Fast web scraping
- Description
- Output Format
- Usage as a CLI Application
- Usage as a Server
- Database Options
- Building and Developing
- Roadmap
- Acknowledgements
scrape
provides a self-contained low-to-no-setup tool to grab metadata and text content from web pages. The server provides a REST API to scrape web metadata, with support for batches, using either a direct client, with headless browser option that's useful for pages that need javascript to load.
Results are stored, so subsequent fetches of a particular URL are fast. Install the binary, and operate it as a shell command or as a server with a REST API. The default SQLite storage backend is performance-optimized and can store to disk or in memory. MySQL is also supported. Resources are stored with a configurable TTL.
The scrape
cli tool provides shell access to scraped content via command-line entry or CSV files, and also provides database management functionality. scrape-server
provides web and API access to content metadata in one-offs or batches.
RSS and Atom feeds are supported via an endpoint in scrape-server
. Loading a feed returns the parsed results for all item links in the feed.
Authorization via JWT keys is supported with a configuration option. The companion scrape-jwt-encode
tool can be used to generate tokens, and to make the secret you need
to securely sign and verify JWT tokens.
The scrape
and scrape-server
binaries should be buildable and runnable in any environment where go
and SQLite3
(or a MySQL
server) are present. A docker build is also included. See make help
for build instructions.
JSON output is a superset of Trafilatura fields. Empty fields may be omitted in responses.
Field | Type | Description |
---|---|---|
url |
String (URL) | The (canonical) URL for the page, as reported by the page itself. If the page doesn't supply that, this field will contain the same value as RequestedURL |
requested_url |
String (URL) | The URL that was actually requested. (Some URL params (e.g. utm_*) may be stripped before the outbound request) |
original_url |
String (URL) | Exactly the url that was in the inbound request |
fetch_time |
ISO8601 | The time that URL was retrieved |
fetch_method |
String | The type of client used to fetch this resource (DefaultClient or HeadlessBrowser ) |
status_code |
Int | The status code returned by the target server when fetching this page |
error |
String | Error message(s), if there were any, while processing this page |
hostname |
Domain name | The domain serving this resource |
date |
ISO8601 | The publish date of the page, in UTC time |
sitename |
String | Identifies the publisher. Can be domain, company name, or other text, IRL usage not consistent |
title |
String | The page's title |
authors |
[]String | Authors |
description |
String | Page summary or excerpt |
categories |
[]String | Content categories, if supplied |
tags |
[]String | Tags, if supplied |
language |
String | 2-letter language code |
page_type |
String | If it's there it's usually "article" following the `og`` usage |
image |
String (URL) | Hero image link |
license |
String | Generally empty |
content_text |
String | The text of the page, with all HTML removed |
Parsed field content is largely dependent on metadata included in the page. GIGO/YMMV.
Here's an example, with long fields truncated:
{
"url": "https://www.nasa.gov/missions/webb/nasas-webb-stuns-with-new-high-definition-look-at-exploded-star/",
"requested_url": "https://www.nasa.gov/missions/webb/nasas-webb-stuns-with-new-high-definition-look-at-exploded-star/",
"original_url": "https://www.nasa.gov/missions/webb/nasas-webb-stuns-with-new-high-definition-look-at-exploded-star/",
"fetch_time": "2024-01-09T03:57:44Z",
"fetch_method": "direct",
"status_code": 200,
"hostname": "www.nasa.gov",
"date": "2023-12-10T00:00:00Z",
"sitename": "NASA",
"title": "NASA’s Webb Stuns With New High-Definition Look at Exploded Star - NASA",
"authors": [
"Steve Sabia"
],
"description": "Like a shiny, round ornament ready to be placed in the perfect spot on a holiday tree, supernova remnant Cassiopeia A (Cas A) gleams in a new image from",
"categories": [
"Astrophysics",
"Goddard Space Flight Center",
"James Webb Space Telescope (JWST)",
"Missions",
"Nebulae",
"Science \u0026 Research",
"Stars",
"Supernovae",
"The Universe"
],
"tags": [
"Astrophysics",
"Goddard Space Flight Center",
"James Webb Space Telescope (JWST)",
"Missions",
"Nebulae",
"Science \u0026 Research",
"Stars",
"Supernovae",
"The Universe"
],
"language": "en",
"image": "https://www.nasa.gov/wp-content/uploads/2023/12/webb-stsci-01hggzdyh8ghhssnwzd71mf0xh-2k.png",
"page_type": "article",
"content_text": "Mysterious features hide in near-infrared light Like a shiny, round ornament ready to be placed in the perfect spot on a holiday tree, supernova remnant Cassiopeia A (Cas A) gleams in a new image from NASA’s James Webb Space Telescope. As part of the 2023...(there's about 10x more content in this example, truncated in the docs for readability)",
}
go install github.com/efixler/scrape/cmd/scrape@latest
The scrape
command provides single and batch retrieval, using or bypassing the connected storage db. It also provides commands to manage the backing store.
> scrape http://www.foo.com/some/url/path
That's actually it. The database will be created if it doesn't exist already.
scrape % ./scrape -h
Usage:
scrape [flags] :url [...urls]
In addition to http[s] URLs, file:/// urls are supported, using the current working directory as the base path.
Flags:
-h
Show this help message
-clear
Clear the database and exit
-csv value
CSV file path
-csv-column value
The index of the column in the CSV that contains the URLs
Environment: SCRAPE_CSV_COLUMN (default 1)
-database value
Database type:path
Environment: SCRAPE_DB (default sqlite:scrape_data/scrape.db)
-db-password value
Database password
Environment: SCRAPE_DB_PASSWORD
-db-user value
Database user
Environment: SCRAPE_DB_USER
-headless
Use headless browser for extraction
-log-level value
Set the log level [debug|error|info|warn]
Environment: SCRAPE_LOG_LEVEL (default WARN)
-maintain
Execute database maintenance and exit
-migrate value
Issue a db migration command: up, reset, or status
-notext
Skip text content
Environment: SCRAPE_NOTEXT
-ping
Ping the database and exit
-user-agent value
User agent to use for fetching
Environment: SCRAPE_USER_AGENT (default Mozilla/5.0 (X11; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0)
The -migrate
flag can be used to create (or update) the database. SQLite databases will be automatically brought up to date whenever scrape
or scrape-server
are invoked; MySQL
databases need to be explicitly migrated.
There are 3 accepted arguments to the -migrate
flag:
up
: Bring the database up to the latest version, creating if necessary.reset
: Bring the database down to no-tables and clear all data. The empty schema and permissions are preserved.status
: Show the current migration version and state.
The server provides a REST API to get resource data one-at-a-time or in bulk. The root URL serves up a page that can be used to spot check results for any url.
Running scrape-server
with no arguments will bring up a server on port 8080 with a SQLite database, storing scraped pages for 30 days and without any authorization controls. See below for guidance on how to change these settings.
go install github.com/efixler/scrape/cmd/scrape-server@latest
scrape % ./build/scrape-server -h
Usage:
-----
scrape-server [-port nnnn] [-h]
Some options have environment variable equivalents. Invalid environment settings
are ignored. Command line options override environment variables.
If environment variables are set, they'll override the defaults displayed in this
help message.
Command line options:
--------------------
-h
Show this help message
-database value
Database type:path
Environment: SCRAPE_DB (default sqlite:scrape_data/scrape.db)
-db-password value
Database password
Environment: SCRAPE_DB_PASSWORD
-db-user value
Database user
Environment: SCRAPE_DB_USER
-enable-headless
Enable headless browser extraction functionality
Environment: SCRAPE_ENABLE_HEADLESS
-host value
TCP address to listen on (empty for all interfaces)
Environment: SCRAPE_HOST
-log-level value
Set the log level [debug|error|info|warn]
Environment: SCRAPE_LOG_LEVEL (default info)
-port value
Port to run the server on
Environment: SCRAPE_PORT (default 8080)
-profile
Enable profiling at /debug/pprof
Environment: SCRAPE_PROFILE
-public-home
Enable the homepage without requiring a token (when auth is enabled)
Environment: SCRAPE_PUBLIC_HOME
-signing-key value
Base64 encoded HS256 key to verify JWT tokens. Required for JWT auth, and enables JWT auth if set.
Environment: SCRAPE_SIGNING_KEY
-ttl value
TTL for fetched resources
Environment: SCRAPE_TTL (default 720h0m0s)
-user-agent value
User agent for fetching
Environment: SCRAPE_USER_AGENT (default Mozilla/5.0 (X11; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0)
The root path of the server (/
) is browsable and provides a simple way to test URLs and results.
The select on the left lets you select between loading results for a page url or for a feed, or scraping a page using the headless browser instead of a direct http client.
Token entry is shown here when the server is running with token authorization. For instructions on setting up authorization, see below
Returns the metadata for the supplied list of URLs. Returned metadatas are not guaranteed to be in the same order as the request.
The batch
endpoint behaves identically to the extract
endpoint in all ways except two:
- The endpoint returns an array of the JSON payload described above
- When individual items have errors, the request will still return with a 200 status code. Inspect the payload for individual items to determine the status of an individual item request.
Param | Description | Required |
---|---|---|
urls | A JSON array of the urls to fetch | Y |
Fetch the metadata and text content for the specified URL. Returns JSON payload as decribed above.
If the server encounters an error fetching a requested URL, the status code for the request will be set to 422 (Unprocessable Entity). This may change.
The returned JSON payload will include a StatusCode
field in all cases, along with an Error
field when
there's an error fetching or parsing the requested content.
Param | Description | Required |
---|---|---|
url | The url to fetch. Should be url encoded. | Y |
StatusCode | Description |
---|---|
415 | The requested resource was for a content type not supported by this service |
422 | The request could not be completed |
504 | The request for the target url timed out |
In all other cases, requests should return a 200 status code, and any errors received when fetching a resource will be included in the returned JSON payload.
Identical to the extract endpoint, but uses a headless browser to scrape content instead of a direct http client. This endpoint is likely to change, with its functionality folded into the extract
endpoint using a
param.
Feed parses an RSS or Atom feed and returns the parsed results for each of the item links in the feed.
Param | Description | Required |
---|---|---|
url | The feed url to fetch. Should be url encoded. | Y |
StatusCode | Description |
---|---|
422 | The url was not a valid feed |
504 | Request for the feed timed out |
These params work for any endpoint
Param | Value | Description |
---|---|---|
pp | 1 | Pretty print JSON output |
scrape
has two healthchecks:
This is a JSON endpoint that returns data on the application's state, including memory and database runtime info.
This just returns a status 200
with the content OK
By default, scrape
runs without any authorization, all endpoints are open. JWT based authentication is supported, via the scrape-jwt-encode
tool and a scrape-server
configuration option. Here's how to enable it:
(./build
is the path for executables built locally with make
update this path if your binaries are elsewhere)
Running scrape-jwt-encode
with the make-key
flag will generate a cryptographically random HS256 secret, and encode it to Base64.
scrape % ./build/scrape-jwt-encode -make-key
Be sure to save this key, as it can't be re-generated:
b4RThFbyMKfQE3+jAjJcR5rjVgVOeA2Ub9eethtX83M=
You will need this secret to generate tokens and to configure the server for authentication; you'll need to save it, but don't share it via non-secure means, etc.
If the key is in your environment as SCRAPE_SIGNING_KEY
it'll be picked up by both the JWT encoding tool and the server.
Tokens are also generated using scrape-jwt-encode
. Here's the output of scrape-jwt-encode -h
:
scrape % ./build/scrape-jwt-encode -h
Generates JWT tokens for the scrape service. Also makes the signing key to use for the tokens.
Usage:
-----
scrape-jwt-encode -sub subject [-signing-key key] [-exp expiration] [-aud audience]
scrape-jwt-encode -make-key
-aud string
Audience (recipient) for the key (default "moz")
-exp value
Expiration date for the key, in RFC3339 format. Default is 1 year from now. (default 2025-05-16T11:45:45.842362-04:00)
-make-key
Generate a new signing key
-signing-key value
HS256 key to sign the JWT token
Environment: SCRAPE_SIGNING_KEY (default &[])
-sub string
Subject (holder name) for the key (required)
When generating a key, only a subject
is required. Authorization doesn't actually check this value, but it's a good idea to use unique identifying values here, as this may get used in the future and may also get logged.
Here's the output from token generation, after putting the key from above into the environment. The claims are printed out for reference, but it's the token at the bottom that you want to share with API consumers.
scrape % export SCRAPE_SIGNING_KEY=b4RThFbyMKfQE3+jAjJcR5rjVgVOeA2Ub9eethtX83M=
scrape % ./build/scrape-jwt-encode -sub some_user
Claims:
------
{
"iss": "scrape",
"sub": "some_user",
"aud": [
"moz"
],
"exp": 1747410570,
"iat": 1715874570
}
Token:
-----
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzY3JhcGUiLCJzdWIiOiJzb21lX3VzZXIiLCJhdWQiOlsibW96Il0sImV4cCI6MTc0NzQxMDU3MCwiaWF0IjoxNzE1ODc0NTcwfQ.4AapsWfYAK78JhP9AyhupmZAHLeRDyIPlE8ODwwsVRg
When authorization is enabled on the server, API requests must have an Authorization
header that begins with the string Bearer
(with a space) followed by the token.
To enable authorization on the server either:
- Start the server with the
SCRAPE_SIGNING_KEY
environment variable - Pass a
-signing-key [key]
argument to the server when starting up
When enabled, scrape
will check the following qualities of the token, and reject API requests with a 401
unless there is a token passed in the Authorization
header fulfilling the following criteria:
- It's a valid JWT token
- The token has been signed with the same signing key that the server is using
- The token's issuer is
scrape
- The token is not expired
Healthcheck paths don't require authorization. The test console at the root url normally follows the server's authorization configuration, bit it can be configured to allow open access while endpoints require tokens via the -public-home
flag. When this flag is enabled, the server delivers short-lived tokens to the web client when loading the page. As such, this setting is primarily intended for convenience in development environments.
scrape
supports SQLite or MySQL for data storage. Your choice depends on your requirements and environment.
SQLite is the default storage engine for scrape
. There's no need for setup and you can get running right away. The database will autocreate if it doesn't exist.
SQLite is ideal when there's a 1:1 relationship between the service and its backing store, or if you're running the service on a workstation or a 'real' computer.
If you deploy the Docker container to a cloud provider like GCP or AWS there will usually be a few hundred MB of disk storage associated with the container. Storage requirements typically translate to about 3000 url metadatas per 100MB.
When your container shuts down, previously stored data will be lost. This may or may not be a problem, depending on your application. Disk space can be monitored with the healthcheck.
It is also possible to mount a block drive to a container for persistent storage independent of the container lifecycle.
To specify a non-default path to a SQLite database using the command line -database
switch or the equivalent SCRAPE_DB
environment variable, use the form sqlite:/path/to.db
. The special form sqlite::memory:
is supported for a transient, in-memory database.
MySQL will be a good choice for applications that run under higher volumes or where multiple service instances want to share a storage backend.
Here are the configuration options for MySQL:
Flag | Environment | Description | Example |
---|---|---|---|
-database | SCRAPE_DB | mysql: + addr:port | mysql:mysql.domain.co:3306 |
-db-password | SCRAPE_DB_PASSWORD | Password | lkajd901e109i^jhj% |
-db-user | SCRAPE_DB_USER | Username for mysql connections | scrape_user |
Create the MySQL database by running scrape -migrate up
with the applicable values above. For
database creation a privileged user is required. The database will be provisioned with two
roles; scrape_app
for app operations and a scrape_admin
role with full privileges to the
schema. Assign these roles to users, and assign those users to the arguments above, as appropriate.
Best to build with make
. The Makefile has a help target, here is its output:
scrape % make help
Usage:
make
build build the binaries, to the build/ folder (default target)
clean clean the build directory
docker-build build a docker image on the current platform, for local use
docker-push push an amd64/arm64 docker to Docker Hub or to a registry specified by CONTAINER_REGISTRY
docker-run run the local docker image, binding to port 8080, or the env value of SCRAPE_PORT
release-tag create a release tag at the next patch version. Customize with TAG_MESSAGE and/or TAG_VERSION
test run the tests
test-mysql run the MySQL integration tests
vet fmt, vet, and staticcheck
cognitive run the cognitive complexity checker
setup-githooks setup the git hooks
watch-server Start a hot-update scrape-server (requires entr)
help show this help message
The docker-build
target will build a docker on the current architecture. Run this image with
docker-run
(or with the normal Docker cli or desktop tools) to bring up a local instance of the service for testing. You don't need any Go tooling installed to build and run with the Docker.
To push a image to a registry, use docker-push
. This will build a multiplatform amd64/arm64 image
and deploy it upstream. This image is appropriate for cloud platform deployment. The registry username
or organization should match the username or organization of the working repo, and you need the
appropriate permissions.
The docker builds with local sources so use caution when pushing to registries.
By default, the Docker will run using a sqlite database at /scrape_data/scrape.db
on the container itself. This can be changed via the SCRAPE_DB
environment variable. You can also
use a mount to mount this locally.
The docker-run
make target will mount a local folder called docker/data
and bind that to the container for file storage. If you want to use a file-based db you can use this directory, or update the Makefile
to mount the desired local directory.
- Outbound request pacing
- Expose outbound request options (headers, etc)
- Client preference settings (e.g. use headless for specific domains)
- Authentication hooks
Feature request or bug? Post issues here.
scrape
is powered by:
- go-trafilatura HTML parsing
- gofeed Atom and RSS parsing
- goose Database migrations
- sqlite data storage
- go-sqlite3 SQLite client
- go-mysql MySQL client