Chapter 5. Clair security scanner 5.1. Clair configuration overview Clair is configured by a structured YAML file. Each Clair node needs to specify what mode it will run in and a path to a configuration file through CLI flags or environment variables. For example: USD clair -conf ./path/to/config.yaml -mode indexer or USD clair -conf ./path/to/config.yaml -mode matcher The aforementioned commands each start two Clair nodes using the same configuration file. One runs the indexing facilities, while other runs the matching facilities. If you are running Clair in combo mode, you must supply the indexer, matcher, and notifier configuration blocks in the configuration. 5.1.1. Information about using Clair in a proxy environment Environment variables respected by the Go standard library can be specified if needed, for example: HTTP_PROXY USD export HTTP_PROXY=http://<user_name>:<password>@<proxy_host>:<proxy_port> HTTPS_PROXY . USD export HTTPS_PROXY=https://<user_name>:<password>@<proxy_host>:<proxy_port> SSL_CERT_DIR USD export SSL_CERT_DIR=/<path>/<to>/<ssl>/<certificates> NO_PROXY USD export NO_PROXY=<comma_separated_list_of_hosts_and_domains> If you are using a proxy server in your environment with Clair's updater URLs, you must identify which URL needs to be added to the proxy allowlist to ensure that Clair can access them unimpeded. For example, the osv updater requires access to https://osv-vulnerabilities.storage.googleapis.com to fetch ecosystem data dumps. In this scenario, the URL must be added to the proxy allowlist. For a full list of updater URLs, see "Clair updater URLs". You must also ensure that the standard Clair URLs are added to the proxy allowlist: https://search.maven.org/solrsearch/select https://catalog.redhat.com/api/containers/ https://access.redhat.com/security/data/metrics/repository-to-cpe.json https://access.redhat.com/security/data/metrics/container-name-repos-map.json When configuring the proxy server, take into account any authentication requirements or specific proxy settings needed to enable seamless communication between Clair and these URLs. By thoroughly documenting and addressing these considerations, you can ensure that Clair functions effectively while routing its updater traffic through the proxy. 5.1.2. Clair configuration reference The following YAML shows an example Clair configuration: http_listen_addr: "" introspection_addr: "" log_level: "" tls: {} indexer: connstring: "" scanlock_retry: 0 layer_scan_concurrency: 5 migrations: false scanner: {} airgap: false matcher: connstring: "" indexer_addr: "" migrations: false period: "" disable_updaters: false update_retention: 2 matchers: names: nil config: nil updaters: sets: nil config: nil notifier: connstring: "" migrations: false indexer_addr: "" matcher_addr: "" poll_interval: "" delivery_interval: "" disable_summary: false webhook: null amqp: null stomp: null auth: psk: nil trace: name: "" probability: null jaeger: agent: endpoint: "" collector: endpoint: "" username: null password: null service_name: "" tags: nil buffer_max: 0 metrics: name: "" prometheus: endpoint: null dogstatsd: url: "" Note The above YAML file lists every key for completeness. Using this configuration file as-is will result in some options not having their defaults set normally. 5.1.3. Clair general fields The following table describes the general configuration fields available for a Clair deployment. Field Typhttp_listen_ae Description http_listen_addr String Configures where the HTTP API is exposed. Default: :6060 introspection_addr String Configures where Clair's metrics and health endpoints are exposed. log_level String Sets the logging level. Requires one of the following strings: debug-color , debug , info , warn , error , fatal , panic tls String A map containing the configuration for serving the HTTP API of TLS/SSL and HTTP/2. .cert String The TLS certificate to be used. Must be a full-chain certificate. Example configuration for general Clair fields The following example shows a Clair configuration. Example configuration for general Clair fields # ... http_listen_addr: 0.0.0.0:6060 introspection_addr: 0.0.0.0:8089 log_level: info # ... 5.1.4. Clair indexer configuration fields The following table describes the configuration fields for Clair's indexer component. Field Type Description indexer Object Provides Clair indexer node configuration. .airgap Boolean Disables HTTP access to the internet for indexers and fetchers. Private IPv4 and IPv6 addresses are allowed. Database connections are unaffected. .connstring String A Postgres connection string. Accepts format as a URL or libpq connection string. .index_report_request_concurrency Integer Rate limits the number of index report creation requests. Setting this to 0 attemps to auto-size this value. Setting a negative value means unlimited. The auto-sizing is a multiple of the number of available cores. The API returns a 429 status code if concurrency is exceeded. .scanlock_retry Integer A positive integer representing seconds. Concurrent indexers lock on manifest scans to avoid clobbering. This value tunes how often a waiting indexer polls for the lock. .layer_scan_concurrency Integer Positive integer limiting the number of concurrent layer scans. Indexers will match a manifest's layer concurrently. This value tunes the number of layers an indexer scans in parallel. .migrations Boolean Whether indexer nodes handle migrations to their database. .scanner String Indexer configuration. Scanner allows for passing configuration options to layer scanners. The scanner will have this configuration pass to it on construction if designed to do so. .scanner.dist String A map with the name of a particular scanner and arbitrary YAML as a value. .scanner.package String A map with the name of a particular scanner and arbitrary YAML as a value. .scanner.repo String A map with the name of a particular scanner and arbitrary YAML as a value. Example indexer configuration The following example shows a hypothetical indexer configuration for Clair. Example indexer configuration # ... indexer: connstring: host=quay-server.example.com port=5433 dbname=clair user=clairuser password=clairpass sslmode=disable scanlock_retry: 10 layer_scan_concurrency: 5 migrations: true # ... 5.1.5. Clair matcher configuration fields The following table describes the configuration fields for Clair's matcher component. Note Differs from matchers configuration fields. Field Type Description matcher Object Provides Clair matcher node configuration. .cache_age String Controls how long users should be hinted to cache responses for. .connstring String A Postgres connection string. Accepts format as a URL or libpq connection string. .max_conn_pool Integer Limits the database connection pool size. Clair allows for a custom connection pool size. This number directly sets how many active database connections are allowed concurrently. This parameter will be ignored in a future version. Users should configure this through the connection string. .indexer_addr String A matcher contacts an indexer to create a vulnerability report. The location of this indexer is required. Defaults to 30m . .migrations Boolean Whether matcher nodes handle migrations to their databases. .period String Determines how often updates for new security advisories take place. Defaults to 30m . .disable_updaters Boolean Whether to run background updates or not. Default: False .update_retention Integer Sets the number of update operations to retain between garbage collection cycles. This should be set to a safe MAX value based on database size constraints. Defaults to 10m . If a value of less than 0 is provided, garbage collection is disabled. 2 is the minimum value to ensure updates can be compared to notifications. Example matcher configuration Example matcher configuration # ... matcher: connstring: >- host=<DB_HOST> port=5432 dbname=<matcher> user=<DB_USER> password=D<B_PASS> sslmode=verify-ca sslcert=/etc/clair/ssl/cert.pem sslkey=/etc/clair/ssl/key.pem sslrootcert=/etc/clair/ssl/ca.pem indexer_addr: http://clair-v4/ disable_updaters: false migrations: true period: 6h update_retention: 2 # ... 5.1.6. Clair matchers configuration fields The following table describes the configuration fields for Clair's matchers component. Note Differs from matcher configuration fields. Table 5.1. Matchers configuration fields Field Type Description matchers Array of strings Provides configuration for the in-tree matchers . .names String A list of string values informing the matcher factory about enabled matchers. If value is set to null , the default list of matchers run. The following strings are accepted: alpine-matcher , aws-matcher , debian-matcher , gobin , java-maven , oracle , photon , python , rhel , rhel-container-matcher , ruby , suse , ubuntu-matcher .config String Provides configuration to a specific matcher. A map keyed by the name of the matcher containing a sub-object which will be provided to the matchers factory constructor. For example: Example matchers configuration The following example shows a hypothetical Clair deployment that only requires only the alpine , aws , debian , oracle matchers. Example matchers configuration # ... matchers: names: - "alpine-matcher" - "aws" - "debian" - "oracle" # ... 5.1.7. Clair updaters configuration fields The following table describes the configuration fields for Clair's updaters component. Table 5.2. Updaters configuration fields Field Type Description updaters Object Provides configuration for the matcher's update manager. .sets String A list of values informing the update manager which updaters to run. If value is set to null , the default set of updaters runs the following: alpine , aws , clair.cvss , debian , oracle , photon , osv , rhel , rhcc suse , ubuntu If left blank, zero updaters run. .config String Provides configuration to specific updater sets. A map keyed by the name of the updater set containing a sub-object which will be provided to the updater set's constructor. For a list of the sub-objects for each updater, see "Advanced updater configuration". Example updaters configuration In the following configuration, only the rhel set is configured. The ignore_unpatched variable, which is specific to the rhel updater, is also defined. Example updaters configuration # ... updaters: sets: - rhel config: rhel: ignore_unpatched: false # ... 5.1.8. Clair notifier configuration fields The general notifier configuration fields for Clair are listed below. Field Type Description notifier Object Provides Clair notifier node configuration. .connstring String Postgres connection string. Accepts format as URL, or libpq connection string. .migrations Boolean Whether notifier nodes handle migrations to their database. .indexer_addr String A notifier contacts an indexer to create or obtain manifests affected by vulnerabilities. The location of this indexer is required. .matcher_addr String A notifier contacts a matcher to list update operations and acquire diffs. The location of this matcher is required. .poll_interval String The frequency at which the notifier will query a matcher for update operations. .delivery_interval String The frequency at which the notifier attempts delivery of created, or previously failed, notifications. .disable_summary Boolean Controls whether notifications should be summarized to one per manifest. Example notifier configuration The following notifier snippet is for a minimal configuration. Example notifier configuration # ... notifier: connstring: >- host=DB_HOST port=5432 dbname=notifier user=DB_USER password=DB_PASS sslmode=verify-ca sslcert=/etc/clair/ssl/cert.pem sslkey=/etc/clair/ssl/key.pem sslrootcert=/etc/clair/ssl/ca.pem indexer_addr: http://clair-v4/ matcher_addr: http://clair-v4/ delivery_interval: 5s migrations: true poll_interval: 15s webhook: target: "http://webhook/" callback: "http://clair-notifier/notifier/api/v1/notifications" headers: "" amqp: null stomp: null # ... 5.1.8.1. Clair webhook configuration fields The following webhook fields are available for the Clair notifier environment. Table 5.3. Clair webhook fields .webhook Object Configures the notifier for webhook delivery. .webhook.target String URL where the webhook will be delivered. .webhook.callback String The callback URL where notifications can be retrieved. The notification ID will be appended to this URL. This will typically be where the Clair notifier is hosted. .webhook.headers String A map associating a header name to a list of values. Example webhook configuration Example webhook configuration # ... notifier: # ... webhook: target: "http://webhook/" callback: "http://clair-notifier/notifier/api/v1/notifications" # ... 5.1.8.2. Clair amqp configuration fields The following Advanced Message Queuing Protocol (AMQP) fields are available for the Clair notifier environment. .amqp Object Configures the notifier for AMQP delivery. [NOTE] ==== Clair does not declare any AMQP components on its own. All attempts to use an exchange or queue are passive only and will fail. Broker administrators should setup exchanges and queues ahead of time. ==== .amqp.direct Boolean If true , the notifier will deliver individual notifications (not a callback) to the configured AMQP broker. .amqp.rollup Integer When amqp.direct is set to true , this value informs the notifier of how many notifications to send in a direct delivery. For example, if direct is set to true , and amqp.rollup is set to 5 , the notifier delivers no more than 5 notifications in a single JSON payload to the broker. Setting the value to 0 effectively sets it to 1 . .amqp.exchange Object The AMQP exchange to connect to. .amqp.exchange.name String The name of the exchange to connect to. .amqp.exchange.type String The type of the exchange. Typically one of the following: direct , fanout , topic , headers . .amqp.exchange.durability Boolean Whether the configured queue is durable. .amqp.exchange.auto_delete Boolean Whether the configured queue uses an auto_delete_policy . .amqp.routing_key String The name of the routing key each notification is sent with. .amqp.callback String If amqp.direct is set to false , this URL is provided in the notification callback sent to the broker. This URL should point to Clair's notification API endpoint. .amqp.uris String A list of one or more AMQP brokers to connect to, in priority order. .amqp.tls Object Configures TLS/SSL connection to an AMQP broker. .amqp.tls.root_ca String The filesystem path where a root CA can be read. .amqp.tls.cert String The filesystem path where a TLS/SSL certificate can be read. [NOTE] ==== Clair also allows SSL_CERT_DIR , as documented for the Go crypto/x509 package. ==== .amqp.tls.key String The filesystem path where a TLS/SSL private key can be read. Example AMQP configuration The following example shows a hypothetical AMQP configuration for Clair. Example AMQP configuration # ... notifier: # ... amqp: exchange: name: "" type: "direct" durable: true auto_delete: false uris: ["amqp://user:pass@host:10000/vhost"] direct: false routing_key: "notifications" callback: "http://clair-notifier/notifier/api/v1/notifications" tls: root_ca: "optional/path/to/rootca" cert: "madatory/path/to/cert" key: "madatory/path/to/key" # ... 5.1.8.3. Clair STOMP configuration fields The following Simple Text Oriented Message Protocol (STOMP) fields are available for the Clair notifier environment. .stomp Object Configures the notifier for STOMP delivery. .stomp.direct Boolean If true , the notifier delivers individual notifications (not a callback) to the configured STOMP broker. .stomp.rollup Integer If stomp.direct is set to true , this value limits the number of notifications sent in a single direct delivery. For example, if direct is set to true , and rollup is set to 5 , the notifier delivers no more than 5 notifications in a single JSON payload to the broker. Setting the value to 0 effectively sets it to 1 . .stomp.callback String If stomp.callback is set to false , the provided URL in the notification callback is sent to the broker. This URL should point to Clair's notification API endpoint. .stomp.destination String The STOMP destination to deliver notifications to. .stomp.uris String A list of one or more STOMP brokers to connect to in priority order. .stomp.tls Object Configured TLS/SSL connection to STOMP broker. .stomp.tls.root_ca String The filesystem path where a root CA can be read. [NOTE] ==== Clair also respects SSL_CERT_DIR , as documented for the Go crypto/x509 package. ==== .stomp.tls.cert String The filesystem path where a TLS/SSL certificate can be read. .stomp.tls.key String The filesystem path where a TLS/SSL private key can be read. .stomp.user String Configures login details for the STOMP broker. .stomp.user.login String The STOMP login to connect with. .stomp.user.passcode String The STOMP passcode to connect with. Example STOMP configuration The following example shows a hypothetical STOMP configuration for Clair. Example STOMP configuration # ... notifier: # ... stomp: desitnation: "notifications" direct: false callback: "http://clair-notifier/notifier/api/v1/notifications" login: login: "username" passcode: "passcode" tls: root_ca: "optional/path/to/rootca" cert: "madatory/path/to/cert" key: "madatory/path/to/key" # ... 5.1.9. Clair authorization configuration fields The following authorization configuration fields are available for Clair. Field Type Description auth Object Defines Clair's external and intra-service JWT based authentication. If multiple auth mechanisms are defined, Clair picks one. Currently, multiple mechanisms are unsupported. .psk String Defines pre-shared key authentication. .psk.key String A shared base64 encoded key distributed between all parties signing and verifying JWTs. .psk.iss String A list of JWT issuers to verify. An empty list accepts any issuer in a JWT claim. Example authorization configuration The following authorization snippet is for a minimal configuration. Example authorization configuration # ... auth: psk: key: MTU5YzA4Y2ZkNzJoMQ== 1 iss: ["quay"] # ... 5.1.10. Clair trace configuration fields The following trace configuration fields are available for Clair. Field Type Description trace Object Defines distributed tracing configuration based on OpenTelemetry. .name String The name of the application traces will belong to. .probability Integer The probability a trace will occur. .jaeger Object Defines values for Jaeger tracing. .jaeger.agent Object Defines values for configuring delivery to a Jaeger agent. .jaeger.agent.endpoint String An address in the <host>:<post> syntax where traces can be submitted. .jaeger.collector Object Defines values for configuring delivery to a Jaeger collector. .jaeger.collector.endpoint String An address in the <host>:<post> syntax where traces can be submitted. .jaeger.collector.username String A Jaeger username. .jaeger.collector.password String A Jaeger password. .jaeger.service_name String The service name registered in Jaeger. .jaeger.tags String Key-value pairs to provide additional metadata. .jaeger.buffer_max Integer The maximum number of spans that can be buffered in memory before they are sent to the Jaeger backend for storage and analysis. Example trace configuration The following example shows a hypothetical trace configuration for Clair. Example trace configuration # ... trace: name: "jaeger" probability: 1 jaeger: agent: endpoint: "localhost:6831" service_name: "clair" # ... 5.1.11. Clair metrics configuration fields The following metrics configuration fields are available for Clair. Field Type Description metrics Object Defines distributed tracing configuration based on OpenTelemetry. .name String The name of the metrics in use. .prometheus String Configuration for a Prometheus metrics exporter. .prometheus.endpoint String Defines the path where metrics are served. Example metrics configuration The following example shows a hypothetical metrics configuration for Clair. Example metrics configuration # ... metrics: name: "prometheus" prometheus: endpoint: "/metricsz" # ...

Commands:
clair -conf ./path/to/config.yaml -mode indexer
clair -conf ./path/to/config.yaml -mode matcher
export HTTP_PROXY=http://<user_name>:<password>@<proxy_host>:<proxy_port>
export HTTPS_PROXY=https://<user_name>:<password>@<proxy_host>:<proxy_port>
export SSL_CERT_DIR=/<path>/<to>/<ssl>/<certificates>
export NO_PROXY=<comma_separated_list_of_hosts_and_domains>
http_listen_addr: "" introspection_addr: "" log_level: "" tls: {} indexer: connstring: "" scanlock_retry: 0 layer_scan_concurrency: 5 migrations: false scanner: {} airgap: false matcher: connstring: "" indexer_addr: "" migrations: false period: "" disable_updaters: false update_retention: 2 matchers: names: nil config: nil updaters: sets: nil config: nil notifier: connstring: "" migrations: false indexer_addr: "" matcher_addr: "" poll_interval: "" delivery_interval: "" disable_summary: false webhook: null amqp: null stomp: null auth: psk: nil trace: name: "" probability: null jaeger: agent: endpoint: "" collector: endpoint: "" username: null password: null service_name: "" tags: nil buffer_max: 0 metrics: name: "" prometheus: endpoint: null dogstatsd: url: ""
http_listen_addr: 0.0.0.0:6060 introspection_addr: 0.0.0.0:8089 log_level: info
indexer: connstring: host=quay-server.example.com port=5433 dbname=clair user=clairuser password=clairpass sslmode=disable scanlock_retry: 10 layer_scan_concurrency: 5 migrations: true
matcher: connstring: >- host=<DB_HOST> port=5432 dbname=<matcher> user=<DB_USER> password=D<B_PASS> sslmode=verify-ca sslcert=/etc/clair/ssl/cert.pem sslkey=/etc/clair/ssl/key.pem sslrootcert=/etc/clair/ssl/ca.pem indexer_addr: http://clair-v4/ disable_updaters: false migrations: true period: 6h update_retention: 2
matchers: names: - "alpine-matcher" - "aws" - "debian" - "oracle"
updaters: sets: - rhel config: rhel: ignore_unpatched: false
notifier: connstring: >- host=DB_HOST port=5432 dbname=notifier user=DB_USER password=DB_PASS sslmode=verify-ca sslcert=/etc/clair/ssl/cert.pem sslkey=/etc/clair/ssl/key.pem sslrootcert=/etc/clair/ssl/ca.pem indexer_addr: http://clair-v4/ matcher_addr: http://clair-v4/ delivery_interval: 5s migrations: true poll_interval: 15s webhook: target: "http://webhook/" callback: "http://clair-notifier/notifier/api/v1/notifications" headers: "" amqp: null stomp: null
notifier: webhook: target: "http://webhook/" callback: "http://clair-notifier/notifier/api/v1/notifications"
notifier: amqp: exchange: name: "" type: "direct" durable: true auto_delete: false uris: ["amqp://user:pass@host:10000/vhost"] direct: false routing_key: "notifications" callback: "http://clair-notifier/notifier/api/v1/notifications" tls: root_ca: "optional/path/to/rootca" cert: "madatory/path/to/cert" key: "madatory/path/to/key"
notifier: stomp: desitnation: "notifications" direct: false callback: "http://clair-notifier/notifier/api/v1/notifications" login: login: "username" passcode: "passcode" tls: root_ca: "optional/path/to/rootca" cert: "madatory/path/to/cert" key: "madatory/path/to/key"
auth: psk: key: MTU5YzA4Y2ZkNzJoMQ== 1 iss: ["quay"]
trace: name: "jaeger" probability: 1 jaeger: agent: endpoint: "localhost:6831" service_name: "clair"
metrics: name: "prometheus" prometheus: endpoint: "/metricsz"