Extensions & Integrations
Multisite Apostrophe Assembly



@apostrophecms-pro/multisite
For Apostrophe 3.x. This is a private npm module, please contact ApostropheCMS for an enterprise license.
What's it do?
This module lets you have many ApostropheCMS websites running on a single codebase in a single Node.js process. Each has its own database, users, media uploads, etc. Sites can be created and managed via a dashboard site.
Those using this module should be members of our strongly advised to join our Apostrophe Enterprise Support program. We will work with you to make sure your customers receive the high availability and durability this module is designed to provide.
Note: you do not need this module in most Apostrophe projects. It is designed to support projects that require many independently edited sites with the same source code and configuration.
Requirements (Node 14 or better)
You must have a release of Node.js which is under LTS support and supported by Apostrophe 3.x, currently Node 14.x or better.
The minimum version of Apostrophe to be used in a project is 3.24.0
.
Installation
This software is released as an npm private package. Here are the steps to install it.
First, create an npm account if you do not have one.
Second, provide your npm account username to your Apostrophe Technologies representative, requesting access to install the cloud tools. You may receive a confirmation email from npm.
Third, log into npm with the npm login
command if you have not already done so.
Now you will be able to install the package normally. However, you will also need an access token in your CI/CD or other deployment system. See "npm private package deployment" below.
# You must be logged into an npm account that has been granted membership
# in our apostrophecms-pro npm organization
npm login
npm install @apostrophecms-pro/multisite
npm install apostrophe
Sample app.js
const multi = require('@apostrophecms-pro/multisite')({
// Port to listen on, or set the `PORT` env var (which Heroku will do for you)
port: 3000,
// Change to a fallback prefix more appropriate so you can have multiple unrelated
// multisite projects
shortNamePrefix: process.env.SHORTNAME_PREFIX || 'multisite-',
// MongoDB URL for database connection. If you have multiple physical
// servers then you MUST configure this to a SHARED server (which
// may be a replica set). Can be set via MONGODB_URL env var
mongodbUrl: 'mongodb://localhost:27017',
// Session secret. Please use a unique string.
sessionSecret: 'thisismadeup',
// This is our default HTTP Keep-Alive time, in ms, for reuse of
// connections. Should be longer than that of the reverse proxy
// (nginx: 75 seconds, AWS ELB: 60 seconds, etc)
keepAliveTimeout: 100 * 1000,
// Apostrophe configuration for your hosted sites.
// Just one config for all of them; per-site config could be
// user editable settings in apostrophe-global.
// You can also do much more in `sites/lib/modules`,
// following Apostrophe's usual patterns
sites: {
modules: {
'@apostrophecms/page': {
choices: [
{
label: 'Home',
name: '@apostrophecms/home-page'
},
{
label: 'Default',
name: 'default-page'
}
]
}
}
},
// Apostrophe configuration for the dashboard site.
// A `site` module always exists. This is a piece type
// that represents each of the individual sites beyond
// the dashboard.
//
// You can also do much more in `dashboard/lib/modules`,
// following Apostrophe's usual patterns
dashboard: {
modules: {
'site': {
options: {
baseUrlDomains: {
dev: 'localhost:3000',
staging: 'test.dev',
prod: 'test.com'
}
}
}
}
}
}).then(function(result) {
// There is no top level await so we catch this here.
// At this point either the task has run or the site is up.
}).catch(function(err) {
console.error(err);
process.exit(1);
});
Setting baseUrl
and naming environments
It is strongly recommended that you set up the baseUrlDomains
option to the site
module of the dashboard as shown above in order to map all of your sites to subdomains of certain working domains, one per environment. For example you might have one domain for local testing (dev
), one domain for testing code on a cloud that is not the production environment (staging
), and one domain for production (prod
).
When you do so, each site will have a shortname
field in its configuration. That name will be prepended to the appropriate domain in each environment. For instance, in the above configuration, if a site's shortname
is set to products
then the dev
, staging
and prod
hostnames will be http://products.localhost:3000
, https://products.test.dev
, and https://products.test.com
.
The first environment does not have to be named dev
, but Apostrophe does assume the first environment is for local testing on developer workstations. So it is essential to add the port number you plan to test with to the first entry in baseUrlDomains
, as shown above (usually 3000
), and keep in mind that test URLs will use http://
. All other environments assume https://
.
localhost:3000
is a popular choice fordev
because if you test in Chrome, subdomains oflocalhost
automatically resolve to your computer. In other browsers you might need to edit your/etc/hosts
file.
The environment name prod
is special. Only this environment will attempt to serve a site based on its prodHostname
field setting.
Starting up Apostrophe in a specific environment
To let @apostrophecms/multisite
know what environment it is currently running in set an environment variable when starting your app:
ENV=prod node app.js
It is also possible to do it by adding the property env
to your server's data/local.js
file:
module.exports = {
env: 'prod'
}
npm private package deployment
To install this private package in your CI / CD or other deployment system, you will need to generate an npm access token, and configure your project to use it.
First, on your workstation where you have already logged into npm, generate the token:
npm token create --read-only
Second, add a .npmrc
file to the root of your project, exactly as shown. Do not paste the actual token here.
//registry.npmjs.org/:_authToken=${NPM_TOKEN}
Third, add your token as a "secret" in your CI/CD environment, such that it becomes the value of the NPM_TOKEN
environment variable.
For more information and examples, see using npm private packages in a CI/CD workflow.
Running in production: server-specific settings
Sometimes you'll need to change certain options for production use.
You can use a data/local.js
file, like this. It merges automatically with your configuration, do not require the file yourself:
module.exports = {
mongodbUrl: 'mongodb://somewhere-else:27017',
dashboardHostname: [ 'dashboard-prod.myservice.com' ]
};
You should exclude this file from deployment so it can be different on staging and production servers, as opposed to local dev environments.
Your hosted sites share
sites/data/local.js
, and your dashboard site can havedashboard/data/local.js
. They do not read the top-leveldata/local.js
, it is exclusively for the multisite module. All three folders should be excluded from deployment.
Or, you can use environment variables as enumerated above in the example configuration. This is the only way to go with a host like Heroku that does not offer persistent storage on the local drive.
If you simply use a load balancer to point to several processes or servers running
@apostrophecms-pro/multisite
, you will eventually haveapos
objects live for every site that is accessed in each process. This is fine, generally speaking, but if you have hundreds of sites it would make more sense to configure your load balancer to only send site X to servers A, B, and C (to provide some redundancy), and so forth. However that is a load balancer configuration task outside the scope of this module.
Creating sites via the dashboard
First you need to be able to log into the dashboard:
node app @apostrophecms/user:add admin --site=dashboard
Now log into http://dashboard:3000
.
Then, go to the admin bar, pick "Sites", and add a site, giving it one of the hostnames you added to /etc/hosts
. Let's say the hostname is one
.
Remember that you'll need to add staging and production hostnames here too at some point.
Now you can access:
http://one:3000
But, you still don't have any users for one
. So make a user there:
node app @apostrophecms/user:add admin --site=one
How to run tasks
To run a task for the dashboard site:
node app @apostrophecms/migration:migrate --site=dashboard
To run a task for an individual site, by its hostname or _id
:
node app @apostrophecms/migration:migrate --site=example.com
To run a task for all hosted sites (not the dashboard):
node app @apostrophecms/migration:migrate --all-sites
To run that task without forking a new process for each invocation, which works only with well-behaved tasks that don't try to exit the process on their own:
node app @apostrophecms/migration:migrate --all-sites --without-forking --concurrency=3
This significantly improves performance. The appropriate level of concurrency
depends on your task; you may leave this argument off.
We do fork just a little. To combat any memory leaks, if there are more than ten sites to run the task for, sub-processes will be forked to process them sequentially in groups of 10 using the
--sites
option. The end result is the same, andconcurrency
still applies within each group.
To run a task on a temporary "hosted" site which will be deleted after the task:
node app @apostrophecms/asset:build --temporary-site
--temporary-site
is good for generating assets that are shared between the hosted sites, but not the dashboard. Note that--temporary-site
and--all-sites
do not work for interactive tasks that prompt for information, like@apostrophecms/user:change-password
, or otherwise read from standard input. Currently these options print all output at the end.
If the site objects in your dashboard have a theme
schema field (typically of type select
), then you may generate assets for each theme:
# TODO does this make sense in 3.x?
node app @apostrophecms/asset:build --temporary-site --theme=theme-one
node app @apostrophecms/asset:build --temporary-site --theme=theme-two
For a complete solution to generate per-theme assets you will also need to override the
getNamespace
method of@apostrophecms/asset
as shown here.
Running scheduled tasks just once across a cluster
You may have multiple application servers or workers which could potentially run each task, and need them to run, for instance, only once per hour. You need them to run only once even if you have many servers.
You can do that by configuring cron jobs like this across all servers. These cron jobs don't call out the specific tasks, they just provide a point of entry:
0 0 * * * ( cd /opt/stagecoach/apps/my-app/current && node app tasks --frequency=daily )
0 * * * * ( cd /opt/stagecoach/apps/my-app/current && node app tasks --frequency=hourly )
Now configure the top-level tasks
option, which is a peer of sites
and dashboard
, it is not nested within them:
tasks: {
// These tasks are run for all sites, i.e. like the `--all-sites` option
'all-sites': {
hourly: [
// Run this task hourly but only on the server that
// happens to grab the lock first
'products:sync'
],
daily: [ ... also supported ]
},
// These tasks are run for the dashboard site, i.e. like `--site=dashboard`
dashboard: {
hourly: [
'some-module-name:some-task-name'
],
daily: [ ... also supported ]
}
}
This way your crontab file doesn't have to contain any
custom state. It just contains these standard entries and
your configuration in app.js
determines what tasks are run,
leveraging cron only as a way to begin invocation at the
right time.
Apostrophe will use locks and check the most recent start time to avoid redundancy.
Code and templates for the hosted sites
These live in sites/lib/modules
of your project.
Code and templates for the dashboard site
These live in dashboard/lib/modules
of your project. Be aware that there is already a pieces module called sites
, which powers the proxy that routes traffic to the individual sites. You can extend that module with more fields.
"But where do I configure the individual sites?"
The entire point of this module is to share all of the code between sites. If we didn't want that, we'd build and deploy separate sites and we wouldn't need this module.
So if you are using this approach, then all configuration that varies between sites must take place via the user interface.
For instance, you might use the @apostrophecms/palettapostrophe-palette
module, or just use @apostrophecms/global
preferences for high level choices like site-wide styles or Google Analytics IDs, as documented on the Apostrophe website.
"How can I mirror certain properties between apostrophe-global of individual sites and the site
piece in the dashboard, so they both can see that stuff?"
TODO.
Is there a way to customize per-site configuration as if they had their own app.js
?
Yes. If the sites
option is a function rather than an object, it is invoked with the site
object, and must return an object.
This function may be an async
function and will be awaited.
This allows you to take the properties of the dashboard’s site
object into account when the site “spins up.”
In addition, any time a site
piece is saved in the dashboard, all existing apos
objects for that site are invalidated, meaning that they will be created anew on the next web request. This allows the options.sites
function to take the new properties of site
into account.
This can be used to achieve effects such as passing a new list of locales to apostrophe-workflow
based on user input in the dashboard.
Note that this means the site
object should not be updated frequently or for trivial reasons via Apostrophe’s update
method — only when significant configuration changes occur. However, it is never a good idea in any case to implement a hit counter via Apostrophe’s model layer methods. As always, use a direct MongoDB update
with $inc
for such purposes.
Separate frontend assets for separate themes
There is one limitation to per-site configuration: the sites function must always result in the same set of assets being pushed by the modules, except if the decision is made based on a theme
property of each site object. If you add a theme
field to the sites
pieces module in the dashboard, you may use logic based on site.theme
in the sites function to decide which modules will be included in the project, even if this changes the assets.
In addition, to produce a different asset bundle for each theme, you must override the getNamespace
method of the @apostrophecms/asset
module for your sites. This function must return the theme name associated with your site.
Here is a working example.
// in app.js
sites(site) => {
return {
// Pass the theme name in as a global option to the apos object. If you
// add support for themes later in your project, make sure you provide
// a default theme name for old sites
theme: site.theme || 'default',
modules: {
// Other configuration here. Include various modules, or not,
// based on `site.theme`
}
};
}
// in sites/modules/@apostrophecms/asset/index.js
module.exports = {
methods(self, options) {
return {
getNamespace() {
return self.apos.options.theme;
}
};
}
};
In order to speed up your development build, you may build only a specific theme while in development via the APOS_THEME
environment variable. In the folowing example only the demo
theme will be automatically built at startup.
APOS_THEME=demo npm run dev
Websockets
This module optionally supports forwarding websocket connections correctly to each site. To take advantage of this feature you must provide an Apostrophe module named websocket
within the sites
and/or dashboard
folder of your project. If there is such a module, new websocket connections with the appropriate hostname will automatically be passed to its connected
method, which must exist. As with everything else it is possible to provide such a module in some themes and not others. If a particular site (or the dashboard) receives a websocket connection and has no websocket
module, the connection will be immediately closed.
To activate this feature, the top-level websocket: true
option must also be set in app.js
.
For example:
// app.js
const multi = require('@apostrophecms-pro/multisite')({
// ...among other options ...
websocket: true
});
// sites/index.js
module.exports = {
modules: {
// Activate the websocket module
websocket: {}
}
};
// sites/modules/websocket/index.js
//
// Implement the websocket module
module.exports = {
methods(self) {
return {
connected(ws, req) {
ws.send(JSON.stringify({
type: 'hello'
}));
ws.on('message', message => {
// handle an incoming message
});
ws.on('close', {
// handle closure
});
}
}
}
}
⚠️
req.session
andreq.user
do not automatically carry over to websocket connections. Thereq
object is a raw Node.jshttp.ClientRequest
object, it does not have all of the features of an Expressreq
object. You can however accessreq.headers
and other useful properties.
Using AWS (or Azure, etc.)
You can achieve this by passing uploadfs settings to the @apostrophecms/attachment
module for both dashboard
and sites
, or just set these environment variables when running the application:
APOS_S3_BUCKET YOUR-bucket-name
APOS_S3_SECRET YOUR-s3-secret
APOS_S3_KEY YOUR-s3-key
APOS_S3_REGION YOUR-chosen-region
@apostrophecms-pro/multisite
will automatically add a distinct prefix to the paths for each individual site's assets.
Serving static assets via AWS, Azure, etc.
In addition to the above environment variables, add:
NODE_ENV=production
APOS_UPLOADFS_ASSETS=1
All of these must be set both when running the asset build task and when running the actual sites. The asset build task will copy the assets to the appropriate bucket.
Using a CDN
If you are using a CDN such as Cloudfront or Cloudflare that automatically mirrors the contents of your S3 bucket or other uploadfs cloud storage, you can specify that CDN so that Apostrophe generates public URLs that reference it instead of pointing directly to the cloud storage:
CDN=https://myproject.my-cdn.com
Since the sites share a single cloud storage facility with a single URL, they also share a single CDN in front of that.
Deployment issues
If you are not using AWS S3 or similar, you will need to persist sites/public/uploads
and dashboard/public/uploads
between deployments.
Logging
By default only warnings and errors are logged when NODE_ENV
is production
. In development, everything is logged by default.
To log everything in production, set the VERBOSE environment variable:
VERBOSE=1 node app
You can also select one or more of the four possible logging levels:
LOG_LEVEL=info,debug,warn,error node app
info
and debug
are written to standard output, while warn
and error
are written to standard error. When not running a command line task on behalf of a single site, the output is prefaced with the shortname of the site responsible. TODO: provide options to replace this simple logger.
Private dashboards
The dashboard
configuration object accepts a top-level privateDashboards
option. If set to true
, non-admin dashboard users can only see sites they created in the dashboard, unless the new "All Sites" field is checked for that user. This allows multiple tenants to have the privilege of creating sites without having access to modify each other's sites.
When creating a user for this purpose, don't forget to also give the new dashboard user the "Editor" role. The "Guest" role is not sufficient to create sites.
This is unrelated to permissions within individual sites, which are separate from the dashboard as always.
Accessing the MongoDB utilities for a specific site
The database name for a site is the prefix, followed by the _id
of the site piece. However this is awkward to look up on your own, so we have provided utility tasks to access the MongoDB utilities:
# Mongo shell for the dashboard site
node app mongo:mongo --site=dashboard
# Mongo shell for an individual site; use its hostname
# in the appropriate environment
node app mongo:mongo --site=test1.localhost
# mongodump
node app mongo:mongodump --site=test1.localhost
# mongorestore, with the --drop option to prevent
# doubled content
node app mongo:mongorestore --site=test1.localhost -- --drop
Note the use of --
by itself as an end marker for the options to Apostrophe, allowing the --drop
option to be passed on to mongodump
.
Resource leak mitigation
If you suspect your application is slowly leaking memory, HTTP sockets or some other resource that eventually renders it nonresponsive, you can set the maxRequestsBeforeShutdown
option. The application will automatically exit after that number of requests. By default, this mechanism calls process.exit(0)
. You can change this behavior by passing a custom exit
function to @apostrophecms-pro/multisite
as an option.
10000
is a reasonable value for this option.
Of course this assumes you are using pm2
, forever
or another mechanism to restart the application when it exits, and that you are also running at least one other process concurrently, so that they can cover for each other during restarts.
To avoid 502 Bad Gateway errors when all of the processes stop at the same time, for instance due to round robin scheduling that delivers equal numbers of requests to them, a random number of additional requests between 0 and 1000 are accepted per process. This can be adjusted via the additionalRequestsBeforeShutdown
option; set to 0 for no random factor at all.
Legacy features
Using the dashboardHostname
option
The dashboardHostname
option may be configured to specify the hostname of the dashboard, or an array of permissible hostnames for the dashboard. However best practice is to let Apostrophe infer it from the baseUrlDomains
option, to which dashboard.
will be prepended automatically.
Leaving out baseUrlDomains
The baseUrlDomains
option to the site
module can be skipped. If it is missing, three url fields (dev, staging, and prod) will become part of the schema for each site. This is more work and provides less flexibility. We recommend baseUrlDomains
.
If sites were previously created using this default method, after having configured baseUrlDomains
it is possible to run the task node app sites:transition-shortname --site=dashboard
to fill in the missing shortname for each site base on the first populated hostname field, if any.
Project contribution
Run tests
Tests can be run locally if hosts are on your machine with sudo nano /etc/hosts
on Linux or MacOS.
Add this line to the /etc/hosts
file: 127.0.0.1 dashboard.test site.test site2.test fr.site.test en-gb.site.test site.test.prod fr.site.test.prod en-gb.site.test.prod example.com exemple.fr
and save.
If modification of the hosts file is not an option, tests can be run through Docker by installing Docker and docker-compose. Then, run docker-compose up
. By default, it will launch npm test
. You can also add a TEST_CMD
variable to launch another command. For example, TEST_CMD='npm run test:watch' docker-compose up
to launch tests in watch mode and reload tests as you modify them.
Code linting
When contributing to this project, run npm run lint
before pushing code in order to facilitate code review.
Localized domain names
It is possible to allow dashboard administrators to define the locales for each site.
To do that, you must set the flag localizedSites
to true, in the site
module options.
// in dashboard/modules/site/index.js
module.exports = {
options: {
baseUrlDomains: {
local: 'localhost:3000',
staging: 'staging.com',
prod: 'production.com'
},
localizedSites: true,
}
}
baseUrlDomains
must be defined to allow localized domains.
Once this has been done, you can access new fields in the locales
tab when editing your site on the dashboard.
You can add as many locales as you want, and for each of them you can give it a name, label, prefix, choose if you want a separate host, and if so, set a separate production hostname.
If the separate host is set to true
, the locale will be used as a subdomain of the domain name
in addition to the separate production hostname if that field has been filled out and DNS has been configured for it.
The prefix will always be used if it exists, allowing multiple locales to share the same separateProductionHostname
.
Let's say we have a French locale with these options:
Fields | Values |
---|---|
Label | French |
Prefix | |
Separate Host | true |
Separate Production Hostname | my-french-site.com |
And our site piece shortName
is set to site
.
In this case, if the environment variable ENV
is set to staging
, we will have fr.site.staging.com
as the hostname.
If we are in production, so ENV
is set to prod
, we will have fr.site.production.com
and my-french-site.com
(only in production) as hostnames.
If we set a prefix, such as /fr
, then only URLs in which the path part begins with /fr
will display content from that locale. This way some locales can share the same separateProductionHostname
being differentiated by the prefix.
If separateHost
is set to false
and prefix
is /fr
, we simply use the latter to differentiate locales: site.localhost:3000/fr
, site.staging.com/fr
, site.production.com/fr
.
Note that you can have only one locale with no prefix and no separate host, that would be the default one.
Private locales
You can make a locale private
, meaning that this locale is only visible for logged in users.
There is a new boolean
field with the label Private Locale
for each configured locale in your dashboard.
When adding the option localizedSites
to the site
module of your project, instead of true
you can pass an object and specify the option privateByDefault
.
If this sub-option is set to true
, every new locale created will have its private
property set to true
by default, otherwise they will be public by default.
{
options: {
baseUrlDomains: { ... },
localizedSites: {
privateByDefault: true
}
}
}
The private
option will be editable from the dashboard when editing your site locales.
Renaming locales
It is possible to rename a locale via the interface. However this is time consuming and pauses access to the site so it is best to address this early before the site is public.
Customizing paused sites
In the rare event that a site has been paused to perform an sensitive operation, such as renaming a locale, a maintenance page automatically appears, reassuring the user and refreshing every 10 seconds until the site is available.
The status code defaults to 503
but can be customized via the pausedStatus
option to
the multisite module.
It is also possible to completely customize this page by passing a pausedHandler
function to the multisite module.
This function receives the req, res
(e.g. the Express request and response objects) and must send a
response to res
, as in this minimal example. Note that the status code becomes your responsibility if
you pass a pausedHandler
function.
pausedHandler(req, res) {
res.status(self.options.pausedStatus || 503);
return res.send(`
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>One Moment Please</title>
<script>
setTimeout(function() {
window.location.reload();
}, 10000);
</script>
</head>
<body>
<h1>One Moment Please</h1>
<p>This page will refresh in 10 seconds.</p>
</body>
</html>
`.trim());
}
The handler must be self-contained because of the risk that any operations within Apostrophe could trigger the race conditions that the pause mechanism is designed to avoid.
Unpausing sites
In the very unlikely event of an uncaught exception during an operation such as renaming a locale, a site could remain in the paused state. This can be cleared with the following command line task:
node app site:unpause shortname-of-site-goes-here --site=dashboard
The hostname of _id
of the site can also be used. Note that --site
is set to dashboard
because this task operates at the dashboard level.