Add linting for markdown files (#465)

Author: lucacome

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,6 +9,7 @@ A clear and concise description of what the bug is.
 
 **To reproduce**
 Steps to reproduce the behavior:
+
 1. Deploy using 'some_command'
 2. View logs '....'
 3. See error
@@ -17,10 +18,11 @@ Steps to reproduce the behavior:
 A clear and concise description of what you expected to happen.
 
 **Your environment**
-* Version of the Prometheus exporter - release version or a specific commit
-* Version of Docker/Kubernetes
-* [if applicable] Kubernetes platform (e.g. Mini-kube or GCP)
-* Using NGINX or NGINX Plus
+
+- Version of the Prometheus exporter - release version or a specific commit
+- Version of Docker/Kubernetes
+- [if applicable] Kubernetes platform (e.g. Mini-kube or GCP)
+- Using NGINX or NGINX Plus
 
 **Additional context**
 Add any other context about the problem here. Any log files you want to share.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,10 +1,14 @@
 ### Proposed changes
-Describe the use case and detail of the change. If this PR addresses an issue on GitHub, make sure to include a link to that issue here in this description (not in the title of the PR).
+
+Describe the use case and detail of the change. If this PR addresses an issue on GitHub, make sure to include a link to
+that issue here in this description (not in the title of the PR).
 
 ### Checklist
+
 Before creating a PR, run through this checklist and mark each as complete.
 
-- [ ] I have read the [CONTRIBUTING](https://github.com/nginxinc/nginx-prometheus-exporter/blob/main/CONTRIBUTING.md) guide
+- [ ] I have read the [CONTRIBUTING](https://github.com/nginxinc/nginx-prometheus-exporter/blob/main/CONTRIBUTING.md)
+  guide
 - [ ] I have proven my fix is effective or that my feature works
 - [ ] I have checked that all unit tests pass after adding my changes
 - [ ] I have ensured the README is up to date

.markdownlint-cli2.yaml

@@ -0,0 +1,18 @@
+# Rule configuration.
+# For rule descriptions and how to fix: https://github.com/DavidAnson/markdownlint/tree/main#rules--aliases
+config:
+  ul-style:
+    style: dash
+  no-duplicate-heading:
+    siblings_only: true
+  line-length:
+    line_length: 120
+    code_blocks: false
+    tables: false
+
+# Define glob expressions to ignore
+ignores:
+  - ".github/"
+
+# Fix any fixable errors
+fix: true

.pre-commit-config.yaml

@@ -24,6 +24,7 @@ repos:
   - id: no-commit-to-branch
   - id: requirements-txt-fixer
   - id: fix-byte-order-marker
+
 - repo: local
   hooks:
   - id: golang-diff
@@ -32,15 +33,22 @@ repos:
     language: system
     types: [go]
     pass_filenames: false
+
 - repo: https://github.com/golangci/golangci-lint
   rev: v1.53.3
   hooks:
   - id: golangci-lint
     args: [--new-from-patch=/tmp/diff.patch]
+
 - repo: https://github.com/gitleaks/gitleaks
   rev: v8.17.0
   hooks:
   - id: gitleaks
 
+- repo: https://github.com/DavidAnson/markdownlint-cli2
+  rev: v0.8.1
+  hooks:
+  - id: markdownlint-cli2
+
 ci:
   skip: [golang-diff, golangci-lint]

CHANGELOG.md

@@ -1,156 +1,202 @@
 # Changelog
 
-### 0.11.0
+## 0.11.0
 
 A list of changes can be found on Github at: [Release v0.11.0](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.11.0)
 
-### 0.10.0
+## 0.10.0
 
 A list of changes can be found on Github at: [Release v0.10.0](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.10.0)
 
-### 0.9.0
+## 0.9.0
 
 A list of changes can be found on Github at: [Release v0.9.0](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.9.0)
 
-### 0.8.0
+## 0.8.0
 
 CHANGES:
-* [103](https://github.com/nginxinc/nginx-prometheus-exporter/pull/103): Switch to `gcr.io/distroless/static` image. Use a non-root user to run the exporter process by default. Thanks to [Alex SZAKALY](https://github.com/alex1989hu).
-* Update Go version to 1.14
 
-BUGFIXES:
-* [99](https://github.com/nginxinc/nginx-prometheus-exporter/pull/99): Fix link to metrics path. Thanks to [Yoan Blanc](https://github.com/greut).
-* [101](https://github.com/nginxinc/nginx-prometheus-exporter/pull/101): docs: fix dockerfile link. Thanks to [Eric Carboni](https://github.com/eric-hc).
+- [103](https://github.com/nginxinc/nginx-prometheus-exporter/pull/103): Switch to `gcr.io/distroless/static` image. Use
+  a non-root user to run the exporter process by default. Thanks to [Alex SZAKALY](https://github.com/alex1989hu).
+- Update Go version to 1.14
+
+FIXES:
+
+- [99](https://github.com/nginxinc/nginx-prometheus-exporter/pull/99): Fix link to metrics path. Thanks to [Yoan Blanc](https://github.com/greut).
+- [101](https://github.com/nginxinc/nginx-prometheus-exporter/pull/101): docs: fix dockerfile link. Thanks to [Eric Carboni](https://github.com/eric-hc).
 
 UPGRADE:
-* Use the 0.8.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.8.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.8.0).
+
+- Use the 0.8.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.8.0`
+- Download the latest binaries from [GitHub releases
+  page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.8.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R19 or newer.
 
-### 0.7.0
+- NGINX 0.1.18 or newer.
+- NGINX Plus R19 or newer.
+
+## 0.7.0
 
 FEATURES:
-* [86](https://github.com/nginxinc/nginx-prometheus-exporter/pull/86): Implemented TLS client certificate authentication. Thanks to [Fabian Lüpke](https://github.com/Fluepke).
 
-BUGFIXES:
-* [96](https://github.com/nginxinc/nginx-prometheus-exporter/pull/96): Add const labels to upMetric. Thanks to [Robert Toth](https://github.com/robert-toth).
+- [86](https://github.com/nginxinc/nginx-prometheus-exporter/pull/86): Implemented TLS client certificate
+  authentication. Thanks to [Fabian Lüpke](https://github.com/Fluepke).
+
+FIXES:
+
+- [96](https://github.com/nginxinc/nginx-prometheus-exporter/pull/96): Add const labels to upMetric. Thanks to [Robert
+  Toth](https://github.com/robert-toth).
 
 UPGRADE:
-* Use the 0.7.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.7.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.7.0).
+
+- Use the 0.7.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.7.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.7.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R19 or newer.
 
-### 0.6.0
+- NGINX 0.1.18 or newer.
+- NGINX Plus R19 or newer.
+
+## 0.6.0
 
 FEATURES:
-* [77](https://github.com/nginxinc/nginx-prometheus-exporter/pull/77): Add constLabels support via cli arg/env variable.
+
+- [77](https://github.com/nginxinc/nginx-prometheus-exporter/pull/77): Add constLabels support via cli arg/env variable.
 
 CHANGES:
-* Update alpine image.
+
+- Update alpine image.
 
 UPGRADE:
-* Use the 0.6.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.6.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.6.0).
+
+- Use the 0.6.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.6.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.6.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R19 or newer.
 
-### 0.5.0
+- NGINX 0.1.18 or newer.
+- NGINX Plus R19 or newer.
+
+## 0.5.0
 
 FEATURES:
-* [70](https://github.com/nginxinc/nginx-prometheus-exporter/pull/70): Set user agent on scrape requests to nginx.
-* [68](https://github.com/nginxinc/nginx-prometheus-exporter/pull/68): Add ability to scrape and listen on unix domain sockets.
-* [64](https://github.com/nginxinc/nginx-prometheus-exporter/pull/64): Add location zone and resolver metric support.
 
-BUGFIXES:
-* [73](https://github.com/nginxinc/nginx-prometheus-exporter/pull/73): Fix typo in stream_zone_sync_status_nodes_online metric description.
-* [71](https://github.com/nginxinc/nginx-prometheus-exporter/pull/71): Do not assume default datasource in Grafana panels.
-* [62](https://github.com/nginxinc/nginx-prometheus-exporter/pull/62): Set correct nginx_up query and instance variable expression.
+- [70](https://github.com/nginxinc/nginx-prometheus-exporter/pull/70): Set user agent on scrape requests to nginx.
+- [68](https://github.com/nginxinc/nginx-prometheus-exporter/pull/68): Add ability to scrape and listen on unix domain
+  sockets.
+- [64](https://github.com/nginxinc/nginx-prometheus-exporter/pull/64): Add location zone and resolver metric support.
+
+FIXES:
+
+- [73](https://github.com/nginxinc/nginx-prometheus-exporter/pull/73): Fix typo in stream_zone_sync_status_nodes_online
+  metric description.
+- [71](https://github.com/nginxinc/nginx-prometheus-exporter/pull/71): Do not assume default datasource in Grafana
+  panels.
+- [62](https://github.com/nginxinc/nginx-prometheus-exporter/pull/62): Set correct nginx_up query and instance variable
+  expression.
 
 UPGRADE:
-* Use the 0.5.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.5.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.5.0).
+
+- Use the 0.5.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.5.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.5.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R19 or newer.
 
-### 0.4.2
+- NGINX 0.1.18 or newer.
+- NGINX Plus R19 or newer.
+
+## 0.4.2
 
-BUGFIXES:
-* [60](https://github.com/nginxinc/nginx-prometheus-exporter/pull/60): *Fix session metrics for stream server zones*. Session metrics with a status of `4xx` or `5xx` are now correctly reported. Previously they were always reported as `0`.
+FIXES:
+
+- [60](https://github.com/nginxinc/nginx-prometheus-exporter/pull/60): *Fix session metrics for stream server zones*.
+  Session metrics with a status of `4xx` or `5xx` are now correctly reported. Previously they were always reported as
+  `0`.
 
 UPGRADE:
-* Use the 0.4.2 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.2`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.2).
+
+- Use the 0.4.2 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.2`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.2).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R18 or newer.
 
-### 0.4.1
+- NGINX 0.1.18 or newer.
+- NGINX Plus R18 or newer.
+
+## 0.4.1
+
+FIXES:
 
-BUGFIXES:
-* [55](https://github.com/nginxinc/nginx-prometheus-exporter/pull/55): Do not export zone sync metrics if they are not reported by NGINX Plus. Previously, in such case, the metrics were exported with zero values.
+- [55](https://github.com/nginxinc/nginx-prometheus-exporter/pull/55): Do not export zone sync metrics if they are not
+  reported by NGINX Plus. Previously, in such case, the metrics were exported with zero values.
 
 UPGRADE:
-* Use the 0.4.1 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.1`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.1).
+
+- Use the 0.4.1 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.1`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.1).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R18 or newer.
 
-### 0.4.0
+- NGINX 0.1.18 or newer.
+- NGINX Plus R18 or newer.
+
+## 0.4.0
 
 FEATURES:
-* [50](https://github.com/nginxinc/nginx-prometheus-exporter/pull/50): Add zone sync metrics support.
-* [37](https://github.com/nginxinc/nginx-prometheus-exporter/pull/37): Implement a way to retry connection to NGINX if it is unreachable. Add -nginx.retries for setting the number of retries and -nginx.retry-interval for setting the interval between retries, both as cli-arguments.
+
+- [50](https://github.com/nginxinc/nginx-prometheus-exporter/pull/50): Add zone sync metrics support.
+- [37](https://github.com/nginxinc/nginx-prometheus-exporter/pull/37): Implement a way to retry connection to NGINX if
+  it is unreachable. Add -nginx.retries for setting the number of retries and -nginx.retry-interval for setting the
+  interval between retries, both as cli-arguments.
 
 UPGRADE:
-* Use the 0.4.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.0).
+
+- Use the 0.4.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.4.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.4.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R18 or newer.
 
-### 0.3.0
+- NGINX 0.1.18 or newer.
+- NGINX Plus R18 or newer.
+
+## 0.3.0
 
 FEATURES:
-* [32](https://github.com/nginxinc/nginx-prometheus-exporter/pull/32): Add nginxexporter_build_info metric.
-* [31](https://github.com/nginxinc/nginx-prometheus-exporter/pull/31): Implement nginx_up and nginxplus_up metrics. Add -nginx.timeout cli argument for setting a timeout for scrapping metrics from NGINX or NGINX Plus.
+
+- [32](https://github.com/nginxinc/nginx-prometheus-exporter/pull/32): Add nginxexporter_build_info metric.
+- [31](https://github.com/nginxinc/nginx-prometheus-exporter/pull/31): Implement nginx_up and nginxplus_up metrics. Add
+  -nginx.timeout cli argument for setting a timeout for scrapping metrics from NGINX or NGINX Plus.
 
 UPGRADE:
-* Use the 0.3.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.3.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.3.0).
+
+- Use the 0.3.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.3.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.3.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R14 or newer.
+
+- NGINX 0.1.18 or newer.
+- NGINX Plus R14 or newer.
 
 ## 0.2.0
 
 FEATURES:
-* [16](https://github.com/nginxinc/nginx-prometheus-exporter/pull/16): Add stream metrics support.
-* [13](https://github.com/nginxinc/nginx-prometheus-exporter/pull/13): Add a flag for controlling SSL verification of NGINX stub_status/API endpoint. Thanks to [Raza Jhaveri](https://github.com/razaj92).
-* [3](https://github.com/nginxinc/nginx-prometheus-exporter/pull/3): Support for environment variables.
+
+- [16](https://github.com/nginxinc/nginx-prometheus-exporter/pull/16): Add stream metrics support.
+- [13](https://github.com/nginxinc/nginx-prometheus-exporter/pull/13): Add a flag for controlling SSL verification of
+  NGINX stub_status/API endpoint. Thanks to [Raza Jhaveri](https://github.com/razaj92).
+- [3](https://github.com/nginxinc/nginx-prometheus-exporter/pull/3): Support for environment variables.
 
 UPGRADE:
-* Use the 0.2.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.2.0`
-* Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.2.0).
+
+- Use the 0.2.0 image from our DockerHub: `nginx/nginx-prometheus-exporter:0.2.0`
+- Download the latest binaries from [GitHub releases page](https://github.com/nginxinc/nginx-prometheus-exporter/releases/tag/v0.2.0).
 
 COMPATIBILITY:
-* NGINX 0.1.18 or newer.
-* NGINX Plus R14 or newer.
+
+- NGINX 0.1.18 or newer.
+- NGINX Plus R14 or newer.
 
 ## 0.1.0
 
-* Initial release.
+- Initial release.