Add markdownlint.

.github/workflows/markdown.yml

@@ -0,0 +1,24 @@
+name: Markdown checks
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+    paths:
+      - .github/workflows/markdownlint.yml
+      - .markdownlint.yaml
+      - '**.md'
+
+jobs:
+  markdownlint:
+    runs-on: ubuntu-latest
+    steps:
+    - name: check out code
+      uses: actions/checkout@v2
+
+    - name: install markdownlint
+      run: sudo npm install -g markdownlint-cli
+
+    - name: run markdownlint
+      run: markdownlint '**.md' --ignore 'node_modules/**'

.markdownlint.yaml

@@ -0,0 +1,14 @@
+# See https://github.com/DavidAnson/markdownlint/blob/main/doc/Rules.md
+# and https://github.com/DavidAnson/markdownlint/blob/main/README.md
+
+# Default state for all rules
+default: true
+
+ul-style: false
+line-length: false
+no-duplicate-header:
+  siblings_only: true
+ol-prefix:
+  style: ordered
+no-inline-html: false
+fenced-code-language: false

protobuf/README.md

@@ -3,7 +3,7 @@
 A lightweight protoc Docker image, published as otel/build-protobuf to Docker Hub,
 with all dependencies built-in, to generate code in multiple languages.
 
-Forked from https://github.com/jaegertracing/docker-protobuf.
+Forked from <https://github.com/jaegertracing/docker-protobuf>.
 
 ## What's included in the image
 

semantic-conventions/src/tests/data/markdown/missing_end_tag/input.md

@@ -1,4 +1,4 @@
-## Common Attributes
+# Common Attributes
 
 <!-- Re-generate TOC with `TODO: ADD cmd` -->
 <!-- semconv http -->
@@ -15,10 +15,9 @@
 | `http.flavor` | Kind of HTTP protocol used: `"1.0"`, `"1.1"`, `"2"`, `"SPDY"` or `"QUIC"`. |  No |
 | `http.user_agent` | Value of the HTTP [User-Agent][] header sent by the client. | No |
 
-
 It is recommended to also use the general [network attributes][], especially `net.peer.ip`. If `net.transport` is not specified, it can be assumed to be `IP.TCP` except if `http.flavor` is `QUIC`, in which case `IP.UDP` is assumed.
 
 [network attributes]: span-general.md#general-network-connection-attributes
 [HTTP response status code]: https://tools.ietf.org/html/rfc7231#section-6
 [HTTP reason phrase]: https://tools.ietf.org/html/rfc7230#section-3.1.2
-[User-Agent]: https://tools.ietf.org/html/rfc7231#section-5.5.3
+[User-Agent]: https://tools.ietf.org/html/rfc7231#section-5.5.3

semantic-conventions/src/tests/data/markdown/multiple_enum/expected.md

@@ -56,5 +56,3 @@
 | `5G` | 5G
  |
 <!-- endsemconv -->
-
-

semantic-conventions/src/tests/data/markdown/multiple_enum/input.md

@@ -3,5 +3,3 @@
 <!-- Re-generate TOC with `TODO: ADD cmd` -->
 <!-- semconv network -->
 <!-- endsemconv -->
-
-

semantic-conventions/src/tests/data/markdown/parameter_full/http.md

@@ -20,4 +20,4 @@ At least one of the following is required:
 * `http.scheme`, `http.server_name`, [net.host.port](general.md), `http.target`
 * `http.scheme`, [net.host.name](general.md), [net.host.port](general.md), `http.target`
 
-<!-- endsemconv -->
+<!-- endsemconv -->

semantic-conventions/src/tests/data/markdown/parameter_tag/input.md

@@ -2,5 +2,4 @@
 
 <!-- semconv db(tag=connection-level) -->
 
-
 <!-- endsemconv -->

semantic-conventions/src/tests/data/markdown/parameter_tag_empty/input.md

@@ -2,5 +2,4 @@
 
 <!-- semconv db(tag) -->
 
-
 <!-- endsemconv -->

semantic-conventions/src/tests/data/markdown/parameter_tag_no_attr/input.md

@@ -2,5 +2,4 @@
 
 <!-- semconv db(tag=wrong) -->
 
-
 <!-- endsemconv -->

semantic-conventions/src/tests/data/markdown/wrong_semconv_id/input.md

@@ -1,4 +1,4 @@
-## Common Attributes
+# Common Attributes
 
 <!-- Re-generate TOC with `TODO: ADD cmd` -->
 <!-- semconv db -->
@@ -15,10 +15,9 @@
 | `http.flavor` | Kind of HTTP protocol used: `"1.0"`, `"1.1"`, `"2"`, `"SPDY"` or `"QUIC"`. |  No |
 | `http.user_agent` | Value of the HTTP [User-Agent][] header sent by the client. | No |
 
-
 It is recommended to also use the general [network attributes][], especially `net.peer.ip`. If `net.transport` is not specified, it can be assumed to be `IP.TCP` except if `http.flavor` is `QUIC`, in which case `IP.UDP` is assumed.
 
 [network attributes]: span-general.md#general-network-connection-attributes
 [HTTP response status code]: https://tools.ietf.org/html/rfc7231#section-6
 [HTTP reason phrase]: https://tools.ietf.org/html/rfc7230#section-3.1.2
-[User-Agent]: https://tools.ietf.org/html/rfc7231#section-5.5.3
+[User-Agent]: https://tools.ietf.org/html/rfc7231#section-5.5.3