Rename environment variables and add legacy support.

As we are no longer HackMD the short tag `HMD` doesn't match anymore. We
move it to the matching prefix `CMD` and inform our users about the
change.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

Author: SISheogorath

README.md

@@ -165,80 +165,82 @@ There are some config settings you need to change in the files below.
 | --------- | ------ | ----------- |
 | `NODE_ENV`  | `production` or `development` | set current environment (will apply corresponding settings in the `config.json`) |
 | `DEBUG` | `true` or `false` | set debug mode; show more logs |
-| `HMD_DOMAIN` | `codimd.org` | domain name |
-| `HMD_URL_PATH` | `codimd` | sub URL path, like `www.example.com/<URL_PATH>` |
-| `HMD_PORT` | `80` | web app port |
-| `HMD_ALLOW_ORIGIN` | `localhost, codimd.org` | domain name whitelist (use comma to separate) |
-| `HMD_PROTOCOL_USESSL` | `true` or `false` | set to use SSL protocol for resources path (only applied when domain is set) |
-| `HMD_URL_ADDPORT` | `true` or `false` | set to add port on callback URL (ports `80` or `443` won't be applied) (only applied when domain is set) |
-| `HMD_USECDN` | `true` or `false` | set to use CDN resources or not (default is `true`) |
-| `HMD_ALLOW_ANONYMOUS` | `true` or `false` | set to allow anonymous usage (default is `true`) |
-| `HMD_ALLOW_ANONYMOUS_EDITS` | `true` or `false` | if `allowAnonymous` is `true`, allow users to select `freely` permission, allowing guests to edit existing notes (default is `false`) |
-| `HMD_ALLOW_FREEURL` | `true` or `false` | set to allow new note creation by accessing a nonexistent note URL |
-| `HMD_DEFAULT_PERMISSION` | `freely`, `editable`, `limited`, `locked` or `private` | set notes default permission (only applied on signed users) |
-| `HMD_DB_URL` | `mysql://localhost:3306/database` | set the database URL |
-| `HMD_SESSION_SECRET` | no example | Secret used to sign the session cookie. If non is set, one will randomly generated on startup |
-| `HMD_SESSION_LIFE` | `1209600000` | Session life time. (milliseconds) |
-| `HMD_FACEBOOK_CLIENTID` | no example | Facebook API client id |
-| `HMD_FACEBOOK_CLIENTSECRET` | no example | Facebook API client secret |
-| `HMD_TWITTER_CONSUMERKEY` | no example | Twitter API consumer key |
-| `HMD_TWITTER_CONSUMERSECRET` | no example | Twitter API consumer secret |
-| `HMD_GITHUB_CLIENTID` | no example | GitHub API client id |
-| `HMD_GITHUB_CLIENTSECRET` | no example | GitHub API client secret |
-| `HMD_GITLAB_SCOPE` | `read_user` or `api` | GitLab API requested scope (default is `api`) (GitLab snippet import/export need `api` scope) |
-| `HMD_GITLAB_BASEURL` | no example | GitLab authentication endpoint, set to use other endpoint than GitLab.com (optional) |
-| `HMD_GITLAB_CLIENTID` | no example | GitLab API client id |
-| `HMD_GITLAB_CLIENTSECRET` | no example | GitLab API client secret |
-| `HMD_MATTERMOST_BASEURL` | no example | Mattermost authentication endpoint |
-| `HMD_MATTERMOST_CLIENTID` | no example | Mattermost API client id |
-| `HMD_MATTERMOST_CLIENTSECRET` | no example | Mattermost API client secret |
-| `HMD_DROPBOX_CLIENTID` | no example | Dropbox API client id |
-| `HMD_DROPBOX_CLIENTSECRET` | no example | Dropbox API client secret |
-| `HMD_GOOGLE_CLIENTID` | no example | Google API client id |
-| `HMD_GOOGLE_CLIENTSECRET` | no example | Google API client secret |
-| `HMD_LDAP_URL` | `ldap://example.com` | URL of LDAP server |
-| `HMD_LDAP_BINDDN` | no example | bindDn for LDAP access |
-| `HMD_LDAP_BINDCREDENTIALS` | no example | bindCredentials for LDAP access |
-| `HMD_LDAP_SEARCHBASE` | `o=users,dc=example,dc=com` | LDAP directory to begin search from |
-| `HMD_LDAP_SEARCHFILTER` | `(uid={{username}})` | LDAP filter to search with |
-| `HMD_LDAP_SEARCHATTRIBUTES` | `displayName, mail` | LDAP attributes to search with (use comma to separate) |
-| `HMD_LDAP_USERIDFIELD` | `uidNumber` or `uid` or `sAMAccountName` | The LDAP field which is used uniquely identify a user on CodiMD |
-| `HMD_LDAP_USERNAMEFIELD` | Fallback to userid | The LDAP field which is used as the username on CodiMD |
-| `HMD_LDAP_TLS_CA` | `server-cert.pem, root.pem` | Root CA for LDAP TLS in PEM format (use comma to separate) |
-| `HMD_LDAP_PROVIDERNAME` | `My institution` | Optional name to be displayed at login form indicating the LDAP provider |
-| `HMD_SAML_IDPSSOURL` | `https://idp.example.com/sso` | authentication endpoint of IdP. for details, see [guide](docs/guides/auth.md#saml-onelogin). |
-| `HMD_SAML_IDPCERT` | `/path/to/cert.pem` | certificate file path of IdP in PEM format |
-| `HMD_SAML_ISSUER` | no example | identity of the service provider (optional, default: serverurl)" |
-| `HMD_SAML_IDENTIFIERFORMAT` | no example | name identifier format (optional, default: `urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress`) |
-| `HMD_SAML_GROUPATTRIBUTE` | `memberOf` | attribute name for group list (optional) |
-| `HMD_SAML_REQUIREDGROUPS` | `Hackmd-users` | group names that allowed (use vertical bar to separate) (optional) |
-| `HMD_SAML_EXTERNALGROUPS` | `Temporary-staff` | group names that not allowed (use vertical bar to separate) (optional) |
-| `HMD_SAML_ATTRIBUTE_ID` | `sAMAccountName` | attribute map for `id` (optional, default: NameID of SAML response) |
-| `HMD_SAML_ATTRIBUTE_USERNAME` | `mailNickname` | attribute map for `username` (optional, default: NameID of SAML response) |
-| `HMD_SAML_ATTRIBUTE_EMAIL` | `mail` | attribute map for `email` (optional, default: NameID of SAML response if `HMD_SAML_IDENTIFIERFORMAT` is default) |
-| `HMD_IMGUR_CLIENTID` | no example | Imgur API client id |
-| `HMD_EMAIL` | `true` or `false` | set to allow email signin |
-| `HMD_ALLOW_PDF_EXPORT` | `true` or `false` | Enable or disable PDF exports |
-| `HMD_ALLOW_EMAIL_REGISTER` | `true` or `false` | set to allow email register (only applied when email is set, default is `true`. Note `bin/manage_users` might help you if registration is `false`.) |
-| `HMD_ALLOW_GRAVATAR` | `true` or `false` | set to `false` to disable gravatar as profile picture source on your instance |
-| `HMD_IMAGE_UPLOAD_TYPE` | `imgur`, `s3`, `minio` or `filesystem` | Where to upload images. For S3, see our Image Upload Guides for [S3](docs/guides/s3-image-upload.md) or [Minio](docs/guides/minio-image-upload.md) |
-| `HMD_S3_ACCESS_KEY_ID` | no example | AWS access key id |
-| `HMD_S3_SECRET_ACCESS_KEY` | no example | AWS secret key |
-| `HMD_S3_REGION` | `ap-northeast-1` | AWS S3 region |
-| `HMD_S3_BUCKET` | no example | AWS S3 bucket name |
-| `HMD_MINIO_ACCESS_KEY` | no example | Minio access key |
-| `HMD_MINIO_SECRET_KEY` | no example | Minio secret key |
-| `HMD_MINIO_ENDPOINT` | `minio.example.org` | Address of your Minio endpoint/instance |
-| `HMD_MINIO_PORT` | `9000` | Port that is used for your Minio instance |
-| `HMD_MINIO_SECURE` | `true` | If set to `true` HTTPS is used for Minio |
-| `HMD_AZURE_CONNECTION_STRING` | no example | Azure Blob Storage connection string |
-| `HMD_AZURE_CONTAINER` | no example | Azure Blob Storage container name (automatically created if non existent) |
-| `HMD_HSTS_ENABLE` | ` true`  | set to enable [HSTS](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) if HTTPS is also enabled (default is ` true`) |
-| `HMD_HSTS_INCLUDE_SUBDOMAINS` | `true` | set to include subdomains in HSTS (default is `true`) |
-| `HMD_HSTS_MAX_AGE` | `31536000` | max duration in seconds to tell clients to keep HSTS status (default is a year) |
-| `HMD_HSTS_PRELOAD` | `true` | whether to allow preloading of the site's HSTS status (e.g. into browsers) |
-| `HMD_CSP_ENABLE` | `true` | whether to enable Content Security Policy (directives cannot be configured with environment variables) |
-| `HMD_CSP_REPORTURI` | `https://<someid>.report-uri.com/r/d/csp/enforce` | Allows to add a URL for CSP reports in case of violations |
+| `CMD_DOMAIN` | `codimd.org` | domain name |
+| `CMD_URL_PATH` | `codimd` | sub URL path, like `www.example.com/<URL_PATH>` |
+| `CMD_PORT` | `80` | web app port |
+| `CMD_ALLOW_ORIGIN` | `localhost, codimd.org` | domain name whitelist (use comma to separate) |
+| `CMD_PROTOCOL_USESSL` | `true` or `false` | set to use SSL protocol for resources path (only applied when domain is set) |
+| `CMD_URL_ADDPORT` | `true` or `false` | set to add port on callback URL (ports `80` or `443` won't be applied) (only applied when domain is set) |
+| `CMD_USECDN` | `true` or `false` | set to use CDN resources or not (default is `true`) |
+| `CMD_ALLOW_ANONYMOUS` | `true` or `false` | set to allow anonymous usage (default is `true`) |
+| `CMD_ALLOW_ANONYMOUS_EDITS` | `true` or `false` | if `allowAnonymous` is `true`, allow users to select `freely` permission, allowing guests to edit existing notes (default is `false`) |
+| `CMD_ALLOW_FREEURL` | `true` or `false` | set to allow new note creation by accessing a nonexistent note URL |
+| `CMD_DEFAULT_PERMISSION` | `freely`, `editable`, `limited`, `locked` or `private` | set notes default permission (only applied on signed users) |
+| `CMD_DB_URL` | `mysql://localhost:3306/database` | set the database URL |
+| `CMD_SESSION_SECRET` | no example | Secret used to sign the session cookie. If non is set, one will randomly generated on startup |
+| `CMD_SESSION_LIFE` | `1209600000` | Session life time. (milliseconds) |
+| `CMD_FACEBOOK_CLIENTID` | no example | Facebook API client id |
+| `CMD_FACEBOOK_CLIENTSECRET` | no example | Facebook API client secret |
+| `CMD_TWITTER_CONSUMERKEY` | no example | Twitter API consumer key |
+| `CMD_TWITTER_CONSUMERSECRET` | no example | Twitter API consumer secret |
+| `CMD_GITHUB_CLIENTID` | no example | GitHub API client id |
+| `CMD_GITHUB_CLIENTSECRET` | no example | GitHub API client secret |
+| `CMD_GITLAB_SCOPE` | `read_user` or `api` | GitLab API requested scope (default is `api`) (GitLab snippet import/export need `api` scope) |
+| `CMD_GITLAB_BASEURL` | no example | GitLab authentication endpoint, set to use other endpoint than GitLab.com (optional) |
+| `CMD_GITLAB_CLIENTID` | no example | GitLab API client id |
+| `CMD_GITLAB_CLIENTSECRET` | no example | GitLab API client secret |
+| `CMD_MATTERMOST_BASEURL` | no example | Mattermost authentication endpoint |
+| `CMD_MATTERMOST_CLIENTID` | no example | Mattermost API client id |
+| `CMD_MATTERMOST_CLIENTSECRET` | no example | Mattermost API client secret |
+| `CMD_DROPBOX_CLIENTID` | no example | Dropbox API client id |
+| `CMD_DROPBOX_CLIENTSECRET` | no example | Dropbox API client secret |
+| `CMD_GOOGLE_CLIENTID` | no example | Google API client id |
+| `CMD_GOOGLE_CLIENTSECRET` | no example | Google API client secret |
+| `CMD_LDAP_URL` | `ldap://example.com` | URL of LDAP server |
+| `CMD_LDAP_BINDDN` | no example | bindDn for LDAP access |
+| `CMD_LDAP_BINDCREDENTIALS` | no example | bindCredentials for LDAP access |
+| `CMD_LDAP_SEARCHBASE` | `o=users,dc=example,dc=com` | LDAP directory to begin search from |
+| `CMD_LDAP_SEARCHFILTER` | `(uid={{username}})` | LDAP filter to search with |
+| `CMD_LDAP_SEARCHATTRIBUTES` | `displayName, mail` | LDAP attributes to search with (use comma to separate) |
+| `CMD_LDAP_USERIDFIELD` | `uidNumber` or `uid` or `sAMAccountName` | The LDAP field which is used uniquely identify a user on CodiMD |
+| `CMD_LDAP_USERNAMEFIELD` | Fallback to userid | The LDAP field which is used as the username on CodiMD |
+| `CMD_LDAP_TLS_CA` | `server-cert.pem, root.pem` | Root CA for LDAP TLS in PEM format (use comma to separate) |
+| `CMD_LDAP_PROVIDERNAME` | `My institution` | Optional name to be displayed at login form indicating the LDAP provider |
+| `CMD_SAML_IDPSSOURL` | `https://idp.example.com/sso` | authentication endpoint of IdP. for details, see [guide](docs/guides/auth.md#saml-onelogin). |
+| `CMD_SAML_IDPCERT` | `/path/to/cert.pem` | certificate file path of IdP in PEM format |
+| `CMD_SAML_ISSUER` | no example | identity of the service provider (optional, default: serverurl)" |
+| `CMD_SAML_IDENTIFIERFORMAT` | no example | name identifier format (optional, default: `urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress`) |
+| `CMD_SAML_GROUPATTRIBUTE` | `memberOf` | attribute name for group list (optional) |
+| `CMD_SAML_REQUIREDGROUPS` | `Hackmd-users` | group names that allowed (use vertical bar to separate) (optional) |
+| `CMD_SAML_EXTERNALGROUPS` | `Temporary-staff` | group names that not allowed (use vertical bar to separate) (optional) |
+| `CMD_SAML_ATTRIBUTE_ID` | `sAMAccountName` | attribute map for `id` (optional, default: NameID of SAML response) |
+| `CMD_SAML_ATTRIBUTE_USERNAME` | `mailNickname` | attribute map for `username` (optional, default: NameID of SAML response) |
+| `CMD_SAML_ATTRIBUTE_EMAIL` | `mail` | attribute map for `email` (optional, default: NameID of SAML response if `CMD_SAML_IDENTIFIERFORMAT` is default) |
+| `CMD_IMGUR_CLIENTID` | no example | Imgur API client id |
+| `CMD_EMAIL` | `true` or `false` | set to allow email signin |
+| `CMD_ALLOW_PDF_EXPORT` | `true` or `false` | Enable or disable PDF exports |
+| `CMD_ALLOW_EMAIL_REGISTER` | `true` or `false` | set to allow email register (only applied when email is set, default is `true`. Note `bin/manage_users` might help you if registration is `false`.) |
+| `CMD_ALLOW_GRAVATAR` | `true` or `false` | set to `false` to disable gravatar as profile picture source on your instance |
+| `CMD_IMAGE_UPLOAD_TYPE` | `imgur`, `s3`, `minio` or `filesystem` | Where to upload images. For S3, see our Image Upload Guides for [S3](docs/guides/s3-image-upload.md) or [Minio](docs/guides/minio-image-upload.md) |
+| `CMD_S3_ACCESS_KEY_ID` | no example | AWS access key id |
+| `CMD_S3_SECRET_ACCESS_KEY` | no example | AWS secret key |
+| `CMD_S3_REGION` | `ap-northeast-1` | AWS S3 region |
+| `CMD_S3_BUCKET` | no example | AWS S3 bucket name |
+| `CMD_MINIO_ACCESS_KEY` | no example | Minio access key |
+| `CMD_MINIO_SECRET_KEY` | no example | Minio secret key |
+| `CMD_MINIO_ENDPOINT` | `minio.example.org` | Address of your Minio endpoint/instance |
+| `CMD_MINIO_PORT` | `9000` | Port that is used for your Minio instance |
+| `CMD_MINIO_SECURE` | `true` | If set to `true` HTTPS is used for Minio |
+| `CMD_AZURE_CONNECTION_STRING` | no example | Azure Blob Storage connection string |
+| `CMD_AZURE_CONTAINER` | no example | Azure Blob Storage container name (automatically created if non existent) |
+| `CMD_HSTS_ENABLE` | ` true`  | set to enable [HSTS](https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security) if HTTPS is also enabled (default is ` true`) |
+| `CMD_HSTS_INCLUDE_SUBDOMAINS` | `true` | set to include subdomains in HSTS (default is `true`) |
+| `CMD_HSTS_MAX_AGE` | `31536000` | max duration in seconds to tell clients to keep HSTS status (default is a year) |
+| `CMD_HSTS_PRELOAD` | `true` | whether to allow preloading of the site's HSTS status (e.g. into browsers) |
+| `CMD_CSP_ENABLE` | `true` | whether to enable Content Security Policy (directives cannot be configured with environment variables) |
+| `CMD_CSP_REPORTURI` | `https://<someid>.report-uri.com/r/d/csp/enforce` | Allows to add a URL for CSP reports in case of violations |
+
+***Note:** Due to the rename process we renamed all `HMD_`-prefix variables to be `CMD_`-prefixed. The old ones continue to work.*
 
 ## Application settings `config.json`