[Caddy2] Caddyfile 使用其它 DNS provider

安装 caddy 的 dns provider 模块。

https://github.com/caddy-dns/cloudflare

如果是在 Docker 中 build 模块按文档进行，通过 caddy:2.0.0-builder 安装需要的模块，

然后 COPY --from=builder /usr/bin/caddy /usr/bin/caddy

https://hub.docker.com/_/caddy

#@maintainer <cnblogs.com/farwish>

FROM caddy:2.0.0-builder AS builder

RUN go env -w GO111MODULE=on
RUN go env -w GOPROXY=https://goproxy.io,direct

RUN caddy-builder github.com/caddy-dns/cloudflare

FROM caddy:2.0.0

ENV CLOUDFLARE_API_TOKEN=xxxxx

COPY --from=builder /usr/bin/caddy /usr/bin/caddy

COPY Caddyfile /etc/caddy/Caddyfile

使用 tls 指令配置 dns provider。

tls {
    dns cloudflare {env.CLOUDFLARE_API_TOKEN}
}

https://caddyserver.com/docs/caddyfile/directives/tls#tls

Ref： [Caddy2] cloudflare, acme: cleaning up failed: no memory of presenting a DNS record 

Link：https://www.cnblogs.com/farwish/p/13110016.html