Bump alpine from 3.14 to 3.15 in /build (#2218)

* Bump alpine from 3.14 to 3.15 in /build

Bumps alpine from 3.14 to 3.15.

---
updated-dependencies:
- dependency-name: alpine
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

build/Dockerfile

@@ -26,7 +26,7 @@ RUN apk add --no-cache libcap \
 
 
 ############################################# Base image for Alpine with NGINX Plus #############################################
-FROM alpine:3.14 as alpine-plus
+FROM alpine:3.15 as alpine-plus
 ARG NGINX_PLUS_VERSION
 
 RUN --mount=type=secret,id=nginx-repo.crt,dst=/etc/apk/cert.pem,mode=0644 \

docs/content/technical-specifications.md

@@ -45,7 +45,7 @@ NGINX Plus images are available through the F5 Container registry `private-regis
 {{% table %}}
 |Name | Base image | Third-party modules | F5 Container Registry Image | Architectures |
 | ---| ---| --- | --- | --- |
-|Alpine-based image | ``alpine:3.14`` | NGINX Plus JavaScript module | `nginx-ic/nginx-plus-ingress:2.1.0-alpine` | arm64, amd64 |
+|Alpine-based image | ``alpine:3.15`` | NGINX Plus JavaScript module | `nginx-ic/nginx-plus-ingress:2.1.0-alpine` | arm64, amd64 |
 |Debian-based image | ``debian:bullseye-slim`` | NGINX Plus JavaScript module | `nginx-ic/nginx-plus-ingress:2.1.0` | arm64, amd64 |
 |Debian-based image with OpenTracing | ``debian:bullseye-slim`` | NGINX Plus OpenTracing module, OpenTracing tracers for Jaeger, Zipkin and Datadog; NGINX Plus JavaScript module | `nginx-ic/nginx-plus-ingress:2.1.0-ot` | arm64, amd64 |
 |Debian-based image with App Protect WAF|  ``debian:buster-slim`` | NGINX Plus App Protect WAF module; NGINX Plus JavaScript module | `nginx-ic-nap/nginx-plus-ingress:2.1.0` | amd64 |