juanfont/headscale · error

cannot use autogroup:danger-all as a dst

Error message

cannot use autogroup:danger-all as a dst

What it means

Returned by validateAutogroupForDst (hscontrol/policy/v2/types.go:2058) when autogroup:danger-all appears on the destination side of an ACL rule. danger-all matches every possible source (a deliberate footgun allowed only on src, mirroring Tailscale); allowing it as a dst would grant the entire universe access to internal services, so it is hard-rejected.

Source

Thrown at hscontrol/policy/v2/types.go:139

	ErrInvalidAutoApprover         = errors.New("invalid auto approver format")
	ErrInvalidOwner                = errors.New("invalid owner format")
	ErrGroupNotDefined             = errors.New("group not defined in policy")
	ErrInvalidGroupMember          = errors.New("invalid group member type")
	ErrGroupValueNotArray          = errors.New("group value must be an array of users")
	ErrInvalidHostIP               = errors.New("hostname contains invalid IP address")
	ErrTagNotDefined               = errors.New("tag not found")
	ErrAutoApproverNotAlias        = errors.New("auto approver is not an alias")
	ErrInvalidACLAction            = errors.New("invalid ACL action")
	ErrInvalidSSHAction            = errors.New("invalid SSH action")
	ErrInvalidProtocolNumber       = errors.New("invalid protocol number")
	ErrProtocolLeadingZero         = errors.New("leading 0 not permitted in protocol number")
	ErrProtocolOutOfRange          = errors.New("protocol number out of range (0-255)")
	ErrAutogroupNotSupported       = errors.New("autogroup not supported in headscale")
	ErrAutogroupInternetSrc        = errors.New("autogroup:internet can only be used in ACL destinations")
	ErrAutogroupSelfSrc            = errors.New("\"autogroup:self\" not valid on the src side of a rule")
	ErrAutogroupNotSupportedACLSrc = errors.New("autogroup not supported for ACL sources")
	ErrAutogroupNotSupportedACLDst = errors.New("autogroup not supported for ACL destinations")
	ErrAutogroupDangerAllDst       = errors.New("cannot use autogroup:danger-all as a dst")
	ErrAutogroupNotSupportedSSHSrc = errors.New("autogroup not supported for SSH sources")
	ErrAutogroupNotSupportedSSHDst = errors.New("autogroup not supported for SSH destinations")
	ErrHostNotDefined              = errors.New("host not defined in policy")
	ErrSSHSourceAliasNotSupported  = errors.New("alias not supported for SSH source")
	ErrSSHDestAliasNotSupported    = errors.New("alias not supported for SSH destination")
	ErrUnknownField                = errors.New("unknown field")
	ErrProtocolNoSpecificPorts     = errors.New("protocol does not support specific ports")
	ErrTestEmptyAssertions         = errors.New("test entry must have at least one of \"accept\" or \"deny\"")
	ErrTestProtocolNotAllowed      = errors.New("test protocol must be tcp, udp, sctp, or empty")
	ErrTestDestinationMultiPort    = errors.New("test destination port must be a single port")
	ErrTestDestinationCIDR         = errors.New("test destination must be a single host, not a CIDR range")
	ErrAutogroupInternetTestDst    = errors.New("autogroup:internet not valid as a test destination")
	ErrSSHTestEmptySrc             = errors.New("SSH tests entry must have a non-empty src")
	ErrSSHTestEmptyDst             = errors.New("SSH tests entry must have at least one dst")
	ErrSSHTestDstUnknownTag        = errors.New("SSH tests dst contains unknown tag")
	ErrSSHTestDstDisallowedElement = errors.New("SSH tests dst contains disallowed element")
)

View on GitHub (pinned to 565fd254d0)

Solutions

  1. Remove autogroup:danger-all from dst; if you truly want allow-all in a lab, use "*:*" as the dst with an explicit src
  2. Keep autogroup:danger-all (if at all) only on the src side
  3. Prefer explicit groups/tags to avoid unintended exposure

Example fix

// before
{"action": "accept", "src": ["autogroup:member"], "dst": ["autogroup:danger-all:*"]}

// after (lab-only allow-all)
{"action": "accept", "src": ["autogroup:member"], "dst": ["*:*"]}
Defensive patterns

Strategy: validation

Validate before calling

for _, d := range acl.Dst {
	if strings.HasPrefix(d.Alias, "autogroup:danger-all") {
		return errors.New("autogroup:danger-all cannot be a dst")
	}
}

Type guard

func isAutogroupDangerAllDst(err error) bool {
	return errors.Is(err, policy.ErrAutogroupDangerAllDst)
}

Try / catch

if err := p.Validate(); err != nil {
	if errors.Is(err, policy.ErrAutogroupDangerAllDst) {
		return fmt.Errorf("danger-all is src-only; use *:port or explicit targets as dst: %w", err)
	}
	return err
}

Prevention

When it happens

Trigger: Policy with "acls": [{"action": "accept", "src": ["autogroup:member"], "dst": ["autogroup:danger-all:*"]}] or any dst alias spelling of autogroup:danger-all.

Common situations: Attempt to write 'everyone can reach everything' — sometimes done in lab tailnets. Also from templating that injects danger-all into both sides of generated rules.

Related errors

AI-assisted analysis of juanfont/headscale@565fd254d0 (2026-08-15). Data as JSON: /api/errors/76dd83f9bbee6f98. Report an issue: GitHub.