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 at medium scale.
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.
The scrape and scrape-server binaries should be buildable and runnable in any cgo-enabled environment where SQLite3 is present. A docker build is also included.
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 |
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",
"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 provide command 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
-create
Create 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
-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 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.
scrape-server is intended for use in closed environments at medium scale. There's no authentication, rate limiting or url sanitization beyond encoding checks. Don't deploy this on an open public network. Do deploy it as a sidecar, in a firewalled environment, or another environment that won't get unbounded quantities of hits.
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
-headless
Enable headless browser extraction functionality
-log-level value
Set the log level [debug|error|info|warn]
Environment: SCRAPE_LOG_LEVEL
-port value
Port to run the server on
Environment: SCRAPE_PORT (default 8080)
-profile
Enable profiling at /debug/pprof
Environment: SCRAPE_PROFILE
-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 url to test URLs and results.
The pulldown on the right lets you select between loading results for a page url or for a feed.
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 indentically 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.
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
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 -- 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 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 better choice for applications that run under higher volumes and/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 -create 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 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 image to Docker Hub or to a registry specfied by CONTAINER_REGISTRY
docker-run run the docker image, binding to port 8080, or the env value of SCRAPE_PORT
test run the tests
vet fmt, vet, and staticcheck
cognitive run the cognitive complexity checker
help show this help message
The docker-build target will build a docker on the current architecture. Run this image with
docker-run to bring up a local instance of the service for testing. You don't need any Go
tooling installed locally to build and run via 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, timeouts, etc)
- Headless fallback for pages that require Javascript
- Explore performance optimizations, e.g.
- Batch request parallelization
- zstd compression for stored resources
- Explore alternate fetch/parse backends
Feature request or bug? Post issues here.
scrape is powered by:
- go-trafilatura HTML parsing
- gofeed Atom and RSS parsing
- sqlite data storage
- go-sqlite3 SQLite client
- go-mysql MySQL client