Driver ip.sgcp_dnsalias

Minimal configlet:

[ip#1]
type = sgcp_dnsalias
zone_id = 

Minimal setup command:

om test/svc/foo set \
	--kw="type=sgcp_dnsalias" \
	--kw="zone_id="

Supported keywords:

• blocking_post_provision
• blocking_post_start
• blocking_post_stop
• blocking_post_unprovision
• blocking_pre_provision
• blocking_pre_start
• blocking_pre_stop
• blocking_pre_unprovision
• comment
• disable
• encap
• endpoint
• monitor
• name
• optional
• pg_blkio_weight
• pg_cpu_burst
• pg_cpu_quota
• pg_cpu_shares
• pg_cpus
• pg_mem_high
• pg_mem_limit
• pg_mem_oom_control
• pg_mem_swappiness
• pg_mems
• pg_pids_max
• pg_vmem_limit
• post_provision
• post_start
• post_stop
• post_unprovision
• pre_provision
• pre_start
• pre_stop
• pre_unprovision
• provision
• provision_requires
• restart
• restart_delay
• secret
• shared
• standby
• start_requires
• stat_timeout
• stop_requires
• subset
• tags
• target
• type
• unprovision
• unprovision_requires
• uuid
• zone_id

Keyword blocking_post_provision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource provision action.

Errors interrupt the action.

This trigger is only executed on leaders.

Keyword blocking_post_start

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource start action.

Errors interrupt the action.

Keyword blocking_post_stop

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource stop action.

Errors interrupt the action.

Keyword blocking_post_unprovision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource unprovision action.

Errors interrupt the action.

This trigger is only executed on leaders.

Keyword blocking_pre_provision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource provision action.

Errors interrupt the action.

Keyword blocking_pre_start

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource start action.

Errors interrupt the action.

Keyword blocking_pre_stop

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource stop action.

Errors interrupt the action.

Keyword blocking_pre_unprovision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource unprovision action.

Errors interrupt the action.

Keyword comment

required:    false
scopable:    false

Description:

A free form text describing the role of the object, of the node, or of the section it is set in.

The keyword is accepted in any section, so the DEFAULT section can document a configuration as a whole, and a resource, pool, heartbeat, array or network section can document itself.

The agent does not interpret the value.

Keyword disable

required:    false
scopable:    true
convert:     bool

Description:

A disabled resource will be ignored on start, stop, provision and unprovision actions.

A disabled resource status is n/a.

If set in the DEFAULT section of an object, the object is disabled and ignores start, stop, shutdown, provision and unprovision actions.

These actions immediately return success.

om <path> disable sets DEFAULT.disable=true.

om <path> enable sets DEFAULT.disable=false.

Note: The enable and disable actions preserve the individual resource disable state.

Keyword encap

required:    false
scopable:    false
convert:     bool

Description:

Set to true to ignore this resource in the nodes context and consider it in the encapnodes context. The resource is thus handled by agents deployed in the service containers.

Keyword endpoint

required:    false
scopable:    true
rbac:        Requires the root grant.

Description:

The api url to use for DNS alias management.

By default, the api results are served from a local cache to the status evaluations run by the daemon scheduler, and to the ones run by an action with a resource selection that neither includes nor requires this resource, like om <path> app start. Every other action, an operator status or an action on or requiring this resource first of all, reads the api again. Set the OSVC_SGCP_CACHE environment variable to override this default whatever the action: 1 serves the cached values, 0 never does, the daemon scheduler included. Any other value is ignored, with a warning in the resource status.

A cached value is only served while younger than the cache.ttl_seconds value from the sgcp configuration file, and a zero ttl disables the cache.

Keyword monitor

required:    false
scopable:    true
convert:     bool

Description:

A resource with monitor=true will trigger the monitor_action (crash or reboot the node, freezestop or switch the service) if:

• The resource is down.

• The instance has local_expect=started in its daemon monitor data, which means the daemon considers this instance is and should remain started.

• All restart tentatives failed.

Keyword name

required:    false
scopable:    true
stop first:  a change is refused while the resource is up
rbac:        Requires the root grant.

Description:

The DNS alias name to control. If set, ensure alias name is correct during start, or check.

Keyword optional

required:    false
scopable:    true
convert:     bool

Description:

Action errors on optional resources are logged but do not interrupt the action sequence.

The status of optional resources is not included in the instance availability status but is considered in the overall status.

The status of task and sync resources is always included in the overall status, regardless of whether they are marked as optional.

Resources tagged as noaction are considered optional by default.

Dump filesystems are a typical use case for optional=true.

Keyword pg_blkio_weight

required:    false
scopable:    true

Example:

pg_blkio_weight=50

Description:

Block IO relative weight. Value: between 10 and 1000.

The kernel default is 100.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_cpu_burst

required:    false
scopable:    true

Example:

pg_cpu_burst=20%

Description:

The cpu time the group banks under its quota, and spends above it.

It is the time the processes of the group may bank while under their pg_cpu_quota, and spend above it in a short spike, in the notation of pg_cpu_quota: 20% lets the group run a fifth of a cpu above its quota during a period, out of what it left unused before.

It serves a latency-sensitive service capped tightly: a request arriving after an idle spell is served at the speed of the burst, rather than throttled for the rest of the period. Over a longer time the group still uses no more than its quota.

It needs pg_cpu_quota, and cannot exceed it: the kernel refuses a burst larger than the quota. Only the unified cgroup hierarchy has it.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_cpu_quota

required:    false
scopable:    true

Example:

pg_cpu_quota=50%@all

Description:

The percentage of cpu time the processes of the group may use.

Accepted expressions:

• 50% Half of one cpu.

• 50%@all Half of every cpu the node has.

• 10%@2 A tenth of two cpus.

Unlike pg_cpu_shares, which only arbitrates when the node is cpu-bound, a quota caps the group whether or not the node is busy.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_cpu_shares

required:    false
scopable:    true
convert:     size

Example:

pg_cpu_shares=512

Description:

The share of cpu the group gets when the node is cpu-bound.

The share is relative to the other groups.

The actual percentile depends on the shares allowed to the other services. Unset, the kernel default is used, which usually is 1024 shares.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_cpus

required:    false
scopable:    true
depends:     create_pg=true

Example:

pg_cpus=0-2

Description:

The cpus the processes of the group may run on.

Cpus are specified as list or range : 0,1,2 or 0-2.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_mem_high

required:    false
scopable:    true
convert:     size

Example:

pg_mem_high=384m

Description:

The memory past which the kernel throttles the group, in bytes.

Past it, the kernel slows the processes of the group down, reclaiming their memory and throttling their allocations.

Unlike pg_mem_limit, reaching it does not wake the Out-Of-Memory killer: a group above it keeps running, slower, while the kernel reclaims. Set below pg_mem_limit, it gives a process growing too much the time to be noticed, or to shrink, before it is killed.

It is a soft limit, so it is not what a memory claim counts: the claim counts pg_mem_limit. Only the unified cgroup hierarchy has it.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_mem_limit

required:    false
scopable:    true
convert:     size

Example:

pg_mem_limit=512m

Description:

The memory the processes of the group may use, in bytes.

The Out-Of-Memory killer is triggered in case of tresspassing.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_mem_oom_control

required:    false
scopable:    true

Example:

pg_mem_oom_control=1

Description:

Whether the Out of Memory killer runs for the group: 0 enables it.

It is a flag (0 or 1) enabling or disabling the Out of Memory killer for the processes of the group.

• If enabled (0), tasks that attempt to consume more memory than they are allowed are immediately killed by the OOM killer.
• If disabled (1), tasks are allowed to continue to try allocating memory, stressing the system.

The OOM killer is enabled by default in every cgroup using the memory controller.

This keyword caps nothing on a node holding the unified cgroup hierarchy, which has no memory.oom_control: that file is of the v1 hierarchy. Setting it there is warned about, and ignored.

Keyword pg_mem_swappiness

required:    false
scopable:    true

Example:

pg_mem_swappiness=40

Description:

Set a swappiness percentile value for the process group.

This keyword caps nothing on a node holding the unified cgroup hierarchy, which has no memory.swappiness: that file is of the v1 hierarchy. Setting it there is warned about, and ignored.

Keyword pg_mems

required:    false
scopable:    true

Example:

pg_mems=0-2

Description:

The memory nodes the processes of the group may allocate from.

Memory nodes are specified as list or range : 0,1,2 or 0-2.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_pids_max

required:    false
scopable:    true

Example:

pg_pids_max=512

Description:

The most processes and threads the group may run at once.

A fork beyond it fails in the process that asked for it, and nothing else of the node is touched: it is what keeps a runaway fork loop from exhausting the process table of the node.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword pg_vmem_limit

required:    false
scopable:    true
convert:     size

Example:

pg_vmem_limit=1g

Description:

The memory plus swap the processes of the group may use, in bytes.

The Out-Of-Memory killer is triggered in case of tresspassing. The specified value must be greater than pg_mem_limit.

Setting this keyword to default puts the capping back where a node that never capped anything leaves it. Removing the keyword does not: what was written stays written, whether om wrote it or something else did.

Keyword post_provision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource provision action.

Errors do not interrupt the action.

This trigger is only executed on leaders.

Keyword post_start

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource start action.

Errors do not interrupt the action.

Keyword post_stop

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource stop action.

Errors do not interrupt the action.

Keyword post_unprovision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute after the resource unprovision action.

Errors do not interrupt the action.

This trigger is only executed on leaders.

Keyword pre_provision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource provision action.

Errors do not interrupt the action.

Keyword pre_start

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource start action.

Errors do not interrupt the action.

Keyword pre_stop

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource stop action.

Errors do not interrupt the action.

Keyword pre_unprovision

required:    false
scopable:    true
rbac:        Triggers require the root grant.

Description:

A command or script to execute before the resource unprovision action.

Errors do not interrupt the action.

Keyword provision

required:    false
scopable:    false
default:     true
convert:     bool

Description:

Set to false to ignore the provision and unprovision actions on the resource.

Warning: provision and unprovision use data-destructive operations like formatting.

It is recommended to set provision=false on long-lived critical objects, to force administrators to remove this setting when they really want to destroy data.

Keyword provision_requires

required:    false
scopable:    false

Example:

provision_requires=ip#0 fs#0(down,stdby down)

Description:

A whitespace-separated list of conditions to meet to accept a ‘provision’ action.

A condition is expressed as <rid>(<state>,...).

If states are omitted, up,stdby up is used as the default expected states.

Keyword restart

required:    false
scopable:    true
default:     0
convert:     int

Description:

The daemon will try to restart a resource if:

• The resource is down, stdby down or warn.

• The instance has local_expect=started in its daemon monitor data, which means the daemon considers this instance is and should remain started.

• The node is not frozen

• The instance is not frozen

In this case, the daemon try restart=<n> times before falling back to the monitor action.

The restart_delay keyword sets the interval after a failed restart before the next tentative.

Resources with standby=true have restart forced to a minimum of 2, to increase chances of a restart success.

Keyword restart_delay

required:    false
scopable:    true
default:     500ms
convert:     duration

Description:

The minimum delay between two restart tentatives on the resource.

Keyword secret

required:    false
scopable:    true
rbac:        Requires the root grant.

Description:

The name of the secret object in the same namespace containing the api access credentials (account_id, client_id and client_secret).

Keyword shared

required:    false
scopable:    true
convert:     bool

Description:

If true, the resource will be considered shared during provision and unprovision actions.

A shared resource driver can implement a different behaviour depending on weither it is run from the leader instance, or not:

• When --leader is set, the driver creates and configures the system objects. For example the disk.disk driver allocates a SAN disk and discover its block devices.

• When --leader is not set, the driver does not redo the actions already done by the leader, but may do some. For example, the disk.disk driver skips the SAN disk allocation, but discovers the block devices.

The daemon takes care of setting the --leader flags on the commands it submits during deploy, purge, provision and unprovision orchestrations.

Warning: If admins want to submit --local provision or unprovision commands themselves, they have to set the --leader flag correctly.

Flex objects usually don’t use shared resources. But if they do, only the flex primary gets --leader commands.

Warning: All resources depending on a shared resource must also be flagged as shared.

Keyword standby

required:    false
scopable:    true
convert:     bool

Description:

If true, always start the resource, even on non-started instances.

The daemon is responsible for starting standby resources.

A resource can be set standby on a subset of nodes using keyword scoping.

A typical use-case is a synchronized filesystem on non-shared disks. The remote filesystem must be mounted to not overflow the underlying filesystem.

Warning: In most situation, don’t set shared resources standby, a non-clustered fs on shared disks for example.

Keyword start_requires

required:    false
scopable:    false

Example:

start_requires=ip#0 fs#0(down,stdby down)

Description:

A whitespace-separated list of conditions to meet to accept a ‘start’ action.

A condition is expressed as <rid>(<state>,...).

If states are omitted, up,stdby up is used as the default expected states.

Keyword stat_timeout

required:    false
scopable:    true
convert:     duration

Description:

The fs resources status evaluation includes a stat syscall test. This keyword defines the maximum wait time for those stat calls to respond.

When expired, the resource status is degraded is to warn, which can trigger a monitor action (reboot or crash the node) if the resource is monitored.

Keyword stop_requires

required:    false
scopable:    false

Example:

stop_requires=ip#0 fs#0(down,stdby down)

Description:

A whitespace-separated list of conditions to meet to accept a ‘stop’ action.

A condition is expressed as <rid>(<state>,...).

If states are omitted, up,stdby up is used as the default expected states.

Keyword subset

required:    false
scopable:    true

Description:

The name of the subset this resource is assigned to.

Resources of a same driver group and a same subset are ordered and acted upon together, and are configured as a whole in a [subset#<group>:<name>] section, or in a less precise [subset#<name>] one.

That section accepts parallel, to act on the members concurrently rather than one after the other, and the pg_* keywords, to place the members in their own process group.

Keyword tags

required:    false
scopable:    true
convert:     set

Description:

A whitespace-separated list of tags.

Tags can be used for resource selection by tag.

Some tags can influence the driver behaviour:

• noaction

  Skip any state changing action on the resource and imply optional=true.

• nostatus

  Force the status n/a.

Keyword target

required:    false
scopable:    true
rbac:        Requires the root grant.

Default:

The node hostname Description:

The DNS record name to point the alias to.

Keyword type

required:    false
scopable:    false
rbac:        Requires the root grant, except for a cni address, for a netns address om draws from a cluster network, and for a host address om draws from a lan network, on the interface and with the netmask the network says.

Description:

The resource driver name.

Keyword unprovision

required:    false
scopable:    false
default:     true
convert:     bool

Description:

Set to false to ignore the unprovision action on the resource.

Warning: unprovision use data-destructive operations like formatting.

It is recommended to set provision=false on long-lived critical objects, to force administrators to remove this setting when they really want to destroy data.

Keyword unprovision_requires

required:    false
scopable:    false

Example:

unprovision_requires=ip#0 fs#0(down,stdby down)

Description:

A whitespace-separated list of conditions to meet to accept a ‘unprovision’ action.

A condition is expressed as <rid>(<state>,...).

If states are omitted, up,stdby up is used as the default expected states.

Keyword uuid

required:    false
scopable:    true
stop first:  a change is refused while the resource is up
rbac:        Requires the root grant.

Description:

The DNS alias uuid to control. If set, the stop does not delete the DNS API object, but sets ‘none.’ as the target instead. If not set, the start tries to detect uuid to update, or create new one, the stop delete alias with name.

Keyword zone_id

required:    true
scopable:    true
stop first:  a change is refused while the resource is up
rbac:        Requires the root grant.

Description:

The DNS zone identifier.