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>

4 files changed, 292 insertions, 160 deletions

diff --git a/README.md b/README.md
index d9301de7..4cae291b 100644
--- a/README.md
+++ b/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`
 
diff --git a/lib/config/environment.js b/lib/config/environment.js
index 0ca3d920..d850ac9d 100644
--- a/lib/config/environment.js
+++ b/lib/config/environment.js
@@ -3,123 +3,123 @@
 const {toBooleanConfig, toArrayConfig, toIntegerConfig} = require('./utils')
 
 module.exports = {
-  domain: process.env.HMD_DOMAIN,
-  urlPath: process.env.HMD_URL_PATH,
-  port: toIntegerConfig(process.env.HMD_PORT),
-  urlAddPort: toBooleanConfig(process.env.HMD_URL_ADDPORT),
-  useSSL: toBooleanConfig(process.env.HMD_USESSL),
+  domain: process.env.CMD_DOMAIN,
+  urlPath: process.env.CMD_URL_PATH,
+  port: toIntegerConfig(process.env.CMD_PORT),
+  urlAddPort: toBooleanConfig(process.env.CMD_URL_ADDPORT),
+  useSSL: toBooleanConfig(process.env.CMD_USESSL),
   hsts: {
-    enable: toBooleanConfig(process.env.HMD_HSTS_ENABLE),
-    maxAgeSeconds: process.env.HMD_HSTS_MAX_AGE,
-    includeSubdomains: toBooleanConfig(process.env.HMD_HSTS_INCLUDE_SUBDOMAINS),
-    preload: toBooleanConfig(process.env.HMD_HSTS_PRELOAD)
+    enable: toBooleanConfig(process.env.CMD_HSTS_ENABLE),
+    maxAgeSeconds: process.env.CMD_HSTS_MAX_AGE,
+    includeSubdomains: toBooleanConfig(process.env.CMD_HSTS_INCLUDE_SUBDOMAINS),
+    preload: toBooleanConfig(process.env.CMD_HSTS_PRELOAD)
   },
   csp: {
-    enable: toBooleanConfig(process.env.HMD_CSP_ENABLE),
-    reportURI: process.env.HMD_CSP_REPORTURI
-  },
-  protocolUseSSL: toBooleanConfig(process.env.HMD_PROTOCOL_USESSL),
-  allowOrigin: toArrayConfig(process.env.HMD_ALLOW_ORIGIN),
-  useCDN: toBooleanConfig(process.env.HMD_USECDN),
-  allowAnonymous: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS),
-  allowAnonymousEdits: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS_EDITS),
-  allowFreeURL: toBooleanConfig(process.env.HMD_ALLOW_FREEURL),
-  defaultPermission: process.env.HMD_DEFAULT_PERMISSION,
-  dbURL: process.env.HMD_DB_URL,
-  sessionSecret: process.env.HMD_SESSION_SECRET,
-  sessionLife: toIntegerConfig(process.env.HMD_SESSION_LIFE),
-  imageUploadType: process.env.HMD_IMAGE_UPLOAD_TYPE,
+    enable: toBooleanConfig(process.env.CMD_CSP_ENABLE),
+    reportURI: process.env.CMD_CSP_REPORTURI
+  },
+  protocolUseSSL: toBooleanConfig(process.env.CMD_PROTOCOL_USESSL),
+  allowOrigin: toArrayConfig(process.env.CMD_ALLOW_ORIGIN),
+  useCDN: toBooleanConfig(process.env.CMD_USECDN),
+  allowAnonymous: toBooleanConfig(process.env.CMD_ALLOW_ANONYMOUS),
+  allowAnonymousEdits: toBooleanConfig(process.env.CMD_ALLOW_ANONYMOUS_EDITS),
+  allowFreeURL: toBooleanConfig(process.env.CMD_ALLOW_FREEURL),
+  defaultPermission: process.env.CMD_DEFAULT_PERMISSION,
+  dbURL: process.env.CMD_DB_URL,
+  sessionSecret: process.env.CMD_SESSION_SECRET,
+  sessionLife: toIntegerConfig(process.env.CMD_SESSION_LIFE),
+  imageUploadType: process.env.CMD_IMAGE_UPLOAD_TYPE,
   imgur: {
-    clientID: process.env.HMD_IMGUR_CLIENTID
+    clientID: process.env.CMD_IMGUR_CLIENTID
   },
   s3: {
-    accessKeyId: process.env.HMD_S3_ACCESS_KEY_ID,
-    secretAccessKey: process.env.HMD_S3_SECRET_ACCESS_KEY,
-    region: process.env.HMD_S3_REGION
+    accessKeyId: process.env.CMD_S3_ACCESS_KEY_ID,
+    secretAccessKey: process.env.CMD_S3_SECRET_ACCESS_KEY,
+    region: process.env.CMD_S3_REGION
   },
   minio: {
-    accessKey: process.env.HMD_MINIO_ACCESS_KEY,
-    secretKey: process.env.HMD_MINIO_SECRET_KEY,
-    endPoint: process.env.HMD_MINIO_ENDPOINT,
-    secure: toBooleanConfig(process.env.HMD_MINIO_SECURE),
-    port: toIntegerConfig(process.env.HMD_MINIO_PORT)
+    accessKey: process.env.CMD_MINIO_ACCESS_KEY,
+    secretKey: process.env.CMD_MINIO_SECRET_KEY,
+    endPoint: process.env.CMD_MINIO_ENDPOINT,
+    secure: toBooleanConfig(process.env.CMD_MINIO_SECURE),
+    port: toIntegerConfig(process.env.CMD_MINIO_PORT)
   },
-  s3bucket: process.env.HMD_S3_BUCKET,
+  s3bucket: process.env.CMD_S3_BUCKET,
   azure: {
-    connectionString: process.env.HMD_AZURE_CONNECTION_STRING,
-    container: process.env.HMD_AZURE_CONTAINER
+    connectionString: process.env.CMD_AZURE_CONNECTION_STRING,
+    container: process.env.CMD_AZURE_CONTAINER
   },
   facebook: {
-    clientID: process.env.HMD_FACEBOOK_CLIENTID,
-    clientSecret: process.env.HMD_FACEBOOK_CLIENTSECRET
+    clientID: process.env.CMD_FACEBOOK_CLIENTID,
+    clientSecret: process.env.CMD_FACEBOOK_CLIENTSECRET
   },
   twitter: {
-    consumerKey: process.env.HMD_TWITTER_CONSUMERKEY,
-    consumerSecret: process.env.HMD_TWITTER_CONSUMERSECRET
+    consumerKey: process.env.CMD_TWITTER_CONSUMERKEY,
+    consumerSecret: process.env.CMD_TWITTER_CONSUMERSECRET
   },
   github: {
-    clientID: process.env.HMD_GITHUB_CLIENTID,
-    clientSecret: process.env.HMD_GITHUB_CLIENTSECRET
+    clientID: process.env.CMD_GITHUB_CLIENTID,
+    clientSecret: process.env.CMD_GITHUB_CLIENTSECRET
   },
   gitlab: {
-    baseURL: process.env.HMD_GITLAB_BASEURL,
-    clientID: process.env.HMD_GITLAB_CLIENTID,
-    clientSecret: process.env.HMD_GITLAB_CLIENTSECRET,
-    scope: process.env.HMD_GITLAB_SCOPE
+    baseURL: process.env.CMD_GITLAB_BASEURL,
+    clientID: process.env.CMD_GITLAB_CLIENTID,
+    clientSecret: process.env.CMD_GITLAB_CLIENTSECRET,
+    scope: process.env.CMD_GITLAB_SCOPE
   },
   mattermost: {
-    baseURL: process.env.HMD_MATTERMOST_BASEURL,
-    clientID: process.env.HMD_MATTERMOST_CLIENTID,
-    clientSecret: process.env.HMD_MATTERMOST_CLIENTSECRET
+    baseURL: process.env.CMD_MATTERMOST_BASEURL,
+    clientID: process.env.CMD_MATTERMOST_CLIENTID,
+    clientSecret: process.env.CMD_MATTERMOST_CLIENTSECRET
   },
   oauth2: {
-    baseURL: process.env.HMD_OAUTH2_BASEURL,
-    userProfileURL: process.env.HMD_OAUTH2_USER_PROFILE_URL,
-    userProfileUsernameAttr: process.env.HMD_OAUTH2_USER_PROFILE_USERNAME_ATTR,
-    userProfileDisplayNameAttr: process.env.HMD_OAUTH2_USER_PROFILE_DISPLAY_NAME_ATTR,
-    userProfileEmailAttr: process.env.HMD_OAUTH2_USER_PROFILE_EMAIL_ATTR,
-    tokenURL: process.env.HMD_OAUTH2_TOKEN_URL,
-    authorizationURL: process.env.HMD_OAUTH2_AUTHORIZATION_URL,
-    clientID: process.env.HMD_OAUTH2_CLIENT_ID,
-    clientSecret: process.env.HMD_OAUTH2_CLIENT_SECRET
+    baseURL: process.env.CMD_OAUTH2_BASEURL,
+    userProfileURL: process.env.CMD_OAUTH2_USER_PROFILE_URL,
+    userProfileUsernameAttr: process.env.CMD_OAUTH2_USER_PROFILE_USERNAME_ATTR,
+    userProfileDisplayNameAttr: process.env.CMD_OAUTH2_USER_PROFILE_DISPLAY_NAME_ATTR,
+    userProfileEmailAttr: process.env.CMD_OAUTH2_USER_PROFILE_EMAIL_ATTR,
+    tokenURL: process.env.CMD_OAUTH2_TOKEN_URL,
+    authorizationURL: process.env.CMD_OAUTH2_AUTHORIZATION_URL,
+    clientID: process.env.CMD_OAUTH2_CLIENT_ID,
+    clientSecret: process.env.CMD_OAUTH2_CLIENT_SECRET
   },
   dropbox: {
-    clientID: process.env.HMD_DROPBOX_CLIENTID,
-    clientSecret: process.env.HMD_DROPBOX_CLIENTSECRET,
-    appKey: process.env.HMD_DROPBOX_APPKEY
+    clientID: process.env.CMD_DROPBOX_CLIENTID,
+    clientSecret: process.env.CMD_DROPBOX_CLIENTSECRET,
+    appKey: process.env.CMD_DROPBOX_APPKEY
   },
   google: {
-    clientID: process.env.HMD_GOOGLE_CLIENTID,
-    clientSecret: process.env.HMD_GOOGLE_CLIENTSECRET
+    clientID: process.env.CMD_GOOGLE_CLIENTID,
+    clientSecret: process.env.CMD_GOOGLE_CLIENTSECRET
   },
   ldap: {
-    providerName: process.env.HMD_LDAP_PROVIDERNAME,
-    url: process.env.HMD_LDAP_URL,
-    bindDn: process.env.HMD_LDAP_BINDDN,
-    bindCredentials: process.env.HMD_LDAP_BINDCREDENTIALS,
-    searchBase: process.env.HMD_LDAP_SEARCHBASE,
-    searchFilter: process.env.HMD_LDAP_SEARCHFILTER,
-    searchAttributes: toArrayConfig(process.env.HMD_LDAP_SEARCHATTRIBUTES),
-    usernameField: process.env.HMD_LDAP_USERNAMEFIELD,
-    useridField: process.env.HMD_LDAP_USERIDFIELD,
-    tlsca: process.env.HMD_LDAP_TLS_CA
+    providerName: process.env.CMD_LDAP_PROVIDERNAME,
+    url: process.env.CMD_LDAP_URL,
+    bindDn: process.env.CMD_LDAP_BINDDN,
+    bindCredentials: process.env.CMD_LDAP_BINDCREDENTIALS,
+    searchBase: process.env.CMD_LDAP_SEARCHBASE,
+    searchFilter: process.env.CMD_LDAP_SEARCHFILTER,
+    searchAttributes: toArrayConfig(process.env.CMD_LDAP_SEARCHATTRIBUTES),
+    usernameField: process.env.CMD_LDAP_USERNAMEFIELD,
+    useridField: process.env.CMD_LDAP_USERIDFIELD,
+    tlsca: process.env.CMD_LDAP_TLS_CA
   },
   saml: {
-    idpSsoUrl: process.env.HMD_SAML_IDPSSOURL,
-    idpCert: process.env.HMD_SAML_IDPCERT,
-    issuer: process.env.HMD_SAML_ISSUER,
-    identifierFormat: process.env.HMD_SAML_IDENTIFIERFORMAT,
-    groupAttribute: process.env.HMD_SAML_GROUPATTRIBUTE,
-    externalGroups: toArrayConfig(process.env.HMD_SAML_EXTERNALGROUPS, '|', []),
-    requiredGroups: toArrayConfig(process.env.HMD_SAML_REQUIREDGROUPS, '|', []),
+    idpSsoUrl: process.env.CMD_SAML_IDPSSOURL,
+    idpCert: process.env.CMD_SAML_IDPCERT,
+    issuer: process.env.CMD_SAML_ISSUER,
+    identifierFormat: process.env.CMD_SAML_IDENTIFIERFORMAT,
+    groupAttribute: process.env.CMD_SAML_GROUPATTRIBUTE,
+    externalGroups: toArrayConfig(process.env.CMD_SAML_EXTERNALGROUPS, '|', []),
+    requiredGroups: toArrayConfig(process.env.CMD_SAML_REQUIREDGROUPS, '|', []),
     attribute: {
-      id: process.env.HMD_SAML_ATTRIBUTE_ID,
-      username: process.env.HMD_SAML_ATTRIBUTE_USERNAME,
-      email: process.env.HMD_SAML_ATTRIBUTE_EMAIL
+      id: process.env.CMD_SAML_ATTRIBUTE_ID,
+      username: process.env.CMD_SAML_ATTRIBUTE_USERNAME,
+      email: process.env.CMD_SAML_ATTRIBUTE_EMAIL
     }
   },
-  email: toBooleanConfig(process.env.HMD_EMAIL),
-  allowEmailRegister: toBooleanConfig(process.env.HMD_ALLOW_EMAIL_REGISTER),
-  allowGravatar: toBooleanConfig(process.env.HMD_ALLOW_GRAVATAR),
-  allowPDFExport: toBooleanConfig(process.env.HMD_ALLOW_PDF_EXPORT)
+  email: toBooleanConfig(process.env.CMD_EMAIL),
+  allowEmailRegister: toBooleanConfig(process.env.CMD_ALLOW_EMAIL_REGISTER),
+  allowGravatar: toBooleanConfig(process.env.CMD_ALLOW_GRAVATAR),
+  allowPDFExport: toBooleanConfig(process.env.CMD_ALLOW_PDF_EXPORT)
 }
diff --git a/lib/config/hackmdEnvironment.js b/lib/config/hackmdEnvironment.js
new file mode 100644
index 00000000..e1c11569
--- /dev/null
+++ b/lib/config/hackmdEnvironment.js
@@ -0,0 +1,124 @@
+'use strict'
+
+const {toBooleanConfig, toArrayConfig, toIntegerConfig} = require('./utils')
+
+module.exports = {
+  domain: process.env.HMD_DOMAIN,
+  urlPath: process.env.HMD_URL_PATH,
+  port: toIntegerConfig(process.env.HMD_PORT),
+  urlAddPort: toBooleanConfig(process.env.HMD_URL_ADDPORT),
+  useSSL: toBooleanConfig(process.env.HMD_USESSL),
+  hsts: {
+    enable: toBooleanConfig(process.env.HMD_HSTS_ENABLE),
+    maxAgeSeconds: process.env.HMD_HSTS_MAX_AGE,
+    includeSubdomains: toBooleanConfig(process.env.HMD_HSTS_INCLUDE_SUBDOMAINS),
+    preload: toBooleanConfig(process.env.HMD_HSTS_PRELOAD)
+  },
+  csp: {
+    enable: toBooleanConfig(process.env.HMD_CSP_ENABLE),
+    reportURI: process.env.HMD_CSP_REPORTURI
+  },
+  protocolUseSSL: toBooleanConfig(process.env.HMD_PROTOCOL_USESSL),
+  allowOrigin: toArrayConfig(process.env.HMD_ALLOW_ORIGIN),
+  useCDN: toBooleanConfig(process.env.HMD_USECDN),
+  allowAnonymous: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS),
+  allowAnonymousEdits: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS_EDITS),
+  allowFreeURL: toBooleanConfig(process.env.HMD_ALLOW_FREEURL),
+  defaultPermission: process.env.HMD_DEFAULT_PERMISSION,
+  dbURL: process.env.HMD_DB_URL,
+  sessionSecret: process.env.HMD_SESSION_SECRET,
+  sessionLife: toIntegerConfig(process.env.HMD_SESSION_LIFE),
+  imageUploadType: process.env.HMD_IMAGE_UPLOAD_TYPE,
+  imgur: {
+    clientID: process.env.HMD_IMGUR_CLIENTID
+  },
+  s3: {
+    accessKeyId: process.env.HMD_S3_ACCESS_KEY_ID,
+    secretAccessKey: process.env.HMD_S3_SECRET_ACCESS_KEY,
+    region: process.env.HMD_S3_REGION
+  },
+  minio: {
+    accessKey: process.env.HMD_MINIO_ACCESS_KEY,
+    secretKey: process.env.HMD_MINIO_SECRET_KEY,
+    endPoint: process.env.HMD_MINIO_ENDPOINT,
+    secure: toBooleanConfig(process.env.HMD_MINIO_SECURE),
+    port: toIntegerConfig(process.env.HMD_MINIO_PORT)
+  },
+  s3bucket: process.env.HMD_S3_BUCKET,
+  azure: {
+    connectionString: process.env.HMD_AZURE_CONNECTION_STRING,
+    container: process.env.HMD_AZURE_CONTAINER
+  },
+  facebook: {
+    clientID: process.env.HMD_FACEBOOK_CLIENTID,
+    clientSecret: process.env.HMD_FACEBOOK_CLIENTSECRET
+  },
+  twitter: {
+    consumerKey: process.env.HMD_TWITTER_CONSUMERKEY,
+    consumerSecret: process.env.HMD_TWITTER_CONSUMERSECRET
+  },
+  github: {
+    clientID: process.env.HMD_GITHUB_CLIENTID,
+    clientSecret: process.env.HMD_GITHUB_CLIENTSECRET
+  },
+  gitlab: {
+    baseURL: process.env.HMD_GITLAB_BASEURL,
+    clientID: process.env.HMD_GITLAB_CLIENTID,
+    clientSecret: process.env.HMD_GITLAB_CLIENTSECRET,
+    scope: process.env.HMD_GITLAB_SCOPE
+  },
+  mattermost: {
+    baseURL: process.env.HMD_MATTERMOST_BASEURL,
+    clientID: process.env.HMD_MATTERMOST_CLIENTID,
+    clientSecret: process.env.HMD_MATTERMOST_CLIENTSECRET
+  },
+  oauth2: {
+    baseURL: process.env.HMD_OAUTH2_BASEURL,
+    userProfileURL: process.env.HMD_OAUTH2_USER_PROFILE_URL,
+    userProfileUsernameAttr: process.env.HMD_OAUTH2_USER_PROFILE_USERNAME_ATTR,
+    userProfileDisplayNameAttr: process.env.HMD_OAUTH2_USER_PROFILE_DISPLAY_NAME_ATTR,
+    userProfileEmailAttr: process.env.HMD_OAUTH2_USER_PROFILE_EMAIL_ATTR,
+    tokenURL: process.env.HMD_OAUTH2_TOKEN_URL,
+    authorizationURL: process.env.HMD_OAUTH2_AUTHORIZATION_URL,
+    clientID: process.env.HMD_OAUTH2_CLIENT_ID,
+    clientSecret: process.env.HMD_OAUTH2_CLIENT_SECRET
+  },
+  dropbox: {
+    clientID: process.env.HMD_DROPBOX_CLIENTID,
+    clientSecret: process.env.HMD_DROPBOX_CLIENTSECRET,
+    appKey: process.env.HMD_DROPBOX_APPKEY
+  },
+  google: {
+    clientID: process.env.HMD_GOOGLE_CLIENTID,
+    clientSecret: process.env.HMD_GOOGLE_CLIENTSECRET
+  },
+  ldap: {
+    providerName: process.env.HMD_LDAP_PROVIDERNAME,
+    url: process.env.HMD_LDAP_URL,
+    bindDn: process.env.HMD_LDAP_BINDDN,
+    bindCredentials: process.env.HMD_LDAP_BINDCREDENTIALS,
+    searchBase: process.env.HMD_LDAP_SEARCHBASE,
+    searchFilter: process.env.HMD_LDAP_SEARCHFILTER,
+    searchAttributes: toArrayConfig(process.env.HMD_LDAP_SEARCHATTRIBUTES),
+    usernameField: process.env.HMD_LDAP_USERNAMEFIELD,
+    useridField: process.env.HMD_LDAP_USERIDFIELD,
+    tlsca: process.env.HMD_LDAP_TLS_CA
+  },
+  saml: {
+    idpSsoUrl: process.env.HMD_SAML_IDPSSOURL,
+    idpCert: process.env.HMD_SAML_IDPCERT,
+    issuer: process.env.HMD_SAML_ISSUER,
+    identifierFormat: process.env.HMD_SAML_IDENTIFIERFORMAT,
+    groupAttribute: process.env.HMD_SAML_GROUPATTRIBUTE,
+    externalGroups: toArrayConfig(process.env.HMD_SAML_EXTERNALGROUPS, '|', []),
+    requiredGroups: toArrayConfig(process.env.HMD_SAML_REQUIREDGROUPS, '|', []),
+    attribute: {
+      id: process.env.HMD_SAML_ATTRIBUTE_ID,
+      username: process.env.HMD_SAML_ATTRIBUTE_USERNAME,
+      email: process.env.HMD_SAML_ATTRIBUTE_EMAIL
+    }
+  },
+  email: toBooleanConfig(process.env.HMD_EMAIL),
+  allowEmailRegister: toBooleanConfig(process.env.HMD_ALLOW_EMAIL_REGISTER),
+  allowPDFExport: toBooleanConfig(process.env.HMD_ALLOW_PDF_EXPORT)
+}
diff --git a/lib/config/index.js b/lib/config/index.js
index 79330443..760d94a1 100644
--- a/lib/config/index.js
+++ b/lib/config/index.js
@@ -33,6 +33,7 @@ merge(config, debugConfig)
 merge(config, packageConfig)
 merge(config, fileConfig)
 merge(config, require('./oldEnvironment'))
+merge(config, require('./hackmdEnvironment'))
 merge(config, require('./environment'))
 merge(config, require('./dockerSecret'))
 
@@ -122,6 +123,11 @@ for (let i = keys.length; i--;) {
   }
 }
 
+// Notify users about the prefix change and inform them they use legacy prefix for environment variables
+if (Object.keys(process.env).toString().indexOf('HMD_') !== -1) {
+  logger.warn('Using legacy HMD prefix for environment variables. Please change your variables in future. For details see: https://github.com/hackmdio/codimd#environment-variables-will-overwrite-other-server-configs')
+}
+
 // Generate session secret if it stays on default values
 if (config.sessionSecret === 'secret') {
   logger.warn('Session secret not set. Using random generated one. Please set `sessionSecret` in your config.js file. All users will be logged out.')