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Docs: ACME Overhaul

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Jonas Thelemann 2018-06-05 10:36:03 +02:00 committed by Traefiker Bot
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docs/configuration/acme.md
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@ -1,6 +1,6 @@
# ACME (Let's Encrypt) configuration
# ACME (Let's Encrypt) Configuration
See also [Let's Encrypt examples](/user-guide/examples/#lets-encrypt-support) and [Docker & Let's Encrypt user guide](/user-guide/docker-and-lets-encrypt).
See [Let's Encrypt examples](/user-guide/examples/#lets-encrypt-support) and [Docker & Let's Encrypt user guide](/user-guide/docker-and-lets-encrypt) as well.
## Configuration
@ -63,14 +63,14 @@ entryPoint = "https"
#
# acmeLogging = true
# Enable on demand certificate generation.
# Deprecated. Enable on demand certificate generation.
#
# Optional (Deprecated)
# Optional
# Default: false
#
# onDemand = true
# Enable certificate generation on frontends Host rules.
# Enable certificate generation on frontends host rules.
#
# Optional
# Default: false
@ -78,8 +78,8 @@ entryPoint = "https"
# onHostRule = true
# CA server to use.
# - Uncomment the line to run on the staging let's encrypt server.
# - Leave comment to go to prod.
# Uncomment the line to use Let's Encrypt's staging server,
# leave commented to go to prod.
#
# Optional
# Default: "https://acme-v02.api.letsencrypt.org/directory"
@ -94,15 +94,13 @@ entryPoint = "https"
# sans = ["test1.local1.com", "test2.local1.com"]
# [[acme.domains]]
# main = "local2.com"
# sans = ["test1.local2.com", "test2.local2.com"]
# [[acme.domains]]
# main = "local3.com"
# [[acme.domains]]
# main = "local4.com"
# main = "*.local3.com"
# sans = ["local3.com", "test1.test1.local3.com"]
# Use a HTTP-01 acme challenge.
# Use a HTTP-01 ACME challenge.
#
# Optional but recommend
# Optional (but recommended)
#
[acme.httpChallenge]
@ -112,21 +110,21 @@ entryPoint = "https"
#
entryPoint = "http"
# Use a DNS-01/DNS-01 acme challenge rather than HTTP-01 challenge.
# Note : Mandatory for wildcard certificates generation.
# Use a DNS-01 ACME challenge rather than HTTP-01 challenge.
# Note: mandatory for wildcard certificate generation.
#
# Optional
#
# [acme.dnsChallenge]
# Provider used.
# DNS provider used.
#
# Required
#
# provider = "digitalocean"
# By default, the provider will verify the TXT DNS challenge record before letting ACME verify.
# If delayBeforeCheck is greater than zero, avoid this & instead just wait so many seconds.
# If delayBeforeCheck is greater than zero, this check is delayed for the configured duration in seconds.
# Useful if internal networks block external DNS queries.
#
# Optional
@ -135,97 +133,134 @@ entryPoint = "https"
# delayBeforeCheck = 0
```
!!! note
If `HTTP-01` challenge is used, `acme.httpChallenge.entryPoint` has to be defined and reachable by Let's Encrypt through the port 80.
These are Let's Encrypt limitations as described on the [community forum](https://community.letsencrypt.org/t/support-for-ports-other-than-80-and-443/3419/72).
### `caServer`
!!! note
Wildcard certificates can only be generated if the `acme.dnsChallenge` option is enabled.
The CA server to use.
### Let's Encrypt downtime
Let's Encrypt functionality will be limited until Træfik is restarted.
If Let's Encrypt is not reachable, these certificates will be used :
- ACME certificates already generated before downtime
- Expired ACME certificates
- Provided certificates
!!! note
Default Træfik certificate will be used instead of ACME certificates for new (sub)domains (which need Let's Encrypt challenge).
### `storage`
This example shows the usage of Let's Encrypt's staging server:
```toml
[acme]
# ...
storage = "acme.json"
caServer = "https://acme-staging-v02.api.letsencrypt.org/directory"
# ...
```
The `storage` option sets where are stored your ACME certificates.
### `dnsChallenge`
There are two kind of `storage` :
Use the `DNS-01` challenge to generate and renew ACME certificates by provisioning a DNS record.
- a JSON file,
- a KV store entry.
```toml
[acme]
# ...
[acme.dnsChallenge]
provider = "digitalocean"
delayBeforeCheck = 0
# ...
```
!!! danger "DEPRECATED"
`storage` replaces `storageFile` which is deprecated.
#### `delayBeforeCheck`
By default, the `provider` will verify the TXT DNS challenge record before letting ACME verify.
If `delayBeforeCheck` is greater than zero, this check is delayed for the configured duration in seconds.
Useful if internal networks block external DNS queries.
!!! note
During Træfik configuration migration from a configuration file to a KV store (thanks to `storeconfig` subcommand as described [here](/user-guide/kv-config/#store-configuration-in-key-value-store)), if ACME certificates have to be migrated too, use both `storageFile` and `storage`.
A `provider` is mandatory.
- `storageFile` will contain the path to the `acme.json` file to migrate.
- `storage` will contain the key where the certificates will be stored.
#### `provider`
#### Store data in a file
Here is a list of supported `provider`s, that can automate the DNS verification, along with the required environment variables and their [wildcard & root domain support](/configuration/acme/#wildcard-domains) for each. Do not hesitate to complete it.
ACME certificates can be stored in a JSON file which with the `600` right mode.
| Provider Name | Provider Code | Environment Variables | Wildcard & Root Domain Support |
|--------------------------------------------------------|----------------|-----------------------------------------------------------------------------------------------------------------------------|--------------------------------|
| [Auroradns](https://www.pcextreme.com/aurora/dns) | `auroradns` | `AURORA_USER_ID`, `AURORA_KEY`, `AURORA_ENDPOINT` | Not tested yet |
| [Azure](https://azure.microsoft.com/services/dns/) | `azure` | `AZURE_CLIENT_ID`, `AZURE_CLIENT_SECRET`, `AZURE_SUBSCRIPTION_ID`, `AZURE_TENANT_ID`, `AZURE_RESOURCE_GROUP` | Not tested yet |
| [Blue Cat](https://www.bluecatnetworks.com/) | `bluecat` | `BLUECAT_SERVER_URL`, `BLUECAT_USER_NAME`, `BLUECAT_PASSWORD`, `BLUECAT_CONFIG_NAME`, `BLUECAT_DNS_VIEW` | Not tested yet |
| [Cloudflare](https://www.cloudflare.com) | `cloudflare` | `CLOUDFLARE_EMAIL`, `CLOUDFLARE_API_KEY` - The `Global API Key` needs to be used, not the `Origin CA Key` | YES |
| [CloudXNS](https://www.cloudxns.net) | `cloudxns` | `CLOUDXNS_API_KEY`, `CLOUDXNS_SECRET_KEY` | Not tested yet |
| [DigitalOcean](https://www.digitalocean.com) | `digitalocean` | `DO_AUTH_TOKEN` | YES |
| [DNSimple](https://dnsimple.com) | `dnsimple` | `DNSIMPLE_OAUTH_TOKEN`, `DNSIMPLE_BASE_URL` | Not tested yet |
| [DNS Made Easy](https://dnsmadeeasy.com) | `dnsmadeeasy` | `DNSMADEEASY_API_KEY`, `DNSMADEEASY_API_SECRET`, `DNSMADEEASY_SANDBOX` | Not tested yet |
| [DNSPod](http://www.dnspod.net/) | `dnspod` | `DNSPOD_API_KEY` | Not tested yet |
| [Duck DNS](https://www.duckdns.org/) | `duckdns` | `DUCKDNS_TOKEN` | Not tested yet |
| [Dyn](https://dyn.com) | `dyn` | `DYN_CUSTOMER_NAME`, `DYN_USER_NAME`, `DYN_PASSWORD` | Not tested yet |
| External Program | `exec` | `EXEC_PATH` | Not tested yet |
| [Exoscale](https://www.exoscale.ch) | `exoscale` | `EXOSCALE_API_KEY`, `EXOSCALE_API_SECRET`, `EXOSCALE_ENDPOINT` | Not tested yet |
| [Fast DNS](https://www.akamai.com/) | `fastdns` | `AKAMAI_CLIENT_TOKEN`, `AKAMAI_CLIENT_SECRET`, `AKAMAI_ACCESS_TOKEN` | Not tested yet |
| [Gandi](https://www.gandi.net) | `gandi` | `GANDI_API_KEY` | Not tested yet |
| [Gandi V5](http://doc.livedns.gandi.net) | `gandiv5` | `GANDIV5_API_KEY` | Not tested yet |
| [Glesys](https://glesys.com/) | `glesys` | `GLESYS_API_USER`, `GLESYS_API_KEY`, `GLESYS_DOMAIN` | Not tested yet |
| [GoDaddy](https://godaddy.com/domains) | `godaddy` | `GODADDY_API_KEY`, `GODADDY_API_SECRET` | Not tested yet |
| [Google Cloud DNS](https://cloud.google.com/dns/docs/) | `gcloud` | `GCE_PROJECT`, `GCE_SERVICE_ACCOUNT_FILE` | YES |
| [Lightsail](https://aws.amazon.com/lightsail/) | `lightsail` | `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `DNS_ZONE` | Not tested yet |
| [Linode](https://www.linode.com) | `linode` | `LINODE_API_KEY` | Not tested yet |
| manual | - | none, but you need to run Træfik interactively, turn on `acmeLogging` to see instructions and press <kbd>Enter</kbd>. | YES |
| [Namecheap](https://www.namecheap.com) | `namecheap` | `NAMECHEAP_API_USER`, `NAMECHEAP_API_KEY` | Not tested yet |
| [name.com](https://www.name.com/) | `namedotcom` | `NAMECOM_USERNAME`, `NAMECOM_API_TOKEN`, `NAMECOM_SERVER` | Not tested yet |
| [Ns1](https://ns1.com/) | `ns1` | `NS1_API_KEY` | Not tested yet |
| [Open Telekom Cloud](https://cloud.telekom.de/en/) | `otc` | `OTC_DOMAIN_NAME`, `OTC_USER_NAME`, `OTC_PASSWORD`, `OTC_PROJECT_NAME`, `OTC_IDENTITY_ENDPOINT` | Not tested yet |
| [OVH](https://www.ovh.com) | `ovh` | `OVH_ENDPOINT`, `OVH_APPLICATION_KEY`, `OVH_APPLICATION_SECRET`, `OVH_CONSUMER_KEY` | YES |
| [PowerDNS](https://www.powerdns.com) | `pdns` | `PDNS_API_KEY`, `PDNS_API_URL` | Not tested yet |
| [Rackspace](https://www.rackspace.com/cloud/dns) | `rackspace` | `RACKSPACE_USER`, `RACKSPACE_API_KEY` | Not tested yet |
| [RFC2136](https://tools.ietf.org/html/rfc2136) | `rfc2136` | `RFC2136_TSIG_KEY`, `RFC2136_TSIG_SECRET`, `RFC2136_TSIG_ALGORITHM`, `RFC2136_NAMESERVER` | Not tested yet |
| [Route 53](https://aws.amazon.com/route53/) | `route53` | `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `AWS_REGION`, `AWS_HOSTED_ZONE_ID` or a configured user/instance IAM profile. | YES |
| [VULTR](https://www.vultr.com) | `vultr` | `VULTR_API_KEY` | Not tested yet |
There are two ways to store ACME certificates in a file from Docker:
### `domains`
You can provide SANs (alternative domains) to each main domain.
All domains must have A/AAAA records pointing to Træfik.
Each domain & SAN will lead to a certificate request.
- create a file on your host and mount it as a volume:
```toml
storage = "acme.json"
```
```bash
docker run -v "/my/host/acme.json:acme.json" traefik
```
- mount the folder containing the file as a volume
```toml
storage = "/etc/traefik/acme/acme.json"
```
```bash
docker run -v "/my/host/acme:/etc/traefik/acme" traefik
[acme]
# ...
[[acme.domains]]
main = "local1.com"
sans = ["test1.local1.com", "test2.local1.com"]
[[acme.domains]]
main = "local2.com"
[[acme.domains]]
main = "*.local3.com"
sans = ["local3.com", "test1.test1.local3.com"]
# ...
```
!!! warning
This file cannot be shared per many instances of Træfik at the same time.
If you have to use Træfik cluster mode, please use [a KV Store entry](/configuration/acme/#storage-kv-entry).
#### Store data in a KV store entry
ACME certificates can be stored in a KV Store entry.
```toml
storage = "traefik/acme/account"
```
**This kind of storage is mandatory in cluster mode.**
Because KV stores (like Consul) have limited entries size, the certificates list is compressed before to be set in a KV store entry.
Take note that Let's Encrypt applies [rate limiting](https://letsencrypt.org/docs/rate-limits).
!!! note
It's possible to store up to approximately 100 ACME certificates in Consul.
Wildcard certificates can only be verified through a `DNS-01` challenge.
#### Wildcard Domains
[ACME V2](https://community.letsencrypt.org/t/acme-v2-and-wildcard-certificate-support-is-live/55579) allows wildcard certificate support.
As described in [Let's Encrypt's post](https://community.letsencrypt.org/t/staging-endpoint-for-acme-v2/49605) wildcard certificates can only be generated through a [`DNS-01` challenge](/configuration/acme/#dnschallenge).
```toml
[acme]
# ...
[[acme.domains]]
main = "*.local1.com"
sans = ["local1.com"]
# ...
```
It is not possible to request a double wildcard certificate for a domain (for example `*.*.local.com`).
Due to ACME limitation it is not possible to define wildcards in SANs (alternative domains). Thus, the wildcard domain has to be defined as a main domain.
Most likely the root domain should receive a certificate too, so it needs to be specified as SAN and 2 `DNS-01` challenges are executed.
In this case the generated DNS TXT record for both domains is the same.
Eventhough this behaviour is [DNS RFC](https://community.letsencrypt.org/t/wildcard-issuance-two-txt-records-for-the-same-name/54528/2) compliant, it can lead to problems as all DNS providers keep DNS records cached for a certain time (TTL) and this TTL can be superior to the challenge timeout making the `DNS-01` challenge fail.
The Træfik ACME client library [LEGO](https://github.com/xenolf/lego) supports some but not all DNS providers to work around this issue.
The [`provider` table](/configuration/acme/#provider) indicates if they allow generating certificates for a wildcard domain and its root domain.
### `httpChallenge`
Use `HTTP-01` challenge to generate/renew ACME certificates.
Use the `HTTP-01` challenge to generate and renew ACME certificates by provisioning a HTTP resource under a well-known URI.
The redirection is fully compatible with the HTTP-01 challenge.
You can use redirection with HTTP-01 challenge without problem.
Redirection is fully compatible with the `HTTP-01` challenge.
```toml
[acme]
@ -235,6 +270,10 @@ entryPoint = "https"
entryPoint = "http"
```
!!! note
If the `HTTP-01` challenge is used, `acme.httpChallenge.entryPoint` has to be defined and reachable by Let's Encrypt through port 80.
This is a Let's Encrypt limitation as described on the [community forum](https://community.letsencrypt.org/t/support-for-ports-other-than-80-and-443/3419/72).
#### `entryPoint`
Specify the entryPoint to use during the challenges.
@ -258,73 +297,7 @@ defaultEntryPoints = ["http", "https"]
```
!!! note
`acme.httpChallenge.entryPoint` has to be reachable by Let's Encrypt through the port 80.
It's a Let's Encrypt limitation as described on the [community forum](https://community.letsencrypt.org/t/support-for-ports-other-than-80-and-443/3419/72).
### `dnsChallenge`
Use `DNS-01/DNS-01` challenge to generate/renew ACME certificates.
```toml
[acme]
# ...
[acme.dnsChallenge]
provider = "digitalocean"
delayBeforeCheck = 0
# ...
```
!!! note
ACME wildcard certificates can only be generated thanks to a `DNS-01` challenge.
#### `provider`
Select the provider that matches the DNS domain that will host the challenge TXT record, and provide environment variables to enable setting it:
| Provider Name | Provider code | Configuration |
|--------------------------------------------------------|----------------|---------------------------------------------------------------------------------------------------------------------------|
| [Auroradns](https://www.pcextreme.com/aurora/dns) | `auroradns` | `AURORA_USER_ID`, `AURORA_KEY`, `AURORA_ENDPOINT` |
| [Azure](https://azure.microsoft.com/services/dns/) | `azure` | `AZURE_CLIENT_ID`, `AZURE_CLIENT_SECRET`, `AZURE_SUBSCRIPTION_ID`, `AZURE_TENANT_ID`, `AZURE_RESOURCE_GROUP` |
| [Blue Cat](https://www.bluecatnetworks.com/) | `bluecat` | `BLUECAT_SERVER_URL`, `BLUECAT_USER_NAME`, `BLUECAT_PASSWORD`, `BLUECAT_CONFIG_NAME`, `BLUECAT_DNS_VIEW` |
| [Cloudflare](https://www.cloudflare.com) | `cloudflare` | `CLOUDFLARE_EMAIL`, `CLOUDFLARE_API_KEY` - The Cloudflare `Global API Key` needs to be used and not the `Origin CA Key` |
| [CloudXNS](https://www.cloudxns.net) | `cloudxns` | `CLOUDXNS_API_KEY`, `CLOUDXNS_SECRET_KEY` |
| [DigitalOcean](https://www.digitalocean.com) | `digitalocean` | `DO_AUTH_TOKEN` |
| [DNSimple](https://dnsimple.com) | `dnsimple` | `DNSIMPLE_OAUTH_TOKEN`, `DNSIMPLE_BASE_URL` |
| [DNS Made Easy](https://dnsmadeeasy.com) | `dnsmadeeasy` | `DNSMADEEASY_API_KEY`, `DNSMADEEASY_API_SECRET`, `DNSMADEEASY_SANDBOX` |
| [DNSPod](http://www.dnspod.net/) | `dnspod` | `DNSPOD_API_KEY` |
| [Duck DNS](https://www.duckdns.org/) | `duckdns` | `DUCKDNS_TOKEN` |
| [Dyn](https://dyn.com) | `dyn` | `DYN_CUSTOMER_NAME`, `DYN_USER_NAME`, `DYN_PASSWORD` |
| External Program | `exec` | `EXEC_PATH` |
| [Exoscale](https://www.exoscale.ch) | `exoscale` | `EXOSCALE_API_KEY`, `EXOSCALE_API_SECRET`, `EXOSCALE_ENDPOINT` |
| [Fast DNS](https://www.akamai.com/) | `fastdns` | `AKAMAI_CLIENT_TOKEN`, `AKAMAI_CLIENT_SECRET`, `AKAMAI_ACCESS_TOKEN` |
| [Gandi](https://www.gandi.net) | `gandi` | `GANDI_API_KEY` |
| [Gandi V5](http://doc.livedns.gandi.net) | `gandiv5` | `GANDIV5_API_KEY` |
| [Glesys](https://glesys.com/) | `glesys` | `GLESYS_API_USER`, `GLESYS_API_KEY`, `GLESYS_DOMAIN` |
| [GoDaddy](https://godaddy.com/domains) | `godaddy` | `GODADDY_API_KEY`, `GODADDY_API_SECRET` |
| [Google Cloud DNS](https://cloud.google.com/dns/docs/) | `gcloud` | `GCE_PROJECT`, `GCE_SERVICE_ACCOUNT_FILE` |
| [Lightsail](https://aws.amazon.com/lightsail/) | `lightsail` | `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `DNS_ZONE` |
| [Linode](https://www.linode.com) | `linode` | `LINODE_API_KEY` |
| manual | - | none, but run Træfik interactively & turn on `acmeLogging` to see instructions & press <kbd>Enter</kbd>. |
| [Namecheap](https://www.namecheap.com) | `namecheap` | `NAMECHEAP_API_USER`, `NAMECHEAP_API_KEY` |
| [name.com](https://www.name.com/) | `namedotcom` | `NAMECOM_USERNAME`, `NAMECOM_API_TOKEN`, `NAMECOM_SERVER` |
| [Ns1](https://ns1.com/) | `ns1` | `NS1_API_KEY` |
| [Open Telekom Cloud](https://cloud.telekom.de/en/) | `otc` | `OTC_DOMAIN_NAME`, `OTC_USER_NAME`, `OTC_PASSWORD`, `OTC_PROJECT_NAME`, `OTC_IDENTITY_ENDPOINT` |
| [OVH](https://www.ovh.com) | `ovh` | `OVH_ENDPOINT`, `OVH_APPLICATION_KEY`, `OVH_APPLICATION_SECRET`, `OVH_CONSUMER_KEY` |
| [PowerDNS](https://www.powerdns.com) | `pdns` | `PDNS_API_KEY`, `PDNS_API_URL` |
| [Rackspace](https://www.rackspace.com/cloud/dns) | `rackspace` | `RACKSPACE_USER`, `RACKSPACE_API_KEY` |
| [RFC2136](https://tools.ietf.org/html/rfc2136) | `rfc2136` | `RFC2136_TSIG_KEY`, `RFC2136_TSIG_SECRET`, `RFC2136_TSIG_ALGORITHM`, `RFC2136_NAMESERVER` |
| [Route 53](https://aws.amazon.com/route53/) | `route53` | `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `AWS_REGION`, `AWS_HOSTED_ZONE_ID` or configured user/instance IAM profile. |
| [VULTR](https://www.vultr.com) | `vultr` | `VULTR_API_KEY` |
#### `delayBeforeCheck`
By default, the `provider` will verify the TXT DNS challenge record before letting ACME verify.
If `delayBeforeCheck` is greater than zero, avoid this & instead just wait so many seconds.
Useful if internal networks block external DNS queries.
!!! note
This field has no sense if a `provider` is not defined.
`acme.httpChallenge.entryPoint` has to be reachable through port 80. It's a Let's Encrypt limitation as described on the [community forum](https://community.letsencrypt.org/t/support-for-ports-other-than-80-and-443/3419/72).
### `onDemand` (Deprecated)
@ -338,15 +311,15 @@ onDemand = true
# ...
```
Enable on demand certificate.
Enable on demand certificate generation.
This will request a certificate from Let's Encrypt during the first TLS handshake for a host name that does not yet have a certificate.
This will request certificates from Let's Encrypt during the first TLS handshake for host names that do not yet have certificates.
!!! warning
TLS handshakes will be slow when requesting a host name certificate for the first time, this can lead to DoS attacks.
TLS handshakes are slow when requesting a host name certificate for the first time. This can lead to DoS attacks!
!!! warning
Take note that Let's Encrypt have [rate limiting](https://letsencrypt.org/docs/rate-limits).
Take note that Let's Encrypt applies [rate limiting](https://letsencrypt.org/docs/rate-limits).
### `onHostRule`
@ -357,199 +330,94 @@ onHostRule = true
# ...
```
Enable certificate generation on frontends `Host` rules (for frontends wired on the `acme.entryPoint`).
Enable certificate generation on frontend `Host` rules (for frontends wired to the `acme.entryPoint`).
This will request a certificate from Let's Encrypt for each frontend with a Host rule.
For example, a rule `Host:test1.traefik.io,test2.traefik.io` will request a certificate with main domain `test1.traefik.io` and SAN `test2.traefik.io`.
For example, the rule `Host:test1.traefik.io,test2.traefik.io` will request a certificate with main domain `test1.traefik.io` and SAN `test2.traefik.io`.
!!! warning
`onHostRule` option can not be used to generate wildcard certificates.
Refer to [the wildcard generation section](/configuration/acme/#wildcard-domain) for more information.
Refer to [wildcard generation](/configuration/acme/#wildcard-domain) for further information.
### `caServer`
### `storage`
The `storage` option sets the location where your ACME certificates are saved to.
```toml
[acme]
# ...
caServer = "https://acme-staging-v02.api.letsencrypt.org/directory"
storage = "acme.json"
# ...
```
CA server to use.
The value can refer to two kinds of storage:
- Uncomment the line to run on the staging Let's Encrypt server.
- Leave comment to go to prod.
- a JSON file
- a KV store entry
### `domains`
!!! danger "DEPRECATED"
`storage` replaces `storageFile` which is deprecated.
!!! note
During migration to a KV store use both `storageFile` and `storage` to migrate ACME certificates too. See [`storeconfig` subcommand](/user-guide/kv-config/#store-configuration-in-key-value-store) for further information.
#### As a File
ACME certificates can be stored in a JSON file that needs to have file mode `600`.
In Docker you can either mount the JSON file or the folder containing it:
```bash
docker run -v "/my/host/acme.json:acme.json" traefik
```
```bash
docker run -v "/my/host/acme:/etc/traefik/acme" traefik
```
!!! warning
This file cannot be shared across multiple instances of Træfik at the same time. Please use a [KV Store entry](/configuration/acme/#as-a-key-value-store-entry) instead.
#### As a Key Value Store Entry
ACME certificates can be stored in a KV Store entry. This kind of storage is **mandatory in cluster mode**.
```toml
[acme]
# ...
[[acme.domains]]
main = "local1.com"
sans = ["test1.local1.com", "test2.local1.com"]
[[acme.domains]]
main = "local2.com"
sans = ["test1.local2.com", "test2.local2.com"]
[[acme.domains]]
main = "local3.com"
[[acme.domains]]
main = "*.local4.com"
sans = ["local4.com", "test1.test1.local4.com"]
# ...
storage = "traefik/acme/account"
```
#### Wildcard domains
Because KV stores (like Consul) have limited entry size the certificates list is compressed before it is saved as KV store entry.
Wildcard domain has to be defined as a main domain.
All domains must have A/AAAA records pointing to Træfik.
!!! note
It is possible to store up to approximately 100 ACME certificates in Consul.
Due to ACME limitation, it's not possible to define a wildcard as a SAN (alternative domains).
It's neither possible to define a wildcard on a wildcard domain (for example `*.*.local.com`).
#### ACME v2 Migration
!!! warning
Note that Let's Encrypt has [rate limiting](https://letsencrypt.org/docs/rate-limits).
During migration from ACME v1 to ACME v2, using a storage file, a backup of the original file is created in the same place as the latter (with a `.bak` extension).
Each domain & SANs will lead to a certificate request.
For example: if `acme.storage`'s value is `/etc/traefik/acme/acme.json`, the backup file will be `/etc/traefik/acme/acme.json.bak`.
#### Others domains
You can provide SANs (alternative domains) to each main domain.
All domains must have A/AAAA records pointing to Træfik.
!!! warning
Take note that Let's Encrypt have [rate limiting](https://letsencrypt.org/docs/rate-limits).
Each domain & SANs will lead to a certificate request.
!!! note
When Træfik is launched in a container, the storage file's parent directory needs to be mounted to be able to access the backup file on the host.
Otherwise the backup file will be deleted when the container is stopped. Træfik will only generate it once!
### `dnsProvider` (Deprecated)
!!! danger "DEPRECATED"
This option is deprecated, use [dnsChallenge.provider](/configuration/acme/#dnschallenge) instead.
This option is deprecated. Please use [dnsChallenge.provider](/configuration/acme/#provider) instead.
### `delayDontCheckDNS` (Deprecated)
!!! danger "DEPRECATED"
This option is deprecated, use [dnsChallenge.delayBeforeCheck](/configuration/acme/#dnschallenge) instead.
This option is deprecated. Please use [dnsChallenge.delayBeforeCheck](/configuration/acme/#dnschallenge) instead.
## Wildcard certificates
## Fallbacks
[ACME V2](https://community.letsencrypt.org/t/acme-v2-and-wildcard-certificate-support-is-live/55579) allows wildcard certificate support.
However, this feature needs a specific configuration.
If Let's Encrypt is not reachable, these certificates will be used:
### DNS-01 Challenge
As described in [Let's Encrypt post](https://community.letsencrypt.org/t/staging-endpoint-for-acme-v2/49605), wildcard certificates can only be generated through a `DNS-01` Challenge.
This challenge is linked to the Træfik option `acme.dnsChallenge`.
```toml
[acme]
# ...
[acme.dnsChallenge]
provider = "digitalocean"
delayBeforeCheck = 0
# ...
```
For more information about this option, please refer to the [dnsChallenge section](/configuration/acme/#dnschallenge).
### Wildcard domain
Wildcard domains can currently be provided only by to the `acme.domains` option.
```toml
[acme]
# ...
[[acme.domains]]
main = "*.local1.com"
sans = ["local1.com"]
[[acme.domains]]
main = "*.local2.com"
# ...
```
For more information about this option, please refer to the [domains section](/configuration/acme/#domains).
### Limitations
Let's Encrypt wildcard support have some limitations to take into account :
- Wildcard domain can not be a SAN (alternative domain),
- Wildcard domain on a wildcard domain is forbidden (for example `*.*.local.com`),
- A DNS-01 Challenge is executed for each domain (CN and SANs), DNS provider can not manage correctly this behavior as explained in the [DNS provider support section](/configuration/acme/#dns-provider-support)
### DNS provider support
All DNS providers allow creating ACME wildcard certificates.
However, many troubles can appear for wildcard domains with SANs.
If a wildcard domain is defined with it root domain as SAN, as described below, 2 DNS-01 Challenges will be executed.
```toml
[acme]
# ...
[[acme.domains]]
main = "*.local1.com"
sans = ["local1.com"]
# ...
```
When a DNS-01 Challenge is done, Let's Encrypt checks if a TXT record is created with a given name and a given value.
When a certificate is generated for a wildcard domain is defined with it root domain as SAN, the requested TXT record name for both the wildcard domain and the root domain is the same.
The [DNS RFC](https://community.letsencrypt.org/t/wildcard-issuance-two-txt-records-for-the-same-name/54528/2) allows this behavior.
But all DNS providers keep TXT records values in a cache with a TTL.
In function of the parameters given by the Træfik ACME client library ([LEGO](https://github.com/xenolf/lego)), the TXT record TTL can be superior to challenge Timeout.
In that event, the DNS-01 Challenge will not work correctly.
[LEGO](https://github.com/xenolf/lego) will involve in the way to be adapted to all of DNS providers.
Meanwhile, the table described below contains all the DNS providers supported by Træfik and indicates if they allow generating certificates for a wildcard domain and its root domain.
Do not hesitate to complete it.
| Provider Name | Provider code | Wildcard and Root Domain Support |
|--------------------------------------------------------|----------------|----------------------------------|
| [Auroradns](https://www.pcextreme.com/aurora/dns) | `auroradns` | Not tested yet |
| [Azure](https://azure.microsoft.com/services/dns/) | `azure` | Not tested yet |
| [Blue Cat](https://www.bluecatnetworks.com/) | `bluecat` | Not tested yet |
| [Cloudflare](https://www.cloudflare.com) | `cloudflare` | YES |
| [CloudXNS](https://www.cloudxns.net) | `cloudxns` | Not tested yet |
| [DigitalOcean](https://www.digitalocean.com) | `digitalocean` | YES |
| [DNSimple](https://dnsimple.com) | `dnsimple` | Not tested yet |
| [DNS Made Easy](https://dnsmadeeasy.com) | `dnsmadeeasy` | Not tested yet |
| [DNSPod](http://www.dnspod.net/) | `dnspod` | Not tested yet |
| [Duck DNS](https://www.duckdns.org/) | `duckdns` | Not tested yet |
| [Dyn](https://dyn.com) | `dyn` | Not tested yet |
| External Program | `exec` | Not tested yet |
| [Exoscale](https://www.exoscale.ch) | `exoscale` | Not tested yet |
| [Fast DNS](https://www.akamai.com/) | `fastdns` | Not tested yet |
| [Gandi](https://www.gandi.net) | `gandi` | Not tested yet |
| [Gandi V5](http://doc.livedns.gandi.net) | `gandiv5` | Not tested yet |
| [Glesys](https://glesys.com/) | `glesys` | Not tested yet |
| [GoDaddy](https://godaddy.com/domains) | `godaddy` | Not tested yet |
| [Google Cloud DNS](https://cloud.google.com/dns/docs/) | `gcloud` | YES |
| [Lightsail](https://aws.amazon.com/lightsail/) | `lightsail` | Not tested yet |
| [Linode](https://www.linode.com) | `linode` | Not tested yet |
| manual | - | YES |
| [Namecheap](https://www.namecheap.com) | `namecheap` | Not tested yet |
| [name.com](https://www.name.com/) | `namedotcom` | Not tested yet |
| [Ns1](https://ns1.com/) | `ns1` | Not tested yet |
| [Open Telekom Cloud](https://cloud.telekom.de/en/) | `otc` | Not tested yet |
| [OVH](https://www.ovh.com) | `ovh` | YES |
| [PowerDNS](https://www.powerdns.com) | `pdns` | Not tested yet |
| [Rackspace](https://www.rackspace.com/cloud/dns) | `rackspace` | Not tested yet |
| [RFC2136](https://tools.ietf.org/html/rfc2136) | `rfc2136` | Not tested yet |
| [Route 53](https://aws.amazon.com/route53/) | `route53` | YES |
| [VULTR](https://www.vultr.com) | `vultr` | Not tested yet |
## ACME V2 migration
During migration from ACME V1 to ACME V2 with a storage file, a backup is created with the content of the ACME V1 file.
To obtain the name of the backup file, Træfik concatenates the option `acme.storage` and the suffix `.bak`.
For example : if `acme.storage` value is `/etc/traefik/acme/acme.json`, the backup file will be named `/etc/traefik/acme/acme.json.bak`.
1. ACME certificates already generated before downtime
1. Expired ACME certificates
1. Provided certificates
!!! note
When Træfik is launched in a container, do not forget to create a volume of the parent folder to get the backup file on the host.
Otherwise, the backup file will be permanently deleted when the container is stopped, and Træfik will not be able to generate it again.
For new (sub)domains which need Let's Encrypt authentification, the default Træfik certificate will be used until Træfik is restarted.