Preview links not working with Yunohost

Troubleshooting
1

Summary
I am attempting to achieve a display a preview of website content, image links and YouTube links below the message when available.

Steps to reproduce
I use Mattermost with a Team edition on a Yunohost server installed on a vps, it is a version 6.4.1.
Action Post a link in a channel. I Spent 100 Days in the Metaverse - YouTube

Expected behavior
A preview of the Youtube link with header and description

Observed behavior
Just a plain https link.

1.) “Enable website preview links” are enabled in System Console and have been verified in the config files.
2.) “Website link previews” are enabled in user display settings.

We don’t know why this don’t work, there is a post on yunohost forum about: Preview Links broken [BUG] [MatterMost] - Support apps - YunoHost Forum

I have no particular log also…

my config.json

{
    "ServiceSettings": {
        "SiteURL": "https://mydomain.tld",
        "WebsocketURL": "",
        "LicenseFileLocation": "",
        "ListenAddress": "127.0.0.1:8065",
        "ConnectionSecurity": "",
        "TLSCertFile": "",
        "TLSKeyFile": "",
        "TLSMinVer": "1.2",
        "TLSStrictTransport": false,
        "TLSStrictTransportMaxAge": 63072000,
        "TLSOverwriteCiphers": [],
        "UseLetsEncrypt": false,
        "LetsEncryptCertificateCacheFile": "./config/letsencrypt.cache",
        "Forward80To443": false,
        "TrustedProxyIPHeader": [],
        "ReadTimeout": 300,
        "WriteTimeout": 300,
        "IdleTimeout": 60,
        "MaximumLoginAttempts": 10,
        "GoroutineHealthThreshold": -1,
        "EnableOAuthServiceProvider": false,
        "EnableIncomingWebhooks": true,
        "EnableOutgoingWebhooks": true,
        "EnableCommands": true,
        "EnablePostUsernameOverride": false,
        "EnablePostIconOverride": false,
        "GoogleDeveloperKey": "",
        "EnableLinkPreviews": true,
        "EnablePermalinkPreviews": true,
        "RestrictLinkPreviews": "",
        "EnableTesting": false,
        "EnableDeveloper": false,
        "DeveloperFlags": "",
        "EnableOpenTracing": false,
        "EnableSecurityFixAlert": true,
        "EnableInsecureOutgoingConnections": false,
        "AllowedUntrustedInternalConnections": "",
        "EnableMultifactorAuthentication": false,
        "EnforceMultifactorAuthentication": false,
        "EnableUserAccessTokens": false,
        "AllowCorsFrom": "",
        "CorsExposedHeaders": "",
        "CorsAllowCredentials": false,
        "CorsDebug": false,
        "AllowCookiesForSubdomains": false,
        "ExtendSessionLengthWithActivity": true,
        "SessionLengthWebInDays": 30,
        "SessionLengthMobileInDays": 30,
        "SessionLengthSSOInDays": 30,
        "SessionCacheInMinutes": 10,
        "SessionIdleTimeoutInMinutes": 43200,
        "WebsocketSecurePort": 443,
        "WebsocketPort": 80,
        "WebserverMode": "gzip",
        "EnableGifPicker": false,
        "GfycatAPIKey": "x_xxxcJw",
        "GfycatAPISecret": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
        "EnableCustomEmoji": true,
        "EnableEmojiPicker": true,
        "PostEditTimeLimit": -1,
        "TimeBetweenUserTypingUpdatesMilliseconds": 5000,
        "EnablePostSearch": true,
        "EnableFileSearch": true,
        "MinimumHashtagLength": 3,
        "EnableUserTypingMessages": true,
        "EnableChannelViewedMessages": true,
        "EnableUserStatuses": true,
        "ExperimentalEnableAuthenticationTransfer": true,
        "ClusterLogTimeoutMilliseconds": 2000,
        "EnablePreviewFeatures": true,
        "EnableTutorial": true,
        "EnableOnboardingFlow": true,
        "ExperimentalEnableDefaultChannelLeaveJoinMessages": true,
        "ExperimentalGroupUnreadChannels": "disabled",
        "EnableAPITeamDeletion": false,
        "EnableAPIUserDeletion": false,
        "ExperimentalEnableHardenedMode": false,
        "ExperimentalStrictCSRFEnforcement": false,
        "EnableEmailInvitations": true,
        "DisableBotsWhenOwnerIsDeactivated": true,
        "EnableBotAccountCreation": false,
        "EnableSVGs": false,
        "EnableLatex": false,
        "EnableInlineLatex": true,
        "EnableAPIChannelDeletion": false,
        "EnableLocalMode": false,
        "LocalModeSocketLocation": "/var/run/mattermost/mattermost_local.socket",
        "EnableAWSMetering": false,
        "SplitKey": "",
        "FeatureFlagSyncIntervalSeconds": 30,
        "DebugSplit": false,
        "ThreadAutoFollow": true,
        "CollapsedThreads": "disabled",
        "ManagedResourcePaths": ""
    },

the port 8065 is open in the firewall…

does I need a Entreprise Edition to resolve this issue or is it a mismatch with yunohost configuration ?

2

In mattermost.log I can see this:

{"timestamp":"2022-03-01 02:08:02.073 +01:00","level":"info","msg":"Failed to fetch marketplace plugins for telemetry. Using predefined list.","caller":"telemetry/telemetry.go:1327","error":"Get \"https://api.integrations.mattermost.com/api/v1/plugins?build_enterprise_ready=false&cloud=false&enterprise_plugins=false&filter=&local_only=false&page=0&platform=&plugin_id=&return_all_versions=false&server_version=6.3.3\": address forbidden, you may need to set AllowedUntrustedInternalConnections to allow an integration access to your internal network"

Perhaps I need to set AllowedUntrustedInternalConnections ?
this parameter is not good enough ?
"AllowedUntrustedInternalConnections": "",

3

We have a ticket open that could be related: [MM-40448] - Mattermost.

4

Someone found the matter with Yunohost integration, now preview links work nice… Thanks for reading me…