Add environmental variables for GitHub tokens (#41)

GitHub tokens can be passed only using command line options.
This limits certain deployments which use environmental variables. Systems without a shell cannot expand environmental variables in command line arguments.

This change adds an option to use environmental variables to pass GitHub webhook token and GitHub API token.

Signed-off-by: Patryk Zmigrodzki <[email protected]>

Signed-off-by: Patryk Zmigrodzki <[email protected]>

Author: pzmi-f3

main.go

@@ -21,8 +21,8 @@ var (
 	listenAddress               = kingpin.Flag("web.listen-address", "Address to listen on for web interface and telemetry.").Default(":9101").String()
 	metricsPath                 = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").String()
 	ghWebHookPath               = kingpin.Flag("web.gh-webhook-path", "Path that will be called by the GitHub webhook.").Default("/gh_event").String()
-	githubWebhookToken          = kingpin.Flag("gh.github-webhook-token", "GitHub Webhook Token.").Default("").String()
-	gitHubAPIToken              = kingpin.Flag("gh.github-api-token", "GitHub API Token.").Default("").String()
+	githubWebhookToken          = kingpin.Flag("gh.github-webhook-token", "GitHub Webhook Token.").Envar("GITHUB_WEBHOOK_TOKEN").Default("").String()
+	gitHubAPIToken              = kingpin.Flag("gh.github-api-token", "GitHub API Token.").Envar("GITHUB_API_TOKEN").Default("").String()
 	gitHubOrg                   = kingpin.Flag("gh.github-org", "GitHub Organization.").Default("").String()
 	gitHubUser                  = kingpin.Flag("gh.github-user", "GitHub User.").Default("").String()
 	gitHubBillingPollingSeconds = kingpin.Flag("gh.billing-poll-seconds", "Frequency at which to poll billing API.").Default("5").Int()