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Let's Encrypt

Automatic HTTPS

You can configure Traefik to use an ACME provider (like Let's Encrypt) for automatic certificate generation.

Let's Encrypt and Rate Limiting

Note that Let's Encrypt API has rate limiting.

Configuration Examples

Enabling ACME
[entryPoints]
  [entryPoints.web]
    address = ":80"

  [entryPoints.web-secure]
    address = ":443"

[certificatesResolvers.sample.acme]
  email = "[email protected]"
  storage = "acme.json"
  [certificatesResolvers.sample.acme.httpChallenge]
    # used during the challenge
    entryPoint = "web"
entryPoints:
  web:
    address: ":80"

  web-secure:
    address: ":443"

certificatesResolvers:
  sample:
    acme:
      email: [email protected]
      storage: acme.json
      httpChallenge:
        # used during the challenge
        entryPoint: web
--entryPoints.web.address=":80"
--entryPoints.websecure.address=":443"
# ...
--certificatesResolvers.sample.acme.email="[email protected]"
--certificatesResolvers.sample.acme.storage="acme.json"
# used during the challenge
--certificatesResolvers.sample.acme.httpChallenge.entryPoint=web

Defining a certificates resolver does not result in all routers automatically using it. Each router that is supposed to use the resolver must reference it.

Configuration Reference

There are many available options for ACME. For a quick glance at what's possible, browse the configuration reference:

# Enable ACME (Let's Encrypt): automatic SSL.
[certificatesResolvers.sample.acme]

  # Email address used for registration.
  #
  # Required
  #
  email = "[email protected]"

  # File or key used for certificates storage.
  #
  # Required
  #
  storage = "acme.json"

  # CA server to use.
  # 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"
  #
  # caServer = "https://acme-staging-v02.api.letsencrypt.org/directory"

  # KeyType to use.
  #
  # Optional
  # Default: "RSA4096"
  #
  # Available values : "EC256", "EC384", "RSA2048", "RSA4096", "RSA8192"
  #
  # keyType = "RSA4096"

  # Use a TLS-ALPN-01 ACME challenge.
  #
  # Optional (but recommended)
  #
  [certificatesResolvers.sample.acme.tlsChallenge]

  # Use a HTTP-01 ACME challenge.
  #
  # Optional
  #
  # [certificatesResolvers.sample.acme.httpChallenge]

    # EntryPoint to use for the HTTP-01 challenges.
    #
    # Required
    #
    # entryPoint = "web"

  # Use a DNS-01 ACME challenge rather than HTTP-01 challenge.
  # Note: mandatory for wildcard certificate generation.
  #
  # Optional
  #
  # [certificatesResolvers.sample.acme.dnsChallenge]

    # 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, this check is delayed for the configured duration in seconds.
    # Useful if internal networks block external DNS queries.
    #
    # Optional
    # Default: 0
    #
    # delayBeforeCheck = 0

    # Use following DNS servers to resolve the FQDN authority.
    #
    # Optional
    # Default: empty
    #
    # resolvers = ["1.1.1.1:53", "8.8.8.8:53"]

    # Disable the DNS propagation checks before notifying ACME that the DNS challenge is ready.
    #
    # NOT RECOMMENDED:
    # Increase the risk of reaching Let's Encrypt's rate limits.
    #
    # Optional
    # Default: false
    #
    # disablePropagationCheck = true
certificatesResolvers:
  sample:
    # Enable ACME (Let's Encrypt): automatic SSL.
    acme:

      # Email address used for registration.
      #
      # Required
      #
      email: "[email protected]"

      # File or key used for certificates storage.
      #
      # Required
      #
      storage: "acme.json"

      # CA server to use.
      # 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"
      #
      # caServer: "https://acme-staging-v02.api.letsencrypt.org/directory"

      # KeyType to use.
      #
      # Optional
      # Default: "RSA4096"
      #
      # Available values : "EC256", "EC384", "RSA2048", "RSA4096", "RSA8192"
      #
      # keyType: RSA4096

      # Use a TLS-ALPN-01 ACME challenge.
      #
      # Optional (but recommended)
      #
      tlsChallenge:

      # Use a HTTP-01 ACME challenge.
      #
      # Optional
      #
      # httpChallenge:

        # EntryPoint to use for the HTTP-01 challenges.
        #
        # Required
        #
        # entryPoint: web

      # Use a DNS-01 ACME challenge rather than HTTP-01 challenge.
      # Note: mandatory for wildcard certificate generation.
      #
      # Optional
      #
      # dnsChallenge:

        # 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, this check is delayed for the configured duration in seconds.
        # Useful if internal networks block external DNS queries.
        #
        # Optional
        # Default: 0
        #
        # delayBeforeCheck: 0

        # Use following DNS servers to resolve the FQDN authority.
        #
        # Optional
        # Default: empty
        #
        # resolvers
        # - "1.1.1.1:53"
        # - "8.8.8.8:53"

        # Disable the DNS propagation checks before notifying ACME that the DNS challenge is ready.
        #
        # NOT RECOMMENDED:
        # Increase the risk of reaching Let's Encrypt's rate limits.
        #
        # Optional
        # Default: false
        #
        # disablePropagationCheck: true
# Enable ACME (Let's Encrypt): automatic SSL.

# Email address used for registration.
#
# Required
#
--certificatesResolvers.sample.acme.email="[email protected]"

# File or key used for certificates storage.
#
# Required
#
--certificatesResolvers.sample.acme.storage="acme.json"

# CA server to use.
# 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"
#
--certificatesResolvers.sample.acme.caServer="https://acme-staging-v02.api.letsencrypt.org/directory"

# KeyType to use.
#
# Optional
# Default: "RSA4096"
#
# Available values : "EC256", "EC384", "RSA2048", "RSA4096", "RSA8192"
#
--certificatesResolvers.sample.acme.keyType=RSA4096

# Use a TLS-ALPN-01 ACME challenge.
#
# Optional (but recommended)
#
--certificatesResolvers.sample.acme.tlsChallenge=true

# Use a HTTP-01 ACME challenge.
#
# Optional
#
--certificatesResolvers.sample.acme.httpChallenge=true

# EntryPoint to use for the HTTP-01 challenges.
#
# Required
#
--certificatesResolvers.sample.acme.httpChallenge.entryPoint=web

# Use a DNS-01 ACME challenge rather than HTTP-01 challenge.
# Note: mandatory for wildcard certificate generation.
#
# Optional
#
--certificatesResolvers.sample.acme.dnsChallenge=true

# DNS provider used.
#
# Required
#
--certificatesResolvers.sample.acme.dnsChallenge.provider=digitalocean

# 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.
#
# Optional
# Default: 0
#
--certificatesResolvers.sample.acme.dnsChallenge.delayBeforeCheck=0

# Use following DNS servers to resolve the FQDN authority.
#
# Optional
# Default: empty
#
--certificatesResolvers.sample.acme.dnsChallenge.resolvers="1.1.1.1:53,8.8.8.8:53"

# Disable the DNS propagation checks before notifying ACME that the DNS challenge is ready.
#
# NOT RECOMMENDED:
# Increase the risk of reaching Let's Encrypt's rate limits.
#
# Optional
# Default: false
#
--certificatesResolvers.sample.acme.dnsChallenge.disablePropagationCheck=true

Automatic Renewals

Traefik automatically tracks the expiry date of ACME certificates it generates.

If there are less than 30 days remaining before the certificate expires, Traefik will attempt to renew it automatically.

Certificates that are no longer used may still be renewed, as Traefik does not currently check if the certificate is being used before renewing.

The Different ACME Challenges

Defining a certificates resolver does not result in all routers automatically using it. Each router that is supposed to use the resolver must reference it.

tlsChallenge

Use the TLS-ALPN-01 challenge to generate and renew ACME certificates by provisioning a TLS certificate.

As described on the Let's Encrypt community forum, when using the TLS-ALPN-01 challenge, Traefik must be reachable by Let's Encrypt through port 443.

Configuring the tlsChallenge
[certificatesResolvers.sample.acme]
  # ...
  [certificatesResolvers.sample.acme.tlsChallenge]
certificatesResolvers:
  sample:
    acme:
      # ...
      tlsChallenge: {}
# ...
--certificatesResolvers.sample.acme.tlsChallenge=true

httpChallenge

Use the HTTP-01 challenge to generate and renew ACME certificates by provisioning an HTTP resource under a well-known URI.

As described on the Let's Encrypt community forum, when using the HTTP-01 challenge, certificatesResolvers.sample.acme.httpChallenge.entryPoint must be reachable by Let's Encrypt through port 80.

Using an EntryPoint Called http for the httpChallenge
[entryPoints]
  [entryPoints.web]
    address = ":80"

  [entryPoints.web-secure]
    address = ":443"

[certificatesResolvers.sample.acme]
  # ...
  [certificatesResolvers.sample.acme.httpChallenge]
    entryPoint = "web"
entryPoints:
  web:
    address: ":80"

  web-secure:
    address: ":443"

certificatesResolvers:
  sample:
    acme:
      # ...
      httpChallenge:
        entryPoint: web
--entryPoints.web.address=":80"
--entryPoints.websecure.address=":443"
# ...
--certificatesResolvers.sample.acme.httpChallenge.entryPoint=web

Redirection is fully compatible with the HTTP-01 challenge.

dnsChallenge

Use the DNS-01 challenge to generate and renew ACME certificates by provisioning a DNS record.

Configuring a dnsChallenge with the DigitalOcean Provider
[certificatesResolvers.sample.acme]
  # ...
  [certificatesResolvers.sample.acme.dnsChallenge]
    provider = "digitalocean"
    delayBeforeCheck = 0
# ...
certificatesResolvers:
  sample:
    acme:
      # ...
      dnsChallenge:
        provider: digitalocean
        delayBeforeCheck: 0
    # ...
# ...
--certificatesResolvers.sample.acme.dnsChallenge.provider=digitalocean
--certificatesResolvers.sample.acme.dnsChallenge.delayBeforeCheck=0
# ...

Important

A provider is mandatory.

providers

Here is a list of supported providers, that can automate the DNS verification, along with the required environment variables and their wildcard & root domain support. Do not hesitate to complete it.

Every lego environment variable can be overridden by their respective _FILE counterpart, which should have a filepath to a file that contains the secret as its value. For example, CF_API_EMAIL_FILE=/run/secrets/traefik_cf-api-email could be used to provide a Cloudflare API email address as a Docker secret named traefik_cf-api-email.

Provider Name Provider Code Environment Variables
ACME DNS acme-dns ACME_DNS_API_BASE, ACME_DNS_STORAGE_PATH Additional configuration
Alibaba Cloud alidns ALICLOUD_ACCESS_KEY, ALICLOUD_SECRET_KEY, ALICLOUD_REGION_ID Additional configuration
Auroradns auroradns AURORA_USER_ID, AURORA_KEY, AURORA_ENDPOINT Additional configuration
Azure azure AZURE_CLIENT_ID, AZURE_CLIENT_SECRET, AZURE_SUBSCRIPTION_ID, AZURE_TENANT_ID, AZURE_RESOURCE_GROUP, [AZURE_METADATA_ENDPOINT] Additional configuration
Bindman bindman BINDMAN_MANAGER_ADDRESS Additional configuration
Blue Cat bluecat BLUECAT_SERVER_URL, BLUECAT_USER_NAME, BLUECAT_PASSWORD, BLUECAT_CONFIG_NAME, BLUECAT_DNS_VIEW Additional configuration
ClouDNS cloudns CLOUDNS_AUTH_ID, CLOUDNS_AUTH_PASSWORD Additional configuration
Cloudflare cloudflare CF_API_EMAIL, CF_API_KEY or CF_DNS_API_TOKEN, [CF_ZONE_API_TOKEN] 5 Additional configuration
CloudXNS cloudxns CLOUDXNS_API_KEY, CLOUDXNS_SECRET_KEY Additional configuration
ConoHa conoha CONOHA_TENANT_ID, CONOHA_API_USERNAME, CONOHA_API_PASSWORD Additional configuration
DigitalOcean digitalocean DO_AUTH_TOKEN Additional configuration
DNSimple dnsimple DNSIMPLE_OAUTH_TOKEN, DNSIMPLE_BASE_URL Additional configuration
DNS Made Easy dnsmadeeasy DNSMADEEASY_API_KEY, DNSMADEEASY_API_SECRET, DNSMADEEASY_SANDBOX Additional configuration
DNSPod dnspod DNSPOD_API_KEY Additional configuration
Domain Offensive (do.de) dode DODE_TOKEN Additional configuration
DreamHost dreamhost DREAMHOST_API_KEY Additional configuration
Duck DNS duckdns DUCKDNS_TOKEN Additional configuration
Dyn dyn DYN_CUSTOMER_NAME, DYN_USER_NAME, DYN_PASSWORD Additional configuration
EasyDNS easydns EASYDNS_TOKEN, EASYDNS_KEY Additional configuration
External Program exec EXEC_PATH Additional configuration
Exoscale exoscale EXOSCALE_API_KEY, EXOSCALE_API_SECRET, EXOSCALE_ENDPOINT Additional configuration
Fast DNS fastdns AKAMAI_CLIENT_TOKEN, AKAMAI_CLIENT_SECRET, AKAMAI_ACCESS_TOKEN Additional configuration
Gandi gandi GANDI_API_KEY Additional configuration
Gandi v5 gandiv5 GANDIV5_API_KEY Additional configuration
Glesys glesys GLESYS_API_USER, GLESYS_API_KEY, GLESYS_DOMAIN Additional configuration
GoDaddy godaddy GODADDY_API_KEY, GODADDY_API_SECRET Additional configuration
Google Cloud DNS gcloud GCE_PROJECT, Application Default Credentials 2 3, [GCE_SERVICE_ACCOUNT_FILE] Additional configuration
hosting.de hostingde HOSTINGDE_API_KEY, HOSTINGDE_ZONE_NAME Additional configuration
HTTP request httpreq HTTPREQ_ENDPOINT, HTTPREQ_MODE, HTTPREQ_USERNAME, HTTPREQ_PASSWORD 1 Additional configuration
IIJ iij IIJ_API_ACCESS_KEY, IIJ_API_SECRET_KEY, IIJ_DO_SERVICE_CODE Additional configuration
INWX inwx INWX_USERNAME, INWX_PASSWORD Additional configuration
Joker.com joker JOKER_API_KEY or JOKER_USERNAME, JOKER_PASSWORD Additional configuration
Lightsail lightsail AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, DNS_ZONE Additional configuration
Linode linode LINODE_API_KEY Additional configuration
Linode v4 linodev4 LINODE_TOKEN Additional configuration
Liquid Web liquidweb LIQUID_WEB_PASSWORD, LIQUID_WEB_USERNAME, LIQUID_WEB_ZONE Additional configuration
manual - none, but you need to run Traefik interactively 4, turn on debug log to see instructions and press Enter.
MyDNS.jp mydnsjp MYDNSJP_MASTER_ID, MYDNSJP_PASSWORD Additional configuration
Namecheap namecheap NAMECHEAP_API_USER, NAMECHEAP_API_KEY Additional configuration
name.com namedotcom NAMECOM_USERNAME, NAMECOM_API_TOKEN, NAMECOM_SERVER Additional configuration
Namesilo namesilo NAMESILO_API_KEY Additional configuration
Netcup netcup NETCUP_CUSTOMER_NUMBER, NETCUP_API_KEY, NETCUP_API_PASSWORD Additional configuration
NIFCloud nifcloud NIFCLOUD_ACCESS_KEY_ID, NIFCLOUD_SECRET_ACCESS_KEY Additional configuration
Ns1 ns1 NS1_API_KEY Additional configuration
Open Telekom Cloud otc OTC_DOMAIN_NAME, OTC_USER_NAME, OTC_PASSWORD, OTC_PROJECT_NAME, OTC_IDENTITY_ENDPOINT Additional configuration
OVH ovh OVH_ENDPOINT, OVH_APPLICATION_KEY, OVH_APPLICATION_SECRET, OVH_CONSUMER_KEY Additional configuration
Openstack Designate designate OS_AUTH_URL, OS_USERNAME, OS_PASSWORD, OS_TENANT_NAME, OS_REGION_NAME Additional configuration
Oracle Cloud oraclecloud OCI_COMPARTMENT_OCID, OCI_PRIVKEY_FILE, OCI_PRIVKEY_PASS, OCI_PUBKEY_FINGERPRINT, OCI_REGION, OCI_TENANCY_OCID, OCI_USER_OCID Additional configuration
PowerDNS pdns PDNS_API_KEY, PDNS_API_URL Additional configuration
Rackspace rackspace RACKSPACE_USER, RACKSPACE_API_KEY Additional configuration
RFC2136 rfc2136 RFC2136_TSIG_KEY, RFC2136_TSIG_SECRET, RFC2136_TSIG_ALGORITHM, RFC2136_NAMESERVER Additional configuration
Route 53 route53 AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, [AWS_REGION], [AWS_HOSTED_ZONE_ID] or a configured user/instance IAM profile. Additional configuration
Sakura Cloud sakuracloud SAKURACLOUD_ACCESS_TOKEN, SAKURACLOUD_ACCESS_TOKEN_SECRET Additional configuration
Selectel selectel SELECTEL_API_TOKEN Additional configuration
Stackpath stackpath STACKPATH_CLIENT_ID, STACKPATH_CLIENT_SECRET, STACKPATH_STACK_ID Additional configuration
TransIP transip TRANSIP_ACCOUNT_NAME, TRANSIP_PRIVATE_KEY_PATH Additional configuration
VegaDNS vegadns SECRET_VEGADNS_KEY, SECRET_VEGADNS_SECRET, VEGADNS_URL Additional configuration
Versio versio VERSIO_USERNAME, VERSIO_PASSWORD Additional configuration
Vscale vscale VSCALE_API_TOKEN Additional configuration
VULTR vultr VULTR_API_KEY Additional configuration
Zone.ee zoneee ZONEEE_API_USER, ZONEEE_API_KEY Additional configuration

delayBeforeCheck

By default, the provider verifies the TXT record before letting ACME verify. You can delay this operation by specifying a delay (in seconds) with delayBeforeCheck (value must be greater than zero). This option is useful when internal networks block external DNS queries.

resolvers

Use custom DNS servers to resolve the FQDN authority.

[certificatesResolvers.sample.acme]
  # ...
  [certificatesResolvers.sample.acme.dnsChallenge]
    # ...
    resolvers = ["1.1.1.1:53", "8.8.8.8:53"]
certificatesResolvers:
  sample:
    acme:
      # ...
      dnsChallenge:
        # ...
        resolvers:
          - "1.1.1.1:53"
          - "8.8.8.8:53"
# ...
--certificatesResolvers.sample.acme.dnsChallenge.resolvers:="1.1.1.1:53,8.8.8.8:53"

Wildcard Domains

ACME V2 supports wildcard certificates. As described in Let's Encrypt's post wildcard certificates can only be generated through a DNS-01 challenge.

caServer

Using the Let's Encrypt staging server
[certificatesResolvers.sample.acme]
  # ...
  caServer = "https://acme-staging-v02.api.letsencrypt.org/directory"
  # ...
certificatesResolvers:
  sample:
    acme:
      # ...
      caServer: https://acme-staging-v02.api.letsencrypt.org/directory
      # ...
# ...
--certificatesResolvers.sample.acme.caServer="https://acme-staging-v02.api.letsencrypt.org/directory"
# ...

storage

The storage option sets the location where your ACME certificates are saved to.

[certificatesResolvers.sample.acme]
  # ...
  storage = "acme.json"
  # ...
certificatesResolvers:
  sample:
    acme:
      # ...
      storage: acme.json
      # ...
# ...
--certificatesResolvers.sample.acme.storage=acme.json
# ...

The value can refer to some kinds of storage:

  • a JSON file

In a File

ACME certificates can be stored in a JSON file that needs to have a 600 file mode .

In Docker you can mount either the JSON file, or the folder containing it:

docker run -v "/my/host/acme.json:/acme.json" traefik
docker run -v "/my/host/acme:/etc/traefik/acme" traefik

Warning

For concurrency reason, this file cannot be shared across multiple instances of Traefik. Use a key value store entry instead.

Fallback

If Let's Encrypt is not reachable, the following certificates will apply:

  1. Previously generated ACME certificates (before downtime)
  2. Expired ACME certificates
  3. Provided certificates

Important

For new (sub)domains which need Let's Encrypt authentication, the default Traefik certificate will be used until Traefik is restarted.


  1. more information about the HTTP message format can be found here 

  2. providing_credentials_to_your_application 

  3. google/default.go 

  4. docker stack remark: there is no way to support terminal attached to container when deploying with docker stack, so you might need to run container with docker run -it to generate certificates using manual provider. 

  5. The Global API Key needs to be used, not the Origin CA Key