handlers | ||
mbtiles | ||
vendor | ||
.gitignore | ||
.travis.yml | ||
Dockerfile | ||
go.mod | ||
go.sum | ||
LICENSE | ||
main.go | ||
Procfile | ||
README.md |
mbtileserver
A simple Go-based server for map tiles stored in mbtiles format.
Requires Go 1.10+.
It currently provides support for png
, jpg
, and pbf
(vector tile)
tilesets according to version 1.0 of the mbtiles specification. Tiles
are served following the XYZ tile scheme, based on the Web Mercator
coordinate reference system. UTF8 Grids are also supported.
In addition to tile-level access, it provides:
- TileJSON 2.1.0 endpoint for each tileset, with full metadata from the mbtiles file.
- a preview map for exploring each tileset.
- a minimal ArcGIS tile map service API (work in progress)
We have been able to host a bunch of tilesets on an AWS t2.nano virtual machine without any issues.
Goals
- Provide a web tile API for map tiles stored in mbtiles format
- Be fast
- Run on small resource cloud hosted machines (limited memory & CPU)
- Be easy to install and operate
Installation
You can install this project with
go get github.com/consbio/mbtileserver
This will create and install an executable called mbtileserver
.
Usage
From within the repository root ($GOPATH/bin needs to be in in your $PATH):
$ mbtileserver --help
Serve tiles from mbtiles files.
Usage:
mbtileserver [flags]
Flags:
-c, --cert string X.509 TLS certificate filename. If present, will be used to enable SSL on the server.
-d, --dir string Directory containing mbtiles files. (default "./tilesets")
--domain string Domain name of this server
--dsn string Sentry DSN
-h, --help help for mbtileserver
-k, --key string TLS private key
--path string URL root path of this server (if behind a proxy)
-p, --port int Server port. (default 8000)
-s, --secret-key string Shared secret key used for HMAC authentication
-t, --tls Auto TLS using Let's Encrypt
-r, --redirect Redirect HTTP to HTTPS
--enable-reload Enable graceful reload
-v, --verbose Verbose logging
So hosting tiles is as easy as putting your mbtiles files in the tilesets
directory and starting the server. Woo hoo!
You can have multiple directories in your tilesets
directory; these will be converted into appropriate URLs:
mytiles/foo/bar/baz.mbtiles
will be available at /services/foo/bar/baz
.
When you want to remove, modify, or add new tilesets, simply restart the server process.
If a valid Sentry DSN is provided, warnings, errors, fatal errors, and panics will be reported to Sentry.
If redirect
option is provided, the server also listens on port 80 and redirects to port 443.
If the --tls
option is provided, the Let's Encrypt Terms of Service are accepted automatically on your behalf. Please review them here. Certificates are cached in a .certs
folder created where you are executing mbtileserver
. Please make sure this folder can be written by the mbtileserver
process or you will get errors.
You can also set up server config using environment variables instead of flags, which may be more helpful when deploying in a docker image. Use the associated flag to determine usage. The following variables are available:
PORT
(--port
)TILE_DIR
(--dir
)PATH_PREFIX
(--path
)DOMAIN
(--domain
)TLS_CERT
(--cert
)TLS_PRIVATE_KEY
(--key
)AUTO_TLS
(--tls
)REDIRECT
(--redirect
)DSN
(--dsn
)VERBOSE
(--verbose
)HMAC_SECRET_KEY
(--secret-key
)
Example:
$ PORT=7777 TILE_DIR=./path/to/your/tiles VERBOSE=true mbtileserver
In a docker-compose.yml file it will look like:
mbtileserver:
...
environment:
PORT: 7777
TILE_DIR: "./path/to/your/tiles"
VERBOSE: true
entrypoint: mbtileserver
...
Reload
mbtileserver optionally supports graceful reload (without interrupting any in-progress requests). This functionality
must be enabled with the --enable-reload
flag. When enabled, the server can be reloaded by sending it a HUP
signal:
$ kill -HUP <pid>
Reloading the server will cause it to pick up changes to the tiles directory, adding new tilesets and removing any that are no longer present.
Specifications
- expects mbtiles files to follow version 1.0 of the mbtiles specification. Version 1.1 is preferred.
- implements TileJSON 2.1.0
Creating Tiles
You can create mbtiles files using a variety of tools. We have created tiles for use with mbtileserver using:
- TileMill (image tiles)
- tippecanoe (vector tiles)
- pymbtiles (tiles created using Python)
- tpkutils (image tiles from ArcGIS tile packages)
Examples
TileJSON API for each tileset:
http://localhost/services/states_outline
returns something like this;
{
"bounds": [
-179.23108,
-14.601813,
179.85968,
71.441055
],
"center": [
0.314297,
28.419622,
1
],
"credits": "US Census Bureau",
"description": "States",
"format": "png",
"id": "states_outline",
"legend": "[{\"elements\": [{\"label\": \"\", \"imageData\": \"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAOxAAADsQBlSsOGwAAAGFJREFUOI3tlDEOgEAIBClI5kF+w0fxwXvQdjZywcZEtDI31YaQgWrdPsYzAPFGJCmmEAhJGzCash0wSVE/HHnlKcDMfrPXYgmXcAl/JswK6lCrz89BdGVm1+qrH0bbWDgA3WwmgzD8ueEAAAAASUVORK5CYII=\"}], \"name\": \"tl_2015_us_state\"}]",
"map": "http://localhost/services/states_outline/map",
"maxzoom": 4,
"minzoom": 0,
"name": "states_outline",
"scheme": "xyz",
"tags": "states",
"tilejson": "2.1.0",
"tiles": [
"http://localhost/services/states_outline/tiles/{z}/{x}/{y}.png"
],
"type": "overlay",
"version": "1.0.0"
}
It provides most elements of the metadata
table in the mbtiles file.
XYZ tile endpoint for individual tiles:
http://localhost/services/states_outline/tiles/{z}/{x}/{y}.png
If UTF-8 Grid data are present in the mbtiles file, they will be served up over the
grid endpoint:
http://localhost/services/states_outline/tiles/{z}/{x}/{y}.json
Grids are assumed to be gzip or zlib compressed in the mbtiles file. These grids are automatically spliced with any grid key/value data if such exists in the mbtiles file.
The map endpoint:
http://localhost/services/states_outline/map
provides an interactive Leaflet map for image tiles, including a few helpful plugins like a legend (if compatible legend elements found in TileJSON) and a transparency slider. Vector tiles are previewed using Mapbox GL.
ArcGIS API
This project currently provides a minimal ArcGIS tiled map service API for tiles stored in an mbtiles file. This should be sufficient for use with online platforms such as Data Basin. Because the ArcGIS API relies on a number of properties that are not commonly available within an mbtiles file, so certain aspects are stubbed out with minimal information.
This API is not intended for use with more full-featured ArcGIS applications such as ArcGIS Desktop.
Live Examples
These are hosted on a free dyno by Heroku (thanks Heroku!), so there might be a small delay when you first access these.
- List of services
- TileJSON for a PNG based tileset generated using TileMill.
- Map Preview for a map preview of the above.
- ArcGIS Map Service
Request authorization
Provind a secret key with -s/--secret-key
or by setting the HMAC_SECRET_KEY
environment variable will
restrict access to all server endpoints and tile requests. Requests will only be served if they provide a cryptographic
signature created using the same secret key. This allows, for example, an application server to provide authorized
clients a short-lived token with which the clients can access tiles for a specific service.
Signatures expire 15 minutes from their creation date to prevent exposed or leaked signatures from being useful past a small time window.
Creating signatures
A signature is a URL-safe, base64 encoded HMAC hash using the SHA1
algorithm. The hash key is an SHA1
key created
from a randomly generated salt, and the secret key string. The hash payload is a combination of the ISO-formatted
date when the hash was created, and the authorized service id.
The following is an example signature, created in Go for the serivce id test
, the date
2019-03-08T19:31:12.213831+00:00
, the salt 0EvkK316T-sBLA
, and the secret key
YMIVXikJWAiiR3q-JMz1v2Mfmx3gTXJVNqme5kyaqrY
Create the SHA1 key:
serviceId := "test"
date := "2019-03-08T19:31:12.213831+00:00"
salt := "0EvkK316T-sBLA"
secretKey := "YMIVXikJWAiiR3q-JMz1v2Mfmx3gTXJVNqme5kyaqrY"
key := sha1.New()
key.Write([]byte(salt + secretKey))
Create the signature hash:
hash := hmac.New(sha1.New, key.Sum(nil))
message := fmt.Sprintf("%s:%s", date, serviceId)
hash.Write([]byte(message))
Finally, base64-encode the hash:
b64hash := base64.RawURLEncoding.EncodeToString(hash.Sum(nil))
fmt.Println(b64hash) // Should output: 2y8vHb9xK6RSxN8EXMeAEUiYtZk
Making request
Authenticated requests must include the ISO-fromatted date, and a salt-signature combination in the form of:
<salt>:<signature>
. These can be provided as query parameters:
?date=2019-03-08T19:31:12.213831%2B00:00&signature=0EvkK316T-sBLA:YMIVXikJWAiiR3q-JMz1v2Mfmx3gTXJVNqme5kyaqrY
Or they can be provided as request headers:
X-Signature-Date: 2019-03-08T19:31:12.213831+00:00
X-Signature: 0EvkK316T-sBLA:YMIVXikJWAiiR3q-JMz1v2Mfmx3gTXJVNqme5kyaqrY
Roadmap
See the issues tagged to the 0.5 version for our near term features and improvements.
In short, we are planning to:
- add tests and benchmarks
- get things production ready
Development
Dependencies are managed using go modules. Vendored dependencies are stored in vendor
folder by using go mod vendor
.
On Windows, it is necessary to install gcc
in order to compile mattn/go-sqlite3
.
MinGW or TDM-GCC should work fine.
If you experience very slow builds each time, it may be that you need to first run
go build -a .
to make subsequent builds much faster.
Development of the templates and static assets likely requires using
node
and npm
. Install these tools in the normal way.
From the handlers/templates/static
folder, run
$npm install
to pull in the static dependencies. These are referenced in the
package.json
file.
Then to build the minified version, run:
$gulp build
Modifying the .go
files always requires re-running go build .
.
In case you have modified the templates and static assets, you need to run go generate ./handlers
to ensure that your modifications
are embedded into the executable. For this to work, you must have
[github.com/shurcooL/vfsgen)[https://github.com/shurcooL/vfsgen) installed.
This will rewrite the assets_vfsdata.go
which you must commit along with your
modification. Also you should run go build
after go generate
.
During the development cycle you may use go build -tags dev .
to build the
binary, in which case it will always take the assets from the relative file
path handlers/templates/
directly and you can omit the go generate
step. (note: this is currently not working properly)
But do not forget to perform it in the end.