feat(cache): add Cloudflare SigV4 S3 signature compatibility fix and compile locally

go-cache-plugin-src/cmd/go-cache-plugin/help.go

@@ -0,0 +1,153 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package main
+
+import "github.com/creachadair/command"
+
+var helpTopics = []command.HelpTopic{
+	{
+		Name: "configure",
+		Help: `How to configure the plugin.
+
+To run the plugin, install the program somewhere on your system and set the
+GOCACHEPROG environment variable to the command line of the plugin. You can
+either specify the full path to the program, or install it in your $PATH.
+
+Parameters can be passed either as flags or via environment variables.
+See also "help environment".
+
+The plugin requires credentials to access S3. If you are running in AWS, it can
+get credentials from the instance metadata service; otherwise you will need to
+plumb AWS environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY,
+AWS_ENDPOINT_URL) or set up a configuration file.
+
+See also: "help environment".
+Related:  "direct-mode", "serve-mode", "module-proxy", "reverse-proxy".`,
+	},
+	{
+		Name: "environment",
+		Help: `Environment variables understood by this program.
+
+To make it easier to configure this tool for multiple workflows, most of the
+settings can be set via environment variables as well as flags.
+
+   --------------------------------------------------------------------
+   Flag (global)        Variable                 Format      Default
+   --------------------------------------------------------------------
+    --cache-dir         GOCACHE_DIR              path        (required)
+    --bucket            GOCACHE_S3_BUCKET        string      (required)
+    --region            GOCACHE_S3_REGION        string      based on bucket
+    --s3-path-style     GOCACHE_S3_PATH_STYLE    bool        false
+    --s3-endpoint-url   GOCACHE_S3_ENDPOINT_URL  string      ""
+    --prefix            GOCACHE_KEY_PREFIX       string      ""
+    --min-upload-size   GOCACHE_MIN_SIZE         int64       0
+    --metrics           GOCACHE_METRICS          bool        false
+    --expiry            GOCACHE_EXPIRY           duration    0
+    -c                  GOCACHE_CONCURRENCY      int         runtime.NumCPU
+    -u                  GOCACHE_S3_CONCURRENCY   duration    runtime.NumCPU
+    -v                  GOCACHE_VERBOSE          bool        false
+    --debug             GOCACHE_DEBUG            int         0 (see "help debug")
+
+   --------------------------------------------------------------------
+   Flag (serve)         Variable                 Format      Default
+   --------------------------------------------------------------------
+    --plugin            GOCACHE_PLUGIN           port        (required)
+    --http              GOCACHE_HTTP             [host]:port ""
+    --modproxy          GOCACHE_MODPROXY         bool        false
+    --revproxy          GOCACHE_REVPROXY         host,...    ""
+    --sumdb             GOCACHE_SUMDB            host,...    ""
+
+See also: "help configure".`,
+	},
+	{
+		Name: "direct-mode",
+		Help: `Run the plugin directly as a subprocess of the toolchain.
+
+  export GOCACHEPROG="go-cache-plugin --cache-dir=/tmp/gocache --bucket ..."
+  go build ...
+
+Alternatively:
+
+  export GOCACHE_DIR=/tmp/gocache
+  export GOCACHE_S3_BUCKET=cache-bucket-name
+  export GOCACHEPROG=go-cache-plugin
+  go build ...
+
+In this mode, you must specify the --cache-dir and --bucket settings.`,
+	},
+	{
+		Name: "serve-mode",
+		Help: `Run the plugin as a standalone service.
+
+Use the "serve" subcommand:
+
+  go-cache-plugin serve \
+     --cache-dir=/tmp/gocache --bucket=$B \
+     --plugin $PORT
+
+You can then use the "connect" subcommand to wire up the toolchain:
+
+  export GOCACHEPROG="go-cache-plugin connect $PORT"
+
+In this mode, the server must have credentials to access to S3, but the
+toolchain process does not need AWS credentials.`,
+	},
+	{
+		Name: "module-proxy",
+		Help: `Run a Go module and sum database proxy.
+
+With the --modproxy flag, the server will also export an HTTP proxy for the
+public Go module proxy (proxy.golang.org) and sum DB (sum.golang.org) at the
+given address:
+
+   go-cache-plugin serve ... --http=localhost:5970 --modproxy
+
+To use the module proxy, set the standard GOPROXY environment variable.
+The module proxy serves under the path "/mod/":
+
+   export GOPROXY=http://localhost:5970/mod
+   export GOCACHEPROG="go-cache-plugin connect $PORT"
+   go build ...
+
+To use the sum DB proxy, set the GOSUMDB environment variable.
+The proxy path for a given sumdb (e.g., sum.golang.org) has this format:
+
+   export GOSUMDB="sum.golang.org http://localhost:5970/mod/sumdb/sum.golang.org"
+
+See also: https://proxy.golang.org/`,
+	},
+	{
+		Name: "reverse-proxy",
+		Help: `Run a caching reverse proxy.
+
+With the --revproxy flag, the server will also export a caching reverse
+proxy for the specified hosts, given as a comma-separated list:
+
+   go-cache-plugin serve ... \
+      --http=localhost:5970 \
+      --revproxy='api.example.com,www.example.com'
+
+When this is enabled, you can configure this address as an HTTP proxy:
+
+   HTTPS_PROXY=localhost:5970 curl https://api.example.com/foo
+
+The proxy supports both HTTP and HTTPS backends. For HTTPS proxy targets, the
+server generates its own TLS certificate, and tries to install a custom signing
+cert so that other tools will validate it. The ability to do this varies by
+system and configuration, however.`,
+	},
+	{
+		Name: "debug",
+		Help: `Enable detailed debug logging.
+
+The --debug flag enables (very) verbose debug logging for the components of the
+cache plugin. The value of the flag is a bit mask of:
+
+   1:  Go build cache
+   2:  Go module proxy and sum database
+   4:  HTTP reverse proxy
+
+The default is 0 (no debug logging).`,
+	},
+}