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NixOS module options

services.sandhole.enable

Whether to enable Sandhole, a reverse proxy that lets you expose HTTP/SSH/TCP services through SSH port forwarding.

Type: boolean

Default: false

Example: true

services.sandhole.package

The sandhole package to use.

Type: package

Default: pkgs.sandhole

services.sandhole.openFirewall

Whether to automatically open the necessary ports in the firewall.

Warning: If this option is true and services.sandhole.settings.disableTcp is false (by default), all unprivileged ports (i.e. >= 1024) will be opened.

Type: boolean

Default: false

Example: true

services.sandhole.settings.acmeCacheDirectory

Directory to use as a cache for Let’s Encrypt’s account and certificates. This will automatically be created for you.

Note that this setting ignores the disableDirectoryCreation flag.

Type: absolute path

Default: "/var/lib/sandhole/acme_cache"

Example: ./deploy/acme_cache/

services.sandhole.settings.acmeContactEmail

Contact e-mail to use with Let’s Encrypt. If set, enables ACME for HTTPS certificates.

By providing your e-mail, you agree to the Let’s Encrypt Subscriber Agreement.

Type: null or string

Default: null

Example: "your-email@domain.com"

services.sandhole.settings.acmeUseStaging

Controls whether to use the staging directory for Let’s Encrypt certificates (default is production). Only set this option for testing.

Type: boolean

Default: false

Example: true

services.sandhole.settings.adminKeysDirectory

Directory containing public keys of admin users. Each file must contain at least one key.

Type: absolute path

Default: "/var/lib/sandhole/admin_keys"

Example: ./deploy/admin_keys/

services.sandhole.settings.allowRequestedPorts

Allow user-requested subdomains. By default, subdomains are always random.

Type: boolean

Default: false

Example: true

services.sandhole.settings.allowRequestedSubdomains

Allow user-requested subdomains. By default, subdomains are always random.

Type: boolean

Default: false

Example: true

services.sandhole.settings.authenticationRequestTimeout

Time until a user+password authentication request is canceled. Any timed out requests will not authenticate the user.

Type: null or string

Default: null

Example: "5s"

services.sandhole.settings.bindHostnames

Policy on whether to allow binding specific hostnames.

Beware that this can lead to domain takeovers if misused!

Possible values:

  • all: Allow any hostnames unconditionally, including the main domain.
  • cname: Allow any hostnames with a CNAME record pointing to the main domain.
  • txt (default): Allow any hostnames with a TXT record containing a fingerprint, including the main domain.
  • none: Don’t allow user-provided hostnames, enforce subdomains.

Type: null or one of “all”, “cname”, “txt”, “none”

Default: null

Example: "txt"

services.sandhole.settings.bufferSize

Size to use for bidirectional buffers, in bytes.

A higher value will lead to higher memory consumption.

Type: null or string

Default: null

Example: "32768B"

services.sandhole.settings.certificatesDirectory

Directory containing SSL certificates and keys. Each sub-directory inside of this one must contain a certificate chain in a fullchain.pem file and its private key in a privkey.pem file.

Type: absolute path

Default: "/var/lib/sandhole/certificates"

Example: ./deploy/certificates/

services.sandhole.settings.connectSshOnHttpsPort

Allow connecting to SSH via the HTTPS port as well. This can be useful in networks that block binding to other ports.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableAliasing

Disable all aliasing (i.e. local forwarding). By default, this is enabled globally.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableDirectoryCreation

If set, disables automatic creation of the directories expected by the application. This may result in application errors if the directories are missing.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableHttp

Disable all HTTP tunneling. By default, this is enabled globally.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableHttpLogs

Disable sending HTTP logs to clients.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableHttps

Disable all HTTPS tunneling. By default, this is enabled globally.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disablePrometheus

Disable the admin-only alias for the Prometheus exporter. By default, it is enabled.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableSni

Disable SNI proxy tunneling. By default, this is enabled globally.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableTcp

Disable all TCP port tunneling except HTTP. By default, this is enabled globally.

Type: boolean

Default: false

Example: true

services.sandhole.settings.disableTcpLogs

Disable sending TCP/proxy logs to clients.

Type: boolean

Default: false

Example: true

services.sandhole.settings.domain

The root domain of the application.

Type: string

Example: "sandhole.com.br"

services.sandhole.settings.domainRedirect

Where to redirect requests to the root domain.

Type: null or string

Default: null

Example: "https://github.com/EpicEric/sandhole"

services.sandhole.settings.forceHttps

Always redirect HTTP requests to HTTPS.

Type: boolean

Default: false

Example: true

services.sandhole.settings.httpPort

Port to listen for HTTP connections.

Type: null or 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Default: null

Example: 80

services.sandhole.settings.httpRequestTimeout

Time until an outgoing HTTP request is automatically canceled.

By default, outgoing requests are not terminated by Sandhole.

Type: null or string

Default: null

Example: "60s"

services.sandhole.settings.httpsPort

Port to listen for HTTPS connections.

Type: null or 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Default: null

Example: 443

services.sandhole.settings.idleConnectionTimeout

Grace period for dangling/unauthenticated connections before they are forcefully disconnected…

A low value may cause valid connections to be erroneously removed.

Type: null or string

Default: null

Example: "2s"

services.sandhole.settings.ipAllowlist

List of IP networks to allow. Setting this will block unknown IPs from connecting.

Type: list of string

Default: [ ]

Example:

[
  "192.168.0.1"
  "2001:db1::/32"
]

services.sandhole.settings.ipBlocklist

List of IP networks to block. Setting this will allow unspecified IPs to connect, unless ipAllowlist is set.

Type: list of string

Default: [ ]

Example:

[
  "192.168.0.1"
  "2001:db1::/32"
]

services.sandhole.settings.listenAddress

Address to listen for all client connections.

Type: null or string

Default: null

Example: "::"

services.sandhole.settings.loadBalancing

Strategy for load-balancing when multiple services request the same hostname/port.

By default, traffic towards matching hostnames/ports will be load-balanced.

Possible values:

  • allow (default): Load-balance with all available handlers.
  • replace: Don’t load-balance; When adding a new handler, replace the existing one.
  • deny: Don’t load-balance; Deny the new handler if there’s an existing one.

Type: null or one of “allow”, “replace”, “deny”

Default: null

Example: "allow"

services.sandhole.settings.loadBalancingAlgorithm

Algorithm to use for service selection when load-balancing.

By default, traffic will be randomly distributed between services.

Possible values:

  • random (default): Choose randomly.
  • round-robin: Round robin.
  • ip-hash: Choose based on IP hash.

Type: null or one of “random”, “round-robin”, “ip-hash”

Default: null

Example: "random"

services.sandhole.settings.passwordAuthenticationUrl

If set, defines a URL which password authentication requests will be validated against. This is done by sending the following JSON payload via a POST request:

{"user": "...", "password": "...", "remote_address": "..."}

Any 2xx response indicates that the credentials are authorized.

Type: null or string

Default: null

Example: "https://login-service.com/authenticate"

services.sandhole.settings.privateKeyFile

File path to the server’s secret key. If missing, it will be created for you.

Type: absolute path

Default: "/var/lib/sandhole/server_keys/ssh"

Example: ./deploy/server_keys/ssh

services.sandhole.settings.quotaPerUser

How many services can be exposed for a single user at once. Doesn’t apply to admin users.

Each user is distinguished by their key fingerprint or, in the case of API logins, by their username.

By default, no limit is set.

Type: null or (positive integer, meaning >0)

Default: null

Example: 2

services.sandhole.settings.randomSubdomainFilterProfanities

Prevents random subdomains from containing profanities.

Type: boolean

Default: false

Example: true

services.sandhole.settings.randomSubdomainLength

The length of the string appended to the start of random subdomains.

Type: null or (positive integer, meaning >0)

Default: null

Example: 6

services.sandhole.settings.randomSubdomainSeed

Which value to seed with when generating random subdomains, for determinism. This allows binding to the same random address until Sandhole is restarted.

Beware that this can lead to collisions if misused!

If unset, defaults to a random seed.

Possible values:

  • ip-and-user: From IP address, SSH user, and requested address. Recommended if unsure.
  • user: From SSH user and requested address.
  • fingerprint: From SSH user, key fingerprint, and requested address.
  • address: From SSH connection socket (address + port) and requested address.

Type: null or one of “ip-and-user”, “user”, “fingerprint”, “address”

Default: null

Example: "ip-and-user"

services.sandhole.settings.randomSubdomainValue

Set a value for random subdomains for use in conjunction with randomSubdomainSeed to allow binding to the same random address between Sandhole restarts.

Beware that this can lead to collisions if misused!

If unset, defaults to a random value.

Type: null or (positive integer, meaning >0)

Default: null

Example: 42

services.sandhole.settings.rateLimitPerUser

How many bytes per second a single user’s services can transmit at once. Doesn’t apply to admin users.

Each user is distinguished by their key fingerprint or, in the case of API logins, by their username.

By default, no rate limit is set. For better results, this should be a multiple of bufferSize.

Type: null or (positive integer, meaning >0)

Default: null

Example: 10000000

services.sandhole.settings.requestedDomainFilterProfanities

Prevents user-requested domains from containing profanities.

Beware that this can lead to false positives being blocked!

Type: boolean

Default: false

Example: true

services.sandhole.settings.requestedSubdomainFilterProfanities

Prevents user-requested subdomains from containing profanities.

Beware that this can lead to false positives being blocked!

Type: boolean

Default: false

Example: true

services.sandhole.settings.sshKeepaliveInterval

How long to wait between each keepalive message that is sent to an unresponsive SSH connection.

Type: null or string

Default: null

Example: "15s"

services.sandhole.settings.sshKeepaliveMax

How many keepalive messages are sent to an unresponsive SSH connection before it is dropped.

A value of zero disables timeouts.

The timeout is equal to this value plus one, times sshKeepaliveInterval.

Type: null or (unsigned integer, meaning >=0)

Default: null

Example: 3

services.sandhole.settings.sshPort

Port to listen for SSH connections.

Type: null or 16 bit unsigned integer; between 0 and 65535 (both inclusive)

Default: null

Example: 2222

services.sandhole.settings.tcpConnectionTimeout

How long until TCP connections (including Websockets and local forwardings) are automatically garbage-collected.

By default, these connections are not terminated by Sandhole.

Type: null or string

Default: null

Example: "60s"

services.sandhole.settings.txtRecordPrefix

Prefix for TXT DNS records containing key fingerprints, for authorization to bind under a specific domain.

In other words, valid records will be of the form:

TXT <PREFIX>.<DOMAIN> SHA256:...

Type: null or string

Default: null

Example: "_sandhole"

services.sandhole.settings.unproxiedConnectionTimeout

Grace period for unauthenticated SSH connections after closing the last proxy tunnel before they are forcefully disconnected.

A low value may cause valid proxy/tunnel connections to be erroneously removed.

If unset, this defaults to the value set by idleConnectionTimeout.

Type: null or string

Default: null

Example: "2s"

services.sandhole.settings.userKeysDirectory

Directory containing public keys of authorized users. Each file must contain at least one key.

Type: absolute path

Default: "/var/lib/sandhole/user_keys"

Example: ./deploy/user_keys/