# Driver `ip.host` **Minimal configlet:** [ip#1] type = host **Minimal setup command:** om test/svc/foo set --kw="type=host" **Supported keywords:** - addr - alias - blocking_post_provision - blocking_post_start - blocking_post_stop - blocking_post_unprovision - blocking_pre_provision - blocking_pre_start - blocking_pre_stop - blocking_pre_unprovision - check_carrier - comment - dev - disable - encap - expose - gateway - monitor - name - netmask - network - 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 - shared - standby - start_requires - stat_timeout - stop_requires - subset - tags - type - unprovision - unprovision_requires - wait_dns ## Keyword `addr` required: false scopable: true recorded: written when what it names is made, and reset when the object is cloned stop first: a change is refused while the resource is up rbac: An address of the user's choosing requires the root grant: om writes the address it draws from the network. **Example:** addr=fd01:2345:6789:2902::5:e8 **Description:** The address drawn from the om network the `network` keyword names, which om writes here when the resource first starts, and removes when it is unprovisioned. Every node holds the configuration, so every node uses this address for the resource, whichever node drew it and whatever became of that node: a failover service keeps its address on a node it moves to after the others crashed. Set it to keep an address drawn before, or unset it to have the next start draw another one, and remove the one it replaces from the interface. A configuration copied to create another object leaves it behind, so the copy draws an address of its own rather than bring this one up twice. A resource not shared of a flex object draws an address per instance, as its instances run at once. The address of an instance is not written here: the node keeps it in its reservation store, from a start to the next, until the instance is unprovisioned. Set addr@ to choose the address of an instance; an addr without a node is not taken as one. ## Keyword `alias` required: false scopable: true default: true convert: bool rbac: Requires the root grant. **Description:** Use network interface stacking. Modern ip stack support multiple ip addresses per interface, so `alias` should be set to `false` when possible. ## 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 `check_carrier` required: false scopable: true default: true convert: bool rbac: Requires the root grant. **Description:** Activate the link carrier check. Set to `false` if `dev` is a backend bridge or switch. ## 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 `dev` required: false scopable: true aliases: ipdev stop first: a change is refused while the resource is up rbac: Requires the root grant. **Example:** dev=eth0 **Description:** The interface name to setup the ip address on. When not set, the interface the network the address is drawn from names: the interface of the node on the segment of a `lan` network. This interface can be different from one node to the other, in which case the `dev@` scoping syntax can be used. If the value is expressed as `:`, the stacked interface index is forced to `` instead of the lowest free index. If the value is expressed as `@`, a macvtap interface named `` is created and attached to ``. ## 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 disable` sets `DEFAULT.disable=true`. `om 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 `expose` required: false scopable: true convert: list **Example:** expose=443/tcp:8443 53/udp **Description:** A whitespace-separated list of `/[:]` describing socket services that mandate a SRV exposition. ## Keyword `gateway` required: false scopable: true provision: used only by the provision of the resource rbac: Requires the root grant. **Description:** A zone ip provisioning parameter used in the `sysidcfg` formatting ## 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 aliases: ipname stop first: a change is refused while the resource is up rbac: Requires the root grant. **Example:** name=1.2.3.4 **Description:** The DNS name or IP address of the ip resource. When not set, the address is drawn from the om network the `network` keyword names. Scoping ------- Can be different from one node to the other, in which case the `name@` scoping syntax can be used. This is most useful to specify a different ip when the service starts in DRP mode, where subnets are likely to be different than those of the production datacenter. DNS name caching ---------------- If the value is a DNS name, a lookup is done for every resource status evaluation. * If the lookup succeeds, the addr is store in a cache file. * If the lookup fails, the address is fetched from the cache file. * If the cache is not expired (refreshed in the past 19 minutes) the address is trusted: * The resource status is degraded to from `up` to `warn`. * The resource restarts begin if `restarts > 0`. The restart is a no-op but the resource status is re-evaluated. If the lookup succeeds, the resource status to `up`. * The monitor action is triggered if all restarts failed and `monitor_action` is set. For example, a `freezestop` can still succeed using the cached ip address. * If the cache is expired (older than 19 minutes): * The resource status is `warn`, weither the actual untrusted ip address is plumbed or not. * The `stop` and `start` actions no longer work. An admin action is necessary to repair the configuration or dns lookups. ## Keyword `netmask` required: false scopable: true rbac: Requires the root grant. **Example:** netmask=24 **Description:** The netmask to configure with the address resolved from `name`. If an ip is already plumbed on the root interface, the netmask default is the netmask of this existing ip. `netmask` is mandatory for interfaces dedicated to the object. Dummy interfaces are likely to be in this case. The format is: * dotted or octal for IPv4, ex: `255.255.252.0` or `22`. * octal only for IPv6, ex: `64`. ## Keyword `network` required: false scopable: true stop first: a change is refused while the resource is up rbac: A network named by a path requires the root grant. **Example:** network=san **Description:** The name of the om network the address is drawn from, when `name` is not set. The address is drawn when the resource first starts, and written to the `addr` keyword: every node then uses it, so the address follows a failover service to whichever node it moves to, the floating address of the service, which its clients know it by. It is kept until the resource is unprovisioned, a stop keeping it. The `dev` and `netmask` of the resource are the network's to know, and are taken from it when the configuration does not set them: the interface of the node on the segment of a `lan` network, and the prefix length of the segment. This keyword used to hold the address of the network, in dotted notation. A value that is still an address is obsolete, reported and ignored. ## 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 `(,...)`. 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=` 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 `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 `(,...)`. 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 `(,...)`. 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#:]` section, or in a less precise `[subset#]` 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 `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 `(,...)`. If states are omitted, `up,stdby up` is used as the default expected states. ## Keyword `wait_dns` required: false scopable: true default: 0 convert: duration **Example:** wait_dns=10s **Description:** Wait for the cluster DNS records associated to the resource to appear after a resource start and before the next resource can be started. This can be set when apps or containers require the ip or ip name to be resolvable to provision or start properly.