Reset readme, now that docs will be on official website

CHANGELOG.next.md

@@ -16,9 +16,14 @@
 
 ### Improvements
 
+* Make the README.md a good starting point for contributors. Redirect to main
+  website for ECS documentation itself. #395
+
 ### Deprecated
 
 * Move old `fields.yml` file from the root of the repo to `generated/legacy`. #386
+* Replace the old all-in-one README.md. The official documentation is
+  now on the elastic.co website. #395
 
 <!-- All empty sections:
 

CONTRIBUTING.md

@@ -52,7 +52,9 @@ You can contribute even if you are not an experienced Git user. You'll need a gi
 
 The `fields.yml` files describe the Elastic Common Schema in a structured way. We can use these files to generate an Elasticsearch index template, a Kibana index pattern, or documentation output.
 
-The file structure is similar to this:
+The file structure is documented in [schemas/README.md](schemas).
+
+It looks similar to this:
 
 ```
 - name: agent
@@ -86,29 +88,4 @@ The `type` is the [Elasticsearch field type](https://www.elastic.co/guide/en/ela
 
 ## Guidelines for implementing ECS
 
-* The document MUST have the `@timestamp` field.
-* The [data type](https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-types.html)
-  defined for an ECS field MUST be used.
-* It SHOULD have the field `ecs.version` to define which version of ECS it uses.
-* As many fields as possible should be mapped to ECS.
-
-### Writing fields
-
-* All fields must be lower case
-* Combine words using underscore
-* No special characters except `_`
-
-### Naming fields
-
-* *Present tense.* Use present tense unless field describes historical information.
-* *Singular or plural.* Use singular and plural names properly to reflect the field content. For example, use `requests_per_sec` rather than `request_per_sec`.
-* *General to specific.* Organise the prefixes from general to specific to allow grouping fields into objects with a prefix like `host.*`.
-* *Avoid repetition.* Avoid stuttering of words. If part of the field name is already in the prefix, do not repeat it. Example: `host.host_ip` should be `host.ip`.
-* *Use prefixes.* Fields must be prefixed except for the base fields. For example all `host` fields are prefixed with `host.`. See `dot` notation in FAQ for more details.
-* Do not use abbreviations. (A few exceptions such as `ip`, `os` ,`geo`, exist.)
-
-### Implementation details
-
-* Host can contain hostname and port (hostname:port)
-* Hostname never contains a port number
-
+Look at our [Guidelines and Best Practices](http://example.com) on the ECS documentation website.

Makefile

@@ -40,10 +40,6 @@ clean:
 codegen: gocodegen
 
 # Build schema.csv from schema files.
-.PHONY: csv
-csv: ve
-	$(PYTHON) scripts/schemas.py
-
 # Build the asciidoc book.
 .PHONY: docs
 docs:
@@ -52,16 +48,6 @@ docs:
 	fi
 	./build/docs/build_docs.pl --doc ./docs/index.asciidoc --chunk=1 $(OPEN_DOCS) -out ./build/html_docs
 
-# Build the legacy fields.yml file.
-.PHONY: fields_legacy
-fields_legacy:
-	cat schemas/*.yml > fields.tmp.yml
-	sed -i.bak 's/^/    /g' fields.tmp.yml
-	sed -i.bak 's/---//g' fields.tmp.yml
-	cat generated/legacy/fields_header.yml > generated/legacy/fields.yml
-	cat fields.tmp.yml >> generated/legacy/fields.yml
-	rm -f fields.tmp.yml fields.tmp.yml.bak
-
 # Format code and files in the repo.
 .PHONY: fmt
 fmt: ve
@@ -71,7 +57,11 @@ fmt: ve
 
 # Alias to generate everything.
 .PHONY: generate
-generate: csv readme template fields_legacy codegen generator
+generate: template legacy_fields legacy_csv legacy_use_cases codegen generator
+# Generate the Use Cases
+.PHONY: legacy_use_cases
+legacy_use_cases:
+	$(PYTHON) scripts/use-cases.py --stdout=true >> /dev/null
 
 # Run the new generator
 .PHONY: generator
@@ -88,6 +78,25 @@ gocodegen:
 	        -schema=../schemas \
 	        -out=../code/go/ecs
 
+.PHONY: legacy_csv
+legacy_csv: ve
+	$(PYTHON) scripts/schemas.py
+
+# Build the legacy fields.yml file.
+.PHONY: legacy_fields
+legacy_fields:
+	cat schemas/*.yml > fields.tmp.yml
+	sed -i.bak 's/^/    /g' fields.tmp.yml
+	sed -i.bak 's/---//g' fields.tmp.yml
+	cat generated/legacy/fields_header.yml > generated/legacy/fields.yml
+	cat fields.tmp.yml >> generated/legacy/fields.yml
+	rm -f fields.tmp.yml fields.tmp.yml.bak
+
+# Generate the Use Cases
+.PHONY: legacy_use_cases
+legacy_use_cases:
+	$(PYTHON) scripts/use-cases.py --stdout=true >> /dev/null
+
 # Check Makefile format.
 .PHONY: makelint
 makelint: SHELL:=/bin/bash
@@ -101,17 +110,6 @@ misspell:
 	go get github.com/client9/misspell/cmd/misspell
 	misspell README.md CONTRIBUTING.md
 
-# Build README.md by concatenating various markdown snippets.
-.PHONY: readme
-readme:
-	cat docs/intro.md > README.md
-	$(PYTHON) scripts/schemas.py --stdout=true >> README.md
-	cat docs/use-cases-header.md >> README.md
-	$(PYTHON) scripts/use-cases.py --stdout=true >> README.md
-	cat docs/implementing.md >> README.md
-	cat docs/about.md >> README.md
-	cat docs/generated-files.md >> README.md
-
 # Download and setup tooling dependencies.
 .PHONY: setup
 setup: ve