ // _defaultTransport is a prefix that we apply to an image name to check
+ // docker hub first for the image.
+ _defaultTransport = "docker://"
+
+ // _rootlessConfigPath is the path to the rootless libpod.conf in $HOME.
+ _rootlessConfigPath = ".config/containers/libpod.conf"
+
+ // _conmonMinMajorVersion is the major version required for conmon.
+ _conmonMinMajorVersion = 2
+
+ // _conmonMinMinorVersion is the minor version required for conmon.
+ _conmonMinMinorVersion = 0
+
+ // _conmonMinPatchVersion is the sub-minor version required for conmon.
+ _conmonMinPatchVersion = 1
+
+ // _conmonVersionFormatErr is used when the expected versio-format of conmon
+ // has changed.
+ _conmonVersionFormatErr = "conmon version changed format"
+
+ // InstallPrefix is the prefix where podman will be installed.
+ // It can be overridden at build time.
+ _installPrefix = "/usr"
+
+ // EtcDir is the sysconfdir where podman should look for system config files.
+ // It can be overridden at build time.
+ _etcDir = "/etc"
+
+ // SeccompDefaultPath defines the default seccomp path.
+ SeccompDefaultPath = _installPrefix + "/share/containers/seccomp.json"
+
+ // SeccompOverridePath if this exists it overrides the default seccomp path.
+ SeccompOverridePath = _etcDir + "/crio/seccomp.json"
+
+ // _rootConfigPath is the path to the libpod configuration file
+ // This file is loaded to replace the builtin default config before
+ // runtime options (e.g. WithStorageConfig) are applied.
+ // If it is not present, the builtin default config is used instead
+ // This path can be overridden when the runtime is created by using
+ // NewRuntimeFromConfig() instead of NewRuntime().
+ _rootConfigPath = _installPrefix + "/share/containers/libpod.conf"
+
+ // _rootOverrideConfigPath is the path to an override for the default libpod
+ // configuration file. If OverrideConfigPath exists, it will be used in
+ // place of the configuration file pointed to by ConfigPath.
+ _rootOverrideConfigPath = _etcDir + "/containers/libpod.conf"
+)
+
+// SetOptions contains a subset of options in a Config. It's used to indicate if
+// a given option has either been set by the user or by a parsed libpod
+// configuration file. If not, the corresponding option might be overwritten by
+// values from the database. This behavior guarantess backwards compat with
+// older version of libpod and Podman.
+type SetOptions struct {
+ // StorageConfigRunRootSet indicates if the RunRoot has been explicitly set
+ // by the config or by the user. It's required to guarantee backwards
+ // compatibility with older versions of libpod for which we must query the
+ // database configuration. Not included in the on-disk config.
+ StorageConfigRunRootSet bool `toml:"-"`
+
+ // StorageConfigGraphRootSet indicates if the RunRoot has been explicitly
+ // set by the config or by the user. It's required to guarantee backwards
+ // compatibility with older versions of libpod for which we must query the
+ // database configuration. Not included in the on-disk config.
+ StorageConfigGraphRootSet bool `toml:"-"`
+
+ // StorageConfigGraphDriverNameSet indicates if the GraphDriverName has been
+ // explicitly set by the config or by the user. It's required to guarantee
+ // backwards compatibility with older versions of libpod for which we must
+ // query the database configuration. Not included in the on-disk config.
+ StorageConfigGraphDriverNameSet bool `toml:"-"`
+
+ // VolumePathSet indicates if the VolumePath has been explicitly set by the
+ // config or by the user. It's required to guarantee backwards compatibility
+ // with older versions of libpod for which we must query the database
+ // configuration. Not included in the on-disk config.
+ VolumePathSet bool `toml:"-"`
+
+ // StaticDirSet indicates if the StaticDir has been explicitly set by the
+ // config or by the user. It's required to guarantee backwards compatibility
+ // with older versions of libpod for which we must query the database
+ // configuration. Not included in the on-disk config.
+ StaticDirSet bool `toml:"-"`
+
+ // TmpDirSet indicates if the TmpDir has been explicitly set by the config
+ // or by the user. It's required to guarantee backwards compatibility with
+ // older versions of libpod for which we must query the database
+ // configuration. Not included in the on-disk config.
+ TmpDirSet bool `toml:"-"`
+}
+
+// Config contains configuration options used to set up a libpod runtime
+type Config struct {
+ // NOTE: when changing this struct, make sure to update (*Config).Merge().
+
+ // SetOptions contains a subset of config options. It's used to indicate if
+ // a given option has either been set by the user or by a parsed libpod
+ // configuration file. If not, the corresponding option might be
+ // overwritten by values from the database. This behavior guarantess
+ // backwards compat with older version of libpod and Podman.
+ SetOptions
+
+ // StateType is the type of the backing state store. Avoid using multiple
+ // values for this with the same containers/storage configuration on the
+ // same system. Different state types do not interact, and each will see a
+ // separate set of containers, which may cause conflicts in
+ // containers/storage. As such this is not exposed via the config file.
+ StateType define.RuntimeStateStore `toml:"-"`
+
+ // StorageConfig is the configuration used by containers/storage Not
+ // included in the on-disk config, use the dedicated containers/storage
+ // configuration file instead.
+ StorageConfig storage.StoreOptions `toml:"-"`
+
+ // VolumePath is the default location that named volumes will be created
+ // under. This convention is followed by the default volume driver, but
+ // may not be by other drivers.
+ VolumePath string `toml:"volume_path"`
+
+ // ImageDefaultTransport is the default transport method used to fetch
+ // images.
+ ImageDefaultTransport string `toml:"image_default_transport"`
+
+ // SignaturePolicyPath is the path to a signature policy to use for
+ // validating images. If left empty, the containers/image default signature
+ // policy will be used.
+ SignaturePolicyPath string `toml:"signature_policy_path,omitempty"`
+
+ // OCIRuntime is the OCI runtime to use.
+ OCIRuntime string `toml:"runtime"`
+
+ // OCIRuntimes are the set of configured OCI runtimes (default is runc).
+ OCIRuntimes map[string][]string `toml:"runtimes"`
+
+ // RuntimeSupportsJSON is the list of the OCI runtimes that support
+ // --format=json.
+ RuntimeSupportsJSON []string `toml:"runtime_supports_json"`
+
+ // RuntimeSupportsNoCgroups is a list of OCI runtimes that support
+ // running containers without CGroups.
+ RuntimeSupportsNoCgroups []string `toml:"runtime_supports_nocgroups"`
+
+ // RuntimePath is the path to OCI runtime binary for launching containers.
+ // The first path pointing to a valid file will be used This is used only
+ // when there are no OCIRuntime/OCIRuntimes defined. It is used only to be
+ // backward compatible with older versions of Podman.
+ RuntimePath []string `toml:"runtime_path"`
+
+ // ConmonPath is the path to the Conmon binary used for managing containers.
+ // The first path pointing to a valid file will be used.
+ ConmonPath []string `toml:"conmon_path"`
+
+ // ConmonEnvVars are environment variables to pass to the Conmon binary
+ // when it is launched.
+ ConmonEnvVars []string `toml:"conmon_env_vars"`
+
+ // CGroupManager is the CGroup Manager to use Valid values are "cgroupfs"
+ // and "systemd".
+ CgroupManager string `toml:"cgroup_manager"`
+
+ // InitPath is the path to the container-init binary.
+ InitPath string `toml:"init_path"`
+
+ // StaticDir is the path to a persistent directory to store container
+ // files.
+ StaticDir string `toml:"static_dir"`
+
+ // TmpDir is the path to a temporary directory to store per-boot container
+ // files. Must be stored in a tmpfs.
+ TmpDir string `toml:"tmp_dir"`
+
+ // MaxLogSize is the maximum size of container logfiles.
+ MaxLogSize int64 `toml:"max_log_size,omitempty"`
+
+ // NoPivotRoot sets whether to set no-pivot-root in the OCI runtime.
+ NoPivotRoot bool `toml:"no_pivot_root"`
+
+ // CNIConfigDir sets the directory where CNI configuration files are
+ // stored.
+ CNIConfigDir string `toml:"cni_config_dir"`
+
+ // CNIPluginDir sets a number of directories where the CNI network
+ // plugins can be located.
+ CNIPluginDir []string `toml:"cni_plugin_dir"`
+
+ // CNIDefaultNetwork is the network name of the default CNI network
+ // to attach pods to.
+ CNIDefaultNetwork string `toml:"cni_default_network,omitempty"`
+
+ // HooksDir holds paths to the directories containing hooks
+ // configuration files. When the same filename is present in in
+ // multiple directories, the file in the directory listed last in
+ // this slice takes precedence.
+ HooksDir []string `toml:"hooks_dir"`
+
+ // DefaultMountsFile is the path to the default mounts file for testing
+ // purposes only.
+ DefaultMountsFile string `toml:"-"`
+
+ // Namespace is the libpod namespace to use. Namespaces are used to create
+ // scopes to separate containers and pods in the state. When namespace is
+ // set, libpod will only view containers and pods in the same namespace. All
+ // containers and pods created will default to the namespace set here. A
+ // namespace of "", the empty string, is equivalent to no namespace, and all
+ // containers and pods will be visible. The default namespace is "".
+ Namespace string `toml:"namespace,omitempty"`
+
+ // InfraImage is the image a pod infra container will use to manage
+ // namespaces.
+ InfraImage string `toml:"infra_image"`
+
+ // InfraCommand is the command run to start up a pod infra container.
+ InfraCommand string `toml:"infra_command"`
+
+ // EnablePortReservation determines whether libpod will reserve ports on the
+ // host when they are forwarded to containers. When enabled, when ports are
+ // forwarded to containers, they are held open by conmon as long as the
+ // container is running, ensuring that they cannot be reused by other
+ // programs on the host. However, this can cause significant memory usage if
+ // a container has many ports forwarded to it. Disabling this can save
+ // memory.
+ EnablePortReservation bool `toml:"enable_port_reservation"`
+
+ // EnableLabeling indicates whether libpod will support container labeling.
+ EnableLabeling bool `toml:"label"`
+
+ // NetworkCmdPath is the path to the slirp4netns binary.
+ NetworkCmdPath string `toml:"network_cmd_path"`
+
+ // NumLocks is the number of locks to make available for containers and
+ // pods.
+ NumLocks uint32 `toml:"num_locks,omitempty"`
+
+ // LockType is the type of locking to use.
+ LockType string `toml:"lock_type,omitempty"`
+
+ // EventsLogger determines where events should be logged.
+ EventsLogger string `toml:"events_logger"`
+
+ // EventsLogFilePath is where the events log is stored.
+ EventsLogFilePath string `toml:"events_logfile_path"`
+
+ //DetachKeys is the sequence of keys used to detach a container.
+ DetachKeys string `toml:"detach_keys"`
+
+ // SDNotify tells Libpod to allow containers to notify the host systemd of
+ // readiness using the SD_NOTIFY mechanism.
+ SDNotify bool
+}
+
+// DBConfig is a set of Libpod runtime configuration settings that are saved in
+// a State when it is first created, and can subsequently be retrieved.
+type DBConfig struct {
+ LibpodRoot string
+ LibpodTmp string
+ StorageRoot string
+ StorageTmp string
+ GraphDriver string
+ VolumePath string
+}
+
+// readConfigFromFile reads the specified config file at `path` and attempts to
+// unmarshal its content into a Config.
+func readConfigFromFile(path string) (*Config, error) {
+ var config Config
+
+ configBytes, err := ioutil.ReadFile(path)
+ if err != nil {
+ return nil, err
+ }
+
+ logrus.Debugf("Reading configuration file %q", path)
+ err = toml.Unmarshal(configBytes, &config)
+
+ // For the sake of backwards compat we need to check if the config fields
+ // with *Set suffix are set in the config. Note that the storage-related
+ // fields are NOT set in the config here but in the storage.conf OR directly
+ // by the user.
+ if config.VolumePath != "" {
+ config.VolumePathSet = true
+ }
+ if config.StaticDir != "" {
+ config.StaticDirSet = true
+ }
+ if config.TmpDir != "" {
+ config.TmpDirSet = true
+ }
+
+ return &config, err
+}
+
+// Write decodes the config as TOML and writes it to the specified path.
+func (c *Config) Write(path string) error {
+ f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0666)
+ if err != nil {
+ return errors.Wrapf(err, "error opening config file %q", path)
+ }
+
+ buffer := new(bytes.Buffer)
+ if err := toml.NewEncoder(buffer).Encode(c); err != nil {
+ return errors.Wrapf(err, "error encoding config")
+ }
+
+ if _, err := f.WriteString(buffer.String()); err != nil {
+ return errors.Wrapf(err, "error writing config %q", path)
+ }
+ return err
+}
+
+// FindConmon iterates over (*Config).ConmonPath and returns the path to first
+// (version) matching conmon binary. If non is found, we try to do a path lookup
+// of "conmon".
+func (c *Config) FindConmon() (string, error) {
+ foundOutdatedConmon := false
+ for _, path := range c.ConmonPath {
+ stat, err := os.Stat(path)
+ if err != nil {
+ continue
+ }
+ if stat.IsDir() {
+ continue
+ }
+ if err := probeConmon(path); err != nil {
+ logrus.Warnf("Conmon at %s invalid: %v", path, err)
+ foundOutdatedConmon = true
+ continue
+ }
+ logrus.Debugf("Using conmon: %q", path)
+ return path, nil
+ }
+
+ // Search the $PATH as last fallback
+ if path, err := exec.LookPath("conmon"); err == nil {
+ if err := probeConmon(path); err != nil {
+ logrus.Warnf("Conmon at %s is invalid: %v", path, err)
+ foundOutdatedConmon = true
+ } else {
+ logrus.Debugf("Using conmon from $PATH: %q", path)
+ return path, nil
+ }
+ }
+
+ if foundOutdatedConmon {
+ return "", errors.Wrapf(define.ErrConmonOutdated,
+ "please update to v%d.%d.%d or later",
+ _conmonMinMajorVersion, _conmonMinMinorVersion, _conmonMinPatchVersion)
+ }
+
+ return "", errors.Wrapf(define.ErrInvalidArg,
+ "could not find a working conmon binary (configured options: %v)",
+ c.ConmonPath)
+}
+
+// probeConmon calls conmon --version and verifies it is a new enough version for
+// the runtime expectations podman currently has.
+func probeConmon(conmonBinary string) error {
+ cmd := exec.Command(conmonBinary, "--version")
+ var out bytes.Buffer
+ cmd.Stdout = &out
+ err := cmd.Run()
+ if err != nil {
+ return err
+ }
+ r := regexp.MustCompile(`^conmon version (?P<Major>\d+).(?P<Minor>\d+).(?P<Patch>\d+)`)
+
+ matches := r.FindStringSubmatch(out.String())
+ if len(matches) != 4 {
+ return errors.Wrap(err, _conmonVersionFormatErr)
+ }
+ major, err := strconv.Atoi(matches[1])
+ if err != nil {
+ return errors.Wrap(err, _conmonVersionFormatErr)
+ }
+ if major < _conmonMinMajorVersion {
+ return define.ErrConmonOutdated
+ }
+ if major > _conmonMinMajorVersion {
+ return nil
+ }
+
+ minor, err := strconv.Atoi(matches[2])
+ if err != nil {
+ return errors.Wrap(err, _conmonVersionFormatErr)
+ }
+ if minor < _conmonMinMinorVersion {
+ return define.ErrConmonOutdated
+ }
+ if minor > _conmonMinMinorVersion {
+ return nil
+ }
+
+ patch, err := strconv.Atoi(matches[3])
+ if err != nil {
+ return errors.Wrap(err, _conmonVersionFormatErr)
+ }
+ if patch < _conmonMinPatchVersion {
+ return define.ErrConmonOutdated
+ }
+ if patch > _conmonMinPatchVersion {
+ return nil
+ }
+
+ return nil
+}
+
+// NewConfig creates a new Config. It starts with an empty config and, if
+// specified, merges the config at `userConfigPath` path. Depending if we're
+// running as root or rootless, we then merge the system configuration followed
+// by merging the default config (hard-coded default in memory).
+//
+// Note that the OCI runtime is hard-set to `crun` if we're running on a system
+// with cgroupsv2. Other OCI runtimes are not yet supporting cgroupsv2. This
+// might change in the future.
+func NewConfig(userConfigPath string) (*Config, error) {
+ config := &Config{} // start with an empty config
+
+ // First, try to read the user-specified config
+ if userConfigPath != "" {
+ var err error
+ config, err = readConfigFromFile(userConfigPath)
+ if err != nil {
+ return nil, errors.Wrapf(err, "error reading user config %q", userConfigPath)
+ }
+ }
+
+ // Now, check if the user can access system configs and merge them if needed.
+ if configs, err := systemConfigs(); err != nil {
+ return nil, errors.Wrapf(err, "error finding config on system")
+ } else {
+ for _, path := range configs {
+ systemConfig, err := readConfigFromFile(path)
+ if err != nil {
+ return nil, errors.Wrapf(err, "error reading system config %q", path)
+ }
+ // Merge the it into the config. Any unset field in config will be
+ // over-written by the systemConfig.
+ if err := config.mergeConfig(systemConfig); err != nil {
+ return nil, errors.Wrapf(err, "error merging system config")
+ }
+ logrus.Debugf("Merged system config %q: %v", path, config)
+ }
+ }
+
+ // Finally, create a default config from memory and forcefully merge it into
+ // the config. This way we try to make sure that all fields are properly set
+ // and that user AND system config can partially set.
+ if defaultConfig, err := defaultConfigFromMemory(); err != nil {
+ return nil, errors.Wrapf(err, "error generating default config from memory")
+ } else {
+ if err := config.mergeConfig(defaultConfig); err != nil {
+ return nil, errors.Wrapf(err, "error merging default config from memory")
+ }
+ }
+
+ // Relative paths can cause nasty bugs, because core paths we use could
+ // shift between runs (or even parts of the program - the OCI runtime
+ // uses a different working directory than we do, for example.
+ if !filepath.IsAbs(config.StaticDir) {
+ return nil, errors.Wrapf(define.ErrInvalidArg, "static directory must be an absolute path - instead got %q", config.StaticDir)
+ }
+ if !filepath.IsAbs(config.TmpDir) {
+ return nil, errors.Wrapf(define.ErrInvalidArg, "temporary directory must be an absolute path - instead got %q", config.TmpDir)
+ }
+ if !filepath.IsAbs(config.VolumePath) {
+ return nil, errors.Wrapf(define.ErrInvalidArg, "volume path must be an absolute path - instead got %q", config.VolumePath)
+ }
+
+ // Check if we need to switch to cgroupfs on rootless.
+ config.checkCgroupsAndAdjustConfig()
+
+ return config, nil
+}
+
+func rootlessConfigPath() (string, error) {
+ home, err := util.HomeDir()
+ if err != nil {
+ return "", err
+ }
+
+ return filepath.Join(home, _rootlessConfigPath), nil
+}
+
+func systemConfigs() ([]string, error) {
+ if rootless.IsRootless() {
+ path, err := rootlessConfigPath()
+ if err != nil {
+ return nil, err
+ }
+ if _, err := os.Stat(path); err == nil {
+ return []string{path}, nil
+ }
+ return nil, err
+ }
+
+ configs := []string{}
+ if _, err := os.Stat(_rootOverrideConfigPath); err == nil {
+ configs = append(configs, _rootOverrideConfigPath)
+ }
+ if _, err := os.Stat(_rootConfigPath); err == nil {
+ configs = append(configs, _rootConfigPath)
+ }
+ return configs, nil
+}
+
+// checkCgroupsAndAdjustConfig checks if we're running rootless with the systemd
+// cgroup manager. In case the user session isn't available, we're switching the
+// cgroup manager to cgroupfs. Note, this only applies to rootless.
+func (c *Config) checkCgroupsAndAdjustConfig() {
+ if !rootless.IsRootless() || c.CgroupManager != define.SystemdCgroupsManager {
+ return
+ }
+
+ session := os.Getenv("DBUS_SESSION_BUS_ADDRESS")
+ hasSession := session != ""
+ if hasSession && strings.HasPrefix(session, "unix:path=") {
+ _, err := os.Stat(strings.TrimPrefix(session, "unix:path="))
+ hasSession = err == nil
+ }
+
+ if !hasSession {
+ logrus.Warningf("The cgroups manager is set to systemd but there is no systemd user session available")
+ logrus.Warningf("For using systemd, you may need to login using an user session")
+ logrus.Warningf("Alternatively, you can enable lingering with: `loginctl enable-linger %d` (possibly as root)", rootless.GetRootlessUID())
+ logrus.Warningf("Falling back to --cgroup-manager=cgroupfs")
+ c.CgroupManager = define.CgroupfsCgroupsManager
+ }
+}