Server not found when trying to preview the course

Tutor
1

Hi all,

Tutor version: 14.0.5
Local deployment

I am working on a brand new installation of Tutor edX (but on the same server I had before) and experiencing an error that I had never experienced before (previous version : edX Lilac installed with Tutor).

I can edit a course on the CMS but whenever I want to preview the course, I get a “Server not found” error (the browser cannot find the page).
I tried to check the logs using tutor local logs --follow and here is what I obtained:

tutor_local-lms-1                        | 2022-09-20 21:32:33,892 INFO 7 [openedx.core.djangoapps.cors_csrf.helpers] [user 4] [ip 89.159.63.160] helpers.py:64 - Origin 'https://mooc.krounix.org' was not in `CORS_ORIGIN_WHITELIST`; full referer was 'https://mooc.krounix.org/dashboard' and requested host was 'mooc.krounix.org'; CORS_ORIGIN_ALLOW_ALL=False
tutor_local-caddy-1                      | {"level":"info","ts":1663709554.3998997,"logger":"http.log.access.log0","msg":"handled request","request":{"remote_addr":"89.159.63.160:50194","proto":"HTTP/2.0","method":"GET","host":"mooc.krounix.org","uri":"/dashboard","tls":{"resumed":false,"version":772,"cipher_suite":4865,"proto":"h2","proto_mutual":true,"server_name":"mooc.krounix.org"}},"user_id":"","duration":0.552479977,"size":22142,"status":200}
tutor_local-lms-1                        | [pid: 7|app: 0|req: 36/160] 172.18.0.18 () {56 vars in 3072 bytes} [Tue Sep 20 21:32:33 2022] GET /dashboard => generated 22142 bytes in 550 msecs (HTTP/1.1 200) 7 headers in 505 bytes (1 switches on core 0)
tutor_local-caddy-1                      | {"level":"info","ts":1663709562.4331686,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"preview.mooc.krounix.org","challenge_type":"tls-alpn-01","ca":"https://acme-staging-v02.api.letsencrypt.org/directory"}
tutor_local-caddy-1                      | {"level":"error","ts":1663709563.7673244,"logger":"tls.issuance.acme.acme_client","msg":"challenge failed","identifier":"preview.mooc.krounix.org","challenge_type":"tls-alpn-01","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for preview.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for preview.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]}}
tutor_local-caddy-1                      | {"level":"error","ts":1663709563.7678325,"logger":"tls.issuance.acme.acme_client","msg":"validating authorization","identifier":"preview.mooc.krounix.org","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for preview.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for preview.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]},"order":"https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165094294","attempt":1,"max_attempts":3}
tutor_local-caddy-1                      | {"level":"info","ts":1663709565.077906,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"preview.mooc.krounix.org","challenge_type":"http-01","ca":"https://acme-staging-v02.api.letsencrypt.org/directory"}
tutor_local-caddy-1                      | {"level":"error","ts":1663709566.0212393,"logger":"tls.issuance.acme.acme_client","msg":"challenge failed","identifier":"preview.mooc.krounix.org","challenge_type":"http-01","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for preview.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for preview.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]}}
tutor_local-caddy-1                      | {"level":"error","ts":1663709566.0213344,"logger":"tls.issuance.acme.acme_client","msg":"validating authorization","identifier":"preview.mooc.krounix.org","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for preview.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for preview.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]},"order":"https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165094984","attempt":2,"max_attempts":3}
tutor_local-caddy-1                      | {"level":"error","ts":1663709567.4888368,"logger":"tls.obtain","msg":"could not get certificate from issuer","identifier":"preview.mooc.krounix.org","issuer":"acme-v02.api.letsencrypt.org-directory","error":"[preview.mooc.krounix.org] solving challenges: preview.mooc.krounix.org: no solvers available for remaining challenges (configured=[tls-alpn-01 http-01] offered=[http-01 dns-01 tls-alpn-01] remaining=[dns-01]) (order=https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165095574) (ca=https://acme-staging-v02.api.letsencrypt.org/directory)"}
tutor_local-caddy-1                      | {"level":"warn","ts":1663709567.4893262,"logger":"tls.issuance.zerossl","msg":"missing email address for ZeroSSL; it is strongly recommended to set one for next time"}
tutor_local-caddy-1                      | {"level":"info","ts":1663709568.04543,"logger":"tls.issuance.zerossl","msg":"generated EAB credentials","key_id":"Ye5aQ7QAw41l2BL6sj3G8w"}
tutor_local-caddy-1                      | {"level":"info","ts":1663709574.16199,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"apps.mooc.krounix.org","challenge_type":"tls-alpn-01","ca":"https://acme-staging-v02.api.letsencrypt.org/directory"}
tutor_local-caddy-1                      | {"level":"error","ts":1663709575.1006238,"logger":"tls.issuance.acme.acme_client","msg":"challenge failed","identifier":"apps.mooc.krounix.org","challenge_type":"tls-alpn-01","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for apps.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for apps.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]}}
tutor_local-caddy-1                      | {"level":"error","ts":1663709575.1006784,"logger":"tls.issuance.acme.acme_client","msg":"validating authorization","identifier":"apps.mooc.krounix.org","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for apps.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for apps.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]},"order":"https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165097024","attempt":1,"max_attempts":3}
tutor_local-caddy-1                      | {"level":"info","ts":1663709575.1193929,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"preview.mooc.krounix.org","challenge_type":"http-01","ca":"https://acme.zerossl.com/v2/DV90"}
tutor_local-caddy-1                      | {"level":"info","ts":1663709576.4244711,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"apps.mooc.krounix.org","challenge_type":"http-01","ca":"https://acme-staging-v02.api.letsencrypt.org/directory"}
tutor_local-caddy-1                      | {"level":"error","ts":1663709576.9685898,"logger":"tls.issuance.acme.acme_client","msg":"challenge failed","identifier":"apps.mooc.krounix.org","challenge_type":"http-01","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for apps.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for apps.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]}}
tutor_local-caddy-1                      | {"level":"error","ts":1663709576.9686472,"logger":"tls.issuance.acme.acme_client","msg":"validating authorization","identifier":"apps.mooc.krounix.org","problem":{"type":"urn:ietf:params:acme:error:dns","title":"","detail":"DNS problem: NXDOMAIN looking up A for apps.mooc.krounix.org - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for apps.mooc.krounix.org - check that a DNS record exists for this domain","instance":"","subproblems":[]},"order":"https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165097534","attempt":2,"max_attempts":3}
tutor_local-caddy-1                      | {"level":"error","ts":1663709578.4286416,"logger":"tls.obtain","msg":"could not get certificate from issuer","identifier":"apps.mooc.krounix.org","issuer":"acme-v02.api.letsencrypt.org-directory","error":"[apps.mooc.krounix.org] solving challenges: apps.mooc.krounix.org: no solvers available for remaining challenges (configured=[tls-alpn-01 http-01] offered=[http-01 dns-01 tls-alpn-01] remaining=[dns-01]) (order=https://acme-staging-v02.api.letsencrypt.org/acme/order/69052174/4165098024) (ca=https://acme-staging-v02.api.letsencrypt.org/directory)"}
tutor_local-caddy-1                      | {"level":"warn","ts":1663709578.4290972,"logger":"tls.issuance.zerossl","msg":"missing email address for ZeroSSL; it is strongly recommended to set one for next time"}
tutor_local-caddy-1                      | {"level":"info","ts":1663709578.7234554,"logger":"tls.issuance.zerossl","msg":"generated EAB credentials","key_id":"SSMyLb9b9uT66OSMCoswxQ"}
tutor_local-caddy-1                      | {"level":"info","ts":1663709586.8014517,"logger":"tls.issuance.acme.acme_client","msg":"trying to solve challenge","identifier":"apps.mooc.krounix.org","challenge_type":"http-01","ca":"https://acme.zerossl.com/v2/DV90"}

It seems to be a DNS issue. But I have not changed any DNS configuration between the old and new platform version.

Any idea what may cause the problem?

Thank you in advance.

2

Fixed my problem by adding a DNS record of type A for the subdomains apps.{lms_domain} and preview.{lms_domain}
I did not see anything in the Tutor documentation (e.g., requirements section). Perhaps it is a good idea to add it ? (except if I am missing something)

3

It is usually recommended to add a CNAME to point all subdomains of the LMS to the same server: Installing Tutor — Tutor documentation

In the future please use the official Open edX forums (see the big " :warning: Please do not open new topics here :warning:" banner above).

4

Sorry about that. Actually, I saw the banner few minutes after answering my own question and I did not manage to delete my post and put it on openedx forum. :sweat_smile:

But thanks for your reply :grinning:

5

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