config_linux.go: replace omitempty with omitzero

For some fields (like nested struct fields), omitempty has no effect
but omitzero does. Let's use it (everywhere -- for consistency).

NOTE it might result in some compatibility issues since now
zero-only fields are not serialized.

Since linter-extra thinks it's a new code, add some naming exceptions.

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

.golangci-extra.yml

@@ -23,3 +23,5 @@ linters:
       # Legacy names we can't change without breaking compatibility.
       - path: stats.go
         text: "(type|struct field) (CpuUsage|CpuStats) should be "
+      - path: config_linux.go
+        text: "struct field (CpuShares|CpuQuota|CpuBurst|CpuPeriod|CpuRtRuntime|CpuWeight) should be "

config_linux.go

@@ -16,132 +16,132 @@ const (
 // Cgroup holds properties of a cgroup on Linux.
 type Cgroup struct {
 	// Name specifies the name of the cgroup
-	Name string `json:"name,omitempty"`
+	Name string `json:"name,omitzero"`
 
 	// Parent specifies the name of parent of cgroup or slice
-	Parent string `json:"parent,omitempty"`
+	Parent string `json:"parent,omitzero"`
 
 	// Path specifies the path to cgroups that are created and/or joined by the container.
 	// The path is assumed to be relative to the host system cgroup mountpoint.
-	Path string `json:"path,omitempty"`
+	Path string `json:"path,omitzero"`
 
 	// ScopePrefix describes prefix for the scope name.
-	ScopePrefix string `json:"scope_prefix,omitempty"`
+	ScopePrefix string `json:"scope_prefix,omitzero"`
 
 	// Resources contains various cgroups settings to apply.
 	*Resources
 
 	// Systemd tells if systemd should be used to manage cgroups.
-	Systemd bool `json:"Systemd,omitempty"`
+	Systemd bool `json:"Systemd,omitzero"`
 
 	// SystemdProps are any additional properties for systemd,
 	// derived from org.systemd.property.xxx annotations.
 	// Ignored unless systemd is used for managing cgroups.
 	SystemdProps []systemdDbus.Property `json:"-"`
 
 	// Rootless tells if rootless cgroups should be used.
-	Rootless bool `json:"Rootless,omitempty"`
+	Rootless bool `json:"Rootless,omitzero"`
 
 	// The host UID that should own the cgroup, or nil to accept
 	// the default ownership.  This should only be set when the
 	// cgroupfs is to be mounted read/write.
 	// Not all cgroup manager implementations support changing
 	// the ownership.
-	OwnerUID *int `json:"owner_uid,omitempty"`
+	OwnerUID *int `json:"owner_uid,omitzero"`
 }
 
 type Resources struct {
 	// Devices is the set of access rules for devices in the container.
-	Devices []*devices.Rule `json:"devices,omitempty"`
+	Devices []*devices.Rule `json:"devices,omitzero"`
 
 	// Memory limit (in bytes).
-	Memory int64 `json:"memory,omitempty"`
+	Memory int64 `json:"memory,omitzero"`
 
 	// Memory reservation or soft_limit (in bytes).
-	MemoryReservation int64 `json:"memory_reservation,omitempty"`
+	MemoryReservation int64 `json:"memory_reservation,omitzero"`
 
 	// Total memory usage (memory+swap); use -1 for unlimited swap.
-	MemorySwap int64 `json:"memory_swap,omitempty"`
+	MemorySwap int64 `json:"memory_swap,omitzero"`
 
 	// CPU shares (relative weight vs. other containers).
-	CpuShares uint64 `json:"cpu_shares,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuShares should be CPUShares".
+	CpuShares uint64 `json:"cpu_shares,omitzero"`
 
 	// CPU hardcap limit (in usecs). Allowed cpu time in a given period.
-	CpuQuota int64 `json:"cpu_quota,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuQuota should be CPUQuota".
+	CpuQuota int64 `json:"cpu_quota,omitzero"`
 
 	// CPU hardcap burst limit (in usecs). Allowed accumulated cpu time additionally for burst in a given period.
-	CpuBurst *uint64 `json:"cpu_burst,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuBurst should be CPUBurst".
+	CpuBurst *uint64 `json:"cpu_burst,omitzero"`
 
 	// CPU period to be used for hardcapping (in usecs). 0 to use system default.
-	CpuPeriod uint64 `json:"cpu_period,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuPeriod should be CPUPeriod".
+	CpuPeriod uint64 `json:"cpu_period,omitzero"`
 
 	// How many time CPU will use in realtime scheduling (in usecs).
-	CpuRtRuntime int64 `json:"cpu_rt_quota,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuRtRuntime should be CPURtRuntime".
+	CpuRtRuntime int64 `json:"cpu_rt_quota,omitzero"`
 
 	// CPU period to be used for realtime scheduling (in usecs).
-	CpuRtPeriod uint64 `json:"cpu_rt_period,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuQuota should be CPUQuota".
+	CpuRtPeriod uint64 `json:"cpu_rt_period,omitzero"`
 
 	// Cpuset CPUs to use.
-	CpusetCpus string `json:"cpuset_cpus,omitempty"`
+	CpusetCpus string `json:"cpuset_cpus,omitzero"`
 
 	// Cpuset memory nodes to use.
-	CpusetMems string `json:"cpuset_mems,omitempty"`
+	CpusetMems string `json:"cpuset_mems,omitzero"`
 
 	// Cgroup's SCHED_IDLE value.
-	CPUIdle *int64 `json:"cpu_idle,omitempty"`
+	CPUIdle *int64 `json:"cpu_idle,omitzero"`
 
 	// Process limit; set < `0' to disable limit. `nil` means "keep current limit".
-	PidsLimit *int64 `json:"pids_limit,omitempty"`
+	PidsLimit *int64 `json:"pids_limit,omitzero"`
 
 	// Specifies per cgroup weight, range is from 10 to 1000.
-	BlkioWeight uint16 `json:"blkio_weight,omitempty"`
+	BlkioWeight uint16 `json:"blkio_weight,omitzero"`
 
 	// Tasks' weight in the given cgroup while competing with the cgroup's child cgroups, range is from 10 to 1000, cfq scheduler only.
-	BlkioLeafWeight uint16 `json:"blkio_leaf_weight,omitempty"`
+	BlkioLeafWeight uint16 `json:"blkio_leaf_weight,omitzero"`
 
 	// Weight per cgroup per device, can override BlkioWeight.
-	BlkioWeightDevice []*WeightDevice `json:"blkio_weight_device,omitempty"`
+	BlkioWeightDevice []*WeightDevice `json:"blkio_weight_device,omitzero"`
 
 	// IO read rate limit per cgroup per device, bytes per second.
-	BlkioThrottleReadBpsDevice []*ThrottleDevice `json:"blkio_throttle_read_bps_device,omitempty"`
+	BlkioThrottleReadBpsDevice []*ThrottleDevice `json:"blkio_throttle_read_bps_device,omitzero"`
 
 	// IO write rate limit per cgroup per device, bytes per second.
-	BlkioThrottleWriteBpsDevice []*ThrottleDevice `json:"blkio_throttle_write_bps_device,omitempty"`
+	BlkioThrottleWriteBpsDevice []*ThrottleDevice `json:"blkio_throttle_write_bps_device,omitzero"`
 
 	// IO read rate limit per cgroup per device, IO per second.
-	BlkioThrottleReadIOPSDevice []*ThrottleDevice `json:"blkio_throttle_read_iops_device,omitempty"`
+	BlkioThrottleReadIOPSDevice []*ThrottleDevice `json:"blkio_throttle_read_iops_device,omitzero"`
 
 	// IO write rate limit per cgroup per device, IO per second.
-	BlkioThrottleWriteIOPSDevice []*ThrottleDevice `json:"blkio_throttle_write_iops_device,omitempty"`
+	BlkioThrottleWriteIOPSDevice []*ThrottleDevice `json:"blkio_throttle_write_iops_device,omitzero"`
 
 	// Freeze value for the process.
-	Freezer FreezerState `json:"freezer,omitempty"`
+	Freezer FreezerState `json:"freezer,omitzero"`
 
 	// Hugetlb limit (in bytes).
-	HugetlbLimit []*HugepageLimit `json:"hugetlb_limit,omitempty"`
+	HugetlbLimit []*HugepageLimit `json:"hugetlb_limit,omitzero"`
 
 	// Whether to disable OOM killer.
-	OomKillDisable bool `json:"oom_kill_disable,omitempty"`
+	OomKillDisable bool `json:"oom_kill_disable,omitzero"`
 
 	// Tuning swappiness behaviour per cgroup.
-	MemorySwappiness *uint64 `json:"memory_swappiness,omitempty"`
+	MemorySwappiness *uint64 `json:"memory_swappiness,omitzero"`
 
 	// Set priority of network traffic for container.
-	NetPrioIfpriomap []*IfPrioMap `json:"net_prio_ifpriomap,omitempty"`
+	NetPrioIfpriomap []*IfPrioMap `json:"net_prio_ifpriomap,omitzero"`
 
 	// Set class identifier for container's network packets.
-	NetClsClassid uint32 `json:"net_cls_classid_u,omitempty"`
+	NetClsClassid uint32 `json:"net_cls_classid_u,omitzero"`
 
 	// Rdma resource restriction configuration.
-	Rdma map[string]LinuxRdma `json:"rdma,omitempty"`
+	Rdma map[string]LinuxRdma `json:"rdma,omitzero"`
 
 	// Used on cgroups v2:
 
 	// CpuWeight sets a proportional bandwidth limit.
-	CpuWeight uint64 `json:"cpu_weight,omitempty"` //nolint:revive // Suppress "var-naming: struct field CpuWeight should be CPUWeight".
+	CpuWeight uint64 `json:"cpu_weight,omitzero"`
 
 	// Unified is cgroupv2-only key-value map.
-	Unified map[string]string `json:"unified,omitempty"`
+	Unified map[string]string `json:"unified,omitzero"`
 
 	// SkipDevices allows to skip configuring device permissions.
 	// Used by e.g. kubelet while creating a parent cgroup (kubepods)
@@ -165,5 +165,5 @@ type Resources struct {
 	// MemoryCheckBeforeUpdate is a flag for cgroup v2 managers to check
 	// if the new memory limits (Memory and MemorySwap) being set are lower
 	// than the current memory usage, and reject if so.
-	MemoryCheckBeforeUpdate bool `json:"memory_check_before_update,omitempty"`
+	MemoryCheckBeforeUpdate bool `json:"memory_check_before_update,omitzero"`
 }