VictoriaMetrics/app/vmauth

vmauth

vmauth is a simple auth proxy, router and load balancer for VictoriaMetrics. It reads auth credentials from Authorization http header (Basic Auth, Bearer token and InfluxDB authorization is supported), matches them against configs pointed by -auth.config command-line flag and proxies incoming HTTP requests to the configured per-user url_prefix on successful match. The -auth.config can point to either local file or to http url.

Quick start

Just download vmutils-* archive from releases page, unpack it and pass the following flag to vmauth binary in order to start authorizing and routing requests:

/path/to/vmauth -auth.config=/path/to/auth/config.yml

After that vmauth starts accepting HTTP requests on port 8427 and routing them according to the provided -auth.config. The port can be modified via -httpListenAddr command-line flag.

The auth config can be reloaded via the following ways:

• By passing SIGHUP signal to vmauth.
• By querying /-/reload http endpoint. This endpoint can be protected with -reloadAuthKey command-line flag. See security docs for more details.
• By specifying -configCheckInterval command-line flag to the interval between config re-reads. For example, -configCheckInterval=5s will re-read the config and apply new changes every 5 seconds.

Docker images for vmauth are available here.

Pass -help to vmauth in order to see all the supported command-line flags with their descriptions.

Feel free contacting us if you need customized auth proxy for VictoriaMetrics with the support of LDAP, SSO, RBAC, SAML, accounting and rate limiting such as vmgateway.

Load balancing

Each url_prefix in the -auth.config may contain either a single url or a list of urls. In the latter case vmauth balances load among the configured urls in least-loaded round-robin manner. vmauth retries failing GET requests across the configured list of urls. This feature is useful for balancing the load among multiple vmselect and/or vminsert nodes in VictoriaMetrics cluster.

Concurrency limiting

vmauth limits the number of concurrent requests it can proxy according to the following command-line flags:

• -maxConcurrentRequests limits the global number of concurrent requests vmauth can serve across all the configured users.
• -maxConcurrentPerUserRequests limits the number of concurrent requests vmauth can serve per each configured user.

It is also possible to set individual limits on the number of concurrent requests per each user with the max_concurrent_requests option - see auth config example.

vmauth responds with 429 Too Many Requests HTTP error when the number of concurrent requests exceeds the configured limits.

The following metrics related to concurrency limits are exposed by vmauth:

• vmauth_concurrent_requests_capacity - the global limit on the number of concurrent requests vmauth can serve. It is set via -maxConcurrentRequests command-line flag.
• vmauth_concurrent_requests_current - the current number of concurrent requests vmauth processes.
• vmauth_concurrent_requests_limit_reached_total - the number of requests rejected with 429 Too Many Requests error because of the global concurrency limit has been reached.
• vmauth_user_concurrent_requests_capacity{username="..."} - the limit on the number of concurrent requests for the given username.
• vmauth_user_concurrent_requests_current{username="..."} - the current number of concurrent requests for the given username.
• vmauth_user_concurrent_requests_limit_reached_total{username="foo"} - the number of requests rejected with 429 Too Many Requests error because of the concurrency limit has been reached for the given username.

Auth config

-auth.config is represented in the following simple yml format:

# Arbitrary number of usernames may be put here.
# It is possible to set multiple identical usernames with different passwords.
# Such usernames can be differentiated by `name` option.

users:
  # Requests with the 'Authorization: Bearer XXXX' and 'Authorization: Token XXXX'
  # header are proxied to http://localhost:8428 .
  # For example, http://vmauth:8427/api/v1/query is proxied to http://localhost:8428/api/v1/query
  # Requests with the Basic Auth username=XXXX are proxied to http://localhost:8428 as well.
- bearer_token: "XXXX"
  url_prefix: "http://localhost:8428"

  # Requests with the 'Authorization: Bearer YYY' header are proxied to http://localhost:8428 ,
  # The `X-Scope-OrgID: foobar` http header is added to every proxied request.
  # For example, http://vmauth:8427/api/v1/query is proxied to http://localhost:8428/api/v1/query
- bearer_token: "YYY"
  url_prefix: "http://localhost:8428"
  headers:
  - "X-Scope-OrgID: foobar"

  # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
  # are proxied to http://localhost:8428 .
  # For example, http://vmauth:8427/api/v1/query is proxied to http://localhost:8428/api/v1/query
  #
  # The given user can send maximum 10 concurrent requests according to the provided max_concurrent_requests.
  # Excess concurrent requests are rejected with 429 HTTP status code.
  # See also -maxConcurrentPerUserRequests and -maxConcurrentRequests command-line flags.
- username: "local-single-node"
  password: "***"
  url_prefix: "http://localhost:8428"
  max_concurrent_requests: 10

  # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
  # are proxied to http://localhost:8428 with extra_label=team=dev query arg.
  # For example, http://vmauth:8427/api/v1/query is routed to http://localhost:8428/api/v1/query?extra_label=team=dev
- username: "local-single-node2"
  password: "***"
  url_prefix: "http://localhost:8428?extra_label=team=dev"

  # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
  # are load-balanced among http://vmselect1:8481/select/123/prometheus and http://vmselect2:8481/select/123/prometheus
  # For example, http://vmauth:8427/api/v1/query is proxied to the following urls in a round-robin manner:
  #   - http://vmselect1:8481/select/123/prometheus/api/v1/select
  #   - http://vmselect2:8481/select/123/prometheus/api/v1/select
- username: "cluster-select-account-123"
  password: "***"
  url_prefix:
  - "http://vmselect1:8481/select/123/prometheus"
  - "http://vmselect2:8481/select/123/prometheus"

  # All the requests to http://vmauth:8427 with the given Basic Auth (username:password)
  # are load-balanced between http://vminsert1:8480/insert/42/prometheus and http://vminsert2:8480/insert/42/prometheus
  # For example, http://vmauth:8427/api/v1/write is proxied to the following urls in a round-robin manner:
  #   - http://vminsert1:8480/insert/42/prometheus/api/v1/write
  #   - http://vminsert2:8480/insert/42/prometheus/api/v1/write
- username: "cluster-insert-account-42"
  password: "***"
  url_prefix:
  - "http://vminsert1:8480/insert/42/prometheus"
  - "http://vminsert2:8480/insert/42/prometheus"

  # A single user for querying and inserting data:
  # - Requests to http://vmauth:8427/api/v1/query, http://vmauth:8427/api/v1/query_range
  #   and http://vmauth:8427/api/v1/label/<label_name>/values are proxied to the following urls in a round-robin manner:
  #     - http://vmselect1:8481/select/42/prometheus
  #     - http://vmselect2:8481/select/42/prometheus
  #   For example, http://vmauth:8427/api/v1/query is proxied to http://vmselect1:8480/select/42/prometheus/api/v1/query
  #   or to http://vmselect2:8480/select/42/prometheus/api/v1/query .
  # - Requests to http://vmauth:8427/api/v1/write are proxied to http://vminsert:8480/insert/42/prometheus/api/v1/write .
  #   The "X-Scope-OrgID: abc" http header is added to these requests.
- username: "foobar"
  url_map:
  - src_paths:
    - "/api/v1/query"
    - "/api/v1/query_range"
    - "/api/v1/label/[^/]+/values"
    url_prefix:
    - "http://vmselect1:8481/select/42/prometheus"
    - "http://vmselect2:8481/select/42/prometheus"
  - src_paths: ["/api/v1/write"]
    url_prefix: "http://vminsert:8480/insert/42/prometheus"
    headers:
    - "X-Scope-OrgID: abc"

The config may contain %{ENV_VAR} placeholders, which are substituted by the corresponding ENV_VAR environment variable values. This may be useful for passing secrets to the config.

Security

It is expected that all the backend services protected by vmauth are located in an isolated private network, so they can be accessed by external users only via vmauth.

Do not transfer Basic Auth headers in plaintext over untrusted networks. Enable https. This can be done by passing the following -tls* command-line flags to vmauth:

  -tls
     Whether to enable TLS (aka HTTPS) for incoming requests. -tlsCertFile and -tlsKeyFile must be set if -tls is set
  -tlsCertFile string
     Path to file with TLS certificate. Used only if -tls is set. Prefer ECDSA certs instead of RSA certs, since RSA certs are slow
  -tlsKeyFile string
     Path to file with TLS key. Used only if -tls is set

Alternatively, https termination proxy may be put in front of vmauth.

It is recommended protecting following endpoints with authKeys:

• /-/reload with -reloadAuthKey command-line flag, so external users couldn't trigger config reload.
• /flags with -flagsAuthkey command-line flag, so unauthorized users couldn't get application command-line flags.
• /metrics with metricsAuthkey command-line flag, so unauthorized users couldn't get access to vmauth metrics.
• /debug/pprof with pprofAuthKey command-line flag, so unauthorized users couldn't get access to profiling information.

Monitoring

vmauth exports various metrics in Prometheus exposition format at http://vmauth-host:8427/metrics page. It is recommended setting up regular scraping of this page either via vmagent or via Prometheus, so the exported metrics could be analyzed later.

vmauth exports vmauth_user_requests_total metric with username label. The username label value equals to username field value set in the -auth.config file. It is possible to override or hide the value in the label by specifying name field. For example, the following config will result in vmauth_user_requests_total{username="foobar"} instead of vmauth_user_requests_total{username="secret_user"}:

users:
- username: "secret_user"
  name: "foobar"
  # other config options here

How to build from sources

It is recommended using binary releases - vmauth is located in vmutils-* archives there.

Development build

1. Install Go. The minimum supported version is Go 1.19.
2. Run make vmauth from the root folder of the repository. It builds vmauth binary and puts it into the bin folder.

Production build

1. Install docker.
2. Run make vmauth-prod from the root folder of the repository. It builds vmauth-prod binary and puts it into the bin folder.

Building docker images

Run make package-vmauth. It builds victoriametrics/vmauth:<PKG_TAG> docker image locally. <PKG_TAG> is auto-generated image tag, which depends on source code in the repository. The <PKG_TAG> may be manually set via PKG_TAG=foobar make package-vmauth.

The base docker image is alpine but it is possible to use any other base image by setting it via <ROOT_IMAGE> environment variable. For example, the following command builds the image on top of scratch image:

ROOT_IMAGE=scratch make package-vmauth

Profiling

vmauth provides handlers for collecting the following Go profiles:

• Memory profile. It can be collected with the following command (replace 0.0.0.0 with hostname if needed):

curl http://0.0.0.0:8427/debug/pprof/heap > mem.pprof

• CPU profile. It can be collected with the following command (replace 0.0.0.0 with hostname if needed):

curl http://0.0.0.0:8427/debug/pprof/profile > cpu.pprof

The command for collecting CPU profile waits for 30 seconds before returning.

The collected profiles may be analyzed with go tool pprof. It is safe sharing the collected profiles from security point of view, since they do not contain sensitive information.

Advanced usage

Pass -help command-line arg to vmauth in order to see all the configuration options:

./vmauth -help

vmauth authenticates and authorizes incoming requests and proxies them to VictoriaMetrics.

See the docs at https://docs.victoriametrics.com/vmauth.html .

  -auth.config string
     Path to auth config. It can point either to local file or to http url. See https://docs.victoriametrics.com/vmauth.html for details on the format of this auth config
  -configCheckInterval duration
     Interval for config file re-read. Zero value disables config re-reading. By default, refreshing is disabled, send SIGHUP for config refresh.
  -enableTCP6
     Whether to enable IPv6 for listening and dialing. By default only IPv4 TCP and UDP is used
  -envflag.enable
     Whether to enable reading flags from environment variables additionally to command line. Command line flag values have priority over values from environment vars. Flags are read only from command line if this flag isn't set. See https://docs.victoriametrics.com/#environment-variables for more details
  -envflag.prefix string
     Prefix for environment variables if -envflag.enable is set
  -eula
     By specifying this flag, you confirm that you have an enterprise license and accept the EULA https://victoriametrics.com/assets/VM_EULA.pdf . This flag is available only in VictoriaMetrics enterprise. See https://docs.victoriametrics.com/enterprise.html
  -flagsAuthKey string
     Auth key for /flags endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -fs.disableMmap
     Whether to use pread() instead of mmap() for reading data files. By default mmap() is used for 64-bit arches and pread() is used for 32-bit arches, since they cannot read data files bigger than 2^32 bytes in memory. mmap() is usually faster for reading small data chunks than pread()
  -http.connTimeout duration
     Incoming http connections are closed after the configured timeout. This may help to spread the incoming load among a cluster of services behind a load balancer. Please note that the real timeout may be bigger by up to 10% as a protection against the thundering herd problem (default 2m0s)
  -http.disableResponseCompression
     Disable compression of HTTP responses to save CPU resources. By default compression is enabled to save network bandwidth
  -http.idleConnTimeout duration
     Timeout for incoming idle http connections (default 1m0s)
  -http.maxGracefulShutdownDuration duration
     The maximum duration for a graceful shutdown of the HTTP server. A highly loaded server may require increased value for a graceful shutdown (default 7s)
  -http.pathPrefix string
     An optional prefix to add to all the paths handled by http server. For example, if '-http.pathPrefix=/foo/bar' is set, then all the http requests will be handled on '/foo/bar/*' paths. This may be useful for proxied requests. See https://www.robustperception.io/using-external-urls-and-proxies-with-prometheus
  -http.shutdownDelay duration
     Optional delay before http server shutdown. During this delay, the server returns non-OK responses from /health page, so load balancers can route new requests to other servers
  -httpAuth.password string
     Password for HTTP Basic Auth. The authentication is disabled if -httpAuth.username is empty
  -httpAuth.username string
     Username for HTTP Basic Auth. The authentication is disabled if empty. See also -httpAuth.password
  -httpListenAddr string
     TCP address to listen for http connections. See also -httpListenAddr.useProxyProtocol (default ":8427")
  -httpListenAddr.useProxyProtocol
     Whether to use proxy protocol for connections accepted at -httpListenAddr . See https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
  -internStringMaxLen int
     The maximum length for strings to intern. Lower limit may save memory at the cost of higher CPU usage. See https://en.wikipedia.org/wiki/String_interning (default 500)
  -logInvalidAuthTokens
     Whether to log requests with invalid auth tokens. Such requests are always counted at vmauth_http_request_errors_total{reason="invalid_auth_token"} metric, which is exposed at /metrics page
  -loggerDisableTimestamps
     Whether to disable writing timestamps in logs
  -loggerErrorsPerSecondLimit int
     Per-second limit on the number of ERROR messages. If more than the given number of errors are emitted per second, the remaining errors are suppressed. Zero values disable the rate limit
  -loggerFormat string
     Format for logs. Possible values: default, json (default "default")
  -loggerJSONFields string
     Allows renaming fields in JSON formatted logs. Example: "ts:timestamp,msg:message" renames "ts" to "timestamp" and "msg" to "message". Supported fields: ts, level, caller, msg
  -loggerLevel string
     Minimum level of errors to log. Possible values: INFO, WARN, ERROR, FATAL, PANIC (default "INFO")
  -loggerOutput string
     Output for the logs. Supported values: stderr, stdout (default "stderr")
  -loggerTimezone string
     Timezone to use for timestamps in logs. Timezone must be a valid IANA Time Zone. For example: America/New_York, Europe/Berlin, Etc/GMT+3 or Local (default "UTC")
  -loggerWarnsPerSecondLimit int
     Per-second limit on the number of WARN messages. If more than the given number of warns are emitted per second, then the remaining warns are suppressed. Zero values disable the rate limit
  -maxConcurrentPerUserRequests int
     The maximum number of concurrent requests vmauth can process per each configured user. Other requests are rejected with '429 Too Many Requests' http status code. See also -maxConcurrentRequests command-line option and max_concurrent_requests option in per-user config (default 300)
  -maxConcurrentRequests int
     The maximum number of concurrent requests vmauth can process. Other requests are rejected with '429 Too Many Requests' http status code. See also -maxConcurrentPerUserRequests and -maxIdleConnsPerBackend command-line options (default 1000)
  -maxIdleConnsPerBackend int
     The maximum number of idle connections vmauth can open per each backend host. See also -maxConcurrentRequests (default 100)
  -memory.allowedBytes size
     Allowed size of system memory VictoriaMetrics caches may occupy. This option overrides -memory.allowedPercent if set to a non-zero value. Too low a value may increase the cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache resulting in higher disk IO usage
     Supports the following optional suffixes for size values: KB, MB, GB, TB, KiB, MiB, GiB, TiB (default 0)
  -memory.allowedPercent float
     Allowed percent of system memory VictoriaMetrics caches may occupy. See also -memory.allowedBytes. Too low a value may increase cache miss rate usually resulting in higher CPU and disk IO usage. Too high a value may evict too much data from OS page cache which will result in higher disk IO usage (default 60)
  -metricsAuthKey string
     Auth key for /metrics endpoint. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -pprofAuthKey string
     Auth key for /debug/pprof/* endpoints. It must be passed via authKey query arg. It overrides httpAuth.* settings
  -pushmetrics.extraLabel array
     Optional labels to add to metrics pushed to -pushmetrics.url . For example, -pushmetrics.extraLabel='instance="foo"' adds instance="foo" label to all the metrics pushed to -pushmetrics.url
     Supports an array of values separated by comma or specified via multiple flags.
  -pushmetrics.interval duration
     Interval for pushing metrics to -pushmetrics.url (default 10s)
  -pushmetrics.url array
     Optional URL to push metrics exposed at /metrics page. See https://docs.victoriametrics.com/#push-metrics . By default metrics exposed at /metrics page aren't pushed to any remote storage
     Supports an array of values separated by comma or specified via multiple flags.
  -reloadAuthKey string
     Auth key for /-/reload http endpoint. It must be passed as authKey=...
  -responseTimeout duration
     The timeout for receiving a response from backend (default 5m0s)
  -tls
     Whether to enable TLS for incoming HTTP requests at -httpListenAddr (aka https). -tlsCertFile and -tlsKeyFile must be set if -tls is set
  -tlsCertFile string
     Path to file with TLS certificate if -tls is set. Prefer ECDSA certs instead of RSA certs as RSA certs are slower. The provided certificate file is automatically re-read every second, so it can be dynamically updated
  -tlsCipherSuites array
     Optional list of TLS cipher suites for incoming requests over HTTPS if -tls is set. See the list of supported cipher suites at https://pkg.go.dev/crypto/tls#pkg-constants
     Supports an array of values separated by comma or specified via multiple flags.
  -tlsKeyFile string
     Path to file with TLS key if -tls is set. The provided key file is automatically re-read every second, so it can be dynamically updated
  -tlsMinVersion string
     Optional minimum TLS version to use for incoming requests over HTTPS if -tls is set. Supported values: TLS10, TLS11, TLS12, TLS13
  -version
     Show VictoriaMetrics version