Merge ~ubuntu-docker-images/ubuntu-docker-images/+git/squid:main-wip into ~ubuntu-docker-images/ubuntu-docker-images/+git/squid:main

[Athos Ribeiro]

As per the review suggestions in our mailing list, this MP updates the OCI documentation and allows for parameters to be passed through CMD. The latter was done in a much simpler way than the one present in redis image due to how the parameters are being passed to the image. Moreover, in the most basic use case the users will not need to pass any parameters, but mount the configuration file instead.

[Sergio Durigan Junior (sergiodj)]

Thanks, Athos. LGTM.

review: Approve

diff --git a/Dockerfile b/Dockerfile
index 4b8bfe9..605b3d2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,4 +24,5 @@ VOLUME /var/log/squid \
 	/etc/squid
 
 COPY entrypoint.sh /usr/local/bin/entrypoint.sh
-CMD entrypoint.sh
+ENTRYPOINT ["entrypoint.sh"]
+CMD ["-f", "/etc/squid/squid.conf", "-NYC"]
diff --git a/README.md b/README.md
index 772a2db..4bf9d5a 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ Current Squid Docker Image from Ubuntu. Receives security updates and rolls to n
 
 ## About Squid
 
-Squid is a fully-featured HTTP/1.0 proxy which is almost (but not quite - we're getting there!) a fully-featured HTTP/1.1 proxy. Squid offers a rich access control, authorization and logging environment to develop web proxy and content serving applications. Squid offers a rich set of traffic optimization options, most of which are enabled by default for simpler installation and high performance.
+Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on most available operating systems, including Windows and is licensed under the GNU GPL.
 
 
 ## Tags and Architectures
@@ -65,9 +65,11 @@ docker exec -it squid-container /bin/bash
 Works with any Kubernetes; if you don't have one, we recommend you [install MicroK8s](https://microk8s.io/) and `microk8s.enable dns storage` then `snap alias microk8s.kubectl kubectl`.
 
 Download
-[squid-deployment.yml](TBD) and set `containers.squid.image` in `squid-deployment.yml` to your chosen channel tag (e.g. `ubuntu/squid:4.13-21.10_beta`), then:
+[squid.conf](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/squid/plain/examples/config/squid.conf) and
+[squid-deployment.yml](https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/squid/plain/examples/squid-deployment.yml) and set `containers.squid.image` in `squid-deployment.yml` to your chosen channel tag (e.g. `ubuntu/squid:4.13-21.10_beta`), then:
 
 ```sh
+kubectl create configmap squid-config --from-file=squid=squid.conf
 kubectl apply -f squid-deployment.yml
 ```
 
diff --git a/data/squid.yaml b/data/squid.yaml
index 3079ff7..69acd08 100644
--- a/data/squid.yaml
+++ b/data/squid.yaml
@@ -2,12 +2,11 @@ application: Squid
 main: true
 repo: squid
 description: >
-  Squid is a fully-featured HTTP/1.0 proxy which is almost (but not quite -
-  we're getting there!) a fully-featured HTTP/1.1 proxy. Squid offers a rich
-  access control, authorization and logging environment to develop web proxy
-  and content serving applications. Squid offers a rich set of traffic
-  optimization options, most of which are enabled by default for simpler
-  installation and high performance.
+  Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more.
+  It reduces bandwidth and improves response times by caching and reusing
+  frequently-requested web pages. Squid has extensive access controls and makes
+  a great server accelerator. It runs on most available operating systems,
+  including Windows and is licensed under the GNU GPL.
 version: "4.13"
 base: Ubuntu 21.10
 architectures:
@@ -38,6 +37,12 @@ parameters:
 debug:
   - nothing
 microk8s:
+  configmap:
+    name: squid-config
+    files:
+      - key: squid
+        name: squid.conf
+        link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/squid/plain/examples/config/squid.conf
   deploy:
-    link: TBD
+    link: https://git.launchpad.net/~canonical-server/ubuntu-docker-images/+git/squid/plain/examples/squid-deployment.yml
     access: You can now access the squid proxy on port 3128
diff --git a/entrypoint.sh b/entrypoint.sh
index fe40175..5c3c9cd 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -1,6 +1,23 @@
 #!/bin/bash
 
+# Squid OCI image entrypoint
+
+# This entrypoint aims to forward the squid logs to stdout to assist users of
+# common container related tooling (e.g., kubernetes, docker-compose, etc) to
+# access the service logs.
+
+# Moreover, it invokes the squid binary, leaving all the desired parameters to
+# be provided by the "command" passed to the spawned container. If no command
+# is provided by the user, the default behavior (as per the CMD statement in
+# the Dockerfile) will be to use Ubuntu's default configuration [1] and run
+# squid with the "-NYC" options to mimic the behavior of the Ubuntu provided
+# systemd unit.
+
+# [1] The default configuration is changed in the Dockerfile to allow local
+# network connections. See the Dockerfile for further information.
+
 tail -F /var/log/squid/access.log 2>/dev/null &
 tail -F /var/log/squid/error.log 2>/dev/null &
 tail -F /var/log/squid/store.log 2>/dev/null &
-/usr/sbin/squid -f /etc/squid/squid.conf -NYC
+tail -F /var/log/squid/cache.log 2>/dev/null &
+/usr/sbin/squid "$@"