Chainguard Container for squid-proxy

Squid Proxy is an open-source, high-performance, and highly configurable caching and forwarding web proxy. It is widely used for speeding up web servers by caching web, DNS, and other computer network lookups for a group of people sharing network resources, and for aiding security by filtering traffic.

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/squid-proxy:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

This image provides a high-performance Squid proxy server suitable for a wide range of caching and forwarding requirements. It is a drop-in replacement for traditional Squid proxy images but is enhanced for security and minimized to reduce its attack surface. Ideal for both development and production environments where a proxy server is required.

Note: We are running this image as non-root user called squid by default for more security.

Usage

Running the Squid Proxy Container

To run the squid-proxy container with default settings:

docker run --rm -p 3128:3128 cgr.dev/chainguard/squid-proxy:latest

Testing it with curl

export PROXY_HOST="localhost"
export PROXY_PORT="3128"
export URL="http://example.com"

curl -x http://"$PROXY_HOST":"$PROXY_PORT" "$URL" -o /dev/null -w '%{http_code}\n' -s

You will get a 403 response on this very likely, because of ACL on the default /etc/squid.conf. Access Control Lists (ACLs) in squid.conf are a crucial part of Squid's configuration. They allow you to define rules that grant or deny access to internet resources based on various criteria such as source IP, destination IP, URLs, protocols, and more.

Log may not be visible with default configuration, you can set it using the below custom configuration.

Custom Configuration For Docker

Add the following lines to the 'squid.conf' to redirect the logs to the '/dev/stdout':

http_port 3128
logfile_rotate 0
cache_log stdio:/dev/stdout
access_log stdio:/dev/stdout
cache_store_log stdio:/dev/stdout

For custom configurations, mount your squid.conf file into the container:

docker run --rm -v /path/to/your/squid.conf:/etc/squid.conf -p 3128:3128 cgr.dev/chainguard/squid-proxy:latest

Custom Configuration For Kubernetes

For working in Kubernetes, you can also run a parallel container in a pod containing squid container. This container will tail these (/var/log/squid/{cache,access}.log or any other) logs on its stdout.

---
kind: Pod
apiVersion: v1
metadata:
  name: squid-proxy
  labels:
    app: squid
spec:
  volumes:
  - name: log-dir
    emptyDir: {}
  containers:
  - name: squid
    image: cgr.dev/chainguard/squid-proxy:latest
    volumeMounts:
    - name: log-dir
      mountPath: "/var/log/squid/"
  - name: tailer
    image: busybox
    command:
    - "/bin/sh"
    - "-c"
    args:
    - tail -F /var/log/squid/access.log
    volumeMounts:
    - name: log-dir
      mountPath: "/var/log/squid/"

For more detailed instructions and advanced configurations, refer to the Squid Official Documentation.

What are Chainguard Containers?

Chainguard Containers are minimal container images that are secure by default.

In many cases, the Chainguard Containers tagged as :latest contain only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager. Chainguard Containers are built with Wolfi, our Linux undistro designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a -dev variant.

Although the -dev container image variants have similar security features as their more minimal versions, they feature additional software that is typically not necessary in production environments. We recommend using multi-stage builds to leverage the -dev variants, copying application artifacts into a final minimal container that offers a reduced attack surface that won’t allow package installations or logins.

Learn More

To better understand how to work with Chainguard Containers, please visit Chainguard Academy and Chainguard Courses.

In addition to Containers, Chainguard offers VMs and Libraries. Contact Chainguard to access additional products.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.