This is documentation for the next version of Alloy. For the latest stable release, go to the latest version.
prometheus.operator.podmonitors
prometheus.operator.podmonitors
discovers PodMonitor resources in your kubernetes cluster and scrapes the targets they reference. This component performs three main functions:
- Discover PodMonitor resources from your Kubernetes cluster.
- Discover Pods in your cluster that match those PodMonitors.
- Scrape metrics from those Pods, and forward them to a receiver.
The default configuration assumes Alloy is running inside a Kubernetes cluster, and uses the in-cluster configuration to access the Kubernetes API. It can be run from outside the cluster by supplying connection info in the client
block, but network level access to pods is required to scrape metrics from them.
PodMonitors may reference secrets for authenticating to targets to scrape them. In these cases, the secrets are loaded and refreshed only when the PodMonitor is updated or when this component refreshes its’ internal state, which happens on a 5-minute refresh cycle.
Usage
prometheus.operator.podmonitors "LABEL" {
forward_to = RECEIVER_LIST
}
Arguments
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
forward_to | list(MetricsReceiver) | List of receivers to send scraped metrics to. | yes | |
namespaces | list(string) | List of namespaces to search for PodMonitor resources. If not specified, all namespaces will be searched. | no |
Blocks
The following blocks are supported inside the definition of prometheus.operator.podmonitors
:
Hierarchy | Block | Description | Required |
---|---|---|---|
client | client | Configures Kubernetes client used to find PodMonitors. | no |
client > basic_auth | basic_auth | Configure basic authentication to the Kubernetes API. | no |
client > authorization | authorization | Configure generic authorization to the Kubernetes API. | no |
client > oauth2 | oauth2 | Configure OAuth2 for authenticating to the Kubernetes API. | no |
client > oauth2 > tls_config | tls_config | Configure TLS settings for connecting to the Kubernetes API. | no |
client > tls_config | tls_config | Configure TLS settings for connecting to the Kubernetes API. | no |
rule | rule | Relabeling rules to apply to discovered targets. | no |
scrape | scrape | Default scrape configuration to apply to discovered targets. | no |
selector | selector | Label selector for which PodMonitors to discover. | no |
selector > match_expression | match_expression | Label selector expression for which PodMonitors to discover. | no |
clustering | clustering | Configure the component for when Alloy is running in clustered mode. | no |
The >
symbol indicates deeper levels of nesting. For example, client > basic_auth
refers to a basic_auth
block defined
inside a client
block.
client block
The client
block configures the Kubernetes client used to discover PodMonitors. If the client
block isn’t provided, the default in-cluster
configuration with the service account of the running Alloy pod is
used.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
api_server | string | URL of the Kubernetes API server. | no | |
kubeconfig_file | string | Path of the kubeconfig file to use for connecting to Kubernetes. | no | |
bearer_token_file | string | File containing a bearer token to authenticate with. | no | |
bearer_token | secret | Bearer token to authenticate with. | no | |
enable_http2 | bool | Whether HTTP2 is supported for requests. | true | no |
follow_redirects | bool | Whether redirects returned by the server should be followed. | true | no |
proxy_url | string | HTTP proxy to send requests through. | no | |
no_proxy | string | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. | no | |
proxy_from_environment | bool | Use the proxy URL indicated by environment variables. | false | no |
proxy_connect_header | map(list(secret)) | Specifies headers to send to proxies during CONNECT requests. | no |
At most, one of the following can be provided:
no_proxy
can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers.
proxy_url
must be configured if no_proxy
is configured.
proxy_from_environment
uses the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY (or the lowercase versions thereof).
Requests use the proxy from the environment variable matching their scheme, unless excluded by NO_PROXY.
proxy_url
and no_proxy
must not be configured if proxy_from_environment
is configured.
proxy_connect_header
should only be configured if proxy_url
or proxy_from_environment
are configured.
basic_auth block
Name | Type | Description | Default | Required |
---|---|---|---|---|
password_file | string | File containing the basic auth password. | no | |
password | secret | Basic auth password. | no | |
username | string | Basic auth username. | no |
password
and password_file
are mutually exclusive, and only one can be provided inside a basic_auth
block.
authorization block
Name | Type | Description | Default | Required |
---|---|---|---|---|
credentials_file | string | File containing the secret value. | no | |
credentials | secret | Secret value. | no | |
type | string | Authorization type, for example, “Bearer”. | no |
credential
and credentials_file
are mutually exclusive, and only one can be provided inside an authorization
block.
oauth2 block
Name | Type | Description | Default | Required |
---|---|---|---|---|
client_id | string | OAuth2 client ID. | no | |
client_secret_file | string | File containing the OAuth2 client secret. | no | |
client_secret | secret | OAuth2 client secret. | no | |
endpoint_params | map(string) | Optional parameters to append to the token URL. | no | |
proxy_url | string | HTTP proxy to send requests through. | no | |
no_proxy | string | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. | no | |
proxy_from_environment | bool | Use the proxy URL indicated by environment variables. | false | no |
proxy_connect_header | map(list(secret)) | Specifies headers to send to proxies during CONNECT requests. | no | |
scopes | list(string) | List of scopes to authenticate with. | no | |
token_url | string | URL to fetch the token from. | no |
client_secret
and client_secret_file
are mutually exclusive, and only one can be provided inside an oauth2
block.
The oauth2
block may also contain a separate tls_config
sub-block.
no_proxy
can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers.
proxy_url
must be configured if no_proxy
is configured.
proxy_from_environment
uses the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY (or the lowercase versions thereof).
Requests use the proxy from the environment variable matching their scheme, unless excluded by NO_PROXY.
proxy_url
and no_proxy
must not be configured if proxy_from_environment
is configured.
proxy_connect_header
should only be configured if proxy_url
or proxy_from_environment
are configured.
tls_config block
Name | Type | Description | Default | Required |
---|---|---|---|---|
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
ca_file | string | CA certificate to validate the server with. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
cert_file | string | Certificate file for client authentication. | no | |
insecure_skip_verify | bool | Disables validation of the server certificate. | no | |
key_file | string | Key file for client authentication. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
min_version | string | Minimum acceptable TLS version. | no | |
server_name | string | ServerName extension to indicate the name of the server. | no |
The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:
ca_pem
andca_file
cert_pem
andcert_file
key_pem
andkey_file
When configuring client authentication, both the client certificate (using
cert_pem
or cert_file
) and the client key (using key_pem
or key_file
)
must be provided.
When min_version
is not provided, the minimum acceptable TLS version is
inherited from Go’s default minimum version, TLS 1.2. If min_version
is
provided, it must be set to one of the following strings:
"TLS10"
(TLS 1.0)"TLS11"
(TLS 1.1)"TLS12"
(TLS 1.2)"TLS13"
(TLS 1.3)
rule block
The rule
block contains the definition of any relabeling rules that can be applied to an input metric.
If more than one rule
block is defined, the transformations are applied in top-down order.
The following arguments can be used to configure a rule
.
All arguments are optional. Omitted fields take their default values.
Name | Type | Description | Default | Required |
---|---|---|---|---|
action | string | The relabeling action to perform. | replace | no |
modulus | uint | A positive integer used to calculate the modulus of the hashed source label values. | no | |
regex | string | A valid RE2 expression with support for parenthesized capture groups. Used to match the extracted value from the combination of the source_label and separator fields or filter labels during the labelkeep/labeldrop/labelmap actions. | (.*) | no |
replacement | string | The value against which a regular expression replace is performed, if the regular expression matches the extracted value. Supports previously captured groups. | "$1" | no |
separator | string | The separator used to concatenate the values present in source_labels . | ; | no |
source_labels | list(string) | The list of labels whose values are to be selected. Their content is concatenated using the separator and matched against regex . | no | |
target_label | string | Label to which the resulting value will be written to. | no |
You can use the following actions:
drop
- Drops metrics whereregex
matches the string extracted using thesource_labels
andseparator
.dropequal
- Drop targets for which the concatenatedsource_labels
do matchtarget_label
.hashmod
- Hashes the concatenated labels, calculates its modulomodulus
and writes the result to thetarget_label
.keep
- Keeps metrics whereregex
matches the string extracted using thesource_labels
andseparator
.keepequal
- Drop targets for which the concatenatedsource_labels
do not matchtarget_label
.labeldrop
- Matchesregex
against all label names. Any labels that match are removed from the metric’s label set.labelkeep
- Matchesregex
against all label names. Any labels that don’t match are removed from the metric’s label set.labelmap
- Matchesregex
against all label names. Any labels that match are renamed according to the contents of thereplacement
field.lowercase
- Setstarget_label
to the lowercase form of the concatenatedsource_labels
.replace
- Matchesregex
to the concatenated labels. If there’s a match, it replaces the content of thetarget_label
using the contents of thereplacement
field.uppercase
- Setstarget_label
to the uppercase form of the concatenatedsource_labels
.
Note
The regular expression capture groups can be referred to using either the$CAPTURE_GROUP_NUMBER
or${CAPTURE_GROUP_NUMBER}
notation.
scrape block
Name | Type | Description | Default | Required |
---|---|---|---|---|
default_scrape_interval | duration | The default interval between scraping targets. Used as the default if the target resource doesn’t provide a scrape interval. | 1m | no |
default_scrape_timeout | duration | The default timeout for scrape requests. Used as the default if the target resource doesn’t provide a scrape timeout. | 10s | no |
selector block
The selector
block describes a Kubernetes label selector for PodMonitors.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
match_labels | map(string) | Label keys and values used to discover resources. | {} | no |
When the match_labels
argument is empty, all PodMonitor resources will be matched.
match_expression block
The match_expression
block describes a Kubernetes label matcher expression for
PodMonitors discovery.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
key | string | The label name to match against. | yes | |
operator | string | The operator to use when matching. | yes | |
values | list(string) | The values used when matching. | no |
The operator
argument must be one of the following strings:
"In"
"NotIn"
"Exists"
"DoesNotExist"
If there are multiple match_expressions
blocks inside of a selector
block, they are combined together with AND clauses.
clustering block
Name | Type | Description | Default | Required |
---|---|---|---|---|
enabled | bool | Enables sharing targets with other cluster nodes. | false | yes |
When Alloy is using clustering, and enabled
is set to true,
then this component instance opts-in to participating in
the cluster to distribute scrape load between all cluster nodes.
Clustering assumes that all cluster nodes are running with the same
configuration file, and that all
prometheus.operator.podmonitors
components that have opted-in to using clustering, over
the course of a scrape interval have the same configuration.
All prometheus.operator.podmonitors
components instances opting in to clustering use target
labels and a consistent hashing algorithm to determine ownership for each of
the targets between the cluster peers. Then, each peer only scrapes the subset
of targets that it is responsible for, so that the scrape load is distributed.
When a node joins or leaves the cluster, every peer recalculates ownership and
continues scraping with the new target set. This performs better than hashmod
sharding where all nodes have to be re-distributed, as only 1/N of the
target’s ownership is transferred, but is eventually consistent (rather than
fully consistent like hashmod sharding is).
If Alloy is not running in clustered mode, then the block is a no-op, and
prometheus.operator.podmonitors
scrapes every target it receives in its arguments.
Exported fields
prometheus.operator.podmonitors
does not export any fields. It forwards all metrics it scrapes to the receiver configures with the forward_to
argument.
Component health
prometheus.operator.podmonitors
is reported as unhealthy when given an invalid configuration, Prometheus components fail to initialize, or the connection to the Kubernetes API could not be established properly.
Debug information
prometheus.operator.podmonitors
reports the status of the last scrape for each configured
scrape job on the component’s debug endpoint, including discovered labels, and the last scrape time.
It also exposes some debug information for each PodMonitor it has discovered, including any errors found while reconciling the scrape configuration from the PodMonitor.
Debug metrics
prometheus.operator.podmonitors
does not expose any component-specific debug metrics.
Example
This example discovers all PodMonitors in your cluster, and forwards collected metrics to a prometheus.remote_write
component.
prometheus.remote_write "staging" {
// Send metrics to a locally running Mimir.
endpoint {
url = "http://mimir:9009/api/v1/push"
basic_auth {
username = "example-user"
password = "example-password"
}
}
}
prometheus.operator.podmonitors "pods" {
forward_to = [prometheus.remote_write.staging.receiver]
}
This example will limit discovered PodMonitors to ones with the label team=ops
in a specific namespace: my-app
.
prometheus.operator.podmonitors "pods" {
forward_to = [prometheus.remote_write.staging.receiver]
namespaces = ["my-app"]
selector {
match_expression {
key = "team"
operator = "In"
values = ["ops"]
}
}
}
This example will apply additional relabel rules to discovered targets to filter by hostname. This may be useful if running Alloy as a DaemonSet.
prometheus.operator.podmonitors "pods" {
forward_to = [prometheus.remote_write.staging.receiver]
rule {
action = "keep"
regex = sys.env("HOSTNAME")
source_labels = ["__meta_kubernetes_pod_node_name"]
}
}
Compatible components
prometheus.operator.podmonitors
can accept arguments from the following components:
- Components that export Prometheus
MetricsReceiver
Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.