mirror of https://github.com/hashicorp/consul
80 lines
4.3 KiB
Markdown
80 lines
4.3 KiB
Markdown
#### Common CA Config Options
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The following configuration options are supported by all CA providers:
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- `CSRMaxConcurrent` / `csr_max_concurrent` (`int: 0`) - Sets a limit on the
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number of Certificate Signing Requests that can be processed concurrently. Defaults
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to 0 (disabled). This is useful when you want to limit the number of CPU cores
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available to the server for certificate signing operations. For example, on an
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8 core server, setting this to 1 will ensure that no more than one CPU core
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will be consumed when generating or rotating certificates. Setting this is
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recommended **instead** of `csr_max_per_second` when you want to limit the
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number of cores consumed since it is simpler to reason about limiting CSR
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resources this way without artificially slowing down rotations. Added in 1.4.1.
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- `CSRMaxPerSecond` / `csr_max_per_second` (`float: 50`) - Sets a rate limit
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on the maximum number of Certificate Signing Requests (CSRs) the servers will
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accept. This is used to prevent CA rotation from causing unbounded CPU usage
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on servers. It defaults to 50 which is conservative – a 2017 MacBook can process
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about 100 per second using only ~40% of one CPU core – but sufficient for deployments
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up to ~1500 service instances before the time it takes to rotate is impacted.
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For larger deployments we recommend increasing this based on the expected number
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of server instances and server resources, or use `csr_max_concurrent` instead
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if servers have more than one CPU core. Setting this to zero disables rate limiting.
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Added in 1.4.1.
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- `LeafCertTTL` / `leaf_cert_ttl` (`duration: "72h"`) - The upper bound on the lease
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duration of a leaf certificate issued for a service. In most cases a new leaf
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certificate will be requested by a proxy before this limit is reached. This
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is also the effective limit on how long a server outage can last (with no leader)
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before network connections will start being rejected. Defaults to `72h`. This
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value cannot be lower than 1 hour or higher than 1 year.
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This value is also used when rotating out old root certificates from
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the cluster. When a root certificate has been inactive (rotated out)
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for more than twice the _current_ `leaf_cert_ttl`, it will be removed
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from the trusted list.
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- `RootCertTTL` / `root_cert_ttl` (`duration: "87600h"`) The time to live (TTL) for a root certificate.
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Defaults to 10 years as `87600h`. This value, if provided, needs to be higher than the
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intermediate certificate TTL.
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This setting applies to all Consul CA providers.
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For the Vault provider, this value is only used if the backend is not initialized at first.
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- `PrivateKeyType` / `private_key_type` (`string: "ec"`) - The type of key to generate
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for this CA. This is only used when the provider is generating a new key. If
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`private_key` is set for the Consul provider, or existing root or intermediate
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PKI paths given for Vault then this will be ignored. Currently supported options
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are `ec` or `rsa`. Default is `ec`.
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It is required that all servers in a datacenter have
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the same config for the CA. It is recommended that servers in
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different datacenters use the same key type and size, although the built-in CA
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and Vault provider will both allow mixed CA key types.
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Some CA providers (currently Vault) will not allow cross-signing a
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new CA certificate with a different key type. This means that if you
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migrate from an RSA-keyed Vault CA to an EC-keyed CA from any
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provider, you may have to proceed without cross-signing which risks
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temporary connection issues for workloads during the new certificate
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rollout. We highly recommend testing this outside of production to
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understand the impact, and suggest sticking to same key type where
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possible.
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-> **Note**: This only affects _CA_ keys generated by the provider.
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Leaf certificate keys are always EC 256 regardless of the CA
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configuration.
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- `PrivateKeyBits` / `private_key_bits` (`string: ""`) - The length of key to
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generate for this CA. This is only used when the provider is generating a new
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key. If `private_key` is set for the Consul provider, or existing root or intermediate
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PKI paths given for Vault then this will be ignored.
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Currently supported values are:
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- `private_key_type = ec` (default): `224, 256, 384, 521`
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corresponding to the NIST P-\* curves of the same name.
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- `private_key_type = rsa`: `2048, 4096`
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